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Title: The Critique of Pure Reason
Author: Kant, Immanuel
Language: English
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 By Immanuel Kant

 Translated by J. M. D. Meiklejohn


 Preface to the First Edition (1781)

 Preface to the Second Edition (1787)


 I. Of the difference between Pure and Empirical Knowledge

 II. The Human Intellect, even in an Unphilosophical State, is in
 Possession of Certain Cognitions "a priori".

 III. Philosophy stands in need of a Science which shall Determine the
 Possibility, Principles, and Extent of Human Knowledge "a priori"

 IV. Of the Difference Between Analytical and Synthetical Judgements.

 V. In all Theoretical Sciences of Reason, Synthetical Judgements "a
 priori" are contained as Principles.

 VI. The Universal Problem of Pure Reason.

 VII. Idea and Division of a Particular Science, under the Name of a
 Critique of Pure Reason.

 I. Transcendental Doctrine of Elements


 § 1. Introductory


 § 2. Metaphysical Exposition of this Conception.

 § 3. Transcendental Exposition of the Conception of Space.

 § 4. Conclusions from the foregoing Conceptions.


 § 5. Metaphysical Exposition of this Conception.

 § 6. Transcendental Exposition of the Conception of Time.

 § 7. Conclusions from the above Conceptions.

 § 8. Elucidation.

 § 9. General Remarks on Transcendental Aesthetic.

 § 10. Conclusion of the Transcendental Aesthetic.


 Introduction. Idea of a Transcendental Logic

 I. Of Logic in General

 II. Of Transcendental Logic

 III. Of the Division of General Logic into Analytic and Dialectic

 IV. Of the Division of Transcendental Logic into Transcendental
 Analytic and Dialectic


 BOOK I. Analytic of Conceptions. § 2

 Chapter I. Of the Transcendental Clue to the Discovery of all Pure
 Conceptions of the Understanding

 Introductory § 3

 Section I. Of the Logical Use of the Understanding in General. § 4

 Section II. Of the Logical Function of the Understanding in
 Judgements. § 5

 Section III. Of the Pure Conceptions of the Understanding, or
 Categories. § 6

 Chapter II. Of the Deduction of the Pure Conception of the

 Section I. Of the Principles of a Transcendental Deduction in general
 § 9

 Transition to the Transcendental Deduction of the Categories. § 10

 Section II Transcendental Deduction of the pure Conceptions of the

 Of the Possibility of a Conjunction of the manifold representations
 given by Sense. § 11.

 Of the Originally Synthetical Unity of Apperception. § 12

 The Principle of the Synthetical Unity of Apperception is the highest
 Principle of all exercise of the Understanding. § 13

 What Objective Unity of Self-consciousness is. § 14

 The Logical Form of all Judgements consists in the Objective Unity of
 Apperception of the Conceptions contained therein. § 15

 All Sensuous Intuitions are subject to the Categories, as Conditions
 under which alone the manifold Content of them can be united in one
 Consciousness. § 16

 Observation. § 17

 In Cognition, its Application to Objects of Experience is the only
 legitimate use of the Category. § 18

 Of the Application of the Categories to Objects of the Senses in
 general. § 20

 Transcendental Deduction of the universally possible employment in
 experience of the Pure Conceptions of the Understanding. § 22

 Result of this Deduction of the Conceptions of the Understanding. § 23

 BOOK II. Analytic of Principles

 INTRODUCTION. Of the Transcendental Faculty of judgement in General.


 Chapter I. Of the Schematism at of the Pure Conceptions of the

 Chapter II. System of all Principles of the Pure Understanding.

 Section I. Of the Supreme Principle of all Analytical Judgements.

 Section II. Of the Supreme Principle of all Synthetical Judgements.

 Section III. Systematic Representation of all Synthetical Principles
 of the Pure Understanding.

 Chapter III Of the Ground of the Division of all Objects into
 Phenomena and Noumena.




 I. Of Transcendental Illusory Appearance.

 II. Of Pure Reason as the Seat of Transcendental Illusory Appearance.


 Section I—Of Ideas in General.

 Section II. Of Transcendental Ideas.

 Section III. System of Transcendental Ideas.


 Chapter I. Of the Paralogisms of Pure Reason.

 Chapter II. The Antinomy of Pure Reason.

 Section I. System of Cosmological Ideas.

 Section II. Antithetic of Pure Reason.

 Section III. Of the Interest of Reason in these Self-contradictions.

 Section IV. Of the necessity imposed upon Pure Reason of presenting a
 Solution of its Transcendental Problems.

 Section V. Sceptical Exposition of the Cosmological Problems presented
 in the four Transcendental Ideas.

 Section VI. Transcendental Idealism as the Key to theSolution of Pure
 Cosmological Dialectic.

 Section VII. Critical Solution of the Cosmological Problem.

 Section VIII. Regulative Principle of Pure Reason in relation to the
 Cosmological Ideas.

 Section IX. Of the Empirical Use of the Regulative Principle of Reason
 with regard to the Cosmological Ideas.

 I. Solution of the Cosmological Idea of the Totality of the
 Composition of Phenomena in the Universe.

 II. Solution of the Cosmological Idea of the Totality of the Division
 of a Whole given in Intuition.

 III. Solution of the Cosmological Idea of the Totality of the
 Deduction of Cosmical Events from their Causes.

 IV. Solution of the Cosmological Idea of the Totality of the
 Dependence of Phenomenal Existences.

 Chapter III. The Ideal of Pure Reason.

 Section I. Of the Ideal in General.

 Section II. Of the Transcendental Ideal (Prototypon Trancendentale).

 Section III. Of the Arguments employed by Speculative Reason in Proof
 of the Existence of a Supreme Being.

 Section IV. Of the Impossibility of an Ontological Proof of the
 Existence of God.

 Section V. Of the Impossibility of a Cosmological Proof of the
 Existence of God.

 Section VI. Of the Impossibility of a Physico-Theological Proof.

 Section VII. Critique of all Theology based upon Speculative
 Principles of Reason.

 Appendix. Of the Regulative Employment of the Ideas of Pure Reason.

 II. Transcendental Doctrine of Method

 Chapter I. The Discipline of Pure Reason.

 Section I. The Discipline of Pure Reason in the Sphere of Dogmatism.

 Section II. The Discipline of Pure Reason in Polemics.

 Section III. The Discipline of Pure Reason in Hypothesis.

 Section IV. The Discipline of Pure Reason in Relation to Proofs.

 Chapter II. The Canon of Pure Reason.

 Section I. Of the Ultimate End of the Pure Use of Reason.

 Section II. Of the Ideal of the Summum Bonum as a Determining Ground
 of the Ultimate End of Pure Reason.

 Section III. Of Opinion, Knowledge, and Belief.

 Chapter III. The Architectonic of Pure Reason.

 Chapter IV. The History of Pure Reason.


Human reason, in one sphere of its cognition, is called upon to
consider questions, which it cannot decline, as they are presented by
its own nature, but which it cannot answer, as they transcend every
faculty of the mind.

It falls into this difficulty without any fault of its own. It begins
with principles, which cannot be dispensed with in the field of
experience, and the truth and sufficiency of which are, at the same
time, insured by experience. With these principles it rises, in
obedience to the laws of its own nature, to ever higher and more remote
conditions. But it quickly discovers that, in this way, its labours
must remain ever incomplete, because new questions never cease to
present themselves; and thus it finds itself compelled to have recourse
to principles which transcend the region of experience, while they are
regarded by common sense without distrust. It thus falls into confusion
and contradictions, from which it conjectures the presence of latent
errors, which, however, it is unable to discover, because the
principles it employs, transcending the limits of experience, cannot be
tested by that criterion. The arena of these endless contests is called

Time was, when she was the queen of all the sciences; and, if we take
the will for the deed, she certainly deserves, so far as regards the
high importance of her object-matter, this title of honour. Now, it is
the fashion of the time to heap contempt and scorn upon her; and the
matron mourns, forlorn and forsaken, like Hecuba:

Modo maxima rerum,
Tot generis, natisque potens...
Nunc trahor exul, inops.
—Ovid, Metamorphoses. xiii

At first, her government, under the administration of the dogmatists,
was an absolute despotism. But, as the legislative continued to show
traces of the ancient barbaric rule, her empire gradually broke up, and
intestine wars introduced the reign of anarchy; while the sceptics,
like nomadic tribes, who hate a permanent habitation and settled mode
of living, attacked from time to time those who had organized
themselves into civil communities. But their number was, very happily,
small; and thus they could not entirely put a stop to the exertions of
those who persisted in raising new edifices, although on no settled or
uniform plan. In recent times the hope dawned upon us of seeing those
disputes settled, and the legitimacy of her claims established by a
kind of physiology of the human understanding—that of the celebrated
Locke. But it was found that—although it was affirmed that this
so-called queen could not refer her descent to any higher source than
that of common experience, a circumstance which necessarily brought
suspicion on her claims—as this genealogy was incorrect, she persisted
in the advancement of her claims to sovereignty. Thus metaphysics
necessarily fell back into the antiquated and rotten constitution of
dogmatism, and again became obnoxious to the contempt from which
efforts had been made to save it. At present, as all methods, according
to the general persuasion, have been tried in vain, there reigns nought
but weariness and complete indifferentism—the mother of chaos and night
in the scientific world, but at the same time the source of, or at
least the prelude to, the re-creation and reinstallation of a science,
when it has fallen into confusion, obscurity, and disuse from ill
directed effort.

For it is in reality vain to profess indifference in regard to such
inquiries, the object of which cannot be indifferent to humanity.
Besides, these pretended indifferentists, however much they may try to
disguise themselves by the assumption of a popular style and by changes
on the language of the schools, unavoidably fall into metaphysical
declarations and propositions, which they profess to regard with so
much contempt. At the same time, this indifference, which has arisen in
the world of science, and which relates to that kind of knowledge which
we should wish to see destroyed the last, is a phenomenon that well
deserves our attention and reflection. It is plainly not the effect of
the levity, but of the matured judgement* of the age, which refuses to
be any longer entertained with illusory knowledge, It is, in fact, a
call to reason, again to undertake the most laborious of all tasks—that
of self-examination, and to establish a tribunal, which may secure it
in its well-grounded claims, while it pronounces against all baseless
assumptions and pretensions, not in an arbitrary manner, but according
to its own eternal and unchangeable laws. This tribunal is nothing less
than the critical investigation of pure reason.

[*Footnote: We very often hear complaints of the shallowness of the
present age, and of the decay of profound science. But I do not think
that those which rest upon a secure foundation, such as mathematics,
physical science, etc., in the least deserve this reproach, but that
they rather maintain their ancient fame, and in the latter case,
indeed, far surpass it. The same would be the case with the other kinds
of cognition, if their principles were but firmly established. In the
absence of this security, indifference, doubt, and finally, severe
criticism are rather signs of a profound habit of thought. Our age is
the age of criticism, to which everything must be subjected. The
sacredness of religion, and the authority of legislation, are by many
regarded as grounds of exemption from the examination of this tribunal.
But, if they are exempted, they become the subjects of just suspicion,
and cannot lay claim to sincere respect, which reason accords only to
that which has stood the test of a free and public examination.]

I do not mean by this a criticism of books and systems, but a critical
inquiry into the faculty of reason, with reference to the cognitions to
which it strives to attain without the aid of experience; in other
words, the solution of the question regarding the possibility or
impossibility of metaphysics, and the determination of the origin, as
well as of the extent and limits of this science. All this must be done
on the basis of principles.

This path—the only one now remaining—has been entered upon by me; and I
flatter myself that I have, in this way, discovered the cause of—and
consequently the mode of removing—all the errors which have hitherto
set reason at variance with itself, in the sphere of non-empirical
thought. I have not returned an evasive answer to the questions of
reason, by alleging the inability and limitation of the faculties of
the mind; I have, on the contrary, examined them completely in the
light of principles, and, after having discovered the cause of the
doubts and contradictions into which reason fell, have solved them to
its perfect satisfaction. It is true, these questions have not been
solved as dogmatism, in its vain fancies and desires, had expected; for
it can only be satisfied by the exercise of magical arts, and of these
I have no knowledge. But neither do these come within the compass of
our mental powers; and it was the duty of philosophy to destroy the
illusions which had their origin in misconceptions, whatever darling
hopes and valued expectations may be ruined by its explanations. My
chief aim in this work has been thoroughness; and I make bold to say
that there is not a single metaphysical problem that does not find its
solution, or at least the key to its solution, here. Pure reason is a
perfect unity; and therefore, if the principle presented by it prove to
be insufficient for the solution of even a single one of those
questions to which the very nature of reason gives birth, we must
reject it, as we could not be perfectly certain of its sufficiency in
the case of the others.

While I say this, I think I see upon the countenance of the reader
signs of dissatisfaction mingled with contempt, when he hears
declarations which sound so boastful and extravagant; and yet they are
beyond comparison more moderate than those advanced by the commonest
author of the commonest philosophical programme, in which the dogmatist
professes to demonstrate the simple nature of the soul, or the
necessity of a primal being. Such a dogmatist promises to extend human
knowledge beyond the limits of possible experience; while I humbly
confess that this is completely beyond my power. Instead of any such
attempt, I confine myself to the examination of reason alone and its
pure thought; and I do not need to seek far for the sum-total of its
cognition, because it has its seat in my own mind. Besides, common
logic presents me with a complete and systematic catalogue of all the
simple operations of reason; and it is my task to answer the question
how far reason can go, without the material presented and the aid
furnished by experience.

So much for the completeness and thoroughness necessary in the
execution of the present task. The aims set before us are not
arbitrarily proposed, but are imposed upon us by the nature of
cognition itself.

The above remarks relate to the matter of our critical inquiry. As
regards the form, there are two indispensable conditions, which any one
who undertakes so difficult a task as that of a critique of pure
reason, is bound to fulfil. These conditions are certitude and

As regards _certitude_, I have fully convinced myself that, in this
sphere of thought, opinion is perfectly inadmissible, and that
everything which bears the least semblance of an hypothesis must be
excluded, as of no value in such discussions. For it is a necessary
condition of every cognition that is to be established upon _a priori_
grounds that it shall be held to be absolutely necessary; much more is
this the case with an attempt to determine all pure _a priori_
cognition, and to furnish the standard—and consequently an example—of
all apodeictic (philosophical) certitude. Whether I have succeeded in
what I professed to do, it is for the reader to determine; it is the
author’s business merely to adduce grounds and reasons, without
determining what influence these ought to have on the mind of his
judges. But, lest anything he may have said may become the innocent
cause of doubt in their minds, or tend to weaken the effect which his
arguments might otherwise produce—he may be allowed to point out those
passages which may occasion mistrust or difficulty, although these do
not concern the main purpose of the present work. He does this solely
with the view of removing from the mind of the reader any doubts which
might affect his judgement of the work as a whole, and in regard to its
ultimate aim.

I know no investigations more necessary for a full insight into the
nature of the faculty which we call understanding, and at the same time
for the determination of the rules and limits of its use, than those
undertaken in the second chapter of the “Transcendental Analytic,”
under the title of “Deduction of the Pure Conceptions of the
Understanding”; and they have also cost me by far the greatest
labour—labour which, I hope, will not remain uncompensated. The view
there taken, which goes somewhat deeply into the subject, has two
sides. The one relates to the objects of the pure understanding, and is
intended to demonstrate and to render comprehensible the objective
validity of its a priori conceptions; and it forms for this reason an
essential part of the Critique. The other considers the pure
understanding itself, its possibility and its powers of cognition—that
is, from a subjective point of view; and, although this exposition is
of great importance, it does not belong essentially to the main purpose
of the work, because the grand question is what and how much can reason
and understanding, apart from experience, cognize, and not, how is the
faculty of thought itself possible? As the latter is an inquiry into
the cause of a given effect, and has thus in it some semblance of an
hypothesis (although, as I shall show on another occasion, this is
really not the fact), it would seem that, in the present instance, I
had allowed myself to enounce a mere opinion, and that the reader must
therefore be at liberty to hold a different opinion. But I beg to
remind him that, if my subjective deduction does not produce in his
mind the conviction of its certitude at which I aimed, the objective
deduction, with which alone the present work is properly concerned, is
in every respect satisfactory.

As regards _clearness_, the reader has a right to demand, in the first
place, discursive or logical clearness, that is, on the basis of
conceptions, and, secondly, intuitive or aesthetic clearness, by means
of intuitions, that is, by examples or other modes of illustration in
concreto. I have done what I could for the first kind of
intelligibility. This was essential to my purpose; and it thus became
the accidental cause of my inability to do complete justice to the
second requirement. I have been almost always at a loss, during the
progress of this work, how to settle this question. Examples and
illustrations always appeared to me necessary, and, in the first sketch
of the Critique, naturally fell into their proper places. But I very
soon became aware of the magnitude of my task, and the numerous
problems with which I should be engaged; and, as I perceived that this
critical investigation would, even if delivered in the driest
scholastic manner, be far from being brief, I found it unadvisable to
enlarge it still more with examples and explanations, which are
necessary only from a popular point of view. I was induced to take this
course from the consideration also that the present work is not
intended for popular use, that those devoted to science do not require
such helps, although they are always acceptable, and that they would
have materially interfered with my present purpose. Abbé Terrasson
remarks with great justice that, if we estimate the size of a work, not
from the number of its pages, but from the time which we require to
make ourselves master of it, it may be said of many a book that it
would be much shorter, if it were not so short. On the other hand, as
regards the comprehensibility of a system of speculative cognition,
connected under a single principle, we may say with equal justice: many
a book would have been much clearer, if it had not been intended to be
so very clear. For explanations and examples, and other helps to
intelligibility, aid us in the comprehension of parts, but they
distract the attention, dissipate the mental power of the reader, and
stand in the way of his forming a clear conception of the whole; as he
cannot attain soon enough to a survey of the system, and the colouring
and embellishments bestowed upon it prevent his observing its
articulation or organization—which is the most important consideration
with him, when he comes to judge of its unity and stability.

The reader must naturally have a strong inducement to co-operate with
the present author, if he has formed the intention of erecting a
complete and solid edifice of metaphysical science, according to the
plan now laid before him. Metaphysics, as here represented, is the only
science which admits of completion—and with little labour, if it is
united, in a short time; so that nothing will be left to future
generations except the task of illustrating and applying it
didactically. For this science is nothing more than the inventory of
all that is given us by pure reason, systematically arranged. Nothing
can escape our notice; for what reason produces from itself cannot lie
concealed, but must be brought to the light by reason itself, so soon
as we have discovered the common principle of the ideas we seek. The
perfect unity of this kind of cognitions, which are based upon pure
conceptions, and uninfluenced by any empirical element, or any peculiar
intuition leading to determinate experience, renders this completeness
not only practicable, but also necessary.

Tecum habita, et noris quam sit tibi curta supellex.

—Persius. Satirae iv. 52.

Such a system of pure speculative reason I hope to be able to publish
under the title of Metaphysic of Nature*. The content of this work
(which will not be half so long) will be very much richer than that of
the present Critique, which has to discover the sources of this
cognition and expose the conditions of its possibility, and at the same
time to clear and level a fit foundation for the scientific edifice. In
the present work, I look for the patient hearing and the impartiality
of a judge; in the other, for the good-will and assistance of a
co-labourer. For, however complete the list of principles for this
system may be in the Critique, the correctness of the system requires
that no deduced conceptions should be absent. These cannot be presented
a priori, but must be gradually discovered; and, while the synthesis of
conceptions has been fully exhausted in the Critique, it is necessary
that, in the proposed work, the same should be the case with their
analysis. But this will be rather an amusement than a labour.

[*Footnote: In contradistinction to the Metaphysic of Ethics. This work
was never published.]


Whether the treatment of that portion of our knowledge which lies
within the province of pure reason advances with that undeviating
certainty which characterizes the progress of science, we shall be at
no loss to determine. If we find those who are engaged in metaphysical
pursuits, unable to come to an understanding as to the method which
they ought to follow; if we find them, after the most elaborate
preparations, invariably brought to a stand before the goal is reached,
and compelled to retrace their steps and strike into fresh paths, we
may then feel quite sure that they are far from having attained to the
certainty of scientific progress and may rather be said to be merely
groping about in the dark. In these circumstances we shall render an
important service to reason if we succeed in simply indicating the path
along which it must travel, in order to arrive at any results—even if
it should be found necessary to abandon many of those aims which,
without reflection, have been proposed for its attainment.

That logic has advanced in this sure course, even from the earliest
times, is apparent from the fact that, since Aristotle, it has been
unable to advance a step and, thus, to all appearance has reached its
completion. For, if some of the moderns have thought to enlarge its
domain by introducing psychological discussions on the mental
faculties, such as imagination and wit, metaphysical, discussions on
the origin of knowledge and the different kinds of certitude, according
to the difference of the objects (idealism, scepticism, and so on), or
anthropological discussions on prejudices, their causes and remedies:
this attempt, on the part of these authors, only shows their ignorance
of the peculiar nature of logical science. We do not enlarge but
disfigure the sciences when we lose sight of their respective limits
and allow them to run into one another. Now logic is enclosed within
limits which admit of perfectly clear definition; it is a science which
has for its object nothing but the exposition and proof of the formal
laws of all thought, whether it be a priori or empirical, whatever be
its origin or its object, and whatever the difficulties—natural or
accidental—which it encounters in the human mind.

The early success of logic must be attributed exclusively to the
narrowness of its field, in which abstraction may, or rather must, be
made of all the objects of cognition with their characteristic
distinctions, and in which the understanding has only to deal with
itself and with its own forms. It is, obviously, a much more difficult
task for reason to strike into the sure path of science, where it has
to deal not simply with itself, but with objects external to itself.
Hence, logic is properly only a propaedeutic—forms, as it were, the
vestibule of the sciences; and while it is necessary to enable us to
form a correct judgement with regard to the various branches of
knowledge, still the acquisition of real, substantive knowledge is to
be sought only in the sciences properly so called, that is, in the
objective sciences.

Now these sciences, if they can be termed rational at all, must contain
elements of a priori cognition, and this cognition may stand in a
twofold relation to its object. Either it may have to determine the
conception of the object—which must be supplied extraneously, or it may
have to establish its reality. The former is theoretical, the latter
practical, rational cognition. In both, the pure or a priori element
must be treated first, and must be carefully distinguished from that
which is supplied from other sources. Any other method can only lead to
irremediable confusion.

Mathematics and physics are the two theoretical sciences which have to
determine their objects a priori. The former is purely a priori, the
latter is partially so, but is also dependent on other sources of

In the earliest times of which history affords us any record,
mathematics had already entered on the sure course of science, among
that wonderful nation, the Greeks. Still it is not to be supposed that
it was as easy for this science to strike into, or rather to construct
for itself, that royal road, as it was for logic, in which reason has
only to deal with itself. On the contrary, I believe that it must have
remained long—chiefly among the Egyptians—in the stage of blind groping
after its true aims and destination, and that it was revolutionized by
the happy idea of one man, who struck out and determined for all time
the path which this science must follow, and which admits of an
indefinite advancement. The history of this intellectual
revolution—much more important in its results than the discovery of the
passage round the celebrated Cape of Good Hope—and of its author, has
not been preserved. But Diogenes Laertius, in naming the supposed
discoverer of some of the simplest elements of geometrical
demonstration—elements which, according to the ordinary opinion, do not
even require to be proved—makes it apparent that the change introduced
by the first indication of this new path, must have seemed of the
utmost importance to the mathematicians of that age, and it has thus
been secured against the chance of oblivion. A new light must have
flashed on the mind of the first man (Thales, or whatever may have been
his name) who demonstrated the properties of the isosceles triangle.
For he found that it was not sufficient to meditate on the figure, as
it lay before his eyes, or the conception of it, as it existed in his
mind, and thus endeavour to get at the knowledge of its properties, but
that it was necessary to produce these properties, as it were, by a
positive a priori construction; and that, in order to arrive with
certainty at a priori cognition, he must not attribute to the object
any other properties than those which necessarily followed from that
which he had himself, in accordance with his conception, placed in the

A much longer period elapsed before physics entered on the highway of
science. For it is only about a century and a half since the wise Bacon
gave a new direction to physical studies, or rather—as others were
already on the right track—imparted fresh vigour to the pursuit of this
new direction. Here, too, as in the case of mathematics, we find
evidence of a rapid intellectual revolution. In the remarks which
follow I shall confine myself to the empirical side of natural science.

When Galilei experimented with balls of a definite weight on the
inclined plane, when Torricelli caused the air to sustain a weight
which he had calculated beforehand to be equal to that of a definite
column of water, or when Stahl, at a later period, converted metals
into lime, and reconverted lime into metal, by the addition and
subtraction of certain elements; [Footnote: I do not here follow with
exactness the history of the experimental method, of which, indeed, the
first steps are involved in some obscurity.] a light broke upon all
natural philosophers. They learned that reason only perceives that
which it produces after its own design; that it must not be content to
follow, as it were, in the leading-strings of nature, but must proceed
in advance with principles of judgement according to unvarying laws,
and compel nature to reply its questions. For accidental observations,
made according to no preconceived plan, cannot be united under a
necessary law. But it is this that reason seeks for and requires. It is
only the principles of reason which can give to concordant phenomena
the validity of laws, and it is only when experiment is directed by
these rational principles that it can have any real utility. Reason
must approach nature with the view, indeed, of receiving information
from it, not, however, in the character of a pupil, who listens to all
that his master chooses to tell him, but in that of a judge, who
compels the witnesses to reply to those questions which he himself
thinks fit to propose. To this single idea must the revolution be
ascribed, by which, after groping in the dark for so many centuries,
natural science was at length conducted into the path of certain

We come now to metaphysics, a purely speculative science, which
occupies a completely isolated position and is entirely independent of
the teachings of experience. It deals with mere conceptions—not, like
mathematics, with conceptions applied to intuition—and in it, reason is
the pupil of itself alone. It is the oldest of the sciences, and would
still survive, even if all the rest were swallowed up in the abyss of
an all-destroying barbarism. But it has not yet had the good fortune to
attain to the sure scientific method. This will be apparent; if we
apply the tests which we proposed at the outset. We find that reason
perpetually comes to a stand, when it attempts to gain a priori the
perception even of those laws which the most common experience
confirms. We find it compelled to retrace its steps in innumerable
instances, and to abandon the path on which it had entered, because
this does not lead to the desired result. We find, too, that those who
are engaged in metaphysical pursuits are far from being able to agree
among themselves, but that, on the contrary, this science appears to
furnish an arena specially adapted for the display of skill or the
exercise of strength in mock-contests—a field in which no combatant
ever yet succeeded in gaining an inch of ground, in which, at least, no
victory was ever yet crowned with permanent possession.

This leads us to inquire why it is that, in metaphysics, the sure path
of science has not hitherto been found. Shall we suppose that it is
impossible to discover it? Why then should nature have visited our
reason with restless aspirations after it, as if it were one of our
weightiest concerns? Nay, more, how little cause should we have to
place confidence in our reason, if it abandons us in a matter about
which, most of all, we desire to know the truth—and not only so, but
even allures us to the pursuit of vain phantoms, only to betray us in
the end? Or, if the path has only hitherto been missed, what
indications do we possess to guide us in a renewed investigation, and
to enable us to hope for greater success than has fallen to the lot of
our predecessors?

It appears to me that the examples of mathematics and natural
philosophy, which, as we have seen, were brought into their present
condition by a sudden revolution, are sufficiently remarkable to fix
our attention on the essential circumstances of the change which has
proved so advantageous to them, and to induce us to make the experiment
of imitating them, so far as the analogy which, as rational sciences,
they bear to metaphysics may permit. It has hitherto been assumed that
our cognition must conform to the objects; but all attempts to
ascertain anything about these objects a priori, by means of
conceptions, and thus to extend the range of our knowledge, have been
rendered abortive by this assumption. Let us then make the experiment
whether we may not be more successful in metaphysics, if we assume that
the objects must conform to our cognition. This appears, at all events,
to accord better with the possibility of our gaining the end we have in
view, that is to say, of arriving at the cognition of objects a priori,
of determining something with respect to these objects, before they are
given to us. We here propose to do just what Copernicus did in
attempting to explain the celestial movements. When he found that he
could make no progress by assuming that all the heavenly bodies
revolved round the spectator, he reversed the process, and tried the
experiment of assuming that the spectator revolved, while the stars
remained at rest. We may make the same experiment with regard to the
intuition of objects. If the intuition must conform to the nature of
the objects, I do not see how we can know anything of them a priori.
If, on the other hand, the object conforms to the nature of our faculty
of intuition, I can then easily conceive the possibility of such an a
priori knowledge. Now as I cannot rest in the mere intuitions, but—if
they are to become cognitions—must refer them, as representations, to
something, as object, and must determine the latter by means of the
former, here again there are two courses open to me. Either, first, I
may assume that the conceptions, by which I effect this determination,
conform to the object—and in this case I am reduced to the same
perplexity as before; or secondly, I may assume that the objects, or,
which is the same thing, that experience, in which alone as given
objects they are cognized, conform to my conceptions—and then I am at
no loss how to proceed. For experience itself is a mode of cognition
which requires understanding. Before objects, are given to me, that is,
a priori, I must presuppose in myself laws of the understanding which
are expressed in conceptions a priori. To these conceptions, then, all
the objects of experience must necessarily conform. Now there are
objects which reason thinks, and that necessarily, but which cannot be
given in experience, or, at least, cannot be given so as reason thinks
them. The attempt to think these objects will hereafter furnish an
excellent test of the new method of thought which we have adopted, and
which is based on the principle that we only cognize in things a priori
that which we ourselves place in them.*

[*Footnote: This method, accordingly, which we have borrowed from the
natural philosopher, consists in seeking for the elements of pure
reason in that which admits of confirmation or refutation by
experiment. Now the propositions of pure reason, especially when they
transcend the limits of possible experience, do not admit of our making
any experiment with their objects, as in natural science. Hence, with
regard to those conceptions and principles which we assume a priori,
our only course ill be to view them from two different sides. We must
regard one and the same conception, on the one hand, in relation to
experience as an object of the senses and of the understanding, on the
other hand, in relation to reason, isolated and transcending the limits
of experience, as an object of mere thought. Now if we find that, when
we regard things from this double point of view, the result is in
harmony with the principle of pure reason, but that, when we regard
them from a single point of view, reason is involved in
self-contradiction, then the experiment will establish the correctness
of this distinction.]

This attempt succeeds as well as we could desire, and promises to
metaphysics, in its first part—that is, where it is occupied with
conceptions a priori, of which the corresponding objects may be given
in experience—the certain course of science. For by this new method we
are enabled perfectly to explain the possibility of a priori cognition,
and, what is more, to demonstrate satisfactorily the laws which lie a
priori at the foundation of nature, as the sum of the objects of
experience—neither of which was possible according to the procedure
hitherto followed. But from this deduction of the faculty of a priori
cognition in the first part of metaphysics, we derive a surprising
result, and one which, to all appearance, militates against the great
end of metaphysics, as treated in the second part. For we come to the
conclusion that our faculty of cognition is unable to transcend the
limits of possible experience; and yet this is precisely the most
essential object of this science. The estimate of our rational
cognition a priori at which we arrive is that it has only to do with
phenomena, and that things in themselves, while possessing a real
existence, lie beyond its sphere. Here we are enabled to put the
justice of this estimate to the test. For that which of necessity
impels us to transcend the limits of experience and of all phenomena is
the unconditioned, which reason absolutely requires in things as they
are in themselves, in order to complete the series of conditions. Now,
if it appears that when, on the one hand, we assume that our cognition
conforms to its objects as things in themselves, the unconditioned
cannot be thought without contradiction, and that when, on the other
hand, we assume that our representation of things as they are given to
us, does not conform to these things as they are in themselves, but
that these objects, as phenomena, conform to our mode of
representation, the contradiction disappears: we shall then be
convinced of the truth of that which we began by assuming for the sake
of experiment; we may look upon it as established that the
unconditioned does not lie in things as we know them, or as they are
given to us, but in things as they are in themselves, beyond the range
of our cognition.*

[*Footnote: This experiment of pure reason has a great similarity to
that of the chemists, which they term the experiment of reduction, or,
more usually, the synthetic process. The analysis of the metaphysician
separates pure cognition a priori into two heterogeneous elements,
viz., the cognition of things as phenomena, and of things in
themselves. Dialectic combines these again into harmony with the
necessary rational idea of the unconditioned, and finds that this
harmony never results except through the above distinction, which is,
therefore, concluded to be just.]

But, after we have thus denied the power of speculative reason to make
any progress in the sphere of the supersensible, it still remains for
our consideration whether data do not exist in practical cognition
which may enable us to determine the transcendent conception of the
unconditioned, to rise beyond the limits of all possible experience
from a practical point of view, and thus to satisfy the great ends of
metaphysics. Speculative reason has thus, at least, made room for such
an extension of our knowledge: and, if it must leave this space vacant,
still it does not rob us of the liberty to fill it up, if we can, by
means of practical data—nay, it even challenges us to make the

[*Footnote: So the central laws of the movements of the heavenly bodies
established the truth of that which Copernicus, first, assumed only as
a hypothesis, and, at the same time, brought to light that invisible
force (Newtonian attraction) which holds the universe together. The
latter would have remained forever undiscovered, if Copernicus had not
ventured on the experiment—contrary to the senses but still just—of
looking for the observed movements not in the heavenly bodies, but in
the spectator. In this Preface I treat the new metaphysical method as a
hypothesis with the view of rendering apparent the first attempts at
such a change of method, which are always hypothetical. But in the
Critique itself it will be demonstrated, not hypothetically, but
apodeictically, from the nature of our representations of space and
time, and from the elementary conceptions of the understanding.]

This attempt to introduce a complete revolution in the procedure of
metaphysics, after the example of the geometricians and natural
philosophers, constitutes the aim of the Critique of Pure Speculative
Reason. It is a treatise on the method to be followed, not a system of
the science itself. But, at the same time, it marks out and defines
both the external boundaries and the internal structure of this
science. For pure speculative reason has this peculiarity, that, in
choosing the various objects of thought, it is able to define the
limits of its own faculties, and even to give a complete enumeration of
the possible modes of proposing problems to itself, and thus to sketch
out the entire system of metaphysics. For, on the one hand, in
cognition a priori, nothing must be attributed to the objects but what
the thinking subject derives from itself; and, on the other hand,
reason is, in regard to the principles of cognition, a perfectly
distinct, independent unity, in which, as in an organized body, every
member exists for the sake of the others, and all for the sake of each,
so that no principle can be viewed, with safety, in one relationship,
unless it is, at the same time, viewed in relation to the total use of
pure reason. Hence, too, metaphysics has this singular advantage—an
advantage which falls to the lot of no other science which has to do
with objects—that, if once it is conducted into the sure path of
science, by means of this criticism, it can then take in the whole
sphere of its cognitions, and can thus complete its work, and leave it
for the use of posterity, as a capital which can never receive fresh
accessions. For metaphysics has to deal only with principles and with
the limitations of its own employment as determined by these
principles. To this perfection it is, therefore, bound, as the
fundamental science, to attain, and to it the maxim may justly be

Nil actum reputans, si quid superesset agendum.

But, it will be asked, what kind of a treasure is this that we propose
to bequeath to posterity? What is the real value of this system of
metaphysics, purified by criticism, and thereby reduced to a permanent
condition? A cursory view of the present work will lead to the
supposition that its use is merely negative, that it only serves to
warn us against venturing, with speculative reason, beyond the limits
of experience. This is, in fact, its primary use. But this, at once,
assumes a positive value, when we observe that the principles with
which speculative reason endeavours to transcend its limits lead
inevitably, not to the extension, but to the contraction of the use of
reason, inasmuch as they threaten to extend the limits of sensibility,
which is their proper sphere, over the entire realm of thought and,
thus, to supplant the pure (practical) use of reason. So far, then, as
this criticism is occupied in confining speculative reason within its
proper bounds, it is only negative; but, inasmuch as it thereby, at the
same time, removes an obstacle which impedes and even threatens to
destroy the use of practical reason, it possesses a positive and very
important value. In order to admit this, we have only to be convinced
that there is an absolutely necessary use of pure reason—the moral
use—in which it inevitably transcends the limits of sensibility,
without the aid of speculation, requiring only to be insured against
the effects of a speculation which would involve it in contradiction
with itself. To deny the positive advantage of the service which this
criticism renders us would be as absurd as to maintain that the system
of police is productive of no positive benefit, since its main business
is to prevent the violence which citizen has to apprehend from citizen,
that so each may pursue his vocation in peace and security. That space
and time are only forms of sensible intuition, and hence are only
conditions of the existence of things as phenomena; that, moreover, we
have no conceptions of the understanding, and, consequently, no
elements for the cognition of things, except in so far as a
corresponding intuition can be given to these conceptions; that,
accordingly, we can have no cognition of an object, as a thing in
itself, but only as an object of sensible intuition, that is, as
phenomenon—all this is proved in the analytical part of the Critique;
and from this the limitation of all possible speculative cognition to
the mere objects of experience, follows as a necessary result. At the
same time, it must be carefully borne in mind that, while we surrender
the power of cognizing, we still reserve the power of thinking objects,
as things in themselves.* For, otherwise, we should require to affirm
the existence of an appearance, without something that appears—which
would be absurd. Now let us suppose, for a moment, that we had not
undertaken this criticism and, accordingly, had not drawn the necessary
distinction between things as objects of experience and things as they
are in themselves. The principle of causality, and, by consequence, the
mechanism of nature as determined by causality, would then have
absolute validity in relation to all things as efficient causes. I
should then be unable to assert, with regard to one and the same being,
e.g., the human soul, that its will is free, and yet, at the same time,
subject to natural necessity, that is, not free, without falling into a
palpable contradiction, for in both propositions I should take the soul
in the same signification, as a thing in general, as a thing in
itself—as, without previous criticism, I could not but take it. Suppose
now, on the other hand, that we have undertaken this criticism, and
have learnt that an object may be taken in two senses, first, as a
phenomenon, secondly, as a thing in itself; and that, according to the
deduction of the conceptions of the understanding, the principle of
causality has reference only to things in the first sense. We then see
how it does not involve any contradiction to assert, on the one hand,
that the will, in the phenomenal sphere—in visible action—is
necessarily obedient to the law of nature, and, in so far, not free;
and, on the other hand, that, as belonging to a thing in itself, it is
not subject to that law, and, accordingly, is free. Now, it is true
that I cannot, by means of speculative reason, and still less by
empirical observation, cognize my soul as a thing in itself and
consequently, cannot cognize liberty as the property of a being to
which I ascribe effects in the world of sense. For, to do so, I must
cognize this being as existing, and yet not in time, which—since I
cannot support my conception by any intuition—is impossible. At the
same time, while I cannot cognize, I can quite well think freedom, that
is to say, my representation of it involves at least no contradiction,
if we bear in mind the critical distinction of the two modes of
representation (the sensible and the intellectual) and the consequent
limitation of the conceptions of the pure understanding and of the
principles which flow from them. Suppose now that morality necessarily
presupposed liberty, in the strictest sense, as a property of our will;
suppose that reason contained certain practical, original principles a
priori, which were absolutely impossible without this presupposition;
and suppose, at the same time, that speculative reason had proved that
liberty was incapable of being thought at all. It would then follow
that the moral presupposition must give way to the speculative
affirmation, the opposite of which involves an obvious contradiction,
and that liberty and, with it, morality must yield to the mechanism of
nature; for the negation of morality involves no contradiction, except
on the presupposition of liberty. Now morality does not require the
speculative cognition of liberty; it is enough that I can think it,
that its conception involves no contradiction, that it does not
interfere with the mechanism of nature. But even this requirement we
could not satisfy, if we had not learnt the twofold sense in which
things may be taken; and it is only in this way that the doctrine of
morality and the doctrine of nature are confined within their proper
limits. For this result, then, we are indebted to a criticism which
warns us of our unavoidable ignorance with regard to things in
themselves, and establishes the necessary limitation of our theoretical
cognition to mere phenomena.

[*Footnote: In order to cognize an object, I must be able to prove its
possibility, either from its reality as attested by experience, or a
priori, by means of reason. But I can think what I please, provided
only I do not contradict myself; that is, provided my conception is a
possible thought, though I may be unable to answer for the existence of
a corresponding object in the sum of possibilities. But something more
is required before I can attribute to such a conception objective
validity, that is real possibility—the other possibility being merely
logical. We are not, however, confined to theoretical sources of
cognition for the means of satisfying this additional requirement, but
may derive them from practical sources.]

The positive value of the critical principles of pure reason in
relation to the conception of God and of the simple nature of the soul,
admits of a similar exemplification; but on this point I shall not
dwell. I cannot even make the assumption—as the practical interests of
morality require—of God, freedom, and immortality, if I do not deprive
speculative reason of its pretensions to transcendent insight. For to
arrive at these, it must make use of principles which, in fact, extend
only to the objects of possible experience, and which cannot be applied
to objects beyond this sphere without converting them into phenomena,
and thus rendering the practical extension of pure reason impossible. I
must, therefore, abolish knowledge, to make room for belief. The
dogmatism of metaphysics, that is, the presumption that it is possible
to advance in metaphysics without previous criticism, is the true
source of the unbelief (always dogmatic) which militates against

Thus, while it may be no very difficult task to bequeath a legacy to
posterity, in the shape of a system of metaphysics constructed in
accordance with the Critique of Pure Reason, still the value of such a
bequest is not to be depreciated. It will render an important service
to reason, by substituting the certainty of scientific method for that
random groping after results without the guidance of principles, which
has hitherto characterized the pursuit of metaphysical studies. It will
render an important service to the inquiring mind of youth, by leading
the student to apply his powers to the cultivation of genuine science,
instead of wasting them, as at present, on speculations which can never
lead to any result, or on the idle attempt to invent new ideas and
opinions. But, above all, it will confer an inestimable benefit on
morality and religion, by showing that all the objections urged against
them may be silenced for ever by the Socratic method, that is to say,
by proving the ignorance of the objector. For, as the world has never
been, and, no doubt, never will be without a system of metaphysics of
one kind or another, it is the highest and weightiest concern of
philosophy to render it powerless for harm, by closing up the sources
of error.

This important change in the field of the sciences, this loss of its
fancied possessions, to which speculative reason must submit, does not
prove in any way detrimental to the general interests of humanity. The
advantages which the world has derived from the teachings of pure
reason are not at all impaired. The loss falls, in its whole extent, on
the monopoly of the schools, but does not in the slightest degree touch
the interests of mankind. I appeal to the most obstinate dogmatist,
whether the proof of the continued existence of the soul after death,
derived from the simplicity of its substance; of the freedom of the
will in opposition to the general mechanism of nature, drawn from the
subtle but impotent distinction of subjective and objective practical
necessity; or of the existence of God, deduced from the conception of
an ens realissimum—the contingency of the changeable, and the necessity
of a prime mover, has ever been able to pass beyond the limits of the
schools, to penetrate the public mind, or to exercise the slightest
influence on its convictions. It must be admitted that this has not
been the case and that, owing to the unfitness of the common
understanding for such subtle speculations, it can never be expected to
take place. On the contrary, it is plain that the hope of a future life
arises from the feeling, which exists in the breast of every man, that
the temporal is inadequate to meet and satisfy the demands of his
nature. In like manner, it cannot be doubted that the clear exhibition
of duties in opposition to all the claims of inclination, gives rise to
the consciousness of freedom, and that the glorious order, beauty, and
providential care, everywhere displayed in nature, give rise to the
belief in a wise and great Author of the Universe. Such is the genesis
of these general convictions of mankind, so far as they depend on
rational grounds; and this public property not only remains
undisturbed, but is even raised to greater importance, by the doctrine
that the schools have no right to arrogate to themselves a more
profound insight into a matter of general human concernment than that
to which the great mass of men, ever held by us in the highest
estimation, can without difficulty attain, and that the schools should,
therefore, confine themselves to the elaboration of these universally
comprehensible and, from a moral point of view, amply satisfactory
proofs. The change, therefore, affects only the arrogant pretensions of
the schools, which would gladly retain, in their own exclusive
possession, the key to the truths which they impart to the public.

Quod mecum nescit, solus vult scire videri.

At the same time it does not deprive the speculative philosopher of his
just title to be the sole depositor of a science which benefits the
public without its knowledge—I mean, the Critique of Pure Reason. This
can never become popular and, indeed, has no occasion to be so; for
finespun arguments in favour of useful truths make just as little
impression on the public mind as the equally subtle objections brought
against these truths. On the other hand, since both inevitably force
themselves on every man who rises to the height of speculation, it
becomes the manifest duty of the schools to enter upon a thorough
investigation of the rights of speculative reason and, thus, to prevent
the scandal which metaphysical controversies are sure, sooner or later,
to cause even to the masses. It is only by criticism that
metaphysicians (and, as such, theologians too) can be saved from these
controversies and from the consequent perversion of their doctrines.
Criticism alone can strike a blow at the root of materialism, fatalism,
atheism, free-thinking, fanaticism, and superstition, which are
universally injurious—as well as of idealism and scepticism, which are
dangerous to the schools, but can scarcely pass over to the public. If
governments think proper to interfere with the affairs of the learned,
it would be more consistent with a wise regard for the interests of
science, as well as for those of society, to favour a criticism of this
kind, by which alone the labours of reason can be established on a firm
basis, than to support the ridiculous despotism of the schools, which
raise a loud cry of danger to the public over the destruction of
cobwebs, of which the public has never taken any notice, and the loss
of which, therefore, it can never feel.

This critical science is not opposed to the dogmatic procedure of
reason in pure cognition; for pure cognition must always be dogmatic,
that is, must rest on strict demonstration from sure principles a
priori—but to dogmatism, that is, to the presumption that it is
possible to make any progress with a pure cognition, derived from
(philosophical) conceptions, according to the principles which reason
has long been in the habit of employing—without first inquiring in what
way and by what right reason has come into the possession of these
principles. Dogmatism is thus the dogmatic procedure of pure reason
without previous criticism of its own powers, and in opposing this
procedure, we must not be supposed to lend any countenance to that
loquacious shallowness which arrogates to itself the name of
popularity, nor yet to scepticism, which makes short work with the
whole science of metaphysics. On the contrary, our criticism is the
necessary preparation for a thoroughly scientific system of metaphysics
which must perform its task entirely a priori, to the complete
satisfaction of speculative reason, and must, therefore, be treated,
not popularly, but scholastically. In carrying out the plan which the
Critique prescribes, that is, in the future system of metaphysics, we
must have recourse to the strict method of the celebrated Wolf, the
greatest of all dogmatic philosophers. He was the first to point out
the necessity of establishing fixed principles, of clearly defining our
conceptions, and of subjecting our demonstrations to the most severe
scrutiny, instead of rashly jumping at conclusions. The example which
he set served to awaken that spirit of profound and thorough
investigation which is not yet extinct in Germany. He would have been
peculiarly well fitted to give a truly scientific character to
metaphysical studies, had it occurred to him to prepare the field by a
criticism of the organum, that is, of pure reason itself. That he
failed to perceive the necessity of such a procedure must be ascribed
to the dogmatic mode of thought which characterized his age, and on
this point the philosophers of his time, as well as of all previous
times, have nothing to reproach each other with. Those who reject at
once the method of Wolf, and of the Critique of Pure Reason, can have
no other aim but to shake off the fetters of science, to change labour
into sport, certainty into opinion, and philosophy into philodoxy.

In this second edition, I have endeavoured, as far as possible, to
remove the difficulties and obscurity which, without fault of mine
perhaps, have given rise to many misconceptions even among acute
thinkers. In the propositions themselves, and in the demonstrations by
which they are supported, as well as in the form and the entire plan of
the work, I have found nothing to alter; which must be attributed
partly to the long examination to which I had subjected the whole
before offering it to the public and partly to the nature of the case.
For pure speculative reason is an organic structure in which there is
nothing isolated or independent, but every Single part is essential to
all the rest; and hence, the slightest imperfection, whether defect or
positive error, could not fail to betray itself in use. I venture,
further, to hope, that this system will maintain the same unalterable
character for the future. I am led to entertain this confidence, not by
vanity, but by the evidence which the equality of the result affords,
when we proceed, first, from the simplest elements up to the complete
whole of pure reason and, and then, backwards from the whole to each
part. We find that the attempt to make the slightest alteration, in any
part, leads inevitably to contradictions, not merely in this system,
but in human reason itself. At the same time, there is still much room
for improvement in the exposition of the doctrines contained in this
work. In the present edition, I have endeavoured to remove
misapprehensions of the aesthetical part, especially with regard to the
conception of time; to clear away the obscurity which has been found in
the deduction of the conceptions of the understanding; to supply the
supposed want of sufficient evidence in the demonstration of the
principles of the pure understanding; and, lastly, to obviate the
misunderstanding of the paralogisms which immediately precede the
rational psychology. Beyond this point—the end of the second main
division of the “Transcendental Dialectic”—I have not extended my
alterations,* partly from want of time, and partly because I am not
aware that any portion of the remainder has given rise to
misconceptions among intelligent and impartial critics, whom I do not
here mention with that praise which is their due, but who will find
that their suggestions have been attended to in the work itself.

[*Footnote: The only addition, properly so called—and that only in the
method of proof—which I have made in the present edition, consists of a
new refutation of psychological idealism, and a strict
demonstration—the only one possible, as I believe—of the objective
reality of external intuition. However harmless idealism may be
considered—although in reality it is not so—in regard to the essential
ends of metaphysics, it must still remain a scandal to philosophy and
to the general human reason to be obliged to assume, as an article of
mere belief, the existence of things external to ourselves (from which,
yet, we derive the whole material of cognition for the internal sense),
and not to be able to oppose a satisfactory proof to any one who may
call it in question. As there is some obscurity of expression in the
demonstration as it stands in the text, I propose to alter the passage
in question as follows: “But this permanent cannot be an intuition in
me. For all the determining grounds of my existence which can be found
in me are representations and, as such, do themselves require a
permanent, distinct from them, which may determine my existence in
relation to their changes, that is, my existence in time, wherein they
change.” It may, probably, be urged in opposition to this proof that,
after all, I am only conscious immediately of that which is in me, that
is, of my representation of external things, and that, consequently, it
must always remain uncertain whether anything corresponding to this
representation does or does not exist externally to me. But I am
conscious, through internal experience, of my existence in time
(consequently, also, of the determinability of the former in the
latter), and that is more than the simple consciousness of my
representation. It is, in fact, the same as the empirical consciousness
of my existence, which can only be determined in relation to something,
which, while connected with my existence, is external to me. This
consciousness of my existence in time is, therefore, identical with the
consciousness of a relation to something external to me, and it is,
therefore, experience, not fiction, sense, not imagination, which
inseparably connects the external with my internal sense. For the
external sense is, in itself, the relation of intuition to something
real, external to me; and the reality of this something, as opposed to
the mere imagination of it, rests solely on its inseparable connection
with internal experience as the condition of its possibility. If with
the intellectual consciousness of my existence, in the representation:
I am, which accompanies all my judgements, and all the operations of my
understanding, I could, at the same time, connect a determination of my
existence by intellectual intuition, then the consciousness of a
relation to something external to me would not be necessary. But the
internal intuition in which alone my existence can be determined,
though preceded by that purely intellectual consciousness, is itself
sensible and attached to the condition of time. Hence this
determination of my existence, and consequently my internal experience
itself, must depend on something permanent which is not in me, which
can be, therefore, only in something external to me, to which I must
look upon myself as being related. Thus the reality of the external
sense is necessarily connected with that of the internal, in order to
the possibility of experience in general; that is, I am just as
certainly conscious that there are things external to me related to my
sense as I am that I myself exist as determined in time. But in order
to ascertain to what given intuitions objects, external me, really
correspond, in other words, what intuitions belong to the external
sense and not to imagination, I must have recourse, in every particular
case, to those rules according to which experience in general (even
internal experience) is distinguished from imagination, and which are
always based on the proposition that there really is an external
experience. We may add the remark that the representation of something
permanent in existence, is not the same thing as the permanent
representation; for a representation may be very variable and
changing—as all our representations, even that of matter, are—and yet
refer to something permanent, which must, therefore, be distinct from
all my representations and external to me, the existence of which is
necessarily included in the determination of my own existence, and with
it constitutes one experience—an experience which would not even be
possible internally, if it were not also at the same time, in part,
external. To the question How? we are no more able to reply, than we
are, in general, to think the stationary in time, the coexistence of
which with the variable, produces the conception of change.]

In attempting to render the exposition of my views as intelligible as
possible, I have been compelled to leave out or abridge various
passages which were not essential to the completeness of the work, but
which many readers might consider useful in other respects, and might
be unwilling to miss. This trifling loss, which could not be avoided
without swelling the book beyond due limits, may be supplied, at the
pleasure of the reader, by a comparison with the first edition, and
will, I hope, be more than compensated for by the greater clearness of
the exposition as it now stands.

I have observed, with pleasure and thankfulness, in the pages of
various reviews and treatises, that the spirit of profound and thorough
investigation is not extinct in Germany, though it may have been
overborne and silenced for a time by the fashionable tone of a licence
in thinking, which gives itself the airs of genius, and that the
difficulties which beset the paths of criticism have not prevented
energetic and acute thinkers from making themselves masters of the
science of pure reason to which these paths conduct—a science which is
not popular, but scholastic in its character, and which alone can hope
for a lasting existence or possess an abiding value. To these deserving
men, who so happily combine profundity of view with a talent for lucid
exposition—a talent which I myself am not conscious of possessing—I
leave the task of removing any obscurity which may still adhere to the
statement of my doctrines. For, in this case, the danger is not that of
being refuted, but of being misunderstood. For my own part, I must
henceforward abstain from controversy, although I shall carefully
attend to all suggestions, whether from friends or adversaries, which
may be of use in the future elaboration of the system of this
propaedeutic. As, during these labours, I have advanced pretty far in
years this month I reach my sixty-fourth year—it will be necessary for
me to economize time, if I am to carry out my plan of elaborating the
metaphysics of nature as well as of morals, in confirmation of the
correctness of the principles established in this Critique of Pure
Reason, both speculative and practical; and I must, therefore, leave
the task of clearing up the obscurities of the present work—inevitable,
perhaps, at the outset—as well as, the defence of the whole, to those
deserving men, who have made my system their own. A philosophical
system cannot come forward armed at all points like a mathematical
treatise, and hence it may be quite possible to take objection to
particular passages, while the organic structure of the system,
considered as a unity, has no danger to apprehend. But few possess the
ability, and still fewer the inclination, to take a comprehensive view
of a new system. By confining the view to particular passages, taking
these out of their connection and comparing them with one another, it
is easy to pick out apparent contradictions, especially in a work
written with any freedom of style. These contradictions place the work
in an unfavourable light in the eyes of those who rely on the judgement
of others, but are easily reconciled by those who have mastered the
idea of the whole. If a theory possesses stability in itself, the
action and reaction which seemed at first to threaten its existence
serve only, in the course of time, to smooth down any superficial
roughness or inequality, and—if men of insight, impartiality, and truly
popular gifts, turn their attention to it—to secure to it, in a short
time, the requisite elegance also.

Königsberg, April 1787.


 I. Of the difference between Pure and Empirical Knowledge

That all our knowledge begins with experience there can be no doubt.
For how is it possible that the faculty of cognition should be awakened
into exercise otherwise than by means of objects which affect our
senses, and partly of themselves produce representations, partly rouse
our powers of understanding into activity, to compare to connect, or to
separate these, and so to convert the raw material of our sensuous
impressions into a knowledge of objects, which is called experience? In
respect of time, therefore, no knowledge of ours is antecedent to
experience, but begins with it.

But, though all our knowledge begins with experience, it by no means
follows that all arises out of experience. For, on the contrary, it is
quite possible that our empirical knowledge is a compound of that which
we receive through impressions, and that which the faculty of cognition
supplies from itself (sensuous impressions giving merely the occasion),
an addition which we cannot distinguish from the original element given
by sense, till long practice has made us attentive to, and skilful in
separating it. It is, therefore, a question which requires close
investigation, and not to be answered at first sight, whether there
exists a knowledge altogether independent of experience, and even of
all sensuous impressions? Knowledge of this kind is called a priori, in
contradistinction to empirical knowledge, which has its sources a
posteriori, that is, in experience.

But the expression, “a priori,” is not as yet definite enough
adequately to indicate the whole meaning of the question above started.
For, in speaking of knowledge which has its sources in experience, we
are wont to say, that this or that may be known a priori, because we do
not derive this knowledge immediately from experience, but from a
general rule, which, however, we have itself borrowed from experience.
Thus, if a man undermined his house, we say, “he might know a priori
that it would have fallen;” that is, he needed not to have waited for
the experience that it did actually fall. But still, a priori, he could
not know even this much. For, that bodies are heavy, and, consequently,
that they fall when their supports are taken away, must have been known
to him previously, by means of experience.

By the term “knowledge a priori,” therefore, we shall in the sequel
understand, not such as is independent of this or that kind of
experience, but such as is absolutely so of all experience. Opposed to
this is empirical knowledge, or that which is possible only a
posteriori, that is, through experience. Knowledge a priori is either
pure or impure. Pure knowledge a priori is that with which no empirical
element is mixed up. For example, the proposition, “Every change has a
cause,” is a proposition a priori, but impure, because change is a
conception which can only be derived from experience.

 II. The Human Intellect, even in an Unphilosophical State, is in
 Possession of Certain Cognitions “a priori”.

The question now is as to a criterion, by which we may securely
distinguish a pure from an empirical cognition. Experience no doubt
teaches us that this or that object is constituted in such and such a
manner, but not that it could not possibly exist otherwise. Now, in the
first place, if we have a proposition which contains the idea of
necessity in its very conception, it is priori. If, moreover, it is not
derived from any other proposition, unless from one equally involving
the idea of necessity, it is absolutely priori. Secondly, an empirical
judgement never exhibits strict and absolute, but only assumed and
comparative universality (by induction); therefore, the most we can say
is—so far as we have hitherto observed, there is no exception to this
or that rule. If, on the other hand, a judgement carries with it strict
and absolute universality, that is, admits of no possible exception, it
is not derived from experience, but is valid absolutely a priori.

Empirical universality is, therefore, only an arbitrary extension of
validity, from that which may be predicated of a proposition valid in
most cases, to that which is asserted of a proposition which holds good
in all; as, for example, in the affirmation, “All bodies are heavy.”
When, on the contrary, strict universality characterizes a judgement,
it necessarily indicates another peculiar source of knowledge, namely,
a faculty of cognition a priori. Necessity and strict universality,
therefore, are infallible tests for distinguishing pure from empirical
knowledge, and are inseparably connected with each other. But as in the
use of these criteria the empirical limitation is sometimes more easily
detected than the contingency of the judgement, or the unlimited
universality which we attach to a judgement is often a more convincing
proof than its necessity, it may be advisable to use the criteria
separately, each being by itself infallible.

Now, that in the sphere of human cognition we have judgements which are
necessary, and in the strictest sense universal, consequently pure a
priori, it will be an easy matter to show. If we desire an example from
the sciences, we need only take any proposition in mathematics. If we
cast our eyes upon the commonest operations of the understanding, the
proposition, “Every change must have a cause,” will amply serve our
purpose. In the latter case, indeed, the conception of a cause so
plainly involves the conception of a necessity of connection with an
effect, and of a strict universality of the law, that the very notion
of a cause would entirely disappear, were we to derive it, like Hume,
from a frequent association of what happens with that which precedes;
and the habit thence originating of connecting representations—the
necessity inherent in the judgement being therefore merely subjective.
Besides, without seeking for such examples of principles existing a
priori in cognition, we might easily show that such principles are the
indispensable basis of the possibility of experience itself, and
consequently prove their existence a priori. For whence could our
experience itself acquire certainty, if all the rules on which it
depends were themselves empirical, and consequently fortuitous? No one,
therefore, can admit the validity of the use of such rules as first
principles. But, for the present, we may content ourselves with having
established the fact, that we do possess and exercise a faculty of pure
a priori cognition; and, secondly, with having pointed out the proper
tests of such cognition, namely, universality and necessity.

Not only in judgements, however, but even in conceptions, is an a
priori origin manifest. For example, if we take away by degrees from
our conceptions of a body all that can be referred to mere sensuous
experience—colour, hardness or softness, weight, even
impenetrability—the body will then vanish; but the space which it
occupied still remains, and this it is utterly impossible to annihilate
in thought. Again, if we take away, in like manner, from our empirical
conception of any object, corporeal or incorporeal, all properties
which mere experience has taught us to connect with it, still we cannot
think away those through which we cogitate it as substance, or adhering
to substance, although our conception of substance is more determined
than that of an object. Compelled, therefore, by that necessity with
which the conception of substance forces itself upon us, we must
confess that it has its seat in our faculty of cognition a priori.

 III. Philosophy stands in need of a Science which shall Determine the
 Possibility, Principles, and Extent of Human Knowledge “a priori”

Of far more importance than all that has been above said, is the
consideration that certain of our cognitions rise completely above the
sphere of all possible experience, and by means of conceptions, to
which there exists in the whole extent of experience no corresponding
object, seem to extend the range of our judgements beyond its bounds.
And just in this transcendental or supersensible sphere, where
experience affords us neither instruction nor guidance, lie the
investigations of reason, which, on account of their importance, we
consider far preferable to, and as having a far more elevated aim than,
all that the understanding can achieve within the sphere of sensuous
phenomena. So high a value do we set upon these investigations, that
even at the risk of error, we persist in following them out, and permit
neither doubt nor disregard nor indifference to restrain us from the
pursuit. These unavoidable problems of mere pure reason are God,
freedom (of will), and immortality. The science which, with all its
preliminaries, has for its especial object the solution of these
problems is named metaphysics—a science which is at the very outset
dogmatical, that is, it confidently takes upon itself the execution of
this task without any previous investigation of the ability or
inability of reason for such an undertaking.

Now the safe ground of experience being thus abandoned, it seems
nevertheless natural that we should hesitate to erect a building with
the cognitions we possess, without knowing whence they come, and on the
strength of principles, the origin of which is undiscovered. Instead of
thus trying to build without a foundation, it is rather to be expected
that we should long ago have put the question, how the understanding
can arrive at these a priori cognitions, and what is the extent,
validity, and worth which they may possess? We say, “This is natural
enough,” meaning by the word natural, that which is consistent with a
just and reasonable way of thinking; but if we understand by the term,
that which usually happens, nothing indeed could be more natural and
more comprehensible than that this investigation should be left long
unattempted. For one part of our pure knowledge, the science of
mathematics, has been long firmly established, and thus leads us to
form flattering expectations with regard to others, though these may be
of quite a different nature. Besides, when we get beyond the bounds of
experience, we are of course safe from opposition in that quarter; and
the charm of widening the range of our knowledge is so great that,
unless we are brought to a standstill by some evident contradiction, we
hurry on undoubtingly in our course. This, however, may be avoided, if
we are sufficiently cautious in the construction of our fictions, which
are not the less fictions on that account.

Mathematical science affords us a brilliant example, how far,
independently of all experience, we may carry our a priori knowledge.
It is true that the mathematician occupies himself with objects and
cognitions only in so far as they can be represented by means of
intuition. But this circumstance is easily overlooked, because the said
intuition can itself be given a priori, and therefore is hardly to be
distinguished from a mere pure conception. Deceived by such a proof of
the power of reason, we can perceive no limits to the extension of our
knowledge. The light dove cleaving in free flight the thin air, whose
resistance it feels, might imagine that her movements would be far more
free and rapid in airless space. Just in the same way did Plato,
abandoning the world of sense because of the narrow limits it sets to
the understanding, venture upon the wings of ideas beyond it, into the
void space of pure intellect. He did not reflect that he made no real
progress by all his efforts; for he met with no resistance which might
serve him for a support, as it were, whereon to rest, and on which he
might apply his powers, in order to let the intellect acquire momentum
for its progress. It is, indeed, the common fate of human reason in
speculation, to finish the imposing edifice of thought as rapidly as
possible, and then for the first time to begin to examine whether the
foundation is a solid one or no. Arrived at this point, all sorts of
excuses are sought after, in order to console us for its want of
stability, or rather, indeed, to enable Us to dispense altogether with
so late and dangerous an investigation. But what frees us during the
process of building from all apprehension or suspicion, and flatters us
into the belief of its solidity, is this. A great part, perhaps the
greatest part, of the business of our reason consists in the
analysation of the conceptions which we already possess of objects. By
this means we gain a multitude of cognitions, which although really
nothing more than elucidations or explanations of that which (though in
a confused manner) was already thought in our conceptions, are, at
least in respect of their form, prized as new introspections; whilst,
so far as regards their matter or content, we have really made no
addition to our conceptions, but only disinvolved them. But as this
process does furnish a real priori knowledge, which has a sure progress
and useful results, reason, deceived by this, slips in, without being
itself aware of it, assertions of a quite different kind; in which, to
given conceptions it adds others, a priori indeed, but entirely foreign
to them, without our knowing how it arrives at these, and, indeed,
without such a question ever suggesting itself. I shall therefore at
once proceed to examine the difference between these two modes of

 IV. Of the Difference Between Analytical and Synthetical Judgements.

In all judgements wherein the relation of a subject to the predicate is
cogitated (I mention affirmative judgements only here; the application
to negative will be very easy), this relation is possible in two
different ways. Either the predicate B belongs to the subject A, as
somewhat which is contained (though covertly) in the conception A; or
the predicate B lies completely out of the conception A, although it
stands in connection with it. In the first instance, I term the
judgement analytical, in the second, synthetical. Analytical judgements
(affirmative) are therefore those in which the connection of the
predicate with the subject is cogitated through identity; those in
which this connection is cogitated without identity, are called
synthetical judgements. The former may be called explicative, the
latter augmentative judgements; because the former add in the predicate
nothing to the conception of the subject, but only analyse it into its
constituent conceptions, which were thought already in the subject,
although in a confused manner; the latter add to our conceptions of the
subject a predicate which was not contained in it, and which no
analysis could ever have discovered therein. For example, when I say,
“All bodies are extended,” this is an analytical judgement. For I need
not go beyond the conception of body in order to find extension
connected with it, but merely analyse the conception, that is, become
conscious of the manifold properties which I think in that conception,
in order to discover this predicate in it: it is therefore an
analytical judgement. On the other hand, when I say, “All bodies are
heavy,” the predicate is something totally different from that which I
think in the mere conception of a body. By the addition of such a
predicate, therefore, it becomes a synthetical judgement.

Judgements of experience, as such, are always synthetical. For it would
be absurd to think of grounding an analytical judgement on experience,
because in forming such a judgement I need not go out of the sphere of
my conceptions, and therefore recourse to the testimony of experience
is quite unnecessary. That “bodies are extended” is not an empirical
judgement, but a proposition which stands firm a priori. For before
addressing myself to experience, I already have in my conception all
the requisite conditions for the judgement, and I have only to extract
the predicate from the conception, according to the principle of
contradiction, and thereby at the same time become conscious of the
necessity of the judgement, a necessity which I could never learn from
experience. On the other hand, though at first I do not at all include
the predicate of weight in my conception of body in general, that
conception still indicates an object of experience, a part of the
totality of experience, to which I can still add other parts; and this
I do when I recognize by observation that bodies are heavy. I can
cognize beforehand by analysis the conception of body through the
characteristics of extension, impenetrability, shape, etc., all which
are cogitated in this conception. But now I extend my knowledge, and
looking back on experience from which I had derived this conception of
body, I find weight at all times connected with the above
characteristics, and therefore I synthetically add to my conceptions
this as a predicate, and say, “All bodies are heavy.” Thus it is
experience upon which rests the possibility of the synthesis of the
predicate of weight with the conception of body, because both
conceptions, although the one is not contained in the other, still
belong to one another (only contingently, however), as parts of a
whole, namely, of experience, which is itself a synthesis of

But to synthetical judgements a priori, such aid is entirely wanting.
If I go out of and beyond the conception A, in order to recognize
another B as connected with it, what foundation have I to rest on,
whereby to render the synthesis possible? I have here no longer the
advantage of looking out in the sphere of experience for what I want.
Let us take, for example, the proposition, “Everything that happens has
a cause.” In the conception of “something that happens,” I indeed think
an existence which a certain time antecedes, and from this I can derive
analytical judgements. But the conception of a cause lies quite out of
the above conception, and indicates something entirely different from
“that which happens,” and is consequently not contained in that
conception. How then am I able to assert concerning the general
conception—“that which happens”—something entirely different from that
conception, and to recognize the conception of cause although not
contained in it, yet as belonging to it, and even necessarily? what is
here the unknown = X, upon which the understanding rests when it
believes it has found, out of the conception A a foreign predicate B,
which it nevertheless considers to be connected with it? It cannot be
experience, because the principle adduced annexes the two
representations, cause and effect, to the representation existence, not
only with universality, which experience cannot give, but also with the
expression of necessity, therefore completely a priori and from pure
conceptions. Upon such synthetical, that is augmentative propositions,
depends the whole aim of our speculative knowledge a priori; for
although analytical judgements are indeed highly important and
necessary, they are so, only to arrive at that clearness of conceptions
which is requisite for a sure and extended synthesis, and this alone is
a real acquisition.

 V. In all Theoretical Sciences of Reason, Synthetical Judgements “a
 priori” are contained as Principles.

1. Mathematical judgements are always synthetical. Hitherto this fact,
though incontestably true and very important in its consequences, seems
to have escaped the analysts of the human mind, nay, to be in complete
opposition to all their conjectures. For as it was found that
mathematical conclusions all proceed according to the principle of
contradiction (which the nature of every apodeictic certainty
requires), people became persuaded that the fundamental principles of
the science also were recognized and admitted in the same way. But the
notion is fallacious; for although a synthetical proposition can
certainly be discerned by means of the principle of contradiction, this
is possible only when another synthetical proposition precedes, from
which the latter is deduced, but never of itself.

Before all, be it observed, that proper mathematical propositions are
always judgements a priori, and not empirical, because they carry along
with them the conception of necessity, which cannot be given by
experience. If this be demurred to, it matters not; I will then limit
my assertion to pure mathematics, the very conception of which implies
that it consists of knowledge altogether non-empirical and a priori.

We might, indeed at first suppose that the proposition 7 + 5 = 12 is a
merely analytical proposition, following (according to the principle of
contradiction) from the conception of a sum of seven and five. But if
we regard it more narrowly, we find that our conception of the sum of
seven and five contains nothing more than the uniting of both sums into
one, whereby it cannot at all be cogitated what this single number is
which embraces both. The conception of twelve is by no means obtained
by merely cogitating the union of seven and five; and we may analyse
our conception of such a possible sum as long as we will, still we
shall never discover in it the notion of twelve. We must go beyond
these conceptions, and have recourse to an intuition which corresponds
to one of the two—our five fingers, for example, or like Segner in his
Arithmetic five points, and so by degrees, add the units contained in
the five given in the intuition, to the conception of seven. For I
first take the number 7, and, for the conception of 5 calling in the
aid of the fingers of my hand as objects of intuition, I add the units,
which I before took together to make up the number 5, gradually now by
means of the material image my hand, to the number 7, and by this
process, I at length see the number 12 arise. That 7 should be added to
5, I have certainly cogitated in my conception of a sum = 7 + 5, but
not that this sum was equal to 12. Arithmetical propositions are
therefore always synthetical, of which we may become more clearly
convinced by trying large numbers. For it will thus become quite
evident that, turn and twist our conceptions as we may, it is
impossible, without having recourse to intuition, to arrive at the sum
total or product by means of the mere analysis of our conceptions. Just
as little is any principle of pure geometry analytical. “A straight
line between two points is the shortest,” is a synthetical proposition.
For my conception of straight contains no notion of quantity, but is
merely qualitative. The conception of the shortest is therefore fore
wholly an addition, and by no analysis can it be extracted from our
conception of a straight line. Intuition must therefore here lend its
aid, by means of which, and thus only, our synthesis is possible.

Some few principles preposited by geometricians are, indeed, really
analytical, and depend on the principle of contradiction. They serve,
however, like identical propositions, as links in the chain of method,
not as principles—for example, a = a, the whole is equal to itself, or
(a+b) —> a, the whole is greater than its part. And yet even these
principles themselves, though they derive their validity from pure
conceptions, are only admitted in mathematics because they can be
presented in intuition. What causes us here commonly to believe that
the predicate of such apodeictic judgements is already contained in our
conception, and that the judgement is therefore analytical, is merely
the equivocal nature of the expression. We must join in thought a
certain predicate to a given conception, and this necessity cleaves
already to the conception. But the question is, not what we must join
in thought to the given conception, but what we really think therein,
though only obscurely, and then it becomes manifest that the predicate
pertains to these conceptions, necessarily indeed, yet not as thought
in the conception itself, but by virtue of an intuition, which must be
added to the conception.

2. The science of natural philosophy (physics) contains in itself
synthetical judgements a priori, as principles. I shall adduce two
propositions. For instance, the proposition, “In all changes of the
material world, the quantity of matter remains unchanged”; or, that,
“In all communication of motion, action and reaction must always be
equal.” In both of these, not only is the necessity, and therefore
their origin a priori clear, but also that they are synthetical
propositions. For in the conception of matter, I do not cogitate its
permanency, but merely its presence in space, which it fills. I
therefore really go out of and beyond the conception of matter, in
order to think on to it something a priori, which I did not think in
it. The proposition is therefore not analytical, but synthetical, and
nevertheless conceived a priori; and so it is with regard to the other
propositions of the pure part of natural philosophy.

3. As to metaphysics, even if we look upon it merely as an attempted
science, yet, from the nature of human reason, an indispensable one, we
find that it must contain synthetical propositions a priori. It is not
merely the duty of metaphysics to dissect, and thereby analytically to
illustrate the conceptions which we form a priori of things; but we
seek to widen the range of our a priori knowledge. For this purpose, we
must avail ourselves of such principles as add something to the
original conception—something not identical with, nor contained in it,
and by means of synthetical judgements a priori, leave far behind us
the limits of experience; for example, in the proposition, “the world
must have a beginning,” and such like. Thus metaphysics, according to
the proper aim of the science, consists merely of synthetical
propositions a priori.

 VI. The Universal Problem of Pure Reason.

It is extremely advantageous to be able to bring a number of
investigations under the formula of a single problem. For in this
manner, we not only facilitate our own labour, inasmuch as we define it
clearly to ourselves, but also render it more easy for others to decide
whether we have done justice to our undertaking. The proper problem of
pure reason, then, is contained in the question: “How are synthetical
judgements a priori possible?”

That metaphysical science has hitherto remained in so vacillating a
state of uncertainty and contradiction, is only to be attributed to the
fact that this great problem, and perhaps even the difference between
analytical and synthetical judgements, did not sooner suggest itself to
philosophers. Upon the solution of this problem, or upon sufficient
proof of the impossibility of synthetical knowledge a priori, depends
the existence or downfall of the science of metaphysics. Among
philosophers, David Hume came the nearest of all to this problem; yet
it never acquired in his mind sufficient precision, nor did he regard
the question in its universality. On the contrary, he stopped short at
the synthetical proposition of the connection of an effect with its
cause (principium causalitatis), insisting that such proposition a
priori was impossible. According to his conclusions, then, all that we
term metaphysical science is a mere delusion, arising from the fancied
insight of reason into that which is in truth borrowed from experience,
and to which habit has given the appearance of necessity. Against this
assertion, destructive to all pure philosophy, he would have been
guarded, had he had our problem before his eyes in its universality.
For he would then have perceived that, according to his own argument,
there likewise could not be any pure mathematical science, which
assuredly cannot exist without synthetical propositions a priori—an
absurdity from which his good understanding must have saved him.

In the solution of the above problem is at the same time comprehended
the possibility of the use of pure reason in the foundation and
construction of all sciences which contain theoretical knowledge a
priori of objects, that is to say, the answer to the following

How is pure mathematical science possible?

How is pure natural science possible?

Respecting these sciences, as they do certainly exist, it may with
propriety be asked, how they are possible?—for that they must be
possible is shown by the fact of their really existing.* But as to
metaphysics, the miserable progress it has hitherto made, and the fact
that of no one system yet brought forward, far as regards its true aim,
can it be said that this science really exists, leaves any one at
liberty to doubt with reason the very possibility of its existence.

[*Footnote: As to the existence of pure natural science, or physics,
perhaps many may still express doubts. But we have only to look at the
different propositions which are commonly treated of at the
commencement of proper (empirical) physical science—those, for example,
relating to the permanence of the same quantity of matter, the vis
inertiae, the equality of action and reaction, etc.—to be soon
convinced that they form a science of pure physics (physica pura, or
rationalis), which well deserves to be separately exposed as a special
science, in its whole extent, whether that be great or confined.]

Yet, in a certain sense, this kind of knowledge must unquestionably be
looked upon as given; in other words, metaphysics must be considered as
really existing, if not as a science, nevertheless as a natural
disposition of the human mind (metaphysica naturalis). For human
reason, without any instigations imputable to the mere vanity of great
knowledge, unceasingly progresses, urged on by its own feeling of need,
towards such questions as cannot be answered by any empirical
application of reason, or principles derived therefrom; and so there
has ever really existed in every man some system of metaphysics. It
will always exist, so soon as reason awakes to the exercise of its
power of speculation. And now the question arises: “How is metaphysics,
as a natural disposition, possible?” In other words, how, from the
nature of universal human reason, do those questions arise which pure
reason proposes to itself, and which it is impelled by its own feeling
of need to answer as well as it can?

But as in all the attempts hitherto made to answer the questions which
reason is prompted by its very nature to propose to itself, for
example, whether the world had a beginning, or has existed from
eternity, it has always met with unavoidable contradictions, we must
not rest satisfied with the mere natural disposition of the mind to
metaphysics, that is, with the existence of the faculty of pure reason,
whence, indeed, some sort of metaphysical system always arises; but it
must be possible to arrive at certainty in regard to the question
whether we know or do not know the things of which metaphysics treats.
We must be able to arrive at a decision on the subjects of its
questions, or on the ability or inability of reason to form any
judgement respecting them; and therefore either to extend with
confidence the bounds of our pure reason, or to set strictly defined
and safe limits to its action. This last question, which arises out of
the above universal problem, would properly run thus: “How is
metaphysics possible as a science?”

Thus, the critique of reason leads at last, naturally and necessarily,
to science; and, on the other hand, the dogmatical use of reason
without criticism leads to groundless assertions, against which others
equally specious can always be set, thus ending unavoidably in

Besides, this science cannot be of great and formidable prolixity,
because it has not to do with objects of reason, the variety of which
is inexhaustible, but merely with Reason herself and her problems;
problems which arise out of her own bosom, and are not proposed to her
by the nature of outward things, but by her own nature. And when once
Reason has previously become able completely to understand her own
power in regard to objects which she meets with in experience, it will
be easy to determine securely the extent and limits of her attempted
application to objects beyond the confines of experience.

We may and must, therefore, regard the attempts hitherto made to
establish metaphysical science dogmatically as non-existent. For what
of analysis, that is, mere dissection of conceptions, is contained in
one or other, is not the aim of, but only a preparation for metaphysics
proper, which has for its object the extension, by means of synthesis,
of our a priori knowledge. And for this purpose, mere analysis is of
course useless, because it only shows what is contained in these
conceptions, but not how we arrive, a priori, at them; and this it is
her duty to show, in order to be able afterwards to determine their
valid use in regard to all objects of experience, to all knowledge in
general. But little self-denial, indeed, is needed to give up these
pretensions, seeing the undeniable, and in the dogmatic mode of
procedure, inevitable contradictions of Reason with herself, have long
since ruined the reputation of every system of metaphysics that has
appeared up to this time. It will require more firmness to remain
undeterred by difficulty from within, and opposition from without, from
endeavouring, by a method quite opposed to all those hitherto followed,
to further the growth and fruitfulness of a science indispensable to
human reason—a science from which every branch it has borne may be cut
away, but whose roots remain indestructible.

 VII. Idea and Division of a Particular Science, under the Name of a
 Critique of Pure Reason.

From all that has been said, there results the idea of a particular
science, which may be called the Critique of Pure Reason. For reason is
the faculty which furnishes us with the principles of knowledge a
priori. Hence, pure reason is the faculty which contains the principles
of cognizing anything absolutely a priori. An organon of pure reason
would be a compendium of those principles according to which alone all
pure cognitions a priori can be obtained. The completely extended
application of such an organon would afford us a system of pure reason.
As this, however, is demanding a great deal, and it is yet doubtful
whether any extension of our knowledge be here possible, or, if so, in
what cases; we can regard a science of the mere criticism of pure
reason, its sources and limits, as the propaedeutic to a system of pure
reason. Such a science must not be called a doctrine, but only a
critique of pure reason; and its use, in regard to speculation, would
be only negative, not to enlarge the bounds of, but to purify, our
reason, and to shield it against error—which alone is no little gain. I
apply the term transcendental to all knowledge which is not so much
occupied with objects as with the mode of our cognition of these
objects, so far as this mode of cognition is possible a priori. A
system of such conceptions would be called transcendental philosophy.
But this, again, is still beyond the bounds of our present essay. For
as such a science must contain a complete exposition not only of our
synthetical a priori, but of our analytical a priori knowledge, it is
of too wide a range for our present purpose, because we do not require
to carry our analysis any farther than is necessary to understand, in
their full extent, the principles of synthesis a priori, with which
alone we have to do. This investigation, which we cannot properly call
a doctrine, but only a transcendental critique, because it aims not at
the enlargement, but at the correction and guidance, of our knowledge,
and is to serve as a touchstone of the worth or worthlessness of all
knowledge a priori, is the sole object of our present essay. Such a
critique is consequently, as far as possible, a preparation for an
organon; and if this new organon should be found to fail, at least for
a canon of pure reason, according to which the complete system of the
philosophy of pure reason, whether it extend or limit the bounds of
that reason, might one day be set forth both analytically and
synthetically. For that this is possible, nay, that such a system is
not of so great extent as to preclude the hope of its ever being
completed, is evident. For we have not here to do with the nature of
outward objects, which is infinite, but solely with the mind, which
judges of the nature of objects, and, again, with the mind only in
respect of its cognition a priori. And the object of our
investigations, as it is not to be sought without, but, altogether
within, ourselves, cannot remain concealed, and in all probability is
limited enough to be completely surveyed and fairly estimated,
according to its worth or worthlessness. Still less let the reader here
expect a critique of books and systems of pure reason; our present
object is exclusively a critique of the faculty of pure reason itself.
Only when we make this critique our foundation, do we possess a pure
touchstone for estimating the philosophical value of ancient and modern
writings on this subject; and without this criterion, the incompetent
historian or judge decides upon and corrects the groundless assertions
of others with his own, which have themselves just as little

Transcendental philosophy is the idea of a science, for which the
Critique of Pure Reason must sketch the whole plan architectonically,
that is, from principles, with a full guarantee for the validity and
stability of all the parts which enter into the building. It is the
system of all the principles of pure reason. If this Critique itself
does not assume the title of transcendental philosophy, it is only
because, to be a complete system, it ought to contain a full analysis
of all human knowledge a priori. Our critique must, indeed, lay before
us a complete enumeration of all the radical conceptions which
constitute the said pure knowledge. But from the complete analysis of
these conceptions themselves, as also from a complete investigation of
those derived from them, it abstains with reason; partly because it
would be deviating from the end in view to occupy itself with this
analysis, since this process is not attended with the difficulty and
insecurity to be found in the synthesis, to which our critique is
entirely devoted, and partly because it would be inconsistent with the
unity of our plan to burden this essay with the vindication of the
completeness of such an analysis and deduction, with which, after all,
we have at present nothing to do. This completeness of the analysis of
these radical conceptions, as well as of the deduction from the
conceptions a priori which may be given by the analysis, we can,
however, easily attain, provided only that we are in possession of all
these radical conceptions, which are to serve as principles of the
synthesis, and that in respect of this main purpose nothing is wanting.

To the Critique of Pure Reason, therefore, belongs all that constitutes
transcendental philosophy; and it is the complete idea of
transcendental philosophy, but still not the science itself; because it
only proceeds so far with the analysis as is necessary to the power of
judging completely of our synthetical knowledge a priori.

The principal thing we must attend to, in the division of the parts of
a science like this, is that no conceptions must enter it which contain
aught empirical; in other words, that the knowledge a priori must be
completely pure. Hence, although the highest principles and fundamental
conceptions of morality are certainly cognitions a priori, yet they do
not belong to transcendental philosophy; because, though they certainly
do not lay the conceptions of pain, pleasure, desires, inclinations,
etc. (which are all of empirical origin), at the foundation of its
precepts, yet still into the conception of duty—as an obstacle to be
overcome, or as an incitement which should not be made into a
motive—these empirical conceptions must necessarily enter, in the
construction of a system of pure morality. Transcendental philosophy is
consequently a philosophy of the pure and merely speculative reason.
For all that is practical, so far as it contains motives, relates to
feelings, and these belong to empirical sources of cognition.

If we wish to divide this science from the universal point of view of a
science in general, it ought to comprehend, first, a Doctrine of the
Elements, and, secondly, a Doctrine of the Method of pure reason. Each
of these main divisions will have its subdivisions, the separate
reasons for which we cannot here particularize. Only so much seems
necessary, by way of introduction of premonition, that there are two
sources of human knowledge (which probably spring from a common, but to
us unknown root), namely, sense and understanding. By the former,
objects are given to us; by the latter, thought. So far as the faculty
of sense may contain representations a priori, which form the
conditions under which objects are given, in so far it belongs to
transcendental philosophy. The transcendental doctrine of sense must
form the first part of our science of elements, because the conditions
under which alone the objects of human knowledge are given must precede
those under which they are thought.



 § I. Introductory.

In whatsoever mode, or by whatsoever means, our knowledge may relate to
objects, it is at least quite clear that the only manner in which it
immediately relates to them is by means of an intuition. To this as the
indispensable groundwork, all thought points. But an intuition can take
place only in so far as the object is given to us. This, again, is only
possible, to man at least, on condition that the object affect the mind
in a certain manner. The capacity for receiving representations
(receptivity) through the mode in which we are affected by objects,
objects, is called sensibility. By means of sensibility, therefore,
objects are given to us, and it alone furnishes us with intuitions; by
the understanding they are thought, and from it arise conceptions. But
an thought must directly, or indirectly, by means of certain signs,
relate ultimately to intuitions; consequently, with us, to sensibility,
because in no other way can an object be given to us.

The effect of an object upon the faculty of representation, so far as
we are affected by the said object, is sensation. That sort of
intuition which relates to an object by means of sensation is called an
empirical intuition. The undetermined object of an empirical intuition
is called phenomenon. That which in the phenomenon corresponds to the
sensation, I term its matter; but that which effects that the content
of the phenomenon can be arranged under certain relations, I call its
form. But that in which our sensations are merely arranged, and by
which they are susceptible of assuming a certain form, cannot be itself
sensation. It is, then, the matter of all phenomena that is given to us
a posteriori; the form must lie ready a priori for them in the mind,
and consequently can be regarded separately from all sensation.

I call all representations pure, in the transcendental meaning of the
word, wherein nothing is met with that belongs to sensation. And
accordingly we find existing in the mind a priori, the pure form of
sensuous intuitions in general, in which all the manifold content of
the phenomenal world is arranged and viewed under certain relations.
This pure form of sensibility I shall call pure intuition. Thus, if I
take away from our representation of a body all that the understanding
thinks as belonging to it, as substance, force, divisibility, etc., and
also whatever belongs to sensation, as impenetrability, hardness,
colour, etc.; yet there is still something left us from this empirical
intuition, namely, extension and shape. These belong to pure intuition,
which exists a priori in the mind, as a mere form of sensibility, and
without any real object of the senses or any sensation.

The science of all the principles of sensibility a priori, I call
transcendental aesthetic.* There must, then, be such a science forming
the first part of the transcendental doctrine of elements, in
contradistinction to that part which contains the principles of pure
thought, and which is called transcendental logic.

[Footnote: The Germans are the only people who at present use this word
to indicate what others call the critique of taste. At the foundation
of this term lies the disappointed hope, which the eminent analyst,
Baumgarten, conceived, of subjecting the criticism of the beautiful to
principles of reason, and so of elevating its rules into a science. But
his endeavours were vain. For the said rules or criteria are, in
respect to their chief sources, merely empirical, consequently never
can serve as determinate laws a priori, by which our judgement in
matters of taste is to be directed. It is rather our judgement which
forms the proper test as to the correctness of the principles. On this
account it is advisable to give up the use of the term as designating
the critique of taste, and to apply it solely to that doctrine, which
is true science—the science of the laws of sensibility—and thus come
nearer to the language and the sense of the ancients in their
well-known division of the objects of cognition into aiotheta kai
noeta, or to share it with speculative philosophy, and employ it partly
in a transcendental, partly in a psychological signification.]

In the science of transcendental aesthetic accordingly, we shall first
isolate sensibility or the sensuous faculty, by separating from it all
that is annexed to its perceptions by the conceptions of understanding,
so that nothing be left but empirical intuition. In the next place we
shall take away from this intuition all that belongs to sensation, so
that nothing may remain but pure intuition, and the mere form of
phenomena, which is all that the sensibility can afford a priori. From
this investigation it will be found that there are two pure forms of
sensuous intuition, as principles of knowledge a priori, namely, space
and time. To the consideration of these we shall now proceed.

 SECTION I. Of Space.

 § 2. Metaphysical Exposition of this Conception.

By means of the external sense (a property of the mind), we represent
to ourselves objects as without us, and these all in space. Herein
alone are their shape, dimensions, and relations to each other
determined or determinable. The internal sense, by means of which the
mind contemplates itself or its internal state, gives, indeed, no
intuition of the soul as an object; yet there is nevertheless a
determinate form, under which alone the contemplation of our internal
state is possible, so that all which relates to the inward
determinations of the mind is represented in relations of time. Of time
we cannot have any external intuition, any more than we can have an
internal intuition of space. What then are time and space? Are they
real existences? Or, are they merely relations or determinations of
things, such, however, as would equally belong to these things in
themselves, though they should never become objects of intuition; or,
are they such as belong only to the form of intuition, and consequently
to the subjective constitution of the mind, without which these
predicates of time and space could not be attached to any object? In
order to become informed on these points, we shall first give an
exposition of the conception of space. By exposition, I mean the clear,
though not detailed, representation of that which belongs to a
conception; and an exposition is metaphysical when it contains that
which represents the conception as given a priori.

1. Space is not a conception which has been derived from outward
experiences. For, in order that certain sensations may relate to
something without me (that is, to something which occupies a different
part of space from that in which I am); in like manner, in order that I
may represent them not merely as without, of, and near to each other,
but also in separate places, the representation of space must already
exist as a foundation. Consequently, the representation of space cannot
be borrowed from the relations of external phenomena through
experience; but, on the contrary, this external experience is itself
only possible through the said antecedent representation.

2. Space then is a necessary representation a priori, which serves for
the foundation of all external intuitions. We never can imagine or make
a representation to ourselves of the non-existence of space, though we
may easily enough think that no objects are found in it. It must,
therefore, be considered as the condition of the possibility of
phenomena, and by no means as a determination dependent on them, and is
a representation a priori, which necessarily supplies the basis for
external phenomena.

3. Space is no discursive, or as we say, general conception of the
relations of things, but a pure intuition. For, in the first place, we
can only represent to ourselves one space, and, when we talk of divers
spaces, we mean only parts of one and the same space. Moreover, these
parts cannot antecede this one all-embracing space, as the component
parts from which the aggregate can be made up, but can be cogitated
only as existing in it. Space is essentially one, and multiplicity in
it, consequently the general notion of spaces, of this or that space,
depends solely upon limitations. Hence it follows that an a priori
intuition (which is not empirical) lies at the root of all our
conceptions of space. Thus, moreover, the principles of geometry—for
example, that “in a triangle, two sides together are greater than the
third,” are never deduced from general conceptions of line and
triangle, but from intuition, and this a priori, with apodeictic

4. Space is represented as an infinite given quantity. Now every
conception must indeed be considered as a representation which is
contained in an infinite multitude of different possible
representations, which, therefore, comprises these under itself; but no
conception, as such, can be so conceived, as if it contained within
itself an infinite multitude of representations. Nevertheless, space is
so conceived of, for all parts of space are equally capable of being
produced to infinity. Consequently, the original representation of
space is an intuition a priori, and not a conception.

 § 3. Transcendental Exposition of the Conception of Space.

By a transcendental exposition, I mean the explanation of a conception,
as a principle, whence can be discerned the possibility of other
synthetical a priori cognitions. For this purpose, it is requisite,
firstly, that such cognitions do really flow from the given conception;
and, secondly, that the said cognitions are only possible under the
presupposition of a given mode of explaining this conception.

Geometry is a science which determines the properties of space
synthetically, and yet a priori. What, then, must be our representation
of space, in order that such a cognition of it may be possible? It must
be originally intuition, for from a mere conception, no propositions
can be deduced which go out beyond the conception, and yet this happens
in geometry. (Introd. V.) But this intuition must be found in the mind
a priori, that is, before any perception of objects, consequently must
be pure, not empirical, intuition. For geometrical principles are
always apodeictic, that is, united with the consciousness of their
necessity, as: “Space has only three dimensions.” But propositions of
this kind cannot be empirical judgements, nor conclusions from them.
(Introd. II.) Now, how can an external intuition anterior to objects
themselves, and in which our conception of objects can be determined a
priori, exist in the human mind? Obviously not otherwise than in so far
as it has its seat in the subject only, as the formal capacity of the
subject’s being affected by objects, and thereby of obtaining immediate
representation, that is, intuition; consequently, only as the form of
the external sense in general.

Thus it is only by means of our explanation that the possibility of
geometry, as a synthetical science a priori, becomes comprehensible.
Every mode of explanation which does not show us this possibility,
although in appearance it may be similar to ours, can with the utmost
certainty be distinguished from it by these marks.

 § 4. Conclusions from the foregoing Conceptions.

(a) Space does not represent any property of objects as things in
themselves, nor does it represent them in their relations to each
other; in other words, space does not represent to us any determination
of objects such as attaches to the objects themselves, and would
remain, even though all subjective conditions of the intuition were
abstracted. For neither absolute nor relative determinations of objects
can be intuited prior to the existence of the things to which they
belong, and therefore not a priori.

(b) Space is nothing else than the form of all phenomena of the
external sense, that is, the subjective condition of the sensibility,
under which alone external intuition is possible. Now, because the
receptivity or capacity of the subject to be affected by objects
necessarily antecedes all intuitions of these objects, it is easily
understood how the form of all phenomena can be given in the mind
previous to all actual perceptions, therefore a priori, and how it, as
a pure intuition, in which all objects must be determined, can contain
principles of the relations of these objects prior to all experience.

It is therefore from the human point of view only that we can speak of
space, extended objects, etc. If we depart from the subjective
condition, under which alone we can obtain external intuition, or, in
other words, by means of which we are affected by objects, the
representation of space has no meaning whatsoever. This predicate is
only applicable to things in so far as they appear to us, that is, are
objects of sensibility. The constant form of this receptivity, which we
call sensibility, is a necessary condition of all relations in which
objects can be intuited as existing without us, and when abstraction of
these objects is made, is a pure intuition, to which we give the name
of space. It is clear that we cannot make the special conditions of
sensibility into conditions of the possibility of things, but only of
the possibility of their existence as far as they are phenomena. And so
we may correctly say that space contains all which can appear to us
externally, but not all things considered as things in themselves, be
they intuited or not, or by whatsoever subject one will. As to the
intuitions of other thinking beings, we cannot judge whether they are
or are not bound by the same conditions which limit our own intuition,
and which for us are universally valid. If we join the limitation of a
judgement to the conception of the subject, then the judgement will
possess unconditioned validity. For example, the proposition, “All
objects are beside each other in space,” is valid only under the
limitation that these things are taken as objects of our sensuous
intuition. But if I join the condition to the conception and say, “All
things, as external phenomena, are beside each other in space,” then
the rule is valid universally, and without any limitation. Our
expositions, consequently, teach the reality (i.e., the objective
validity) of space in regard of all which can be presented to us
externally as object, and at the same time also the ideality of space
in regard to objects when they are considered by means of reason as
things in themselves, that is, without reference to the constitution of
our sensibility. We maintain, therefore, the empirical reality of space
in regard to all possible external experience, although we must admit
its transcendental ideality; in other words, that it is nothing, so
soon as we withdraw the condition upon which the possibility of all
experience depends and look upon space as something that belongs to
things in themselves.

But, with the exception of space, there is no representation,
subjective and referring to something external to us, which could be
called objective a priori. For there are no other subjective
representations from which we can deduce synthetical propositions a
priori, as we can from the intuition of space. (See § 3.) Therefore, to
speak accurately, no ideality whatever belongs to these, although they
agree in this respect with the representation of space, that they
belong merely to the subjective nature of the mode of sensuous
perception; such a mode, for example, as that of sight, of hearing, and
of feeling, by means of the sensations of colour, sound, and heat, but
which, because they are only sensations and not intuitions, do not of
themselves give us the cognition of any object, least of all, an a
priori cognition. My purpose, in the above remark, is merely this: to
guard any one against illustrating the asserted ideality of space by
examples quite insufficient, for example, by colour, taste, etc.; for
these must be contemplated not as properties of things, but only as
changes in the subject, changes which may be different in different
men. For, in such a case, that which is originally a mere phenomenon, a
rose, for example, is taken by the empirical understanding for a thing
in itself, though to every different eye, in respect of its colour, it
may appear different. On the contrary, the transcendental conception of
phenomena in space is a critical admonition, that, in general, nothing
which is intuited in space is a thing in itself, and that space is not
a form which belongs as a property to things; but that objects are
quite unknown to us in themselves, and what we call outward objects,
are nothing else but mere representations of our sensibility, whose
form is space, but whose real correlate, the thing in itself, is not
known by means of these representations, nor ever can be, but
respecting which, in experience, no inquiry is ever made.


 § 5. Metaphysical Exposition of this Conception.

1. Time is not an empirical conception. For neither coexistence nor
succession would be perceived by us, if the representation of time did
not exist as a foundation a priori. Without this presupposition we
could not represent to ourselves that things exist together at one and
the same time, or at different times, that is, contemporaneously, or in

2. Time is a necessary representation, lying at the foundation of all
our intuitions. With regard to phenomena in general, we cannot think
away time from them, and represent them to ourselves as out of and
unconnected with time, but we can quite well represent to ourselves
time void of phenomena. Time is therefore given a priori. In it alone
is all reality of phenomena possible. These may all be annihilated in
thought, but time itself, as the universal condition of their
possibility, cannot be so annulled.

3. On this necessity a priori is also founded the possibility of
apodeictic principles of the relations of time, or axioms of time in
general, such as: “Time has only one dimension,” “Different times are
not coexistent but successive” (as different spaces are not successive
but coexistent). These principles cannot be derived from experience,
for it would give neither strict universality, nor apodeictic
certainty. We should only be able to say, “so common experience teaches
us,” but not “it must be so.” They are valid as rules, through which,
in general, experience is possible; and they instruct us respecting
experience, and not by means of it.

4. Time is not a discursive, or as it is called, general conception,
but a pure form of the sensuous intuition. Different times are merely
parts of one and the same time. But the representation which can only
be given by a single object is an intuition. Besides, the proposition
that different times cannot be coexistent could not be derived from a
general conception. For this proposition is synthetical, and therefore
cannot spring out of conceptions alone. It is therefore contained
immediately in the intuition and representation of time.

5. The infinity of time signifies nothing more than that every
determined quantity of time is possible only through limitations of one
time lying at the foundation. Consequently, the original
representation, time, must be given as unlimited. But as the
determinate representation of the parts of time and of every quantity
of an object can only be obtained by limitation, the complete
representation of time must not be furnished by means of conceptions,
for these contain only partial representations. Conceptions, on the
contrary, must have immediate intuition for their basis.

 § 6 Transcendental Exposition of the Conception of Time.

I may here refer to what is said above (§ 5, 3), where, for or sake of
brevity, I have placed under the head of metaphysical exposition, that
which is properly transcendental. Here I shall add that the conception
of change, and with it the conception of motion, as change of place, is
possible only through and in the representation of time; that if this
representation were not an intuition (internal) a priori, no
conception, of whatever kind, could render comprehensible the
possibility of change, in other words, of a conjunction of
contradictorily opposed predicates in one and the same object, for
example, the presence of a thing in a place and the non-presence of the
same thing in the same place. It is only in time that it is possible to
meet with two contradictorily opposed determinations in one thing, that
is, after each other. Thus our conception of time explains the
possibility of so much synthetical knowledge a priori, as is exhibited
in the general doctrine of motion, which is not a little fruitful.

 § 7. Conclusions from the above Conceptions.

(a) Time is not something which subsists of itself, or which inheres in
things as an objective determination, and therefore remains, when
abstraction is made of the subjective conditions of the intuition of
things. For in the former case, it would be something real, yet without
presenting to any power of perception any real object. In the latter
case, as an order or determination inherent in things themselves, it
could not be antecedent to things, as their condition, nor discerned or
intuited by means of synthetical propositions a priori. But all this is
quite possible when we regard time as merely the subjective condition
under which all our intuitions take place. For in that case, this form
of the inward intuition can be represented prior to the objects, and
consequently a priori.

(b) Time is nothing else than the form of the internal sense, that is,
of the intuitions of self and of our internal state. For time cannot be
any determination of outward phenomena. It has to do neither with shape
nor position; on the contrary, it determines the relation of
representations in our internal state. And precisely because this
internal intuition presents to us no shape or form, we endeavour to
supply this want by analogies, and represent the course of time by a
line progressing to infinity, the content of which constitutes a series
which is only of one dimension; and we conclude from the properties of
this line as to all the properties of time, with this single exception,
that the parts of the line are coexistent, whilst those of time are
successive. From this it is clear also that the representation of time
is itself an intuition, because all its relations can be expressed in
an external intuition.

(c) Time is the formal condition a priori of all phenomena whatsoever.
Space, as the pure form of external intuition, is limited as a
condition a priori to external phenomena alone. On the other hand,
because all representations, whether they have or have not external
things for their objects, still in themselves, as determinations of the
mind, belong to our internal state; and because this internal state is
subject to the formal condition of the internal intuition, that is, to
time—time is a condition a priori of all phenomena whatsoever—the
immediate condition of all internal, and thereby the mediate condition
of all external phenomena. If I can say a priori, “All outward
phenomena are in space, and determined a priori according to the
relations of space,” I can also, from the principle of the internal
sense, affirm universally, “All phenomena in general, that is, all
objects of the senses, are in time and stand necessarily in relations
of time.”

If we abstract our internal intuition of ourselves and all external
intuitions, possible only by virtue of this internal intuition and
presented to us by our faculty of representation, and consequently take
objects as they are in themselves, then time is nothing. It is only of
objective validity in regard to phenomena, because these are things
which we regard as objects of our senses. It no longer objective we,
make abstraction of the sensuousness of our intuition, in other words,
of that mode of representation which is peculiar to us, and speak of
things in general. Time is therefore merely a subjective condition of
our (human) intuition (which is always sensuous, that is, so far as we
are affected by objects), and in itself, independently of the mind or
subject, is nothing. Nevertheless, in respect of all phenomena,
consequently of all things which come within the sphere of our
experience, it is necessarily objective. We cannot say, “All things are
in time,” because in this conception of things in general, we abstract
and make no mention of any sort of intuition of things. But this is the
proper condition under which time belongs to our representation of
objects. If we add the condition to the conception, and say, “All
things, as phenomena, that is, objects of sensuous intuition, are in
time,” then the proposition has its sound objective validity and
universality a priori.

What we have now set forth teaches, therefore, the empirical reality of
time; that is, its objective validity in reference to all objects which
can ever be presented to our senses. And as our intuition is always
sensuous, no object ever can be presented to us in experience, which
does not come under the conditions of time. On the other hand, we deny
to time all claim to absolute reality; that is, we deny that it,
without having regard to the form of our sensuous intuition, absolutely
inheres in things as a condition or property. Such properties as belong
to objects as things in themselves never can be presented to us through
the medium of the senses. Herein consists, therefore, the
transcendental ideality of time, according to which, if we abstract the
subjective conditions of sensuous intuition, it is nothing, and cannot
be reckoned as subsisting or inhering in objects as things in
themselves, independently of its relation to our intuition. This
ideality, like that of space, is not to be proved or illustrated by
fallacious analogies with sensations, for this reason—that in such
arguments or illustrations, we make the presupposition that the
phenomenon, in which such and such predicates inhere, has objective
reality, while in this case we can only find such an objective reality
as is itself empirical, that is, regards the object as a mere
phenomenon. In reference to this subject, see the remark in Section I
(§ 4)

 § 8. Elucidation.

Against this theory, which grants empirical reality to time, but denies
to it absolute and transcendental reality, I have heard from
intelligent men an objection so unanimously urged that I conclude that
it must naturally present itself to every reader to whom these
considerations are novel. It runs thus: “Changes are real” (this the
continual change in our own representations demonstrates, even though
the existence of all external phenomena, together with their changes,
is denied). Now, changes are only possible in time, and therefore time
must be something real. But there is no difficulty in answering this. I
grant the whole argument. Time, no doubt, is something real, that is,
it is the real form of our internal intuition. It therefore has
subjective reality, in reference to our internal experience, that is, I
have really the representation of time and of my determinations
therein. Time, therefore, is not to be regarded as an object, but as
the mode of representation of myself as an object. But if I could
intuite myself, or be intuited by another being, without this condition
of sensibility, then those very determinations which we now represent
to ourselves as changes, would present to us a knowledge in which the
representation of time, and consequently of change, would not appear.
The empirical reality of time, therefore, remains, as the condition of
all our experience. But absolute reality, according to what has been
said above, cannot be granted it. Time is nothing but the form of our
internal intuition.* If we take away from it the special condition of
our sensibility, the conception of time also vanishes; and it inheres
not in the objects themselves, but solely in the subject (or mind)
which intuites them.

[*Footnote: I can indeed say “my representations follow one another, or
are successive”; but this means only that we are conscious of them as
in a succession, that is, according to the form of the internal sense.
Time, therefore, is not a thing in itself, nor is it any objective
determination pertaining to, or inherent in things.]

But the reason why this objection is so unanimously brought against our
doctrine of time, and that too by disputants who cannot start any
intelligible arguments against the doctrine of the ideality of space,
is this—they have no hope of demonstrating apodeictically the absolute
reality of space, because the doctrine of idealism is against them,
according to which the reality of external objects is not capable of
any strict proof. On the other hand, the reality of the object of our
internal sense (that is, myself and my internal state) is clear
immediately through consciousness. The former—external objects in
space—might be a mere delusion, but the latter—the object of my
internal perception—is undeniably real. They do not, however, reflect
that both, without question of their reality as representations, belong
only to the genus phenomenon, which has always two aspects, the one,
the object considered as a thing in itself, without regard to the mode
of intuiting it, and the nature of which remains for this very reason
problematical, the other, the form of our intuition of the object,
which must be sought not in the object as a thing in itself, but in the
subject to which it appears—which form of intuition nevertheless
belongs really and necessarily to the phenomenal object.

Time and space are, therefore, two sources of knowledge, from which, a
priori, various synthetical cognitions can be drawn. Of this we find a
striking example in the cognitions of space and its relations, which
form the foundation of pure mathematics. They are the two pure forms of
all intuitions, and thereby make synthetical propositions a priori
possible. But these sources of knowledge being merely conditions of our
sensibility, do therefore, and as such, strictly determine their own
range and purpose, in that they do not and cannot present objects as
things in themselves, but are applicable to them solely in so far as
they are considered as sensuous phenomena. The sphere of phenomena is
the only sphere of their validity, and if we venture out of this, no
further objective use can be made of them. For the rest, this formal
reality of time and space leaves the validity of our empirical
knowledge unshaken; for our certainty in that respect is equally firm,
whether these forms necessarily inhere in the things themselves, or
only in our intuitions of them. On the other hand, those who maintain
the absolute reality of time and space, whether as essentially
subsisting, or only inhering, as modifications, in things, must find
themselves at utter variance with the principles of experience itself.
For, if they decide for the first view, and make space and time into
substances, this being the side taken by mathematical natural
philosophers, they must admit two self-subsisting nonentities, infinite
and eternal, which exist (yet without there being anything real) for
the purpose of containing in themselves everything that is real. If
they adopt the second view of inherence, which is preferred by some
metaphysical natural philosophers, and regard space and time as
relations (contiguity in space or succession in time), abstracted from
experience, though represented confusedly in this state of separation,
they find themselves in that case necessitated to deny the validity of
mathematical doctrines a priori in reference to real things (for
example, in space)—at all events their apodeictic certainty. For such
certainty cannot be found in an a posteriori proposition; and the
conceptions a priori of space and time are, according to this opinion,
mere creations of the imagination, having their source really in
experience, inasmuch as, out of relations abstracted from experience,
imagination has made up something which contains, indeed, general
statements of these relations, yet of which no application can be made
without the restrictions attached thereto by nature. The former of
these parties gains this advantage, that they keep the sphere of
phenomena free for mathematical science. On the other hand, these very
conditions (space and time) embarrass them greatly, when the
understanding endeavours to pass the limits of that sphere. The latter
has, indeed, this advantage, that the representations of space and time
do not come in their way when they wish to judge of objects, not as
phenomena, but merely in their relation to the understanding. Devoid,
however, of a true and objectively valid a priori intuition, they can
neither furnish any basis for the possibility of mathematical
cognitions a priori, nor bring the propositions of experience into
necessary accordance with those of mathematics. In our theory of the
true nature of these two original forms of the sensibility, both
difficulties are surmounted.

In conclusion, that transcendental aesthetic cannot contain any more
than these two elements—space and time, is sufficiently obvious from
the fact that all other conceptions appertaining to sensibility, even
that of motion, which unites in itself both elements, presuppose
something empirical. Motion, for example, presupposes the perception of
something movable. But space considered in itself contains nothing
movable, consequently motion must be something which is found in space
only through experience—in other words, an empirical datum. In like
manner, transcendental aesthetic cannot number the conception of change
among its data a priori; for time itself does not change, but only
something which is in time. To acquire the conception of change,
therefore, the perception of some existing object and of the succession
of its determinations, in one word, experience, is necessary.

 § 9. General Remarks on Transcendental Aesthetic.

I. In order to prevent any misunderstanding, it will be requisite, in
the first place, to recapitulate, as clearly as possible, what our
opinion is with respect to the fundamental nature of our sensuous
cognition in general. We have intended, then, to say that all our
intuition is nothing but the representation of phenomena; that the
things which we intuite, are not in themselves the same as our
representations of them in intuition, nor are their relations in
themselves so constituted as they appear to us; and that if we take
away the subject, or even only the subjective constitution of our
senses in general, then not only the nature and relations of objects in
space and time, but even space and time themselves disappear; and that
these, as phenomena, cannot exist in themselves, but only in us. What
may be the nature of objects considered as things in themselves and
without reference to the receptivity of our sensibility is quite
unknown to us. We know nothing more than our mode of perceiving them,
which is peculiar to us, and which, though not of necessity pertaining
to every animated being, is so to the whole human race. With this alone
we have to do. Space and time are the pure forms thereof; sensation the
matter. The former alone can we cognize a priori, that is, antecedent
to all actual perception; and for this reason such cognition is called
pure intuition. The latter is that in our cognition which is called
cognition a posteriori, that is, empirical intuition. The former
appertain absolutely and necessarily to our sensibility, of whatsoever
kind our sensations may be; the latter may be of very diversified
character. Supposing that we should carry our empirical intuition even
to the very highest degree of clearness, we should not thereby advance
one step nearer to a knowledge of the constitution of objects as things
in themselves. For we could only, at best, arrive at a complete
cognition of our own mode of intuition, that is of our sensibility, and
this always under the conditions originally attaching to the subject,
namely, the conditions of space and time; while the question: “What are
objects considered as things in themselves?” remains unanswerable even
after the most thorough examination of the phenomenal world.

To say, then, that all our sensibility is nothing but the confused
representation of things containing exclusively that which belongs to
them as things in themselves, and this under an accumulation of
characteristic marks and partial representations which we cannot
distinguish in consciousness, is a falsification of the conception of
sensibility and phenomenization, which renders our whole doctrine
thereof empty and useless. The difference between a confused and a
clear representation is merely logical and has nothing to do with
content. No doubt the conception of right, as employed by a sound
understanding, contains all that the most subtle investigation could
unfold from it, although, in the ordinary practical use of the word, we
are not conscious of the manifold representations comprised in the
conception. But we cannot for this reason assert that the ordinary
conception is a sensuous one, containing a mere phenomenon, for right
cannot appear as a phenomenon; but the conception of it lies in the
understanding, and represents a property (the moral property) of
actions, which belongs to them in themselves. On the other hand, the
representation in intuition of a body contains nothing which could
belong to an object considered as a thing in itself, but merely the
phenomenon or appearance of something, and the mode in which we are
affected by that appearance; and this receptivity of our faculty of
cognition is called sensibility, and remains toto caelo different from
the cognition of an object in itself, even though we should examine the
content of the phenomenon to the very bottom.

It must be admitted that the Leibnitz-Wolfian philosophy has assigned
an entirely erroneous point of view to all investigations into the
nature and origin of our cognitions, inasmuch as it regards the
distinction between the sensuous and the intellectual as merely
logical, whereas it is plainly transcendental, and concerns not merely
the clearness or obscurity, but the content and origin of both. For the
faculty of sensibility not only does not present us with an indistinct
and confused cognition of objects as things in themselves, but, in
fact, gives us no knowledge of these at all. On the contrary, so soon
as we abstract in thought our own subjective nature, the object
represented, with the properties ascribed to it by sensuous intuition,
entirely disappears, because it was only this subjective nature that
determined the form of the object as a phenomenon.

In phenomena, we commonly, indeed, distinguish that which essentially
belongs to the intuition of them, and is valid for the sensuous faculty
of every human being, from that which belongs to the same intuition
accidentally, as valid not for the sensuous faculty in general, but for
a particular state or organization of this or that sense. Accordingly,
we are accustomed to say that the former is a cognition which
represents the object itself, whilst the latter presents only a
particular appearance or phenomenon thereof. This distinction, however,
is only empirical. If we stop here (as is usual), and do not regard the
empirical intuition as itself a mere phenomenon (as we ought to do), in
which nothing that can appertain to a thing in itself is to be found,
our transcendental distinction is lost, and we believe that we cognize
objects as things in themselves, although in the whole range of the
sensuous world, investigate the nature of its objects as profoundly as
we may, we have to do with nothing but phenomena. Thus, we call the
rainbow a mere appearance of phenomenon in a sunny shower, and the
rain, the reality or thing in itself; and this is right enough, if we
understand the latter conception in a merely physical sense, that is,
as that which in universal experience, and under whatever conditions of
sensuous perception, is known in intuition to be so and so determined,
and not otherwise. But if we consider this empirical datum generally,
and inquire, without reference to its accordance with all our senses,
whether there can be discovered in it aught which represents an object
as a thing in itself (the raindrops of course are not such, for they
are, as phenomena, empirical objects), the question of the relation of
the representation to the object is transcendental; and not only are
the raindrops mere phenomena, but even their circular form, nay, the
space itself through which they fall, is nothing in itself, but both
are mere modifications or fundamental dispositions of our sensuous
intuition, whilst the transcendental object remains for us utterly

The second important concern of our aesthetic is that it does not
obtain favour merely as a plausible hypothesis, but possess as
undoubted a character of certainty as can be demanded of any theory
which is to serve for an organon. In order fully to convince the reader
of this certainty, we shall select a case which will serve to make its
validity apparent, and also to illustrate what has been said in § 3.

Suppose, then, that space and time are in themselves objective, and
conditions of the—possibility of objects as things in themselves. In
the first place, it is evident that both present us, with very many
apodeictic and synthetic propositions a priori, but especially
space—and for this reason we shall prefer it for investigation at
present. As the propositions of geometry are cognized synthetically a
priori, and with apodeictic certainty, I inquire: Whence do you obtain
propositions of this kind, and on what basis does the understanding
rest, in order to arrive at such absolutely necessary and universally
valid truths?

There is no other way than through intuitions or conceptions, as such;
and these are given either a priori or a posteriori. The latter,
namely, empirical conceptions, together with the empirical intuition on
which they are founded, cannot afford any synthetical proposition,
except such as is itself also empirical, that is, a proposition of
experience. But an empirical proposition cannot possess the qualities
of necessity and absolute universality, which, nevertheless, are the
characteristics of all geometrical propositions. As to the first and
only means to arrive at such cognitions, namely, through mere
conceptions or intuitions a priori, it is quite clear that from mere
conceptions no synthetical cognitions, but only analytical ones, can be
obtained. Take, for example, the proposition: “Two straight lines
cannot enclose a space, and with these alone no figure is possible,”
and try to deduce it from the conception of a straight line and the
number two; or take the proposition: “It is possible to construct a
figure with three straight lines,” and endeavour, in like manner, to
deduce it from the mere conception of a straight line and the number
three. All your endeavours are in vain, and you find yourself forced to
have recourse to intuition, as, in fact, geometry always does. You
therefore give yourself an object in intuition. But of what kind is
this intuition? Is it a pure a priori, or is it an empirical intuition?
If the latter, then neither an universally valid, much less an
apodeictic proposition can arise from it, for experience never can give
us any such proposition. You must, therefore, give yourself an object a
priori in intuition, and upon that ground your synthetical proposition.
Now if there did not exist within you a faculty of intuition a priori;
if this subjective condition were not in respect to its form also the
universal condition a priori under which alone the object of this
external intuition is itself possible; if the object (that is, the
triangle) were something in itself, without relation to you the
subject; how could you affirm that that which lies necessarily in your
subjective conditions in order to construct a triangle, must also
necessarily belong to the triangle in itself? For to your conceptions
of three lines, you could not add anything new (that is, the figure);
which, therefore, must necessarily be found in the object, because the
object is given before your cognition, and not by means of it. If,
therefore, space (and time also) were not a mere form of your
intuition, which contains conditions a priori, under which alone things
can become external objects for you, and without which subjective
conditions the objects are in themselves nothing, you could not
construct any synthetical proposition whatsoever regarding external
objects. It is therefore not merely possible or probable, but
indubitably certain, that space and time, as the necessary conditions
of all our external and internal experience, are merely subjective
conditions of all our intuitions, in relation to which all objects are
therefore mere phenomena, and not things in themselves, presented to us
in this particular manner. And for this reason, in respect to the form
of phenomena, much may be said a priori, whilst of the thing in itself,
which may lie at the foundation of these phenomena, it is impossible to
say anything.

II. In confirmation of this theory of the ideality of the external as
well as internal sense, consequently of all objects of sense, as mere
phenomena, we may especially remark that all in our cognition that
belongs to intuition contains nothing more than mere relations. (The
feelings of pain and pleasure, and the will, which are not cognitions,
are excepted.) The relations, to wit, of place in an intuition
(extension), change of place (motion), and laws according to which this
change is determined (moving forces). That, however, which is present
in this or that place, or any operation going on, or result taking
place in the things themselves, with the exception of change of place,
is not given to us by intuition. Now by means of mere relations, a
thing cannot be known in itself; and it may therefore be fairly
concluded, that, as through the external sense nothing but mere
representations of relations are given us, the said external sense in
its representation can contain only the relation of the object to the
subject, but not the essential nature of the object as a thing in

The same is the case with the internal intuition, not only because, in
the internal intuition, the representation of the external senses
constitutes the material with which the mind is occupied; but because
time, in which we place, and which itself antecedes the consciousness
of, these representations in experience, and which, as the formal
condition of the mode according to which objects are placed in the
mind, lies at the foundation of them, contains relations of the
successive, the coexistent, and of that which always must be coexistent
with succession, the permanent. Now that which, as representation, can
antecede every exercise of thought (of an object), is intuition; and
when it contains nothing but relations, it is the form of the
intuition, which, as it presents us with no representation, except in
so far as something is placed in the mind, can be nothing else than the
mode in which the mind is affected by its own activity, to wit—its
presenting to itself representations, consequently the mode in which
the mind is affected by itself; that is, it can be nothing but an
internal sense in respect to its form. Everything that is represented
through the medium of sense is so far phenomenal; consequently, we must
either refuse altogether to admit an internal sense, or the subject,
which is the object of that sense, could only be represented by it as
phenomenon, and not as it would judge of itself, if its intuition were
pure spontaneous activity, that is, were intellectual. The difficulty
here lies wholly in the question: How can the subject have an internal
intuition of itself? But this difficulty is common to every theory. The
consciousness of self (apperception) is the simple representation of
the “ego”; and if by means of that representation alone, all the
manifold representations in the subject were spontaneously given, then
our internal intuition would be intellectual. This consciousness in man
requires an internal perception of the manifold representations which
are previously given in the subject; and the manner in which these
representations are given in the mind without spontaneity, must, on
account of this difference (the want of spontaneity), be called
sensibility. If the faculty of self-consciousness is to apprehend what
lies in the mind, it must all act that and can in this way alone
produce an intuition of self. But the form of this intuition, which
lies in the original constitution of the mind, determines, in the
representation of time, the manner in which the manifold
representations are to combine themselves in the mind; since the
subject intuites itself, not as it would represent itself immediately
and spontaneously, but according to the manner in which the mind is
internally affected, consequently, as it appears, and not as it is.

III. When we say that the intuition of external objects, and also the
self-intuition of the subject, represent both, objects and subject, in
space and time, as they affect our senses, that is, as they appear—this
is by no means equivalent to asserting that these objects are mere
illusory appearances. For when we speak of things as phenomena, the
objects, nay, even the properties which we ascribe to them, are looked
upon as really given; only that, in so far as this or that property
depends upon the mode of intuition of the subject, in the relation of
the given object to the subject, the object as phenomenon is to be
distinguished from the object as a thing in itself. Thus I do not say
that bodies seem or appear to be external to me, or that my soul seems
merely to be given in my self-consciousness, although I maintain that
the properties of space and time, in conformity to which I set both, as
the condition of their existence, abide in my mode of intuition, and
not in the objects in themselves. It would be my own fault, if out of
that which I should reckon as phenomenon, I made mere illusory
appearance.* But this will not happen, because of our principle of the
ideality of all sensuous intuitions. On the contrary, if we ascribe
objective reality to these forms of representation, it becomes
impossible to avoid changing everything into mere appearance. For if we
regard space and time as properties, which must be found in objects as
things in themselves, as sine quibus non of the possibility of their
existence, and reflect on the absurdities in which we then find
ourselves involved, inasmuch as we are compelled to admit the existence
of two infinite things, which are nevertheless not substances, nor
anything really inhering in substances, nay, to admit that they are the
necessary conditions of the existence of all things, and moreover, that
they must continue to exist, although all existing things were
annihilated—we cannot blame the good Berkeley for degrading bodies to
mere illusory appearances. Nay, even our own existence, which would in
this case depend upon the self-existent reality of such a mere
nonentity as time, would necessarily be changed with it into mere
appearance—an absurdity which no one has as yet been guilty of.

[*Footnote: The predicates of the phenomenon can be affixed to the
object itself in relation to our sensuous faculty; for example, the red
colour or the perfume to the rose. But (illusory) appearance never can
be attributed as a predicate to an object, for this very reason, that
it attributes to this object in itself that which belongs to it only in
relation to our sensuous faculty, or to the subject in general, e.g.,
the two handles which were formerly ascribed to Saturn. That which is
never to be found in the object itself, but always in the relation of
the object to the subject, and which moreover is inseparable from our
representation of the object, we denominate phenomenon. Thus the
predicates of space and time are rightly attributed to objects of the
senses as such, and in this there is no illusion. On the contrary, if I
ascribe redness of the rose as a thing in itself, or to Saturn his
handles, or extension to all external objects, considered as things in
themselves, without regarding the determinate relation of these objects
to the subject, and without limiting my judgement to that
relation—then, and then only, arises illusion.]

IV. In natural theology, where we think of an object—God—which never
can be an object of intuition to us, and even to himself can never be
an object of sensuous intuition, we carefully avoid attributing to his
intuition the conditions of space and time—and intuition all his
cognition must be, and not thought, which always includes limitation.
But with what right can we do this if we make them forms of objects as
things in themselves, and such, moreover, as would continue to exist as
a priori conditions of the existence of things, even though the things
themselves were annihilated? For as conditions of all existence in
general, space and time must be conditions of the existence of the
Supreme Being also. But if we do not thus make them objective forms of
all things, there is no other way left than to make them subjective
forms of our mode of intuition—external and internal; which is called
sensuous, because it is not primitive, that is, is not such as gives in
itself the existence of the object of the intuition (a mode of
intuition which, so far as we can judge, can belong only to the
Creator), but is dependent on the existence of the object, is possible,
therefore, only on condition that the representative faculty of the
subject is affected by the object.

It is, moreover, not necessary that we should limit the mode of
intuition in space and time to the sensuous faculty of man. It may well
be that all finite thinking beings must necessarily in this respect
agree with man (though as to this we cannot decide), but sensibility
does not on account of this universality cease to be sensibility, for
this very reason, that it is a deduced (intuitus derivativus), and not
an original (intuitus originarius), consequently not an intellectual
intuition, and this intuition, as such, for reasons above mentioned,
seems to belong solely to the Supreme Being, but never to a being
dependent, quoad its existence, as well as its intuition (which its
existence determines and limits relatively to given objects). This
latter remark, however, must be taken only as an illustration, and not
as any proof of the truth of our aesthetical theory.

 § 10. Conclusion of the Transcendental Aesthetic.

We have now completely before us one part of the solution of the grand
general problem of transcendental philosophy, namely, the question:
“How are synthetical propositions a priori possible?” That is to say,
we have shown that we are in possession of pure a priori intuitions,
namely, space and time, in which we find, when in a judgement a priori
we pass out beyond the given conception, something which is not
discoverable in that conception, but is certainly found a priori in the
intuition which corresponds to the conception, and can be united
synthetically with it. But the judgements which these pure intuitions
enable us to make, never reach farther than to objects of the senses,
and are valid only for objects of possible experience.


 INTRODUCTION. Idea of a Transcendental Logic.

 I. Of Logic in General.

Our knowledge springs from two main sources in the mind, first of which
is the faculty or power of receiving representations (receptivity for
impressions); the second is the power of cognizing by means of these
representations (spontaneity in the production of conceptions). Through
the first an object is given to us; through the second, it is, in
relation to the representation (which is a mere determination of the
mind), thought. Intuition and conceptions constitute, therefore, the
elements of all our knowledge, so that neither conceptions without an
intuition in some way corresponding to them, nor intuition without
conceptions, can afford us a cognition. Both are either pure or
empirical. They are empirical, when sensation (which presupposes the
actual presence of the object) is contained in them; and pure, when no
sensation is mixed with the representation. Sensations we may call the
matter of sensuous cognition. Pure intuition consequently contains
merely the form under which something is intuited, and pure conception
only the form of the thought of an object. Only pure intuitions and
pure conceptions are possible a priori; the empirical only a

We apply the term sensibility to the receptivity of the mind for
impressions, in so far as it is in some way affected; and, on the other
hand, we call the faculty of spontaneously producing representations,
or the spontaneity of cognition, understanding. Our nature is so
constituted that intuition with us never can be other than sensuous,
that is, it contains only the mode in which we are affected by objects.
On the other hand, the faculty of thinking the object of sensuous
intuition is the understanding. Neither of these faculties has a
preference over the other. Without the sensuous faculty no object would
be given to us, and without the understanding no object would be
thought. Thoughts without content are void; intuitions without
conceptions, blind. Hence it is as necessary for the mind to make its
conceptions sensuous (that is, to join to them the object in
intuition), as to make its intuitions intelligible (that is, to bring
them under conceptions). Neither of these faculties can exchange its
proper function. Understanding cannot intuite, and the sensuous faculty
cannot think. In no other way than from the united operation of both,
can knowledge arise. But no one ought, on this account, to overlook the
difference of the elements contributed by each; we have rather great
reason carefully to separate and distinguish them. We therefore
distinguish the science of the laws of sensibility, that is, aesthetic,
from the science of the laws of the understanding, that is, logic.

Now, logic in its turn may be considered as twofold—namely, as logic of
the general, or of the particular use of the understanding. The first
contains the absolutely necessary laws of thought, without which no use
whatsoever of the understanding is possible, and gives laws therefore
to the understanding, without regard to the difference of objects on
which it may be employed. The logic of the particular use of the
understanding contains the laws of correct thinking upon a particular
class of objects. The former may be called elemental logic—the latter,
the organon of this or that particular science. The latter is for the
most part employed in the schools, as a propaedeutic to the sciences,
although, indeed, according to the course of human reason, it is the
last thing we arrive at, when the science has been already matured, and
needs only the finishing touches towards its correction and completion;
for our knowledge of the objects of our attempted science must be
tolerably extensive and complete before we can indicate the laws by
which a science of these objects can be established.

General logic is again either pure or applied. In the former, we
abstract all the empirical conditions under which the understanding is
exercised; for example, the influence of the senses, the play of the
fantasy or imagination, the laws of the memory, the force of habit, of
inclination, etc., consequently also, the sources of prejudice—in a
word, we abstract all causes from which particular cognitions arise,
because these causes regard the understanding under certain
circumstances of its application, and, to the knowledge of them
experience is required. Pure general logic has to do, therefore, merely
with pure a priori principles, and is a canon of understanding and
reason, but only in respect of the formal part of their use, be the
content what it may, empirical or transcendental. General logic is
called applied, when it is directed to the laws of the use of the
understanding, under the subjective empirical conditions which
psychology teaches us. It has therefore empirical principles, although,
at the same time, it is in so far general, that it applies to the
exercise of the understanding, without regard to the difference of
objects. On this account, moreover, it is neither a canon of the
understanding in general, nor an organon of a particular science, but
merely a cathartic of the human understanding.

In general logic, therefore, that part which constitutes pure logic
must be carefully distinguished from that which constitutes applied
(though still general) logic. The former alone is properly science,
although short and dry, as the methodical exposition of an elemental
doctrine of the understanding ought to be. In this, therefore,
logicians must always bear in mind two rules:

1. As general logic, it makes abstraction of all content of the
cognition of the understanding, and of the difference of objects, and
has to do with nothing but the mere form of thought.

2. As pure logic, it has no empirical principles, and consequently
draws nothing (contrary to the common persuasion) from psychology,
which therefore has no influence on the canon of the understanding. It
is a demonstrated doctrine, and everything in it must be certain
completely a priori.

What I called applied logic (contrary to the common acceptation of this
term, according to which it should contain certain exercises for the
scholar, for which pure logic gives the rules), is a representation of
the understanding, and of the rules of its necessary employment in
concreto, that is to say, under the accidental conditions of the
subject, which may either hinder or promote this employment, and which
are all given only empirically. Thus applied logic treats of attention,
its impediments and consequences, of the origin of error, of the state
of doubt, hesitation, conviction, etc., and to it is related pure
general logic in the same way that pure morality, which contains only
the necessary moral laws of a free will, is related to practical
ethics, which considers these laws under all the impediments of
feelings, inclinations, and passions to which men are more or less
subjected, and which never can furnish us with a true and demonstrated
science, because it, as well as applied logic, requires empirical and
psychological principles.

 II. Of Transcendental Logic.

General logic, as we have seen, makes abstraction of all content of
cognition, that is, of all relation of cognition to its object, and
regards only the logical form in the relation of cognitions to each
other, that is, the form of thought in general. But as we have both
pure and empirical intuitions (as transcendental aesthetic proves), in
like manner a distinction might be drawn between pure and empirical
thought (of objects). In this case, there would exist a kind of logic,
in which we should not make abstraction of all content of cognition;
for or logic which should comprise merely the laws of pure thought (of
an object), would of course exclude all those cognitions which were of
empirical content. This kind of logic would also examine the origin of
our cognitions of objects, so far as that origin cannot be ascribed to
the objects themselves; while, on the contrary, general logic has
nothing to do with the origin of our cognitions, but contemplates our
representations, be they given primitively a priori in ourselves, or be
they only of empirical origin, solely according to the laws which the
understanding observes in employing them in the process of thought, in
relation to each other. Consequently, general logic treats of the form
of the understanding only, which can be applied to representations,
from whatever source they may have arisen.

And here I shall make a remark, which the reader must bear well in mind
in the course of the following considerations, to wit, that not every
cognition a priori, but only those through which we cognize that and
how certain representations (intuitions or conceptions) are applied or
are possible only a priori; that is to say, the a priori possibility of
cognition and the a priori use of it are transcendental. Therefore
neither is space, nor any a priori geometrical determination of space,
a transcendental Representation, but only the knowledge that such a
representation is not of empirical origin, and the possibility of its
relating to objects of experience, although itself a priori, can be
called transcendental. So also, the application of space to objects in
general would be transcendental; but if it be limited to objects of
sense it is empirical. Thus, the distinction of the transcendental and
empirical belongs only to the critique of cognitions, and does not
concern the relation of these to their object.

Accordingly, in the expectation that there may perhaps be conceptions
which relate a priori to objects, not as pure or sensuous intuitions,
but merely as acts of pure thought (which are therefore conceptions,
but neither of empirical nor aesthetical origin)—in this expectation, I
say, we form to ourselves, by anticipation, the idea of a science of
pure understanding and rational cognition, by means of which we may
cogitate objects entirely a priori. A science of this kind, which
should determine the origin, the extent, and the objective validity of
such cognitions, must be called transcendental logic, because it has
not, like general logic, to do with the laws of understanding and
reason in relation to empirical as well as pure rational cognitions
without distinction, but concerns itself with these only in an a priori
relation to objects.

 III. Of the Division of General Logic into Analytic and Dialectic.

The old question with which people sought to push logicians into a
corner, so that they must either have recourse to pitiful sophisms or
confess their ignorance, and consequently the vanity of their whole
art, is this: “What is truth?” The definition of the word truth, to
wit, “the accordance of the cognition with its object,” is presupposed
in the question; but we desire to be told, in the answer to it, what is
the universal and secure criterion of the truth of every cognition.

To know what questions we may reasonably propose is in itself a strong
evidence of sagacity and intelligence. For if a question be in itself
absurd and unsusceptible of a rational answer, it is attended with the
danger—not to mention the shame that falls upon the person who proposes
it—of seducing the unguarded listener into making absurd answers, and
we are presented with the ridiculous spectacle of one (as the ancients
said) “milking the he-goat, and the other holding a sieve.”

If truth consists in the accordance of a cognition with its object,
this object must be, ipso facto, distinguished from all others; for a
cognition is false if it does not accord with the object to which it
relates, although it contains something which may be affirmed of other
objects. Now an universal criterion of truth would be that which is
valid for all cognitions, without distinction of their objects. But it
is evident that since, in the case of such a criterion, we make
abstraction of all the content of a cognition (that is, of all relation
to its object), and truth relates precisely to this content, it must be
utterly absurd to ask for a mark of the truth of this content of
cognition; and that, accordingly, a sufficient, and at the same time
universal, test of truth cannot possibly be found. As we have already
termed the content of a cognition its matter, we shall say: “Of the
truth of our cognitions in respect of their matter, no universal test
can be demanded, because such a demand is self-contradictory.”

On the other hand, with regard to our cognition in respect of its mere
form (excluding all content), it is equally manifest that logic, in so
far as it exhibits the universal and necessary laws of the
understanding, must in these very laws present us with criteria of
truth. Whatever contradicts these rules is false, because thereby the
understanding is made to contradict its own universal laws of thought;
that is, to contradict itself. These criteria, however, apply solely to
the form of truth, that is, of thought in general, and in so far they
are perfectly accurate, yet not sufficient. For although a cognition
may be perfectly accurate as to logical form, that is, not
self-contradictory, it is notwithstanding quite possible that it may
not stand in agreement with its object. Consequently, the merely
logical criterion of truth, namely, the accordance of a cognition with
the universal and formal laws of understanding and reason, is nothing
more than the conditio sine qua non, or negative condition of all
truth. Farther than this logic cannot go, and the error which depends
not on the form, but on the content of the cognition, it has no test to

General logic, then, resolves the whole formal business of
understanding and reason into its elements, and exhibits them as
principles of all logical judging of our cognitions. This part of logic
may, therefore, be called analytic, and is at least the negative test
of truth, because all cognitions must first of an be estimated and
tried according to these laws before we proceed to investigate them in
respect of their content, in order to discover whether they contain
positive truth in regard to their object. Because, however, the mere
form of a cognition, accurately as it may accord with logical laws, is
insufficient to supply us with material (objective) truth, no one, by
means of logic alone, can venture to predicate anything of or decide
concerning objects, unless he has obtained, independently of logic,
well-grounded information about them, in order afterwards to examine,
according to logical laws, into the use and connection, in a cohering
whole, of that information, or, what is still better, merely to test it
by them. Notwithstanding, there lies so seductive a charm in the
possession of a specious art like this—an art which gives to all our
cognitions the form of the understanding, although with respect to the
content thereof we may be sadly deficient—that general logic, which is
merely a canon of judgement, has been employed as an organon for the
actual production, or rather for the semblance of production, of
objective assertions, and has thus been grossly misapplied. Now general
logic, in its assumed character of organon, is called dialectic.

Different as are the significations in which the ancients used this
term for a science or an art, we may safely infer, from their actual
employment of it, that with them it was nothing else than a logic of
illusion—a sophistical art for giving ignorance, nay, even intentional
sophistries, the colouring of truth, in which the thoroughness of
procedure which logic requires was imitated, and their topic employed
to cloak the empty pretensions. Now it may be taken as a safe and
useful warning, that general logic, considered as an organon, must
always be a logic of illusion, that is, be dialectical, for, as it
teaches us nothing whatever respecting the content of our cognitions,
but merely the formal conditions of their accordance with the
understanding, which do not relate to and are quite indifferent in
respect of objects, any attempt to employ it as an instrument (organon)
in order to extend and enlarge the range of our knowledge must end in
mere prating; any one being able to maintain or oppose, with some
appearance of truth, any single assertion whatever.

Such instruction is quite unbecoming the dignity of philosophy. For
these reasons we have chosen to denominate this part of logic
dialectic, in the sense of a critique of dialectical illusion, and we
wish the term to be so understood in this place.

 IV. Of the Division of Transcendental Logic into Transcendental
 Analytic and Dialectic.

In transcendental logic we isolate the understanding (as in
transcendental aesthetic the sensibility) and select from our cognition
merely that part of thought which has its origin in the understanding
alone. The exercise of this pure cognition, however, depends upon this
as its condition, that objects to which it may be applied be given to
us in intuition, for without intuition the whole of our cognition is
without objects, and is therefore quite void. That part of
transcendental logic, then, which treats of the elements of pure
cognition of the understanding, and of the principles without which no
object at all can be thought, is transcendental analytic, and at the
same time a logic of truth. For no cognition can contradict it, without
losing at the same time all content, that is, losing all reference to
an object, and therefore all truth. But because we are very easily
seduced into employing these pure cognitions and principles of the
understanding by themselves, and that even beyond the boundaries of
experience, which yet is the only source whence we can obtain matter
(objects) on which those pure conceptions may be employed—understanding
runs the risk of making, by means of empty sophisms, a material and
objective use of the mere formal principles of the pure understanding,
and of passing judgements on objects without distinction—objects which
are not given to us, nay, perhaps cannot be given to us in any way.
Now, as it ought properly to be only a canon for judging of the
empirical use of the understanding, this kind of logic is misused when
we seek to employ it as an organon of the universal and unlimited
exercise of the understanding, and attempt with the pure understanding
alone to judge synthetically, affirm, and determine respecting objects
in general. In this case the exercise of the pure understanding becomes
dialectical. The second part of our transcendental logic must therefore
be a critique of dialectical illusion, and this critique we shall term
transcendental dialectic—not meaning it as an art of producing
dogmatically such illusion (an art which is unfortunately too current
among the practitioners of metaphysical juggling), but as a critique of
understanding and reason in regard to their hyperphysical use. This
critique will expose the groundless nature of the pretensions of these
two faculties, and invalidate their claims to the discovery and
enlargement of our cognitions merely by means of transcendental
principles, and show that the proper employment of these faculties is
to test the judgements made by the pure understanding, and to guard it
from sophistical delusion.


Transcendental analytic is the dissection of the whole of our a priori
knowledge into the elements of the pure cognition of the understanding.
In order to effect our purpose, it is necessary: (1) That the
conceptions be pure and not empirical; (2) That they belong not to
intuition and sensibility, but to thought and understanding; (3) That
they be elementary conceptions, and as such, quite different from
deduced or compound conceptions; (4) That our table of these elementary
conceptions be complete, and fill up the whole sphere of the pure
understanding. Now this completeness of a science cannot be accepted
with confidence on the guarantee of a mere estimate of its existence in
an aggregate formed only by means of repeated experiments and attempts.
The completeness which we require is possible only by means of an idea
of the totality of the a priori cognition of the understanding, and
through the thereby determined division of the conceptions which form
the said whole; consequently, only by means of their connection in a
system. Pure understanding distinguishes itself not merely from
everything empirical, but also completely from all sensibility. It is a
unity self-subsistent, self-sufficient, and not to be enlarged by any
additions from without. Hence the sum of its cognition constitutes a
system to be determined by and comprised under an idea; and the
completeness and articulation of this system can at the same time serve
as a test of the correctness and genuineness of all the parts of
cognition that belong to it. The whole of this part of transcendental
logic consists of two books, of which the one contains the conceptions,
and the other the principles of pure understanding.

 BOOK I. Analytic of Conceptions. § 2

By the term Analytic of Conceptions, I do not understand the analysis
of these, or the usual process in philosophical investigations of
dissecting the conceptions which present themselves, according to their
content, and so making them clear; but I mean the hitherto little
attempted dissection of the faculty of understanding itself, in order
to investigate the possibility of conceptions a priori, by looking for
them in the understanding alone, as their birthplace, and analysing the
pure use of this faculty. For this is the proper duty of a
transcendental philosophy; what remains is the logical treatment of the
conceptions in philosophy in general. We shall therefore follow up the
pure conceptions even to their germs and beginnings in the human
understanding, in which they lie, until they are developed on occasions
presented by experience, and, freed by the same understanding from the
empirical conditions attaching to them, are set forth in their
unalloyed purity.

 Chapter I. Of the Transcendental Clue to the Discovery of all Pure 
 Conceptions of the Understanding

 Introductory § 3

When we call into play a faculty of cognition, different conceptions
manifest themselves according to the different circumstances, and make
known this faculty, and assemble themselves into a more or less
extensive collection, according to the time or penetration that has
been applied to the consideration of them. Where this process,
conducted as it is mechanically, so to speak, will end, cannot be
determined with certainty. Besides, the conceptions which we discover
in this haphazard manner present themselves by no means in order and
systematic unity, but are at last coupled together only according to
resemblances to each other, and arranged in series, according to the
quantity of their content, from the simpler to the more complex—series
which are anything but systematic, though not altogether without a
certain kind of method in their construction.

Transcendental philosophy has the advantage, and moreover the duty, of
searching for its conceptions according to a principle; because these
conceptions spring pure and unmixed out of the understanding as an
absolute unity, and therefore must be connected with each other
according to one conception or idea. A connection of this kind,
however, furnishes us with a ready prepared rule, by which its proper
place may be assigned to every pure conception of the understanding,
and the completeness of the system of all be determined a priori—both
which would otherwise have been dependent on mere choice or chance.

 Section I. Of the Logical Use of the Understanding in General § 4

The understanding was defined above only negatively, as a non-sensuous
faculty of cognition. Now, independently of sensibility, we cannot
possibly have any intuition; consequently, the understanding is no
faculty of intuition. But besides intuition there is no other mode of
cognition, except through conceptions; consequently, the cognition of
every, at least of every human, understanding is a cognition through
conceptions—not intuitive, but discursive. All intuitions, as sensuous,
depend on affections; conceptions, therefore, upon functions. By the
word function I understand the unity of the act of arranging diverse
representations under one common representation. Conceptions, then, are
based on the spontaneity of thought, as sensuous intuitions are on the
receptivity of impressions. Now, the understanding cannot make any
other use of these conceptions than to judge by means of them. As no
representation, except an intuition, relates immediately to its object,
a conception never relates immediately to an object, but only to some
other representation thereof, be that an intuition or itself a
conception. A judgement, therefore, is the mediate cognition of an
object, consequently the representation of a representation of it. In
every judgement there is a conception which applies to, and is valid
for many other conceptions, and which among these comprehends also a
given representation, this last being immediately connected with an
object. For example, in the judgement—“All bodies are divisible,” our
conception of divisible applies to various other conceptions; among
these, however, it is here particularly applied to the conception of
body, and this conception of body relates to certain phenomena which
occur to us. These objects, therefore, are mediately represented by the
conception of divisibility. All judgements, accordingly, are functions
of unity in our representations, inasmuch as, instead of an immediate,
a higher representation, which comprises this and various others, is
used for our cognition of the object, and thereby many possible
cognitions are collected into one. But we can reduce all acts of the
understanding to judgements, so that understanding may be represented
as the faculty of judging. For it is, according to what has been said
above, a faculty of thought. Now thought is cognition by means of
conceptions. But conceptions, as predicates of possible judgements,
relate to some representation of a yet undetermined object. Thus the
conception of body indicates something—for example, metal—which can be
cognized by means of that conception. It is therefore a conception, for
the reason alone that other representations are contained under it, by
means of which it can relate to objects. It is therefore the predicate
to a possible judgement; for example: “Every metal is a body.” All the
functions of the understanding therefore can be discovered, when we can
completely exhibit the functions of unity in judgements. And that this
may be effected very easily, the following section will show.

 Section II. Of the Logical Function of the Understanding in Judgements
 § 5

If we abstract all the content of a judgement, and consider only the
intellectual form thereof, we find that the function of thought in a
judgement can be brought under four heads, of which each contains three
momenta. These may be conveniently represented in the following table:

                                    1 _Quantity of judgements_
                                    Universal Particular Singular

                      2                           3 _Quality           
                             Relation_ Affirmative               
                      Categorical Negative                  
                      Hypothetical Infinite                  

                                    4 _Modality_ Problematical
                                    Assertorical Apodeictical

As this division appears to differ in some, though not essential
points, from the usual technique of logicians, the following
observations, for the prevention of otherwise possible
misunderstanding, will not be without their use.

1. Logicians say, with justice, that in the use of judgements in
syllogisms, singular judgements may be treated like universal ones.
For, precisely because a singular judgement has no extent at all, its
predicate cannot refer to a part of that which is contained in the
conception of the subject and be excluded from the rest. The predicate
is valid for the whole conception just as if it were a general
conception, and had extent, to the whole of which the predicate
applied. On the other hand, let us compare a singular with a general
judgement, merely as a cognition, in regard to quantity. The singular
judgement relates to the general one, as unity to infinity, and is
therefore in itself essentially different. Thus, if we estimate a
singular judgement (_judicium singulare_) not merely according to its
intrinsic validity as a judgement, but also as a cognition generally,
according to its quantity in comparison with that of other cognitions,
it is then entirely different from a general judgement (_judicium
commune_), and in a complete table of the momenta of thought deserves a
separate place—though, indeed, this would not be necessary in a logic
limited merely to the consideration of the use of judgements in
reference to each other.

2. In like manner, in transcendental logic, infinite must be
distinguished from affirmative judgements, although in general logic
they are rightly enough classed under affirmative. General logic
abstracts all content of the predicate (though it be negative), and
only considers whether the said predicate be affirmed or denied of the
subject. But transcendental logic considers also the worth or content
of this logical affirmation—an affirmation by means of a merely
negative predicate, and inquires how much the sum total of our
cognition gains by this affirmation. For example, if I say of the soul,
“It is not mortal”—by this negative judgement I should at least ward
off error. Now, by the proposition, “The soul is not mortal,” I have,
in respect of the logical form, really affirmed, inasmuch as I thereby
place the soul in the unlimited sphere of immortal beings. Now, because
of the whole sphere of possible existences, the mortal occupies one
part, and the immortal the other, neither more nor less is affirmed by
the proposition than that the soul is one among the infinite multitude
of things which remain over, when I take away the whole mortal part.
But by this proceeding we accomplish only this much, that the infinite
sphere of all possible existences is in so far limited that the mortal
is excluded from it, and the soul is placed in the remaining part of
the extent of this sphere. But this part remains, notwithstanding this
exception, infinite, and more and more parts may be taken away from the
whole sphere, without in the slightest degree thereby augmenting or
affirmatively determining our conception of the soul. These judgements,
therefore, infinite in respect of their logical extent, are, in respect
of the content of their cognition, merely limitative; and are
consequently entitled to a place in our transcendental table of all the
momenta of thought in judgements, because the function of the
understanding exercised by them may perhaps be of importance in the
field of its pure a priori cognition.

3. All relations of thought in judgements are those (a) of the
predicate to the subject; (b) of the principle to its consequence; (c)
of the divided cognition and all the members of the division to each
other. In the first of these three classes, we consider only two
conceptions; in the second, two judgements; in the third, several
judgements in relation to each other. The hypothetical proposition, “If
perfect justice exists, the obstinately wicked are punished,” contains
properly the relation to each other of two propositions, namely,
“Perfect justice exists,” and “The obstinately wicked are punished.”
Whether these propositions are in themselves true is a question not
here decided. Nothing is cogitated by means of this judgement except a
certain consequence. Finally, the disjunctive judgement contains a
relation of two or more propositions to each other—a relation not of
consequence, but of logical opposition, in so far as the sphere of the
one proposition excludes that of the other. But it contains at the same
time a relation of community, in so far as all the propositions taken
together fill up the sphere of the cognition. The disjunctive judgement
contains, therefore, the relation of the parts of the whole sphere of a
cognition, since the sphere of each part is a complemental part of the
sphere of the other, each contributing to form the sum total of the
divided cognition. Take, for example, the proposition, “The world
exists either through blind chance, or through internal necessity, or
through an external cause.” Each of these propositions embraces a part
of the sphere of our possible cognition as to the existence of a world;
all of them taken together, the whole sphere. To take the cognition out
of one of these spheres, is equivalent to placing it in one of the
others; and, on the other hand, to place it in one sphere is equivalent
to taking it out of the rest. There is, therefore, in a disjunctive
judgement a certain community of cognitions, which consists in this,
that they mutually exclude each other, yet thereby determine, as a
whole, the true cognition, inasmuch as, taken together, they make up
the complete content of a particular given cognition. And this is all
that I find necessary, for the sake of what follows, to remark in this

4. The modality of judgements is a quite peculiar function, with this
distinguishing characteristic, that it contributes nothing to the
content of a judgement (for besides quantity, quality, and relation,
there is nothing more that constitutes the content of a judgement), but
concerns itself only with the value of the copula in relation to
thought in general. Problematical judgements are those in which the
affirmation or negation is accepted as merely possible (ad libitum). In
the assertorical, we regard the proposition as real (true); in the
apodeictical, we look on it as necessary.* Thus the two judgements
(antecedens et consequens), the relation of which constitutes a
hypothetical judgement, likewise those (the members of the division) in
whose reciprocity the disjunctive consists, are only problematical. In
the example above given the proposition, “There exists perfect
justice,” is not stated assertorically, but as an ad libitum judgement,
which someone may choose to adopt, and the consequence alone is
assertorical. Hence such judgements may be obviously false, and yet,
taken problematically, be conditions of our cognition of the truth.
Thus the proposition, “The world exists only by blind chance,” is in
the disjunctive judgement of problematical import only: that is to say,
one may accept it for the moment, and it helps us (like the indication
of the wrong road among all the roads that one can take) to find out
the true proposition. The problematical proposition is, therefore, that
which expresses only logical possibility (which is not objective); that
is, it expresses a free choice to admit the validity of such a
proposition—a merely arbitrary reception of it into the understanding.
The assertorical speaks of logical reality or truth; as, for example,
in a hypothetical syllogism, the antecedens presents itself in a
problematical form in the major, in an assertorical form in the minor,
and it shows that the proposition is in harmony with the laws of the
understanding. The apodeictical proposition cogitates the assertorical
as determined by these very laws of the understanding, consequently as
affirming a priori, and in this manner it expresses logical necessity.
Now because all is here gradually incorporated with the
understanding—inasmuch as in the first place we judge problematically;
then accept assertorically our judgement as true; lastly, affirm it as
inseparably united with the understanding, that is, as necessary and
apodeictical—we may safely reckon these three functions of modality as
so many momenta of thought.

[*Footnote: Just as if thought were in the first instance a function of
the understanding; in the second, of judgement; in the third, of
reason. A remark which will be explained in the sequel.]

 Section III. Of the Pure Conceptions of the Understanding, or
 Categories § 6

General logic, as has been repeatedly said, makes abstraction of all
content of cognition, and expects to receive representations from some
other quarter, in order, by means of analysis, to convert them into
conceptions. On the contrary, transcendental logic has lying before it
the manifold content of a priori sensibility, which transcendental
aesthetic presents to it in order to give matter to the pure
conceptions of the understanding, without which transcendental logic
would have no content, and be therefore utterly void. Now space and
time contain an infinite diversity of determinations of pure a priori
intuition, but are nevertheless the condition of the mind’s
receptivity, under which alone it can obtain representations of
objects, and which, consequently, must always affect the conception of
these objects. But the spontaneity of thought requires that this
diversity be examined after a certain manner, received into the mind,
and connected, in order afterwards to form a cognition out of it. This
Process I call synthesis.

By the word synthesis, in its most general signification, I understand
the process of joining different representations to each other and of
comprehending their diversity in one cognition. This synthesis is pure
when the diversity is not given empirically but a priori (as that in
space and time). Our representations must be given previously to any
analysis of them; and no conceptions can arise, quoad their content,
analytically. But the synthesis of a diversity (be it given a priori or
empirically) is the first requisite for the production of a cognition,
which in its beginning, indeed, may be crude and confused, and
therefore in need of analysis—still, synthesis is that by which alone
the elements of our cognitions are collected and united into a certain
content, consequently it is the first thing on which we must fix our
attention, if we wish to investigate the origin of our knowledge.

Synthesis, generally speaking, is, as we shall afterwards see, the mere
operation of the imagination—a blind but indispensable function of the
soul, without which we should have no cognition whatever, but of the
working of which we are seldom even conscious. But to reduce this
synthesis to conceptions is a function of the understanding, by means
of which we attain to cognition, in the proper meaning of the term.

Pure synthesis, represented generally, gives us the pure conception of
the understanding. But by this pure synthesis, I mean that which rests
upon a basis of a priori synthetical unity. Thus, our numeration (and
this is more observable in large numbers) is a synthesis according to
conceptions, because it takes place according to a common basis of
unity (for example, the decade). By means of this conception,
therefore, the unity in the synthesis of the manifold becomes

By means of analysis different representations are brought under one
conception—an operation of which general logic treats. On the other
hand, the duty of transcendental logic is to reduce to conceptions, not
representations, but the pure synthesis of representations. The first
thing which must be given to us for the sake of the a priori cognition
of all objects, is the diversity of the pure intuition; the synthesis
of this diversity by means of the imagination is the second; but this
gives, as yet, no cognition. The conceptions which give unity to this
pure synthesis, and which consist solely in the representation of this
necessary synthetical unity, furnish the third requisite for the
cognition of an object, and these conceptions are given by the

The same function which gives unity to the different representation in
a judgement, gives also unity to the mere synthesis of different
representations in an intuition; and this unity we call the pure
conception of the understanding. Thus, the same understanding, and by
the same operations, whereby in conceptions, by means of analytical
unity, it produced the logical form of a judgement, introduces, by
means of the synthetical unity of the manifold in intuition, a
transcendental content into its representations, on which account they
are called pure conceptions of the understanding, and they apply a
priori to objects, a result not within the power of general logic.

In this manner, there arise exactly so many pure conceptions of the
understanding, applying a priori to objects of intuition in general, as
there are logical functions in all possible judgements. For there is no
other function or faculty existing in the understanding besides those
enumerated in that table. These conceptions we shall, with Aristotle,
call categories, our purpose being originally identical with his,
notwithstanding the great difference in the execution.

                     TABLE OF THE CATEGORIES

                    1                         2

              _Of Quantity                Of Quality_ Unity            
                       Reality Plurality                  Negation
              Totality                   Limitation

                           3 _Of Relation_ Of Inherence and Subsistence
                           (substantia et accidens) Of Causality and
                           Dependence (cause and effect) Of Community
                           (reciprocity between the agent and patient)

                           4 _Of Modality_ Possibility—Impossibility

This, then, is a catalogue of all the originally pure conceptions of
the synthesis which the understanding contains a priori, and these
conceptions alone entitle it to be called a pure understanding;
inasmuch as only by them it can render the manifold of intuition
conceivable, in other words, think an object of intuition. This
division is made systematically from a common principle, namely the
faculty of judgement (which is just the same as the power of thought),
and has not arisen rhapsodically from a search at haphazard after pure
conceptions, respecting the full number of which we never could be
certain, inasmuch as we employ induction alone in our search, without
considering that in this way we can never understand wherefore
precisely these conceptions, and none others, abide in the pure
understanding. It was a design worthy of an acute thinker like
Aristotle, to search for these fundamental conceptions. Destitute,
however, of any guiding principle, he picked them up just as they
occurred to him, and at first hunted out ten, which he called
categories (predicaments). Afterwards be believed that he had
discovered five others, which were added under the name of post
predicaments. But his catalogue still remained defective. Besides,
there are to be found among them some of the modes of pure sensibility
(quando, ubi, situs, also prius, simul), and likewise an empirical
conception (motus)—which can by no means belong to this genealogical
register of the pure understanding. Moreover, there are deduced
conceptions (actio, passio) enumerated among the original conceptions,
and, of the latter, some are entirely wanting.

With regard to these, it is to be remarked, that the categories, as the
true primitive conceptions of the pure understanding, have also their
pure deduced conceptions, which, in a complete system of transcendental
philosophy, must by no means be passed over; though in a merely
critical essay we must be contented with the simple mention of the

Let it be allowed me to call these pure, but deduced conceptions of the
understanding, the predicables of the pure understanding, in
contradistinction to predicaments. If we are in possession of the
original and primitive, the deduced and subsidiary conceptions can
easily be added, and the genealogical tree of the understanding
completely delineated. As my present aim is not to set forth a complete
system, but merely the principles of one, I reserve this task for
another time. It may be easily executed by any one who will refer to
the ontological manuals, and subordinate to the category of causality,
for example, the predicables of force, action, passion; to that of
community, those of presence and resistance; to the categories of
modality, those of origination, extinction, change; and so with the
rest. The categories combined with the modes of pure sensibility, or
with one another, afford a great number of deduced a priori
conceptions; a complete enumeration of which would be a useful and not
unpleasant, but in this place a perfectly dispensable, occupation.

I purposely omit the definitions of the categories in this treatise. I
shall analyse these conceptions only so far as is necessary for the
doctrine of method, which is to form a part of this critique. In a
system of pure reason, definitions of them would be with justice
demanded of me, but to give them here would only bide from our view the
main aim of our investigation, at the same time raising doubts and
objections, the consideration of which, without injustice to our main
purpose, may be very well postponed till another opportunity.
Meanwhile, it ought to be sufficiently clear, from the little we have
already said on this subject, that the formation of a complete
vocabulary of pure conceptions, accompanied by all the requisite
explanations, is not only a possible, but an easy undertaking. The
compartments already exist; it is only necessary to fill them up; and a
systematic topic like the present, indicates with perfect precision the
proper place to which each conception belongs, while it readily points
out any that have not yet been filled up.

§ 7

Our table of the categories suggests considerations of some importance,
which may perhaps have significant results in regard to the scientific
form of all rational cognitions. For, that this table is useful in the
theoretical part of philosophy, nay, indispensable for the sketching of
the complete plan of a science, so far as that science rests upon
conceptions a priori, and for dividing it mathematically, according to
fixed principles, is most manifest from the fact that it contains all
the elementary conceptions of the understanding, nay, even the form of
a system of these in the understanding itself, and consequently
indicates all the momenta, and also the internal arrangement of a
projected speculative science, as I have elsewhere shown. [Footnote: In
the Metaphysical Principles of Natural Science.] Here follow some of
these observations.

I. This table, which contains four classes of conceptions of the
understanding, may, in the first instance, be divided into two classes,
the first of which relates to objects of intuition—pure as well as
empirical; the second, to the existence of these objects, either in
relation to one another, or to the understanding.

The former of these classes of categories I would entitle the
mathematical, and the latter the dynamical categories. The former, as
we see, has no correlates; these are only to be found in the second
class. This difference must have a ground in the nature of the human

II. The number of the categories in each class is always the same,
namely, three—a fact which also demands some consideration, because in
all other cases division a priori through conceptions is necessarily
dichotomy. It is to be added, that the third category in each triad
always arises from the combination of the second with the first.

Thus totality is nothing else but plurality contemplated as unity;
limitation is merely reality conjoined with negation; community is the
causality of a substance, reciprocally determining, and determined by
other substances; and finally, necessity is nothing but existence,
which is given through the possibility itself. Let it not be supposed,
however, that the third category is merely a deduced, and not a
primitive conception of the pure understanding. For the conjunction of
the first and second, in order to produce the third conception,
requires a particular function of the understanding, which is by no
means identical with those which are exercised in the first and second.
Thus, the conception of a number (which belongs to the category of
totality) is not always possible, where the conceptions of multitude
and unity exist (for example, in the representation of the infinite).
Or, if I conjoin the conception of a cause with that of a substance, it
does not follow that the conception of influence, that is, how one
substance can be the cause of something in another substance, will be
understood from that. Thus it is evident that a particular act of the
understanding is here necessary; and so in the other instances.

III. With respect to one category, namely, that of community, which is
found in the third class, it is not so easy as with the others to
detect its accordance with the form of the disjunctive judgement which
corresponds to it in the table of the logical functions.

In order to assure ourselves of this accordance, we must observe that
in every disjunctive judgement, the sphere of the judgement (that is,
the complex of all that is contained in it) is represented as a whole
divided into parts; and, since one part cannot be contained in the
other, they are cogitated as co-ordinated with, not subordinated to
each other, so that they do not determine each other unilaterally, as
in a linear series, but reciprocally, as in an aggregate—(if one member
of the division is posited, all the rest are excluded; and conversely).

Now a like connection is cogitated in a whole of things; for one thing
is not subordinated, as effect, to another as cause of its existence,
but, on the contrary, is co-ordinated contemporaneously and
reciprocally, as a cause in relation to the determination of the others
(for example, in a body—the parts of which mutually attract and repel
each other). And this is an entirely different kind of connection from
that which we find in the mere relation of the cause to the effect (the
principle to the consequence), for in such a connection the consequence
does not in its turn determine the principle, and therefore does not
constitute, with the latter, a whole—just as the Creator does not with
the world make up a whole. The process of understanding by which it
represents to itself the sphere of a divided conception, is employed
also when we think of a thing as divisible; and in the same manner as
the members of the division in the former exclude one another, and yet
are connected in one sphere, so the understanding represents to itself
the parts of the latter, as having—each of them—an existence (as
substances), independently of the others, and yet as united in one

§ 8

In the transcendental philosophy of the ancients there exists one more
leading division, which contains pure conceptions of the understanding,
and which, although not numbered among the categories, ought, according
to them, as conceptions a priori, to be valid of objects. But in this
case they would augment the number of the categories; which cannot be.
These are set forth in the proposition, so renowned among the
schoolmen—‘_Quodlibet ens est UNUM, VERUM, BONUM_.’ Now, though the
inferences from this principle were mere tautological propositions, and
though it is allowed only by courtesy to retain a place in modern
metaphysics, yet a thought which maintained itself for such a length of
time, however empty it seems to be, deserves an investigation of its
origin, and justifies the conjecture that it must be grounded in some
law of the understanding, which, as is often the case, has only been
erroneously interpreted. These pretended transcendental predicates are,
in fact, nothing but logical requisites and criteria of all cognition
of objects, and they employ, as the basis for this cognition, the
categories of quantity, namely, unity, plurality, and totality. But
these, which must be taken as material conditions, that is, as
belonging to the possibility of things themselves, they employed merely
in a formal signification, as belonging to the logical requisites of
all cognition, and yet most unguardedly changed these criteria of
thought into properties of objects, as things in themselves. Now, in
every cognition of an object, there is unity of conception, which may
be called qualitative unity, so far as by this term we understand only
the unity in our connection of the manifold; for example, unity of the
theme in a play, an oration, or a story. Secondly, there is truth in
respect of the deductions from it. The more true deductions we have
from a given conception, the more criteria of its objective reality.
This we might call the qualitative plurality of characteristic marks,
which belong to a conception as to a common foundation, but are not
cogitated as a quantity in it. Thirdly, there is perfection—which
consists in this, that the plurality falls back upon the unity of the
conception, and accords completely with that conception and with no
other. This we may denominate qualitative completeness. Hence it is
evident that these logical criteria of the possibility of cognition are
merely the three categories of quantity modified and transformed to
suit an unauthorized manner of applying them. That is to say, the three
categories, in which the unity in the production of the quantum must be
homogeneous throughout, are transformed solely with a view to the
connection of heterogeneous parts of cognition in one act of
consciousness, by means of the quality of the cognition, which is the
principle of that connection. Thus the criterion of the possibility of
a conception (not of its object) is the definition of it, in which the
unity of the conception, the truth of all that may be immediately
deduced from it, and finally, the completeness of what has been thus
deduced, constitute the requisites for the reproduction of the whole
conception. Thus also, the criterion or test of an hypothesis is the
intelligibility of the received principle of explanation, or its unity
(without help from any subsidiary hypothesis)—the truth of our
deductions from it (consistency with each other and with
experience)—and lastly, the completeness of the principle of the
explanation of these deductions, which refer to neither more nor less
than what was admitted in the hypothesis, restoring analytically and a
posteriori, what was cogitated synthetically and a priori. By the
conceptions, therefore, of unity, truth, and perfection, we have made
no addition to the transcendental table of the categories, which is
complete without them. We have, on the contrary, merely employed the
three categories of quantity, setting aside their application to
objects of experience, as general logical laws of the consistency of
cognition with itself.

 Chapter II. Of the Deduction of the Pure Conceptions of the

 Section I. Of the Principles of a Transcendental Deduction in general
 § 9

Teachers of jurisprudence, when speaking of rights and claims,
distinguish in a cause the question of right (quid juris) from the
question of fact (quid facti), and while they demand proof of both,
they give to the proof of the former, which goes to establish right or
claim in law, the name of deduction. Now we make use of a great number
of empirical conceptions, without opposition from any one; and consider
ourselves, even without any attempt at deduction, justified in
attaching to them a sense, and a supposititious signification, because
we have always experience at hand to demonstrate their objective
reality. There exist also, however, usurped conceptions, such as
fortune, fate, which circulate with almost universal indulgence, and
yet are occasionally challenged by the question, “quid juris?” In such
cases, we have great difficulty in discovering any deduction for these
terms, inasmuch as we cannot produce any manifest ground of right,
either from experience or from reason, on which the claim to employ
them can be founded.

Among the many conceptions, which make up the very variegated web of
human cognition, some are destined for pure use a priori, independent
of all experience; and their title to be so employed always requires a
deduction, inasmuch as, to justify such use of them, proofs from
experience are not sufficient; but it is necessary to know how these
conceptions can apply to objects without being derived from experience.
I term, therefore, an examination of the manner in which conceptions
can apply a priori to objects, the transcendental deduction of
conceptions, and I distinguish it from the empirical deduction, which
indicates the mode in which conception is obtained through experience
and reflection thereon; consequently, does not concern itself with the
right, but only with the fact of our obtaining conceptions in such and
such a manner. We have already seen that we are in possession of two
perfectly different kinds of conceptions, which nevertheless agree with
each other in this, that they both apply to objects completely a
priori. These are the conceptions of space and time as forms of
sensibility, and the categories as pure conceptions of the
understanding. To attempt an empirical deduction of either of these
classes would be labour in vain, because the distinguishing
characteristic of their nature consists in this, that they apply to
their objects, without having borrowed anything from experience towards
the representation of them. Consequently, if a deduction of these
conceptions is necessary, it must always be transcendental.

Meanwhile, with respect to these conceptions, as with respect to all
our cognition, we certainly may discover in experience, if not the
principle of their possibility, yet the occasioning causes of their
production. It will be found that the impressions of sense give the
first occasion for bringing into action the whole faculty of cognition,
and for the production of experience, which contains two very
dissimilar elements, namely, a matter for cognition, given by the
senses, and a certain form for the arrangement of this matter, arising
out of the inner fountain of pure intuition and thought; and these, on
occasion given by sensuous impressions, are called into exercise and
produce conceptions. Such an investigation into the first efforts of
our faculty of cognition to mount from particular perceptions to
general conceptions is undoubtedly of great utility; and we have to
thank the celebrated Locke for having first opened the way for this
inquiry. But a deduction of the pure a priori conceptions of course
never can be made in this way, seeing that, in regard to their future
employment, which must be entirely independent of experience, they must
have a far different certificate of birth to show from that of a
descent from experience. This attempted physiological derivation, which
cannot properly be called deduction, because it relates merely to a
quaestio facti, I shall entitle an explanation of the possession of a
pure cognition. It is therefore manifest that there can only be a
transcendental deduction of these conceptions and by no means an
empirical one; also, that all attempts at an empirical deduction, in
regard to pure a priori conceptions, are vain, and can only be made by
one who does not understand the altogether peculiar nature of these

But although it is admitted that the only possible deduction of pure a
priori cognition is a transcendental deduction, it is not, for that
reason, perfectly manifest that such a deduction is absolutely
necessary. We have already traced to their sources the conceptions of
space and time, by means of a transcendental deduction, and we have
explained and determined their objective validity a priori. Geometry,
nevertheless, advances steadily and securely in the province of pure a
priori cognitions, without needing to ask from philosophy any
certificate as to the pure and legitimate origin of its fundamental
conception of space. But the use of the conception in this science
extends only to the external world of sense, the pure form of the
intuition of which is space; and in this world, therefore, all
geometrical cognition, because it is founded upon a priori intuition,
possesses immediate evidence, and the objects of this cognition are
given a priori (as regards their form) in intuition by and through the
cognition itself. With the pure conceptions of understanding, on the
contrary, commences the absolute necessity of seeking a transcendental
deduction, not only of these conceptions themselves, but likewise of
space, because, inasmuch as they make affirmations concerning objects
not by means of the predicates of intuition and sensibility, but of
pure thought a priori, they apply to objects without any of the
conditions of sensibility. Besides, not being founded on experience,
they are not presented with any object in a priori intuition upon
which, antecedently to experience, they might base their synthesis.
Hence results, not only doubt as to the objective validity and proper
limits of their use, but that even our conception of space is rendered
equivocal; inasmuch as we are very ready with the aid of the
categories, to carry the use of this conception beyond the conditions
of sensuous intuition—and, for this reason, we have already found a
transcendental deduction of it needful. The reader, then, must be quite
convinced of the absolute necessity of a transcendental deduction,
before taking a single step in the field of pure reason; because
otherwise he goes to work blindly, and after he has wondered about in
all directions, returns to the state of utter ignorance from which he
started. He ought, moreover, clearly to recognize beforehand the
unavoidable difficulties in his undertaking, so that he may not
afterwards complain of the obscurity in which the subject itself is
deeply involved, or become too soon impatient of the obstacles in his
path; because we have a choice of only two things—either at once to
give up all pretensions to knowledge beyond the limits of possible
experience, or to bring this critical investigation to completion.

We have been able, with very little trouble, to make it comprehensible
how the conceptions of space and time, although a priori cognitions,
must necessarily apply to external objects, and render a synthetical
cognition of these possible, independently of all experience. For
inasmuch as only by means of such pure form of sensibility an object
can appear to us, that is, be an object of empirical intuition, space
and time are pure intuitions, which contain a priori the condition of
the possibility of objects as phenomena, and an a priori synthesis in
these intuitions possesses objective validity.

On the other hand, the categories of the understanding do not represent
the conditions under which objects are given to us in intuition;
objects can consequently appear to us without necessarily connecting
themselves with these, and consequently without any necessity binding
on the understanding to contain a priori the conditions of these
objects. Thus we find ourselves involved in a difficulty which did not
present itself in the sphere of sensibility, that is to say, we cannot
discover how the subjective conditions of thought can have objective
validity, in other words, can become conditions of the possibility of
all cognition of objects; for phenomena may certainly be given to us in
intuition without any help from the functions of the understanding. Let
us take, for example, the conception of cause, which indicates a
peculiar kind of synthesis, namely, that with something, A, something
entirely different, B, is connected according to a law. It is not a
priori manifest why phenomena should contain anything of this kind (we
are of course debarred from appealing for proof to experience, for the
objective validity of this conception must be demonstrated a priori),
and it hence remains doubtful a priori, whether such a conception be
not quite void and without any corresponding object among phenomena.
For that objects of sensuous intuition must correspond to the formal
conditions of sensibility existing a priori in the mind is quite
evident, from the fact that without these they could not be objects for
us; but that they must also correspond to the conditions which
understanding requires for the synthetical unity of thought is an
assertion, the grounds for which are not so easily to be discovered.
For phenomena might be so constituted as not to correspond to the
conditions of the unity of thought; and all things might lie in such
confusion that, for example, nothing could be met with in the sphere of
phenomena to suggest a law of synthesis, and so correspond to the
conception of cause and effect; so that this conception would be quite
void, null, and without significance. Phenomena would nevertheless
continue to present objects to our intuition; for mere intuition does
not in any respect stand in need of the functions of thought.

If we thought to free ourselves from the labour of these investigations
by saying: “Experience is constantly offering us examples of the
relation of cause and effect in phenomena, and presents us with
abundant opportunity of abstracting the conception of cause, and so at
the same time of corroborating the objective validity of this
conception”; we should in this case be overlooking the fact, that the
conception of cause cannot arise in this way at all; that, on the
contrary, it must either have an a priori basis in the understanding,
or be rejected as a mere chimera. For this conception demands that
something, A, should be of such a nature that something else, B, should
follow from it necessarily, and according to an absolutely universal
law. We may certainly collect from phenomena a law, according to which
this or that usually happens, but the element of necessity is not to be
found in it. Hence it is evident that to the synthesis of cause and
effect belongs a dignity, which is utterly wanting in any empirical
synthesis; for it is no mere mechanical synthesis, by means of
addition, but a dynamical one; that is to say, the effect is not to be
cogitated as merely annexed to the cause, but as posited by and through
the cause, and resulting from it. The strict universality of this law
never can be a characteristic of empirical laws, which obtain through
induction only a comparative universality, that is, an extended range
of practical application. But the pure conceptions of the understanding
would entirely lose all their peculiar character, if we treated them
merely as the productions of experience.

 Transition to the Transcendental Deduction of the Categories § 10

There are only two possible ways in which synthetical representation
and its objects can coincide with and relate necessarily to each other,
and, as it were, meet together. Either the object alone makes the
representation possible, or the representation alone makes the object
possible. In the former case, the relation between them is only
empirical, and an a priori representation is impossible. And this is
the case with phenomena, as regards that in them which is referable to
mere sensation. In the latter case—although representation alone (for
of its causality, by means of the will, we do not here speak) does not
produce the object as to its existence, it must nevertheless be a
priori determinative in regard to the object, if it is only by means of
the representation that we can cognize anything as an object. Now there
are only two conditions of the possibility of a cognition of objects;
firstly, intuition, by means of which the object, though only as
phenomenon, is given; secondly, conception, by means of which the
object which corresponds to this intuition is thought. But it is
evident from what has been said on aesthetic that the first condition,
under which alone objects can be intuited, must in fact exist, as a
formal basis for them, a priori in the mind. With this formal condition
of sensibility, therefore, all phenomena necessarily correspond,
because it is only through it that they can be phenomena at all; that
is, can be empirically intuited and given. Now the question is whether
there do not exist, a priori in the mind, conceptions of understanding
also, as conditions under which alone something, if not intuited, is
yet thought as object. If this question be answered in the affirmative,
it follows that all empirical cognition of objects is necessarily
conformable to such conceptions, since, if they are not presupposed, it
is impossible that anything can be an object of experience. Now all
experience contains, besides the intuition of the senses through which
an object is given, a conception also of an object that is given in
intuition. Accordingly, conceptions of objects in general must lie as a
priori conditions at the foundation of all empirical cognition; and
consequently, the objective validity of the categories, as a priori
conceptions, will rest upon this, that experience (as far as regards
the form of thought) is possible only by their means. For in that case
they apply necessarily and a priori to objects of experience, because
only through them can an object of experience be thought.

The whole aim of the transcendental deduction of all a priori
conceptions is to show that these conceptions are a priori conditions
of the possibility of all experience. Conceptions which afford us the
objective foundation of the possibility of experience are for that very
reason necessary. But the analysis of the experiences in which they are
met with is not deduction, but only an illustration of them, because
from experience they could never derive the attribute of necessity.
Without their original applicability and relation to all possible
experience, in which all objects of cognition present themselves, the
relation of the categories to objects, of whatever nature, would be
quite incomprehensible.

The celebrated Locke, for want of due reflection on these points, and
because he met with pure conceptions of the understanding in
experience, sought also to deduce them from experience, and yet
proceeded so inconsequently as to attempt, with their aid, to arrive it
cognitions which lie far beyond the limits of all experience. David
Hume perceived that, to render this possible, it was necessary that the
conceptions should have an a priori origin. But as he could not explain
how it was possible that conceptions which are not connected with each
other in the understanding must nevertheless be thought as necessarily
connected in the object—and it never occurred to him that the
understanding itself might, perhaps, by means of these conceptions, be
the author of the experience in which its objects were presented to
it—he was forced to drive these conceptions from experience, that is,
from a subjective necessity arising from repeated association of
experiences erroneously considered to be objective—in one word, from
habit. But he proceeded with perfect consequence and declared it to be
impossible, with such conceptions and the principles arising from them,
to overstep the limits of experience. The empirical derivation,
however, which both of these philosophers attributed to these
conceptions, cannot possibly be reconciled with the fact that we do
possess scientific a priori cognitions, namely, those of pure
mathematics and general physics.

The former of these two celebrated men opened a wide door to
extravagance—(for if reason has once undoubted right on its side, it
will not allow itself to be confined to set limits, by vague
recommendations of moderation); the latter gave himself up entirely to
scepticism—a natural consequence, after having discovered, as he
thought, that the faculty of cognition was not trustworthy. We now
intend to make a trial whether it be not possible safely to conduct
reason between these two rocks, to assign her determinate limits, and
yet leave open for her the entire sphere of her legitimate activity.

I shall merely premise an explanation of what the categories are. They
are conceptions of an object in general, by means of which its
intuition is contemplated as determined in relation to one of the
logical functions of judgement. The following will make this plain. The
function of the categorical judgement is that of the relation of
subject to predicate; for example, in the proposition: “All bodies are
divisible.” But in regard to the merely logical use of the
understanding, it still remains undetermined to which Of these two
conceptions belongs the function Of subject and to which that of
predicate. For we could also say: “Some divisible is a body.” But the
category of substance, when the conception of a body is brought under
it, determines that; and its empirical intuition in experience must be
contemplated always as subject and never as mere predicate. And so with
all the other categories.

 Section II Transcendental Deduction of the pure Conceptions of the

 Of the Possibility of a Conjunction of the manifold representations
 given by Sense § 11.

The manifold content in our representations can be given in an
intuition which is merely sensuous—in other words, is nothing but
susceptibility; and the form of this intuition can exist a priori in
our faculty of representation, without being anything else but the mode
in which the subject is affected. But the conjunction (conjunctio) of a
manifold in intuition never can be given us by the senses; it cannot
therefore be contained in the pure form of sensuous intuition, for it
is a spontaneous act of the faculty of representation. And as we must,
to distinguish it from sensibility, entitle this faculty understanding;
so all conjunction whether conscious or unconscious, be it of the
manifold in intuition, sensuous or non-sensuous, or of several
conceptions—is an act of the understanding. To this act we shall give
the general appellation of synthesis, thereby to indicate, at the same
time, that we cannot represent anything as conjoined in the object
without having previously conjoined it ourselves. Of all mental
notions, that of conjunction is the only one which cannot be given
through objects, but can be originated only by the subject itself,
because it is an act of its purely spontaneous activity. The reader
will easily enough perceive that the possibility of conjunction must be
grounded in the very nature of this act, and that it must be equally
valid for all conjunction, and that analysis, which appears to be its
contrary, must, nevertheless, always presuppose it; for where the
understanding has not previously conjoined, it cannot dissect or
analyse, because only as conjoined by it, must that which is to be
analysed have been given to our faculty of representation.

But the conception of conjunction includes, besides the conception of
the manifold and of the synthesis of it, that of the unity of it also.
Conjunction is the representation of the synthetical unity of the
manifold.* This idea of unity, therefore, cannot arise out of that of
conjunction; much rather does that idea, by combining itself with the
representation of the manifold, render the conception of conjunction
possible. This unity, which a priori precedes all conceptions of
conjunction, is not the category of unity (§ 6); for all the categories
are based upon logical functions of judgement, and in these functions
we already have conjunction, and consequently unity of given
conceptions. It is therefore evident that the category of unity
presupposes conjunction. We must therefore look still higher for this
unity (as qualitative, § 8), in that, namely, which contains the ground
of the unity of diverse conceptions in judgements, the ground,
consequently, of the possibility of the existence of the understanding,
even in regard to its logical use.

[*Footnote: Whether the representations are in themselves identical,
and consequently whether one can be thought analytically by means of
and through the other, is a question which we need not at present
consider. Our Consciousness of the one, when we speak of the manifold,
is always distinguishable from our consciousness of the other; and it
is only respecting the synthesis of this (possible) consciousness that
we here treat.]

 Of the Originally Synthetical Unity of Apperception § 12

The “I think” must accompany all my representations, for otherwise
something would be represented in me which could not be thought; in
other words, the representation would either be impossible, or at least
be, in relation to me, nothing. That representation which can be given
previously to all thought is called intuition. All the diversity or
manifold content of intuition, has, therefore, a necessary relation to
the “I think,” in the subject in which this diversity is found. But
this representation, “I think,” is an act of spontaneity; that is to
say, it cannot be regarded as belonging to mere sensibility. I call it
pure apperception, in order to distinguish it from empirical; or
primitive apperception, because it is self-consciousness which, whilst
it gives birth to the representation “I think,” must necessarily be
capable of accompanying all our representations. It is in all acts of
consciousness one and the same, and unaccompanied by it, no
representation can exist for me. The unity of this apperception I call
the transcendental unity of self-consciousness, in order to indicate
the possibility of a priori cognition arising from it. For the manifold
representations which are given in an intuition would not all of them
be my representations, if they did not all belong to one
self-consciousness, that is, as my representations (even although I am
not conscious of them as such), they must conform to the condition
under which alone they can exist together in a common
self-consciousness, because otherwise they would not all without
exception belong to me. From this primitive conjunction follow many
important results.

For example, this universal identity of the apperception of the
manifold given in intuition contains a synthesis of representations and
is possible only by means of the consciousness of this synthesis. For
the empirical consciousness which accompanies different representations
is in itself fragmentary and disunited, and without relation to the
identity of the subject. This relation, then, does not exist because I
accompany every representation with consciousness, but because I join
one representation to another, and am conscious of the synthesis of
them. Consequently, only because I can connect a variety of given
representations in one consciousness, is it possible that I can
represent to myself the identity of consciousness in these
representations; in other words, the analytical unity of apperception
is possible only under the presupposition of a synthetical unity.* The
thought, “These representations given in intuition belong all of them
to me,” is accordingly just the same as, “I unite them in one
self-consciousness, or can at least so unite them”; and although this
thought is not itself the consciousness of the synthesis of
representations, it presupposes the possibility of it; that is to say,
for the reason alone that I can comprehend the variety of my
representations in one consciousness, do I call them my
representations, for otherwise I must have as many-coloured and various
a self as are the representations of which I am conscious. Synthetical
unity of the manifold in intuitions, as given a priori, is therefore
the foundation of the identity of apperception itself, which antecedes
a priori all determinate thought. But the conjunction of
representations into a conception is not to be found in objects
themselves, nor can it be, as it were, borrowed from them and taken up
into the understanding by perception, but it is on the contrary an
operation of the understanding itself, which is nothing more than the
faculty of conjoining a priori and of bringing the variety of given
representations under the unity of apperception. This principle is the
highest in all human cognition.

[*Footnote: All general conceptions—as such—depend, for their
existence, on the analytical unity of consciousness. For example, when
I think of red in general, I thereby think to myself a property which
(as a characteristic mark) can be discovered somewhere, or can be
united with other representations; consequently, it is only by means of
a forethought possible synthetical unity that I can think to myself the
analytical. A representation which is cogitated as common to different
representations, is regarded as belonging to such as, besides this
common representation, contain something different; consequently it
must be previously thought in synthetical unity with other although
only possible representations, before I can think in it the analytical
unity of consciousness which makes it a conceptas communis. And thus
the synthetical unity of apperception is the highest point with which
we must connect every operation of the understanding, even the whole of
logic, and after it our transcendental philosophy; indeed, this faculty
is the understanding itself.]

This fundamental principle of the necessary unity of apperception is
indeed an identical, and therefore analytical, proposition; but it
nevertheless explains the necessity for a synthesis of the manifold
given in an intuition, without which the identity of self-consciousness
would be incogitable. For the ego, as a simple representation, presents
us with no manifold content; only in intuition, which is quite
different from the representation ego, can it be given us, and by means
of conjunction it is cogitated in one self-consciousness. An
understanding, in which all the manifold should be given by means of
consciousness itself, would be intuitive; our understanding can only
think and must look for its intuition to sense. I am, therefore,
conscious of my identical self, in relation to all the variety of
representations given to me in an intuition, because I call all of them
my representations. In other words, I am conscious myself of a
necessary a priori synthesis of my representations, which is called the
original synthetical unity of apperception, under which rank all the
representations presented to me, but that only by means of a synthesis.

 The Principle of the Synthetical Unity of Apperception is the highest
 Principle of all exercise of the Understanding § 13

The supreme principle of the possibility of all intuition in relation
to sensibility was, according to our transcendental aesthetic, that all
the manifold in intuition be subject to the formal conditions of space
and time. The supreme principle of the possibility of it in relation to
the understanding is that all the manifold in it be subject to
conditions of the originally synthetical unity or apperception.* To the
former of these two principles are subject all the various
representations of intuition, in so far as they are given to us; to the
latter, in so far as they must be capable of conjunction in one
consciousness; for without this nothing can be thought or cognized,
because the given representations would not have in common the act Of
the apperception “I think” and therefore could not be connected in one

[*Footnote: Space and time, and all portions thereof, are intuitions;
consequently are, with a manifold for their content, single
representations. (See the Transcendental Aesthetic.) Consequently, they
are not pure conceptions, by means of which the same consciousness is
found in a great number of representations; but, on the contrary, they
are many representations contained in one, the consciousness of which
is, so to speak, compounded. The unity of consciousness is nevertheless
synthetical and, therefore, primitive. From this peculiar character of
consciousness follow many important consequences. (See § 21.)]

Understanding is, to speak generally, the faculty Of cognitions. These
consist in the determined relation of given representation to an
object. But an object is that, in the conception of which the manifold
in a given intuition is united. Now all union of representations
requires unity of consciousness in the synthesis of them. Consequently,
it is the unity of consciousness alone that constitutes the possibility
of representations relating to an object, and therefore of their
objective validity, and of their becoming cognitions, and consequently,
the possibility of the existence of the understanding itself.

The first pure cognition of understanding, then, upon which is founded
all its other exercise, and which is at the same time perfectly
independent of all conditions of mere sensuous intuition, is the
principle of the original synthetical unity of apperception. Thus the
mere form of external sensuous intuition, namely, space, affords us,
per se, no cognition; it merely contributes the manifold in a priori
intuition to a possible cognition. But, in order to cognize something
in space (for example, a line), I must draw it, and thus produce
synthetically a determined conjunction of the given manifold, so that
the unity of this act is at the same time the unity of consciousness
(in the conception of a line), and by this means alone is an object (a
determinate space) cognized. The synthetical unity of consciousness is,
therefore, an objective condition of all cognition, which I do not
merely require in order to cognize an object, but to which every
intuition must necessarily be subject, in order to become an object for
me; because in any other way, and without this synthesis, the manifold
in intuition could not be united in one consciousness.

This proposition is, as already said, itself analytical, although it
constitutes the synthetical unity, the condition of all thought; for it
states nothing more than that all my representations in any given
intuition must be subject to the condition which alone enables me to
connect them, as my representation with the identical self, and so to
unite them synthetically in one apperception, by means of the general
expression, “I think.”

But this principle is not to be regarded as a principle for every
possible understanding, but only for the understanding by means of
whose pure apperception in the thought I am, no manifold content is
given. The understanding or mind which contained the manifold in
intuition, in and through the act itself of its own self-consciousness,
in other words, an understanding by and in the representation of which
the objects of the representation should at the same time exist, would
not require a special act of synthesis of the manifold as the condition
of the unity of its consciousness, an act of which the human
understanding, which thinks only and cannot intuite, has absolute need.
But this principle is the first principle of all the operations of our
understanding, so that we cannot form the least conception of any other
possible understanding, either of one such as should be itself
intuition, or possess a sensuous intuition, but with forms different
from those of space and time.

 What Objective Unity of Self-consciousness is § 14

It is by means of the transcendental unity of apperception that all the
manifold, given in an intuition is united into a conception of the
object. On this account it is called objective, and must be
distinguished from the subjective unity of consciousness, which is a
determination of the internal sense, by means of which the said
manifold in intuition is given empirically to be so united. Whether I
can be empirically conscious of the manifold as coexistent or as
successive, depends upon circumstances, or empirical conditions. Hence
the empirical unity of consciousness by means of association of
representations, itself relates to a phenomenal world and is wholly
contingent. On the contrary, the pure form of intuition in time, merely
as an intuition, which contains a given manifold, is subject to the
original unity of consciousness, and that solely by means of the
necessary relation of the manifold in intuition to the “I think,”
consequently by means of the pure synthesis of the understanding, which
lies a priori at the foundation of all empirical synthesis. The
transcendental unity of apperception is alone objectively valid; the
empirical which we do not consider in this essay, and which is merely a
unity deduced from the former under given conditions in concreto,
possesses only subjective validity. One person connects the notion
conveyed in a word with one thing, another with another thing; and the
unity of consciousness in that which is empirical, is, in relation to
that which is given by experience, not necessarily and universally

 The Logical Form of all Judgements consists in the Objective Unity of
 Apperception of the Conceptions contained therein § 15

I could never satisfy myself with the definition which logicians give
of a judgement. It is, according to them, the representation of a
relation between two conceptions. I shall not dwell here on the
faultiness of this definition, in that it suits only for categorical
and not for hypothetical or disjunctive judgements, these latter
containing a relation not of conceptions but of judgements themselves—a
blunder from which many evil results have followed.* It is more
important for our present purpose to observe, that this definition does
not determine in what the said relation consists.

[*Footnote: The tedious doctrine of the four syllogistic figures
concerns only categorical syllogisms; and although it is nothing more
than an artifice by surreptitiously introducing immediate conclusions
(consequentiae immediatae) among the premises of a pure syllogism, to
give ism give rise to an appearance of more modes of drawing a
conclusion than that in the first figure, the artifice would not have
had much success, had not its authors succeeded in bringing categorical
judgements into exclusive respect, as those to which all others must be
referred—a doctrine, however, which, according to § 5, is utterly

But if I investigate more closely the relation of given cognitions in
every judgement, and distinguish it, as belonging to the understanding,
from the relation which is produced according to laws of the
reproductive imagination (which has only subjective validity), I find
that judgement is nothing but the mode of bringing given cognitions
under the objective unit of apperception. This is plain from our use of
the term of relation is in judgements, in order to distinguish the
objective unity of given representations from the subjective unity. For
this term indicates the relation of these representations to the
original apperception, and also their necessary unity, even although
the judgement is empirical, therefore contingent, as in the judgement:
“All bodies are heavy.” I do not mean by this, that these
representations do necessarily belong to each other in empirical
intuition, but that by means of the necessary unity of appreciation
they belong to each other in the synthesis of intuitions, that is to
say, they belong to each other according to principles of the objective
determination of all our representations, in so far as cognition can
arise from them, these principles being all deduced from the main
principle of the transcendental unity of apperception. In this way
alone can there arise from this relation a judgement, that is, a
relation which has objective validity, and is perfectly distinct from
that relation of the very same representations which has only
subjective validity—a relation, to wit, which is produced according to
laws of association. According to these laws, I could only say: “When I
hold in my hand or carry a body, I feel an impression of weight”; but I
could not say: “It, the body, is heavy”; for this is tantamount to
saying both these representations are conjoined in the object, that is,
without distinction as to the condition of the subject, and do not
merely stand together in my perception, however frequently the
perceptive act may be repeated.

 All Sensuous Intuitions are subject to the Categories, as Conditions
 under which alone the manifold Content of them can be united in one
 Consciousness § 16

The manifold content given in a sensuous intuition comes necessarily
under the original synthetical unity of apperception, because thereby
alone is the unity of intuition possible (§ 13). But that act of the
understanding, by which the manifold content of given representations
(whether intuitions or conceptions) is brought under one apperception,
is the logical function of judgements (§ 15). All the manifold,
therefore, in so far as it is given in one empirical intuition, is
determined in relation to one of the logical functions of judgement, by
means of which it is brought into union in one consciousness. Now the
categories are nothing else than these functions of judgement so far as
the manifold in a given intuition is determined in relation to them (§
9). Consequently, the manifold in a given intuition is necessarily
subject to the categories of the understanding.

 Observation § 17

The manifold in an intuition, which I call mine, is represented by
means of the synthesis of the understanding, as belonging to the
necessary unity of self-consciousness, and this takes place by means of
the category.* The category indicates accordingly that the empirical
consciousness of a given manifold in an intuition is subject to a pure
self-consciousness a priori, in the same manner as an empirical
intuition is subject to a pure sensuous intuition, which is also a
priori. In the above proposition, then, lies the beginning of a
deduction of the pure conceptions of the understanding. Now, as the
categories have their origin in the understanding alone, independently
of sensibility, I must in my deduction make abstraction of the mode in
which the manifold of an empirical intuition is given, in order to fix
my attention exclusively on the unity which is brought by the
understanding into the intuition by means of the category. In what
follows (§ 22), it will be shown, from the mode in which the empirical
intuition is given in the faculty of sensibility, that the unity which
belongs to it is no other than that which the category (according to §
16) imposes on the manifold in a given intuition, and thus, its a
priori validity in regard to all objects of sense being established,
the purpose of our deduction will be fully attained.

[*Footnote: The proof of this rests on the represented unity of
intuition, by means of which an object is given, and which always
includes in itself a synthesis of the manifold to be intuited, and also
the relation of this latter to unity of apperception.]

But there is one thing in the above demonstration of which I could not
make abstraction, namely, that the manifold to be intuited must be
given previously to the synthesis of the understanding, and
independently of it. How this takes place remains here undetermined.
For if I cogitate an understanding which was itself intuitive (as, for
example, a divine understanding which should not represent given
objects, but by whose representation the objects themselves should be
given or produced), the categories would possess no significance in
relation to such a faculty of cognition. They are merely rules for an
understanding, whose whole power consists in thought, that is, in the
act of submitting the synthesis of the manifold which is presented to
it in intuition from a very different quarter, to the unity of
apperception; a faculty, therefore, which cognizes nothing per se, but
only connects and arranges the material of cognition, the intuition,
namely, which must be presented to it by means of the object. But to
show reasons for this peculiar character of our understandings, that it
produces unity of apperception a priori only by means of categories,
and a certain kind and number thereof, is as impossible as to explain
why we are endowed with precisely so many functions of judgement and no
more, or why time and space are the only forms of our intuition.

 In Cognition, its Application to Objects of Experience is the only
 legitimate use of the Category § 18

To think an object and to cognize an object are by no means the same
thing. In cognition there are two elements: firstly, the conception,
whereby an object is cogitated (the category); and, secondly, the
intuition, whereby the object is given. For supposing that to the
conception a corresponding intuition could not be given, it would still
be a thought as regards its form, but without any object, and no
cognition of anything would be possible by means of it, inasmuch as, so
far as I knew, there existed and could exist nothing to which my
thought could be applied. Now all intuition possible to us is sensuous;
consequently, our thought of an object by means of a pure conception of
the understanding, can become cognition for us only in so far as this
conception is applied to objects of the senses. Sensuous intuition is
either pure intuition (space and time) or empirical intuition—of that
which is immediately represented in space and time by means of
sensation as real. Through the determination of pure intuition we
obtain a priori cognitions of objects, as in mathematics, but only as
regards their form as phenomena; whether there can exist things which
must be intuited in this form is not thereby established. All
mathematical conceptions, therefore, are not per se cognition, except
in so far as we presuppose that there exist things which can only be
represented conformably to the form of our pure sensuous intuition. But
things in space and time are given only in so far as they are
perceptions (representations accompanied with sensation), therefore
only by empirical representation. Consequently the pure conceptions of
the understanding, even when they are applied to intuitions a priori
(as in mathematics), produce cognition only in so far as these (and
therefore the conceptions of the understanding by means of them) can be
applied to empirical intuitions. Consequently the categories do not,
even by means of pure intuition afford us any cognition of things; they
can only do so in so far as they can be applied to empirical intuition.
That is to say, the categories serve only to render empirical cognition
possible. But this is what we call experience. Consequently, in
cognition, their application to objects of experience is the only
legitimate use of the categories.

§ 19

The foregoing proposition is of the utmost importance, for it
determines the limits of the exercise of the pure conceptions of the
understanding in regard to objects, just as transcendental aesthetic
determined the limits of the exercise of the pure form of our sensuous
intuition. Space and time, as conditions of the possibility of the
presentation of objects to us, are valid no further than for objects of
sense, consequently, only for experience. Beyond these limits they
represent to us nothing, for they belong only to sense, and have no
reality apart from it. The pure conceptions of the understanding are
free from this limitation, and extend to objects of intuition in
general, be the intuition like or unlike to ours, provided only it be
sensuous, and not intellectual. But this extension of conceptions
beyond the range of our intuition is of no advantage; for they are then
mere empty conceptions of objects, as to the possibility or
impossibility of the existence of which they furnish us with no means
of discovery. They are mere forms of thought, without objective
reality, because we have no intuition to which the synthetical unity of
apperception, which alone the categories contain, could be applied, for
the purpose of determining an object. Our sensuous and empirical
intuition can alone give them significance and meaning.

If, then, we suppose an object of a non-sensuous intuition to be given
we can in that case represent it by all those predicates which are
implied in the presupposition that nothing appertaining to sensuous
intuition belongs to it; for example, that it is not extended, or in
space; that its duration is not time; that in it no change (the effect
of the determinations in time) is to be met with, and so on. But it is
no proper knowledge if I merely indicate what the intuition of the
object is not, without being able to say what is contained in it, for I
have not shown the possibility of an object to which my pure conception
of understanding could be applicable, because I have not been able to
furnish any intuition corresponding to it, but am only able to say that
our intuition is not valid for it. But the most important point is
this, that to a something of this kind not one category can be found
applicable. Take, for example, the conception of substance, that is,
something that can exist as subject, but never as mere predicate; in
regard to this conception I am quite ignorant whether there can really
be anything to correspond to such a determination of thought, if
empirical intuition did not afford me the occasion for its application.
But of this more in the sequel.

 Of the Application of the Categories to Objects of the Senses in
 general § 20

The pure conceptions of the understanding apply to objects of intuition
in general, through the understanding alone, whether the intuition be
our own or some other, provided only it be sensuous, but are, for this
very reason, mere forms of thought, by means of which alone no
determined object can be cognized. The synthesis or conjunction of the
manifold in these conceptions relates, we have said, only to the unity
of apperception, and is for this reason the ground of the possibility
of a priori cognition, in so far as this cognition is dependent on the
understanding. This synthesis is, therefore, not merely transcendental,
but also purely intellectual. But because a certain form of sensuous
intuition exists in the mind a priori which rests on the receptivity of
the representative faculty (sensibility), the understanding, as a
spontaneity, is able to determine the internal sense by means of the
diversity of given representations, conformably to the synthetical
unity of apperception, and thus to cogitate the synthetical unity of
the apperception of the manifold of sensuous intuition a priori, as the
condition to which must necessarily be submitted all objects of human
intuition. And in this manner the categories as mere forms of thought
receive objective reality, that is, application to objects which are
given to us in intuition, but that only as phenomena, for it is only of
phenomena that we are capable of a priori intuition.

This synthesis of the manifold of sensuous intuition, which is possible
and necessary a priori, may be called figurative (synthesis speciosa),
in contradistinction to that which is cogitated in the mere category in
regard to the manifold of an intuition in general, and is called
connection or conjunction of the understanding (synthesis
intellectualis). Both are transcendental, not merely because they
themselves precede a priori all experience, but also because they form
the basis for the possibility of other cognition a priori.

But the figurative synthesis, when it has relation only to the
originally synthetical unity of apperception, that is to the
transcendental unity cogitated in the categories, must, to be
distinguished from the purely intellectual conjunction, be entitled the
transcendental synthesis of imagination. Imagination is the faculty of
representing an object even without its presence in intuition. Now, as
all our intuition is sensuous, imagination, by reason of the subjective
condition under which alone it can give a corresponding intuition to
the conceptions of the understanding, belongs to sensibility. But in so
far as the synthesis of the imagination is an act of spontaneity, which
is determinative, and not, like sense, merely determinable, and which
is consequently able to determine sense a priori, according to its
form, conformably to the unity of apperception, in so far is the
imagination a faculty of determining sensibility a priori, and its
synthesis of intuitions according to the categories must be the
transcendental synthesis of the imagination. It is an operation of the
understanding on sensibility, and the first application of the
understanding to objects of possible intuition, and at the same time
the basis for the exercise of the other functions of that faculty. As
figurative, it is distinguished from the merely intellectual synthesis,
which is produced by the understanding alone, without the aid of
imagination. Now, in so far as imagination is spontaneity, I sometimes
call it also the productive imagination, and distinguish it from the
reproductive, the synthesis of which is subject entirely to empirical
laws, those of association, namely, and which, therefore, contributes
nothing to the explanation of the possibility of a priori cognition,
and for this reason belongs not to transcendental philosophy, but to

We have now arrived at the proper place for explaining the paradox
which must have struck every one in our exposition of the internal
sense (§ 6), namely—how this sense represents us to our own
consciousness, only as we appear to ourselves, not as we are in
ourselves, because, to wit, we intuite ourselves only as we are
inwardly affected. Now this appears to be contradictory, inasmuch as we
thus stand in a passive relation to ourselves; and therefore in the
systems of psychology, the internal sense is commonly held to be one
with the faculty of apperception, while we, on the contrary, carefully
distinguish them.

That which determines the internal sense is the understanding, and its
original power of conjoining the manifold of intuition, that is, of
bringing this under an apperception (upon which rests the possibility
of the understanding itself). Now, as the human understanding is not in
itself a faculty of intuition, and is unable to exercise such a power,
in order to conjoin, as it were, the manifold of its own intuition, the
synthesis of understanding is, considered per se, nothing but the unity
of action, of which, as such, it is self-conscious, even apart from
sensibility, by which, moreover, it is able to determine our internal
sense in respect of the manifold which may be presented to it according
to the form of sensuous intuition. Thus, under the name of a
transcendental synthesis of imagination, the understanding exercises an
activity upon the passive subject, whose faculty it is; and so we are
right in saying that the internal sense is affected thereby.
Apperception and its synthetical unity are by no means one and the same
with the internal sense. The former, as the source of all our
synthetical conjunction, applies, under the name of the categories, to
the manifold of intuition in general, prior to all sensuous intuition
of objects. The internal sense, on the contrary, contains merely the
form of intuition, but without any synthetical conjunction of the
manifold therein, and consequently does not contain any determined
intuition, which is possible only through consciousness of the
determination of the manifold by the transcendental act of the
imagination (synthetical influence of the understanding on the internal
sense), which I have named figurative synthesis.

This we can indeed always perceive in ourselves. We cannot cogitate a
geometrical line without drawing it in thought, nor a circle without
describing it, nor represent the three dimensions of space without
drawing three lines from the same point perpendicular to one another.
We cannot even cogitate time, unless, in drawing a straight line (which
is to serve as the external figurative representation of time), we fix
our attention on the act of the synthesis of the manifold, whereby we
determine successively the internal sense, and thus attend also to the
succession of this determination. Motion as an act of the subject (not
as a determination of an object),* consequently the synthesis of the
manifold in space, if we make abstraction of space and attend merely to
the act by which we determine the internal sense according to its form,
is that which produces the conception of succession. The understanding,
therefore, does by no means find in the internal sense any such
synthesis of the manifold, but produces it, in that it affects this
sense. At the same time, how “I who think” is distinct from the “i”
which intuites itself (other modes of intuition being cogitable as at
least possible), and yet one and the same with this latter as the same
subject; how, therefore, I am able to say: “I, as an intelligence and
thinking subject, cognize myself as an object thought, so far as I am,
moreover, given to myself in intuition—only, like other phenomena, not
as I am in myself, and as considered by the understanding, but merely
as I appear”—is a question that has in it neither more nor less
difficulty than the question—“How can I be an object to myself?” or
this—“How I can be an object of my own intuition and internal
perceptions?” But that such must be the fact, if we admit that space is
merely a pure form of the phenomena of external sense, can be clearly
proved by the consideration that we cannot represent time, which is not
an object of external intuition, in any other way than under the image
of a line, which we draw in thought, a mode of representation without
which we could not cognize the unity of its dimension, and also that we
are necessitated to take our determination of periods of time, or of
points of time, for all our internal perceptions from the changes which
we perceive in outward things. It follows that we must arrange the
determinations of the internal sense, as phenomena in time, exactly in
the same manner as we arrange those of the external senses in space.
And consequently, if we grant, respecting this latter, that by means of
them we know objects only in so far as we are affected externally, we
must also confess, with regard to the internal sense, that by means of
it we intuite ourselves only as we are internally affected by
ourselves; in other words, as regards internal intuition, we cognize
our own subject only as phenomenon, and not as it is in itself.**

[*Footnote: Motion of an object in space does not belong to a pure
science, consequently not to geometry; because, that a thing is movable
cannot be known a priori, but only from experience. But motion,
considered as the description of a space, is a pure act of the
successive synthesis of the manifold in external intuition by means of
productive imagination, and belongs not only to geometry, but even to
transcendental philosophy.]

[**Footnote: I do not see why so much difficulty should be found in
admitting that our internal sense is affected by ourselves. Every act
of attention exemplifies it. In such an act the understanding
determines the internal sense by the synthetical conjunction which it
cogitates, conformably to the internal intuition which corresponds to
the manifold in the synthesis of the understanding. How much the mind
is usually affected thereby every one will be able to perceive in

§ 21

On the other hand, in the transcendental synthesis of the manifold
content of representations, consequently in the synthetical unity of
apperception, I am conscious of myself, not as I appear to myself, nor
as I am in myself, but only that “I am.” This representation is a
thought, not an intuition. Now, as in order to cognize ourselves, in
addition to the act of thinking, which subjects the manifold of every
possible intuition to the unity of apperception, there is necessary a
determinate mode of intuition, whereby this manifold is given; although
my own existence is certainly not mere phenomenon (much less mere
illusion), the determination of my existence* Can only take place
conformably to the form of the internal sense, according to the
particular mode in which the manifold which I conjoin is given in
internal intuition, and I have therefore no knowledge of myself as I
am, but merely as I appear to myself. The consciousness of self is thus
very far from a knowledge of self, in which I do not use the
categories, whereby I cogitate an object, by means of the conjunction
of the manifold in one apperception. In the same way as I require, for
the sake of the cognition of an object distinct from myself, not only
the thought of an object in general (in the category), but also an
intuition by which to determine that general conception, in the same
way do I require, in order to the cognition of myself, not only the
consciousness of myself or the thought that I think myself, but in
addition an intuition of the manifold in myself, by which to determine
this thought. It is true that I exist as an intelligence which is
conscious only of its faculty of conjunction or synthesis, but
subjected in relation to the manifold which this intelligence has to
conjoin to a limitative conjunction called the internal sense. My
intelligence (that is, I) can render that conjunction or synthesis
perceptible only according to the relations of time, which are quite
beyond the proper sphere of the conceptions of the understanding and
consequently cognize itself in respect to an intuition (which cannot
possibly be intellectual, nor given by the understanding), only as it
appears to itself, and not as it would cognize itself, if its intuition
were intellectual.

[*Footnote: The “I think” expresses the act of determining my own
existence. My existence is thus already given by the act of
consciousness; but the mode in which I must determine my existence,
that is, the mode in which I must place the manifold belonging to my
existence, is not thereby given. For this purpose intuition of self is
required, and this intuition possesses a form given a priori, namely,
time, which is sensuous, and belongs to our receptivity of the
determinable. Now, as I do not possess another intuition of self which
gives the determining in me (of the spontaneity of which I am
conscious), prior to the act of determination, in the same manner as
time gives the determinable, it is clear that I am unable to determine
my own existence as that of a spontaneous being, but I am only able to
represent to myself the spontaneity of my thought, that is, of my
determination, and my existence remains ever determinable in a purely
sensuous manner, that is to say, like the existence of a phenomenon.
But it is because of this spontaneity that I call myself an

 Transcendental Deduction of the universally possible employment in
 experience of the Pure Conceptions of the Understanding § 22

In the metaphysical deduction, the a priori origin of categories was
proved by their complete accordance with the general logical of
thought; in the transcendental deduction was exhibited the possibility
of the categories as a priori cognitions of objects of an intuition in
general (§ 16 and 17).At present we are about to explain the
possibility of cognizing, a priori, by means of the categories, all
objects which can possibly be presented to our senses, not, indeed,
according to the form of their intuition, but according to the laws of
their conjunction or synthesis, and thus, as it were, of prescribing
laws to nature and even of rendering nature possible. For if the
categories were inadequate to this task, it would not be evident to us
why everything that is presented to our senses must be subject to those
laws which have an a priori origin in the understanding itself.

I premise that by the term synthesis of apprehension I understand the
combination of the manifold in an empirical intuition, whereby
perception, that is, empirical consciousness of the intuition (as
phenomenon), is possible.

We have a priori forms of the external and internal sensuous intuition
in the representations of space and time, and to these must the
synthesis of apprehension of the manifold in a phenomenon be always
comformable, because the synthesis itself can only take place according
to these forms. But space and time are not merely forms of sensuous
intuition, but intuitions themselves (which contain a manifold), and
therefore contain a priori the determination of the unity of this
manifold.* (See the Transcendent Aesthetic.) Therefore is unity of the
synthesis of the manifold without or within us, consequently also a
conjunction to which all that is to be represented as determined in
space or time must correspond, given a priori along with (not in) these
intuitions, as the condition of the synthesis of all apprehension of
them. But this synthetical unity can be no other than that of the
conjunction of the manifold of a given intuition in general, in a
primitive act of consciousness, according to the categories, but
applied to our sensuous intuition. Consequently all synthesis, whereby
alone is even perception possible, is subject to the categories. And,
as experience is cognition by means of conjoined perceptions, the
categories are conditions of the possibility of experience and are
therefore valid a priori for all objects of experience.

[*Footnote: Space represented as an object (as geometry really requires
it to be) contains more than the mere form of the intuition; namely, a
combination of the manifold given according to the form of sensibility
into a representation that can be intuited; so that the form of the
intuition gives us merely the manifold, but the formal intuition gives
unity of representation. In the aesthetic, I regarded this unity as
belonging entirely to sensibility, for the purpose of indicating that
it antecedes all conceptions, although it presupposes a synthesis which
does not belong to sense, through which alone, however, all our
conceptions of space and time are possible. For as by means of this
unity alone (the understanding determining the sensibility) space and
time are given as intuitions, it follows that the unity of this
intuition a priori belongs to space and time, and not to the conception
of the understanding (§ 20).]

When, then, for example, I make the empirical intuition of a house by
apprehension of the manifold contained therein into a perception, the
necessary unity of space and of my external sensuous intuition lies at
the foundation of this act, and I, as it were, draw the form of the
house conformably to this synthetical unity of the manifold in space.
But this very synthetical unity remains, even when I abstract the form
of space, and has its seat in the understanding, and is in fact the
category of the synthesis of the homogeneous in an intuition; that is
to say, the category of quantity, to which the aforesaid synthesis of
apprehension, that is, the perception, must be completely conformable.*

[*Footnote: In this manner it is proved, that the synthesis of
apprehension, which is empirical, must necessarily be conformable to
the synthesis of apperception, which is intellectual, and contained a
priori in the category. It is one and the same spontaneity which at one
time, under the name of imagination, at another under that of
understanding, produces conjunction in the manifold of intuition.]

To take another example, when I perceive the freezing of water, I
apprehend two states (fluidity and solidity), which, as such, stand
toward each other mutually in a relation of time. But in the time,
which I place as an internal intuition, at the foundation of this
phenomenon, I represent to myself synthetical unity of the manifold,
without which the aforesaid relation could not be given in an intuition
as determined (in regard to the succession of time). Now this
synthetical unity, as the a priori condition under which I conjoin the
manifold of an intuition, is, if I make abstraction of the permanent
form of my internal intuition (that is to say, of time), the category
of cause, by means of which, when applied to my sensibility, I
determine everything that occurs according to relations of time.
Consequently apprehension in such an event, and the event itself, as
far as regards the possibility of its perception, stands under the
conception of the relation of cause and effect: and so in all other

Categories are conceptions which prescribe laws a priori to phenomena,
consequently to nature as the complex of all phenomena (natura
materialiter spectata). And now the question arises—inasmuch as these
categories are not derived from nature, and do not regulate themselves
according to her as their model (for in that case they would be
empirical)—how it is conceivable that nature must regulate herself
according to them, in other words, how the categories can determine a
priori the synthesis of the manifold of nature, and yet not derive
their origin from her. The following is the solution of this enigma.

It is not in the least more difficult to conceive how the laws of the
phenomena of nature must harmonize with the understanding and with its
a priori form—that is, its faculty of conjoining the manifold—than it
is to understand how the phenomena themselves must correspond with the
a priori form of our sensuous intuition. For laws do not exist in the
phenomena any more than the phenomena exist as things in themselves.
Laws do not exist except by relation to the subject in which the
phenomena inhere, in so far as it possesses understanding, just as
phenomena have no existence except by relation to the same existing
subject in so far as it has senses. To things as things in themselves,
conformability to law must necessarily belong independently of an
understanding to cognize them. But phenomena are only representations
of things which are utterly unknown in respect to what they are in
themselves. But as mere representations, they stand under no law of
conjunction except that which the conjoining faculty prescribes. Now
that which conjoins the manifold of sensuous intuition is imagination,
a mental act to which understanding contributes unity of intellectual
synthesis, and sensibility, manifoldness of apprehension. Now as all
possible perception depends on the synthesis of apprehension, and this
empirical synthesis itself on the transcendental, consequently on the
categories, it is evident that all possible perceptions, and therefore
everything that can attain to empirical consciousness, that is, all
phenomena of nature, must, as regards their conjunction, be subject to
the categories. And nature (considered merely as nature in general) is
dependent on them, as the original ground of her necessary
conformability to law (as natura formaliter spectata). But the pure
faculty (of the understanding) of prescribing laws a priori to
phenomena by means of mere categories, is not competent to enounce
other or more laws than those on which a nature in general, as a
conformability to law of phenomena of space and time, depends.
Particular laws, inasmuch as they concern empirically determined
phenomena, cannot be entirely deduced from pure laws, although they all
stand under them. Experience must be superadded in order to know these
particular laws; but in regard to experience in general, and everything
that can be cognized as an object thereof, these a priori laws are our
only rule and guide.

 Result of this Deduction of the Conceptions of the Understanding § 23

We cannot think any object except by means of the categories; we cannot
cognize any thought except by means of intuitions corresponding to
these conceptions. Now all our intuitions are sensuous, and our
cognition, in so far as the object of it is given, is empirical. But
empirical cognition is experience; consequently no a priori cognition
is possible for us, except of objects of possible experience.*

[Footnote: Lest my readers should stumble at this assertion, and the
conclusions that may be too rashly drawn from it, I must remind them
that the categories in the act of thought are by no means limited by
the conditions of our sensuous intuition, but have an unbounded sphere
of action. It is only the cognition of the object of thought, the
determining of the object, which requires intuition. In the absence of
intuition, our thought of an object may still have true and useful
consequences in regard to the exercise of reason by the subject. But as
this exercise of reason is not always directed on the determination of
the object, in other words, on cognition thereof, but also on the
determination of the subject and its volition, I do not intend to treat
of it in this place.]

But this cognition, which is limited to objects of experience, is not
for that reason derived entirely, from, experience, but—and this is
asserted of the pure intuitions and the pure conceptions of the
understanding—there are, unquestionably, elements of cognition, which
exist in the mind a priori. Now there are only two ways in which a
necessary harmony of experience with the conceptions of its objects can
be cogitated. Either experience makes these conceptions possible, or
the conceptions make experience possible. The former of these
statements will not bold good with respect to the categories (nor in
regard to pure sensuous intuition), for they are a priori conceptions,
and therefore independent of experience. The assertion of an empirical
origin would attribute to them a sort of generatio aequivoca.
Consequently, nothing remains but to adopt the second alternative
(which presents us with a system, as it were, of the epigenesis of pure
reason), namely, that on the part of the understanding the categories
do contain the grounds of the possibility of all experience. But with
respect to the questions how they make experience possible, and what
are the principles of the possibility thereof with which they present
us in their application to phenomena, the following section on the
transcendental exercise of the faculty of judgement will inform the

It is quite possible that someone may propose a species of
preformation-system of pure reason—a middle way between the two—to wit,
that the categories are neither innate and first a priori principles of
cognition, nor derived from experience, but are merely subjective
aptitudes for thought implanted in us contemporaneously with our
existence, which were so ordered and disposed by our Creator, that
their exercise perfectly harmonizes with the laws of nature which
regulate experience. Now, not to mention that with such an hypothesis
it is impossible to say at what point we must stop in the employment of
predetermined aptitudes, the fact that the categories would in this
case entirely lose that character of necessity which is essentially
involved in the very conception of them, is a conclusive objection to
it. The conception of cause, for example, which expresses the necessity
of an effect under a presupposed condition, would be false, if it
rested only upon such an arbitrary subjective necessity of uniting
certain empirical representations according to such a rule of relation.
I could not then say—“The effect is connected with its cause in the
object (that is, necessarily),” but only, “I am so constituted that I
can think this representation as so connected, and not otherwise.” Now
this is just what the sceptic wants. For in this case, all our
knowledge, depending on the supposed objective validity of our
judgement, is nothing but mere illusion; nor would there be wanting
people who would deny any such subjective necessity in respect to
themselves, though they must feel it. At all events, we could not
dispute with any one on that which merely depends on the manner in
which his subject is organized.

Short view of the above Deduction.

The foregoing deduction is an exposition of the pure conceptions of the
understanding (and with them of all theoretical a priori cognition), as
principles of the possibility of experience, but of experience as the
determination of all phenomena in space and time in general—of
experience, finally, from the principle of the original synthetical
unity of apperception, as the form of the understanding in relation to
time and space as original forms of sensibility.

I consider the division by paragraphs to be necessary only up to this
point, because we had to treat of the elementary conceptions. As we now
proceed to the exposition of the employment of these, I shall not
designate the chapters in this manner any further.

 BOOK II. Analytic of Principles

General logic is constructed upon a plan which coincides exactly with
the division of the higher faculties of cognition. These are,
understanding, judgement, and reason. This science, accordingly, treats
in its analytic of conceptions, judgements, and conclusions in exact
correspondence with the functions and order of those mental powers
which we include generally under the generic denomination of

As this merely formal logic makes abstraction of all content of
cognition, whether pure or empirical, and occupies itself with the mere
form of thought (discursive cognition), it must contain in its analytic
a canon for reason. For the form of reason has its law, which, without
taking into consideration the particular nature of the cognition about
which it is employed, can be discovered a priori, by the simple
analysis of the action of reason into its momenta.

Transcendental logic, limited as it is to a determinate content, that
of pure a priori cognitions, to wit, cannot imitate general logic in
this division. For it is evident that the transcendental employment of
reason is not objectively valid, and therefore does not belong to the
logic of truth (that is, to analytic), but as a logic of illusion,
occupies a particular department in the scholastic system under the
name of transcendental dialectic.

Understanding and judgement accordingly possess in transcendental logic
a canon of objectively valid, and therefore true exercise, and are
comprehended in the analytical department of that logic. But reason, in
her endeavours to arrive by a priori means at some true statement
concerning objects and to extend cognition beyond the bounds of
possible experience, is altogether dialectic, and her illusory
assertions cannot be constructed into a canon such as an analytic ought
to contain.

Accordingly, the analytic of principles will be merely a canon for the
faculty of judgement, for the instruction of this faculty in its
application to phenomena of the pure conceptions of the understanding,
which contain the necessary condition for the establishment of a priori
laws. On this account, although the subject of the following chapters
is the especial principles of understanding, I shall make use of the
term Doctrine of the faculty of judgement, in order to define more
particularly my present purpose.

 INTRODUCTION. Of the Transcendental Faculty of judgement in General

If understanding in general be defined as the faculty of laws or rules,
the faculty of judgement may be termed the faculty of subsumption under
these rules; that is, of distinguishing whether this or that does or
does not stand under a given rule (casus datae legis). General logic
contains no directions or precepts for the faculty of judgement, nor
can it contain any such. For as it makes abstraction of all content of
cognition, no duty is left for it, except that of exposing analytically
the mere form of cognition in conceptions, judgements, and conclusions,
and of thereby establishing formal rules for all exercise of the
understanding. Now if this logic wished to give some general direction
how we should subsume under these rules, that is, how we should
distinguish whether this or that did or did not stand under them, this
again could not be done otherwise than by means of a rule. But this
rule, precisely because it is a rule, requires for itself direction
from the faculty of judgement. Thus, it is evident that the
understanding is capable of being instructed by rules, but that the
judgement is a peculiar talent, which does not, and cannot require
tuition, but only exercise. This faculty is therefore the specific
quality of the so-called mother wit, the want of which no scholastic
discipline can compensate.

For although education may furnish, and, as it were, engraft upon a
limited understanding rules borrowed from other minds, yet the power of
employing these rules correctly must belong to the pupil himself; and
no rule which we can prescribe to him with this purpose is, in the
absence or deficiency of this gift of nature, secure from misuse.* A
physician therefore, a judge or a statesman, may have in his head many
admirable pathological, juridical, or political rules, in a degree that
may enable him to be a profound teacher in his particular science, and
yet in the application of these rules he may very possibly
blunder—either because he is wanting in natural judgement (though not
in understanding) and, whilst he can comprehend the general in
abstracto, cannot distinguish whether a particular case in concreto
ought to rank under the former; or because his faculty of judgement has
not been sufficiently exercised by examples and real practice. Indeed,
the grand and only use of examples, is to sharpen the judgement. For as
regards the correctness and precision of the insight of the
understanding, examples are commonly injurious rather than otherwise,
because, as casus in terminis they seldom adequately fulfil the
conditions of the rule. Besides, they often weaken the power of our
understanding to apprehend rules or laws in their universality,
independently of particular circumstances of experience; and hence,
accustom us to employ them more as formulae than as principles.
Examples are thus the go-cart of the judgement, which he who is
naturally deficient in that faculty cannot afford to dispense with.

[*Footnote: Deficiency in judgement is properly that which is called
stupidity; and for such a failing we know no remedy. A dull or
narrow-minded person, to whom nothing is wanting but a proper degree of
understanding, may be improved by tuition, even so far as to deserve
the epithet of learned. But as such persons frequently labour under a
deficiency in the faculty of judgement, it is not uncommon to find men
extremely learned who in the application of their science betray a
lamentable degree this irremediable want.]

But although general logic cannot give directions to the faculty of
judgement, the case is very different as regards transcendental logic,
insomuch that it appears to be the especial duty of the latter to
secure and direct, by means of determinate rules, the faculty of
judgement in the employment of the pure understanding. For, as a
doctrine, that is, as an endeavour to enlarge the sphere of the
understanding in regard to pure a priori cognitions, philosophy is
worse than useless, since from all the attempts hitherto made, little
or no ground has been gained. But, as a critique, in order to guard
against the mistakes of the faculty of judgement (lapsus judicii) in
the employment of the few pure conceptions of the understanding which
we possess, although its use is in this case purely negative,
philosophy is called upon to apply all its acuteness and penetration.

But transcendental philosophy has this peculiarity, that besides
indicating the rule, or rather the general condition for rules, which
is given in the pure conception of the understanding, it can, at the
same time, indicate a priori the case to which the rule must be
applied. The cause of the superiority which, in this respect,
transcendental philosophy possesses above all other sciences except
mathematics, lies in this: it treats of conceptions which must relate a
priori to their objects, whose objective validity consequently cannot
be demonstrated a posteriori, and is, at the same time, under the
obligation of presenting in general but sufficient tests, the
conditions under which objects can be given in harmony with those
conceptions; otherwise they would be mere logical forms, without
content, and not pure conceptions of the understanding.

Our transcendental doctrine of the faculty of judgement will contain
two chapters. The first will treat of the sensuous condition under
which alone pure conceptions of the understanding can be employed—that
is, of the schematism of the pure understanding. The second will treat
of those synthetical judgements which are derived a priori from pure
conceptions of the understanding under those conditions, and which lie
a priori at the foundation of all other cognitions, that is to say, it
will treat of the principles of the pure understanding.


 Chapter I. Of the Schematism at of the Pure Conceptions of the

In all subsumptions of an object under a conception, the representation
of the object must be homogeneous with the conception; in other words,
the conception must contain that which is represented in the object to
be subsumed under it. For this is the meaning of the expression: “An
object is contained under a conception.” Thus the empirical conception
of a plate is homogeneous with the pure geometrical conception of a
circle, inasmuch as the roundness which is cogitated in the former is
intuited in the latter.

But pure conceptions of the understanding, when compared with empirical
intuitions, or even with sensuous intuitions in general, are quite
heterogeneous, and never can be discovered in any intuition. How then
is the subsumption of the latter under the former, and consequently the
application of the categories to phenomena, possible?—For it is
impossible to say, for example: “Causality can be intuited through the
senses and is contained in the phenomenon.”—This natural and important
question forms the real cause of the necessity of a transcendental
doctrine of the faculty of judgement, with the purpose, to wit, of
showing how pure conceptions of the understanding can be applied to
phenomena. In all other sciences, where the conceptions by which the
object is thought in the general are not so different and heterogeneous
from those which represent the object in concreto—as it is given, it is
quite unnecessary to institute any special inquiries concerning the
application of the former to the latter.

Now it is quite clear that there must be some third thing, which on the
one side is homogeneous with the category, and with the phenomenon on
the other, and so makes the application of the former to the latter
possible. This mediating representation must be pure (without any
empirical content), and yet must on the one side be intellectual, on
the other sensuous. Such a representation is the transcendental schema.

The conception of the understanding contains pure synthetical unity of
the manifold in general. Time, as the formal condition of the manifold
of the internal sense, consequently of the conjunction of all
representations, contains a priori a manifold in the pure intuition.
Now a transcendental determination of time is so far homogeneous with
the category, which constitutes the unity thereof, that it is universal
and rests upon a rule a priori. On the other hand, it is so far
homogeneous with the phenomenon, inasmuch as time is contained in every
empirical representation of the manifold. Thus an application of the
category to phenomena becomes possible, by means of the transcendental
determination of time, which, as the schema of the conceptions of the
understanding, mediates the subsumption of the latter under the former.

After what has been proved in our deduction of the categories, no one,
it is to be hoped, can hesitate as to the proper decision of the
question, whether the employment of these pure conceptions of the
understanding ought to be merely empirical or also transcendental; in
other words, whether the categories, as conditions of a possible
experience, relate a priori solely to phenomena, or whether, as
conditions of the possibility of things in general, their application
can be extended to objects as things in themselves. For we have there
seen that conceptions are quite impossible, and utterly without
signification, unless either to them, or at least to the elements of
which they consist, an object be given; and that, consequently, they
cannot possibly apply to objects as things in themselves without regard
to the question whether and how these may be given to us; and, further,
that the only manner in which objects can be given to us is by means of
the modification of our sensibility; and, finally, that pure a priori
conceptions, in addition to the function of the understanding in the
category, must contain a priori formal conditions of sensibility (of
the internal sense, namely), which again contain the general condition
under which alone the category can be applied to any object. This
formal and pure condition of sensibility, to which the conception of
the understanding is restricted in its employment, we shall name the
schema of the conception of the understanding, and the procedure of the
understanding with these schemata we shall call the schematism of the
pure understanding.

The schema is, in itself, always a mere product of the imagination.
But, as the synthesis of imagination has for its aim no single
intuition, but merely unity in the determination of sensibility, the
schema is clearly distinguishable from the image. Thus, if I place five
points one after another.... this is an image of the number five. On
the other hand, if I only think a number in general, which may be
either five or a hundred, this thought is rather the representation of
a method of representing in an image a sum (e.g., a thousand) in
conformity with a conception, than the image itself, an image which I
should find some little difficulty in reviewing, and comparing with the
conception. Now this representation of a general procedure of the
imagination to present its image to a conception, I call the schema of
this conception.

In truth, it is not images of objects, but schemata, which lie at the
foundation of our pure sensuous conceptions. No image could ever be
adequate to our conception of a triangle in general. For the
generalness of the conception it never could attain to, as this
includes under itself all triangles, whether right-angled,
acute-angled, etc., whilst the image would always be limited to a
single part of this sphere. The schema of the triangle can exist
nowhere else than in thought, and it indicates a rule of the synthesis
of the imagination in regard to pure figures in space. Still less is an
object of experience, or an image of the object, ever to the empirical
conception. On the contrary, the conception always relates immediately
to the schema of the imagination, as a rule for the determination of
our intuition, in conformity with a certain general conception. The
conception of a dog indicates a rule, according to which my imagination
can delineate the figure of a four-footed animal in general, without
being limited to any particular individual form which experience
presents to me, or indeed to any possible image that I can represent to
myself in concreto. This schematism of our understanding in regard to
phenomena and their mere form, is an art, hidden in the depths of the
human soul, whose true modes of action we shall only with difficulty
discover and unveil. Thus much only can we say: “The image is a product
of the empirical faculty of the productive imagination—the schema of
sensuous conceptions (of figures in space, for example) is a product,
and, as it were, a monogram of the pure imagination a priori, whereby
and according to which images first become possible, which, however,
can be connected with the conception only mediately by means of the
schema which they indicate, and are in themselves never fully adequate
to it.” On the other hand, the schema of a pure conception of the
understanding is something that cannot be reduced into any image—it is
nothing else than the pure synthesis expressed by the category,
conformably, to a rule of unity according to conceptions. It is a
transcendental product of the imagination, a product which concerns the
determination of the internal sense, according to conditions of its
form (time) in respect to all representations, in so far as these
representations must be conjoined a priori in one conception,
conformably to the unity of apperception.

Without entering upon a dry and tedious analysis of the essential
requisites of transcendental schemata of the pure conceptions of the
understanding, we shall rather proceed at once to give an explanation
of them according to the order of the categories, and in connection

For the external sense the pure image of all quantities (quantorum) is
space; the pure image of all objects of sense in general, is time. But
the pure schema of quantity (quantitatis) as a conception of the
understanding, is number, a representation which comprehends the
successive addition of one to one (homogeneous quantities). Thus,
number is nothing else than the unity of the synthesis of the manifold
in a homogeneous intuition, by means of my generating time itself in my
apprehension of the intuition.

Reality, in the pure conception of the understanding, is that which
corresponds to a sensation in general; that, consequently, the
conception of which indicates a being (in time). Negation is that the
conception of which represents a not-being (in time). The opposition of
these two consists therefore in the difference of one and the same
time, as a time filled or a time empty. Now as time is only the form of
intuition, consequently of objects as phenomena, that which in objects
corresponds to sensation is the transcendental matter of all objects as
things in themselves (Sachheit, reality). Now every sensation has a
degree or quantity by which it can fill time, that is to say, the
internal sense in respect of the representation of an object, more or
less, until it vanishes into nothing (= 0 = negatio). Thus there is a
relation and connection between reality and negation, or rather a
transition from the former to the latter, which makes every reality
representable to us as a quantum; and the schema of a reality as the
quantity of something in so far as it fills time, is exactly this
continuous and uniform generation of the reality in time, as we descend
in time from the sensation which has a certain degree, down to the
vanishing thereof, or gradually ascend from negation to the quantity

The schema of substance is the permanence of the real in time; that is,
the representation of it as a substratum of the empirical determination
of time; a substratum which therefore remains, whilst all else changes.
(Time passes not, but in it passes the existence of the changeable. To
time, therefore, which is itself unchangeable and permanent,
corresponds that which in the phenomenon is unchangeable in existence,
that is, substance, and it is only by it that the succession and
coexistence of phenomena can be determined in regard to time.)

The schema of cause and of the causality of a thing is the real which,
when posited, is always followed by something else. It consists,
therefore, in the succession of the manifold, in so far as that
succession is subjected to a rule.

The schema of community (reciprocity of action and reaction), or the
reciprocal causality of substances in respect of their accidents, is
the coexistence of the determinations of the one with those of the
other, according to a general rule.

The schema of possibility is the accordance of the synthesis of
different representations with the conditions of time in general (as,
for example, opposites cannot exist together at the same time in the
same thing, but only after each other), and is therefore the
determination of the representation of a thing at any time.

The schema of reality is existence in a determined time.

The schema of necessity is the existence of an object in all time.

It is clear, from all this, that the schema of the category of quantity
contains and represents the generation (synthesis) of time itself, in
the successive apprehension of an object; the schema of quality the
synthesis of sensation with the representation of time, or the filling
up of time; the schema of relation the relation of perceptions to each
other in all time (that is, according to a rule of the determination of
time): and finally, the schema of modality and its categories, time
itself, as the correlative of the determination of an object—whether it
does belong to time, and how. The schemata, therefore, are nothing but
a priori determinations of time according to rules, and these, in
regard to all possible objects, following the arrangement of the
categories, relate to the series in time, the content in time, the
order in time, and finally, to the complex or totality in time.

Hence it is apparent that the schematism of the understanding, by means
of the transcendental synthesis of the imagination, amounts to nothing
else than the unity of the manifold of intuition in the internal sense,
and thus indirectly to the unity of apperception, as a function
corresponding to the internal sense (a receptivity). Thus, the schemata
of the pure conceptions of the understanding are the true and only
conditions whereby our understanding receives an application to
objects, and consequently significance. Finally, therefore, the
categories are only capable of empirical use, inasmuch as they serve
merely to subject phenomena to the universal rules of synthesis, by
means of an a priori necessary unity (on account of the necessary union
of all consciousness in one original apperception); and so to render
them susceptible of a complete connection in one experience. But within
this whole of possible experience lie all our cognitions, and in the
universal relation to this experience consists transcendental truth,
which antecedes all empirical truth, and renders the latter possible.

It is, however, evident at first sight, that although the schemata of
sensibility are the sole agents in realizing the categories, they do,
nevertheless, also restrict them, that is, they limit the categories by
conditions which lie beyond the sphere of understanding—namely, in
sensibility. Hence the schema is properly only the phenomenon, or the
sensuous conception of an object in harmony with the category. (Numerus
est quantitas phaenomenon—sensatio realitas phaenomenon; constans et
perdurabile rerum substantia phaenomenon—aeternitas, necessitas,
phaenomena, etc.) Now, if we remove a restrictive condition, we thereby
amplify, it appears, the formerly limited conception. In this way, the
categories in their pure signification, free from all conditions of
sensibility, ought to be valid of things as they are, and not, as the
schemata represent them, merely as they appear; and consequently the
categories must have a significance far more extended, and wholly
independent of all schemata. In truth, there does always remain to the
pure conceptions of the understanding, after abstracting every sensuous
condition, a value and significance, which is, however, merely logical.
But in this case, no object is given them, and therefore they have no
meaning sufficient to afford us a conception of an object. The notion
of substance, for example, if we leave out the sensuous determination
of permanence, would mean nothing more than a something which can be
cogitated as subject, without the possibility of becoming a predicate
to anything else. Of this representation I can make nothing, inasmuch
as it does not indicate to me what determinations the thing possesses
which must thus be valid as premier subject. Consequently, the
categories, without schemata are merely functions of the understanding
for the production of conceptions, but do not represent any object.
This significance they derive from sensibility, which at the same time
realizes the understanding and restricts it.

 Chapter II. System of all Principles of the Pure Understanding

In the foregoing chapter we have merely considered the general
conditions under which alone the transcendental faculty of judgement is
justified in using the pure conceptions of the understanding for
synthetical judgements. Our duty at present is to exhibit in systematic
connection those judgements which the understanding really produces a
priori. For this purpose, our table of the categories will certainly
afford us the natural and safe guidance. For it is precisely the
categories whose application to possible experience must constitute all
pure a priori cognition of the understanding; and the relation of which
to sensibility will, on that very account, present us with a complete
and systematic catalogue of all the transcendental principles of the
use of the understanding.

Principles a priori are so called, not merely because they contain in
themselves the grounds of other judgements, but also because they
themselves are not grounded in higher and more general cognitions. This
peculiarity, however, does not raise them altogether above the need of
a proof. For although there could be found no higher cognition, and
therefore no objective proof, and although such a principle rather
serves as the foundation for all cognition of the object, this by no
means hinders us from drawing a proof from the subjective sources of
the possibility of the cognition of an object. Such a proof is
necessary, moreover, because without it the principle might be liable
to the imputation of being a mere gratuitous assertion.

In the second place, we shall limit our investigations to those
principles which relate to the categories. For as to the principles of
transcendental aesthetic, according to which space and time are the
conditions of the possibility of things as phenomena, as also the
restriction of these principles, namely, that they cannot be applied to
objects as things in themselves—these, of course, do not fall within
the scope of our present inquiry. In like manner, the principles of
mathematical science form no part of this system, because they are all
drawn from intuition, and not from the pure conception of the
understanding. The possibility of these principles, however, will
necessarily be considered here, inasmuch as they are synthetical
judgements a priori, not indeed for the purpose of proving their
accuracy and apodeictic certainty, which is unnecessary, but merely to
render conceivable and deduce the possibility of such evident a priori

But we shall have also to speak of the principle of analytical
judgements, in opposition to synthetical judgements, which is the
proper subject of our inquiries, because this very opposition will free
the theory of the latter from all ambiguity, and place it clearly
before our eyes in its true nature.


 Section I. Of the Supreme Principle of all Analytical Judgements

Whatever may be the content of our cognition, and in whatever manner
our cognition may be related to its object, the universal, although
only negative conditions of all our judgements is that they do not
contradict themselves; otherwise these judgements are in themselves
(even without respect to the object) nothing. But although there may
exist no contradiction in our judgement, it may nevertheless connect
conceptions in such a manner that they do not correspond to the object,
or without any grounds either a priori or a posteriori for arriving at
such a judgement, and thus, without being self-contradictory, a
judgement may nevertheless be either false or groundless.

Now, the proposition: “No subject can have a predicate that contradicts
it,” is called the principle of contradiction, and is a universal but
purely negative criterion of all truth. But it belongs to logic alone,
because it is valid of cognitions, merely as cognitions and without
respect to their content, and declares that the contradiction entirely
nullifies them. We can also, however, make a positive use of this
principle, that is, not merely to banish falsehood and error (in so far
as it rests upon contradiction), but also for the cognition of truth.
For if the judgement is analytical, be it affirmative or negative, its
truth must always be recognizable by means of the principle of
contradiction. For the contrary of that which lies and is cogitated as
conception in the cognition of the object will be always properly
negatived, but the conception itself must always be affirmed of the
object, inasmuch as the contrary thereof would be in contradiction to
the object.

We must therefore hold the principle of contradiction to be the
universal and fully sufficient Principle of all analytical cognition.
But as a sufficient criterion of truth, it has no further utility or
authority. For the fact that no cognition can be at variance with this
principle without nullifying itself, constitutes this principle the
sine qua non, but not the determining ground of the truth of our
cognition. As our business at present is properly with the synthetical
part of our knowledge only, we shall always be on our guard not to
transgress this inviolable principle; but at the same time not to
expect from it any direct assistance in the establishment of the truth
of any synthetical proposition.

There exists, however, a formula of this celebrated principle—a
principle merely formal and entirely without content—which contains a
synthesis that has been inadvertently and quite unnecessarily mixed up
with it. It is this: “It is impossible for a thing to be and not to be
at the same time.” Not to mention the superfluousness of the addition
of the word impossible to indicate the apodeictic certainty, which
ought to be self-evident from the proposition itself, the proposition
is affected by the condition of time, and as it were says: “A thing =
A, which is something = B, cannot at the same time be non-B.” But both,
B as well as non-B, may quite well exist in succession. For example, a
man who is young cannot at the same time be old; but the same man can
very well be at one time young, and at another not young, that is, old.
Now the principle of contradiction as a merely logical proposition must
not by any means limit its application merely to relations of time, and
consequently a formula like the preceding is quite foreign to its true
purpose. The misunderstanding arises in this way. We first of all
separate a predicate of a thing from the conception of the thing, and
afterwards connect with this predicate its opposite, and hence do not
establish any contradiction with the subject, but only with its
predicate, which has been conjoined with the subject synthetically—a
contradiction, moreover, which obtains only when the first and second
predicate are affirmed in the same time. If I say: “A man who is
ignorant is not learned,” the condition “at the same time” must be
added, for he who is at one time ignorant, may at another be learned.
But if I say: “No ignorant man is a learned man,” the proposition is
analytical, because the characteristic ignorance is now a constituent
part of the conception of the subject; and in this case the negative
proposition is evident immediately from the proposition of
contradiction, without the necessity of adding the condition “the same
time.” This is the reason why I have altered the formula of this
principle—an alteration which shows very clearly the nature of an
analytical proposition.

 Section II. Of the Supreme Principle of all Synthetical Judgements

The explanation of the possibility of synthetical judgements is a task
with which general logic has nothing to do; indeed she needs not even
be acquainted with its name. But in transcendental logic it is the most
important matter to be dealt with—indeed the only one, if the question
is of the possibility of synthetical judgements a priori, the
conditions and extent of their validity. For when this question is
fully decided, it can reach its aim with perfect ease, the
determination, to wit, of the extent and limits of the pure

In an analytical judgement I do not go beyond the given conception, in
order to arrive at some decision respecting it. If the judgement is
affirmative, I predicate of the conception only that which was already
cogitated in it; if negative, I merely exclude from the conception its
contrary. But in synthetical judgements, I must go beyond the given
conception, in order to cogitate, in relation with it, something quite
different from that which was cogitated in it, a relation which is
consequently never one either of identity or contradiction, and by
means of which the truth or error of the judgement cannot be discerned
merely from the judgement itself.

Granted, then, that we must go out beyond a given conception, in order
to compare it synthetically with another, a third thing is necessary,
in which alone the synthesis of two conceptions can originate. Now what
is this tertium quid that is to be the medium of all synthetical
judgements? It is only a complex in which all our representations are
contained, the internal sense to wit, and its form a priori, time.

The synthesis of our representations rests upon the imagination; their
synthetical unity (which is requisite to a judgement), upon the unity
of apperception. In this, therefore, is to be sought the possibility of
synthetical judgements, and as all three contain the sources of a
priori representations, the possibility of pure synthetical judgements
also; nay, they are necessary upon these grounds, if we are to possess
a knowledge of objects, which rests solely upon the synthesis of

If a cognition is to have objective reality, that is, to relate to an
object, and possess sense and meaning in respect to it, it is necessary
that the object be given in some way or another. Without this, our
conceptions are empty, and we may indeed have thought by means of them,
but by such thinking we have not, in fact, cognized anything, we have
merely played with representation. To give an object, if this
expression be understood in the sense of “to present” the object, not
mediately but immediately in intuition, means nothing else than to
apply the representation of it to experience, be that experience real
or only possible. Space and time themselves, pure as these conceptions
are from all that is empirical, and certain as it is that they are
represented fully a priori in the mind, would be completely without
objective validity, and without sense and significance, if their
necessary use in the objects of experience were not shown. Nay, the
representation of them is a mere schema, that always relates to the
reproductive imagination, which calls up the objects of experience,
without which they have no meaning. And so it is with all conceptions
without distinction.

The possibility of experience is, then, that which gives objective
reality to all our a priori cognitions. Now experience depends upon the
synthetical unity of phenomena, that is, upon a synthesis according to
conceptions of the object of phenomena in general, a synthesis without
which experience never could become knowledge, but would be merely a
rhapsody of perceptions, never fitting together into any connected
text, according to rules of a thoroughly united (possible)
consciousness, and therefore never subjected to the transcendental and
necessary unity of apperception. Experience has therefore for a
foundation, a priori principles of its form, that is to say, general
rules of unity in the synthesis of phenomena, the objective reality of
which rules, as necessary conditions even of the possibility of
experience can which rules, as necessary conditions—even of the
possibility of experience—can always be shown in experience. But apart
from this relation, a priori synthetical propositions are absolutely
impossible, because they have no third term, that is, no pure object,
in which the synthetical unity can exhibit the objective reality of its

Although, then, respecting space, or the forms which productive
imagination describes therein, we do cognize much a priori in
synthetical judgements, and are really in no need of experience for
this purpose, such knowledge would nevertheless amount to nothing but a
busy trifling with a mere chimera, were not space to be considered as
the condition of the phenomena which constitute the material of
external experience. Hence those pure synthetical judgements do relate,
though but mediately, to possible experience, or rather to the
possibility of experience, and upon that alone is founded the objective
validity of their synthesis.

While then, on the one hand, experience, as empirical synthesis, is the
only possible mode of cognition which gives reality to all other
synthesis; on the other hand, this latter synthesis, as cognition a
priori, possesses truth, that is, accordance with its object, only in
so far as it contains nothing more than what is necessary to the
synthetical unity of experience.

Accordingly, the supreme principle of all synthetical judgements is:
“Every object is subject to the necessary conditions of the synthetical
unity of the manifold of intuition in a possible experience.”

A priori synthetical judgements are possible when we apply the formal
conditions of the a priori intuition, the synthesis of the imagination,
and the necessary unity of that synthesis in a transcendental
apperception, to a possible cognition of experience, and say: “The
conditions of the possibility of experience in general are at the same
time conditions of the possibility of the objects of experience, and
have, for that reason, objective validity in an a priori synthetical

 Section III. Systematic Representation of all Synthetical Principles
 of the Pure Understanding

That principles exist at all is to be ascribed solely to the pure
understanding, which is not only the faculty of rules in regard to that
which happens, but is even the source of principles according to which
everything that can be presented to us as an object is necessarily
subject to rules, because without such rules we never could attain to
cognition of an object. Even the laws of nature, if they are
contemplated as principles of the empirical use of the understanding,
possess also a characteristic of necessity, and we may therefore at
least expect them to be determined upon grounds which are valid a
priori and antecedent to all experience. But all laws of nature,
without distinction, are subject to higher principles of the
understanding, inasmuch as the former are merely applications of the
latter to particular cases of experience. These higher principles alone
therefore give the conception, which contains the necessary condition,
and, as it were, the exponent of a rule; experience, on the other hand,
gives the case which comes under the rule.

There is no danger of our mistaking merely empirical principles for
principles of the pure understanding, or conversely; for the character
of necessity, according to conceptions which distinguish the latter,
and the absence of this in every empirical proposition, how extensively
valid soever it may be, is a perfect safeguard against confounding
them. There are, however, pure principles a priori, which nevertheless
I should not ascribe to the pure understanding—for this reason, that
they are not derived from pure conceptions, but (although by the
mediation of the understanding) from pure intuitions. But understanding
is the faculty of conceptions. Such principles mathematical science
possesses, but their application to experience, consequently their
objective validity, nay the possibility of such a priori synthetical
cognitions (the deduction thereof) rests entirely upon the pure

On this account, I shall not reckon among my principles those of
mathematics; though I shall include those upon the possibility and
objective validity a priori, of principles of the mathematical science,
which, consequently, are to be looked upon as the principle of these,
and which proceed from conceptions to intuition, and not from intuition
to conceptions.

In the application of the pure conceptions of the understanding to
possible experience, the employment of their synthesis is either
mathematical or dynamical, for it is directed partly on the intuition
alone, partly on the existence of a phenomenon. But the a priori
conditions of intuition are in relation to a possible experience
absolutely necessary, those of the existence of objects of a possible
empirical intuition are in themselves contingent. Hence the principles
of the mathematical use of the categories will possess a character of
absolute necessity, that is, will be apodeictic; those, on the other
hand, of the dynamical use, the character of an a priori necessity
indeed, but only under the condition of empirical thought in an
experience, therefore only mediately and indirectly. Consequently they
will not possess that immediate evidence which is peculiar to the
former, although their application to experience does not, for that
reason, lose its truth and certitude. But of this point we shall be
better able to judge at the conclusion of this system of principles.

The table of the categories is naturally our guide to the table of
principles, because these are nothing else than rules for the objective
employment of the former. Accordingly, all principles of the pure
understanding are:

                                1 Axioms of Intuition

               2                                    3 Anticipations    
                                    Analogies of Perception            
                          of Experience 4 Postulates of Empirical
               Thought in general

These appellations I have chosen advisedly, in order that we might not
lose sight of the distinctions in respect of the evidence and the
employment of these principles. It will, however, soon appear that—a
fact which concerns both the evidence of these principles, and the a
priori determination of phenomena—according to the categories of
quantity and quality (if we attend merely to the form of these), the
principles of these categories are distinguishable from those of the
two others, in as much as the former are possessed of an intuitive, but
the latter of a merely discursive, though in both instances a complete,
certitude. I shall therefore call the former mathematical, and the
latter dynamical principles.* It must be observed, however, that by
these terms I mean just as little in the one case the principles of
mathematics as those of general (physical) dynamics in the other. I
have here in view merely the principles of the pure understanding, in
their application to the internal sense (without distinction of the
representations given therein), by means of which the sciences of
mathematics and dynamics become possible. Accordingly, I have named
these principles rather with reference to their application than their
content; and I shall now proceed to consider them in the order in which
they stand in the table.

[*Footnote: All combination (conjunctio) is either composition
(compositio) or connection (nexus). The former is the synthesis of a
manifold, the parts of which do not necessarily belong to each other.
For example, the two triangles into which a square is divided by a
diagonal, do not necessarily belong to each other, and of this kind is
the synthesis of the homogeneous in everything that can be
mathematically considered. This synthesis can be divided into those of
aggregation and coalition, the former of which is applied to extensive,
the latter to intensive quantities. The second sort of combination
(nexus) is the synthesis of a manifold, in so far as its parts do
belong necessarily to each other; for example, the accident to a
substance, or the effect to the cause. Consequently it is a synthesis
of that which though heterogeneous, is represented as connected a
priori. This combination—not an arbitrary one—I entitle dynamical
because it concerns the connection of the existence of the manifold.
This, again, may be divided into the physical synthesis, of the
phenomena divided among each other, and the metaphysical synthesis, or
the connection of phenomena a priori in the faculty of cognition.]


The principle of these is: All Intuitions are Extensive Quantities.


All phenomena contain, as regards their form, an intuition in space and
time, which lies a priori at the foundation of all without exception.
Phenomena, therefore, cannot be apprehended, that is, received into
empirical consciousness otherwise than through the synthesis of a
manifold, through which the representations of a determinate space or
time are generated; that is to say, through the composition of the
homogeneous and the consciousness of the synthetical unity of this
manifold (homogeneous). Now the consciousness of a homogeneous manifold
in intuition, in so far as thereby the representation of an object is
rendered possible, is the conception of a quantity (quanti).
Consequently, even the perception of an object as phenomenon is
possible only through the same synthetical unity of the manifold of the
given sensuous intuition, through which the unity of the composition of
the homogeneous manifold in the conception of a quantity is cogitated;
that is to say, all phenomena are quantities, and extensive quantities,
because as intuitions in space or time they must be represented by
means of the same synthesis through which space and time themselves are

An extensive quantity I call that wherein the representation of the
parts renders possible (and therefore necessarily antecedes) the
representation of the whole. I cannot represent to myself any line,
however small, without drawing it in thought, that is, without
generating from a point all its parts one after another, and in this
way alone producing this intuition. Precisely the same is the case with
every, even the smallest, portion of time. I cogitate therein only the
successive progress from one moment to another, and hence, by means of
the different portions of time and the addition of them, a determinate
quantity of time is produced. As the pure intuition in all phenomena is
either time or space, so is every phenomenon in its character of
intuition an extensive quantity, inasmuch as it can only be cognized in
our apprehension by successive synthesis (from part to part). All
phenomena are, accordingly, to be considered as aggregates, that is, as
a collection of previously given parts; which is not the case with
every sort of quantities, but only with those which are represented and
apprehended by us as extensive.

On this successive synthesis of the productive imagination, in the
generation of figures, is founded the mathematics of extension, or
geometry, with its axioms, which express the conditions of sensuous
intuition a priori, under which alone the schema of a pure conception
of external intuition can exist; for example, “be tween two points only
one straight line is possible,” “two straight lines cannot enclose a
space,” etc. These are the axioms which properly relate only to
quantities (quanta) as such.

But, as regards the quantity of a thing (quantitas), that is to say,
the answer to the question: “How large is this or that object?”
although, in respect to this question, we have various propositions
synthetical and immediately certain (indemonstrabilia); we have, in the
proper sense of the term, no axioms. For example, the propositions: “If
equals be added to equals, the wholes are equal”; “If equals be taken
from equals, the remainders are equal”; are analytical, because I am
immediately conscious of the identity of the production of the one
quantity with the production of the other; whereas axioms must be a
priori synthetical propositions. On the other hand, the self-evident
propositions as to the relation of numbers, are certainly synthetical
but not universal, like those of geometry, and for this reason cannot
be called axioms, but numerical formulae. That 7 + 5 = 12 is not an
analytical proposition. For neither in the representation of seven, nor
of five, nor of the composition of the two numbers, do I cogitate the
number twelve. (Whether I cogitate the number in the addition of both,
is not at present the question; for in the case of an analytical
proposition, the only point is whether I really cogitate the predicate
in the representation of the subject.) But although the proposition is
synthetical, it is nevertheless only a singular proposition. In so far
as regard is here had merely to the synthesis of the homogeneous (the
units), it cannot take place except in one manner, although our use of
these numbers is afterwards general. If I say: “A triangle can be
constructed with three lines, any two of which taken together are
greater than the third,” I exercise merely the pure function of the
productive imagination, which may draw the lines longer or shorter and
construct the angles at its pleasure. On the contrary, the number seven
is possible only in one manner, and so is likewise the number twelve,
which results from the synthesis of seven and five. Such propositions,
then, cannot be termed axioms (for in that case we should have an
infinity of these), but numerical formulae.

This transcendental principle of the mathematics of phenomena greatly
enlarges our a priori cognition. For it is by this principle alone that
pure mathematics is rendered applicable in all its precision to objects
of experience, and without it the validity of this application would
not be so self-evident; on the contrary, contradictions and confusions
have often arisen on this very point. Phenomena are not things in
themselves. Empirical intuition is possible only through pure intuition
(of space and time); consequently, what geometry affirms of the latter,
is indisputably valid of the former. All evasions, such as the
statement that objects of sense do not conform to the rules of
construction in space (for example, to the rule of the infinite
divisibility of lines or angles), must fall to the ground. For, if
these objections hold good, we deny to space, and with it to all
mathematics, objective validity, and no longer know wherefore, and how
far, mathematics can be applied to phenomena. The synthesis of spaces
and times as the essential form of all intuition, is that which renders
possible the apprehension of a phenomenon, and therefore every external
experience, consequently all cognition of the objects of experience;
and whatever mathematics in its pure use proves of the former, must
necessarily hold good of the latter. All objections are but the
chicaneries of an ill-instructed reason, which erroneously thinks to
liberate the objects of sense from the formal conditions of our
sensibility, and represents these, although mere phenomena, as things
in themselves, presented as such to our understanding. But in this
case, no a priori synthetical cognition of them could be possible,
consequently not through pure conceptions of space and the science
which determines these conceptions, that is to say, geometry, would
itself be impossible.


The principle of these is: In all phenomena the Real, that which is an
object of sensation, has Intensive Quantity, that is, has a Degree.


Perception is empirical consciousness, that is to say, a consciousness
which contains an element of sensation. Phenomena as objects of
perception are not pure, that is, merely formal intuitions, like space
and time, for they cannot be perceived in themselves.

[Footnote: They can be perceived only as phenomena, and some part of
them must always belong to the non-ego; whereas pure intuitions are
entirely the products of the mind itself, and as such are cognized IN

They contain, then, over and above the intuition, the materials for an
object (through which is represented something existing in space or
time), that is to say, they contain the real of sensation, as a
representation merely subjective, which gives us merely the
consciousness that the subject is affected, and which we refer to some
external object. Now, a gradual transition from empirical consciousness
to pure consciousness is possible, inasmuch as the real in this
consciousness entirely vanishes, and there remains a merely formal
consciousness (a priori) of the manifold in time and space;
consequently there is possible a synthesis also of the production of
the quantity of a sensation from its commencement, that is, from the
pure intuition = 0 onwards up to a certain quantity of the sensation.
Now as sensation in itself is not an objective representation, and in
it is to be found neither the intuition of space nor of time, it cannot
possess any extensive quantity, and yet there does belong to it a
quantity (and that by means of its apprehension, in which empirical
consciousness can within a certain time rise from nothing = 0 up to its
given amount), consequently an intensive quantity. And thus we must
ascribe intensive quantity, that is, a degree of influence on sense to
all objects of perception, in so far as this perception contains

All cognition, by means of which I am enabled to cognize and determine
a priori what belongs to empirical cognition, may be called an
anticipation; and without doubt this is the sense in which Epicurus
employed his expression prholepsis. But as there is in phenomena
something which is never cognized a priori, which on this account
constitutes the proper difference between pure and empirical cognition,
that is to say, sensation (as the matter of perception), it follows,
that sensation is just that element in cognition which cannot be at all
anticipated. On the other hand, we might very well term the pure
determinations in space and time, as well in regard to figure as to
quantity, anticipations of phenomena, because they represent a priori
that which may always be given a posteriori in experience. But suppose
that in every sensation, as sensation in general, without any
particular sensation being thought of, there existed something which
could be cognized a priori, this would deserve to be called
anticipation in a special sense—special, because it may seem surprising
to forestall experience, in that which concerns the matter of
experience, and which we can only derive from itself. Yet such really
is the case here.

Apprehension*, by means of sensation alone, fills only one moment, that
is, if I do not take into consideration a succession of many
sensations. As that in the phenomenon, the apprehension of which is not
a successive synthesis advancing from parts to an entire
representation, sensation has therefore no extensive quantity; the want
of sensation in a moment of time would represent it as empty,
consequently = 0. That which in the empirical intuition corresponds to
sensation is reality (realitas phaenomenon); that which corresponds to
the absence of it, negation = 0. Now every sensation is capable of a
diminution, so that it can decrease, and thus gradually disappear.
Therefore, between reality in a phenomenon and negation, there exists a
continuous concatenation of many possible intermediate sensations, the
difference of which from each other is always smaller than that between
the given sensation and zero, or complete negation. That is to say, the
real in a phenomenon has always a quantity, which however is not
discoverable in apprehension, inasmuch as apprehension take place by
means of mere sensation in one instant, and not by the successive
synthesis of many sensations, and therefore does not progress from
parts to the whole. Consequently, it has a quantity, but not an
extensive quantity.

[*Footnote: Apprehension is the Kantian word for preception, in the
largest sense in which we employ that term. It is the genus which
includes under i, as species, perception proper and sensation

Now that quantity which is apprehended only as unity, and in which
plurality can be represented only by approximation to negation = O, I
term intensive quantity. Consequently, reality in a phenomenon has
intensive quantity, that is, a degree. If we consider this reality as
cause (be it of sensation or of another reality in the phenomenon, for
example, a change), we call the degree of reality in its character of
cause a momentum, for example, the momentum of weight; and for this
reason, that the degree only indicates that quantity the apprehension
of which is not successive, but instantaneous. This, however, I touch
upon only in passing, for with causality I have at present nothing to

Accordingly, every sensation, consequently every reality in phenomena,
however small it may be, has a degree, that is, an intensive quantity,
which may always be lessened, and between reality and negation there
exists a continuous connection of possible realities, and possible
smaller perceptions. Every colour—for example, red—has a degree, which,
be it ever so small, is never the smallest, and so is it always with
heat, the momentum of weight, etc.

This property of quantities, according to which no part of them is the
smallest possible (no part simple), is called their continuity. Space
and time are quanta continua, because no part of them can be given,
without enclosing it within boundaries (points and moments),
consequently, this given part is itself a space or a time. Space,
therefore, consists only of spaces, and time of times. Points and
moments are only boundaries, that is, the mere places or positions of
their limitation. But places always presuppose intuitions which are to
limit or determine them; and we cannot conceive either space or time
composed of constituent parts which are given before space or time.
Such quantities may also be called flowing, because synthesis (of the
productive imagination) in the production of these quantities is a
progression in time, the continuity of which we are accustomed to
indicate by the expression flowing.

All phenomena, then, are continuous quantities, in respect both to
intuition and mere perception (sensation, and with it reality). In the
former case they are extensive quantities; in the latter, intensive.
When the synthesis of the manifold of a phenomenon is interrupted,
there results merely an aggregate of several phenomena, and not
properly a phenomenon as a quantity, which is not produced by the mere
continuation of the productive synthesis of a certain kind, but by the
repetition of a synthesis always ceasing. For example, if I call
thirteen dollars a sum or quantity of money, I employ the term quite
correctly, inasmuch as I understand by thirteen dollars the value of a
mark in standard silver, which is, to be sure, a continuous quantity,
in which no part is the smallest, but every part might constitute a
piece of money, which would contain material for still smaller pieces.
If, however, by the words thirteen dollars I understand so many coins
(be their value in silver what it may), it would be quite erroneous to
use the expression a quantity of dollars; on the contrary, I must call
them aggregate, that is, a number of coins. And as in every number we
must have unity as the foundation, so a phenomenon taken as unity is a
quantity, and as such always a continuous quantity (quantum continuum).

Now, seeing all phenomena, whether considered as extensive or
intensive, are continuous quantities, the proposition: “All change
(transition of a thing from one state into another) is continuous,”
might be proved here easily, and with mathematical evidence, were it
not that the causality of a change lies, entirely beyond the bounds of
a transcendental philosophy, and presupposes empirical principles. For
of the possibility of a cause which changes the condition of things,
that is, which determines them to the contrary to a certain given
state, the understanding gives us a priori no knowledge; not merely
because it has no insight into the possibility of it (for such insight
is absent in several a priori cognitions), but because the notion of
change concerns only certain determinations of phenomena, which
experience alone can acquaint us with, while their cause lies in the
unchangeable. But seeing that we have nothing which we could here
employ but the pure fundamental conceptions of all possible experience,
among which of course nothing empirical can be admitted, we dare not,
without injuring the unity of our system, anticipate general physical
science, which is built upon certain fundamental experiences.

Nevertheless, we are in no want of proofs of the great influence which
the principle above developed exercises in the anticipation of
perceptions, and even in supplying the want of them, so far as to
shield us against the false conclusions which otherwise we might rashly

If all reality in perception has a degree, between which and negation
there is an endless sequence of ever smaller degrees, and if,
nevertheless, every sense must have a determinate degree of receptivity
for sensations; no perception, and consequently no experience is
possible, which can prove, either immediately or mediately, an entire
absence of all reality in a phenomenon; in other words, it is
impossible ever to draw from experience a proof of the existence of
empty space or of empty time. For in the first place, an entire absence
of reality in a sensuous intuition cannot of course be an object of
perception; secondly, such absence cannot be deduced from the
contemplation of any single phenomenon, and the difference of the
degrees in its reality; nor ought it ever to be admitted in explanation
of any phenomenon. For if even the complete intuition of a determinate
space or time is thoroughly real, that is, if no part thereof is empty,
yet because every reality has its degree, which, with the extensive
quantity of the phenomenon unchanged, can diminish through endless
gradations down to nothing (the void), there must be infinitely
graduated degrees, with which space or time is filled, and the
intensive quantity in different phenomena may be smaller or greater,
although the extensive quantity of the intuition remains equal and

We shall give an example of this. Almost all natural philosophers,
remarking a great difference in the quantity of the matter of different
kinds in bodies with the same volume (partly on account of the momentum
of gravity or weight, partly on account of the momentum of resistance
to other bodies in motion), conclude unanimously that this volume
(extensive quantity of the phenomenon) must be void in all bodies,
although in different proportion. But who would suspect that these for
the most part mathematical and mechanical inquirers into nature should
ground this conclusion solely on a metaphysical hypothesis—a sort of
hypothesis which they profess to disparage and avoid? Yet this they do,
in assuming that the real in space (I must not here call it
impenetrability or weight, because these are empirical conceptions) is
always identical, and can only be distinguished according to its
extensive quantity, that is, multiplicity. Now to this presupposition,
for which they can have no ground in experience, and which consequently
is merely metaphysical, I oppose a transcendental demonstration, which
it is true will not explain the difference in the filling up of spaces,
but which nevertheless completely does away with the supposed necessity
of the above-mentioned presupposition that we cannot explain the said
difference otherwise than by the hypothesis of empty spaces. This
demonstration, moreover, has the merit of setting the understanding at
liberty to conceive this distinction in a different manner, if the
explanation of the fact requires any such hypothesis. For we perceive
that although two equal spaces may be completely filled by matters
altogether different, so that in neither of them is there left a single
point wherein matter is not present, nevertheless, every reality has
its degree (of resistance or of weight), which, without diminution of
the extensive quantity, can become less and less ad infinitum, before
it passes into nothingness and disappears. Thus an expansion which
fills a space—for example, caloric, or any other reality in the
phenomenal world—can decrease in its degrees to infinity, yet without
leaving the smallest part of the space empty; on the contrary, filling
it with those lesser degrees as completely as another phenomenon could
with greater. My intention here is by no means to maintain that this is
really the case with the difference of matters, in regard to their
specific gravity; I wish only to prove, from a principle of the pure
understanding, that the nature of our perceptions makes such a mode of
explanation possible, and that it is erroneous to regard the real in a
phenomenon as equal quoad its degree, and different only quoad its
aggregation and extensive quantity, and this, too, on the pretended
authority of an a priori principle of the understanding.

Nevertheless, this principle of the anticipation of perception must
somewhat startle an inquirer whom initiation into transcendental
philosophy has rendered cautious. We must naturally entertain some
doubt whether or not the understanding can enounce any such synthetical
proposition as that respecting the degree of all reality in phenomena,
and consequently the possibility of the internal difference of
sensation itself—abstraction being made of its empirical quality. Thus
it is a question not unworthy of solution: “How the understanding can
pronounce synthetically and a priori respecting phenomena, and thus
anticipate these, even in that which is peculiarly and merely
empirical, that, namely, which concerns sensation itself?”

The quality of sensation is in all cases merely empirical, and cannot
be represented a priori (for example, colours, taste, etc.). But the
real—that which corresponds to sensation—in opposition to negation = 0,
only represents something the conception of which in itself contains a
being (ein seyn), and signifies nothing but the synthesis in an
empirical consciousness. That is to say, the empirical consciousness in
the internal sense can be raised from 0 to every higher degree, so that
the very same extensive quantity of intuition, an illuminated surface,
for example, excites as great a sensation as an aggregate of many other
surfaces less illuminated. We can therefore make complete abstraction
of the extensive quantity of a phenomenon, and represent to ourselves
in the mere sensation in a certain momentum, a synthesis of homogeneous
ascension from 0 up to the given empirical consciousness, All
sensations therefore as such are given only a posteriori, but this
property thereof, namely, that they have a degree, can be known a
priori. It is worthy of remark, that in respect to quantities in
general, we can cognize a priori only a single quality, namely,
continuity; but in respect to all quality (the real in phenomena), we
cannot cognize a priori anything more than the intensive quantity
thereof, namely, that they have a degree. All else is left to


The principle of these is: Experience is possible only through the
representation of a necessary connection of Perceptions.


Experience is an empirical cognition; that is to say, a cognition which
determines an object by means of perceptions. It is therefore a
synthesis of perceptions, a synthesis which is not itself contained in
perception, but which contains the synthetical unity of the manifold of
perception in a consciousness; and this unity constitutes the essential
of our cognition of objects of the senses, that is, of experience (not
merely of intuition or sensation). Now in experience our perceptions
come together contingently, so that no character of necessity in their
connection appears, or can appear from the perceptions themselves,
because apprehension is only a placing together of the manifold of
empirical intuition, and no representation of a necessity in the
connected existence of the phenomena which apprehension brings
together, is to be discovered therein. But as experience is a cognition
of objects by means of perceptions, it follows that the relation of the
existence of the existence of the manifold must be represented in
experience not as it is put together in time, but as it is objectively
in time. And as time itself cannot be perceived, the determination of
the existence of objects in time can only take place by means of their
connection in time in general, consequently only by means of a priori
connecting conceptions. Now as these conceptions always possess the
character of necessity, experience is possible only by means of a
representation of the necessary connection of perception.

The three modi of time are permanence, succession, and coexistence.
Accordingly, there are three rules of all relations of time in
phenomena, according to which the existence of every phenomenon is
determined in respect of the unity of all time, and these antecede all
experience and render it possible.

The general principle of all three analogies rests on the necessary
unity of apperception in relation to all possible empirical
consciousness (perception) at every time, consequently, as this unity
lies a priori at the foundation of all mental operations, the principle
rests on the synthetical unity of all phenomena according to their
relation in time. For the original apperception relates to our internal
sense (the complex of all representations), and indeed relates a priori
to its form, that is to say, the relation of the manifold empirical
consciousness in time. Now this manifold must be combined in original
apperception according to relations of time—a necessity imposed by the
a priori transcendental unity of apperception, to which is subjected
all that can belong to my (i.e., my own) cognition, and therefore all
that can become an object for me. This synthetical and a priori
determined unity in relation of perceptions in time is therefore the
rule: “All empirical determinations of time must be subject to rules of
the general determination of time”; and the analogies of experience, of
which we are now about to treat, must be rules of this nature.

These principles have this peculiarity, that they do not concern
phenomena, and the synthesis of the empirical intuition thereof, but
merely the existence of phenomena and their relation to each other in
regard to this existence. Now the mode in which we apprehend a thing in
a phenomenon can be determined a priori in such a manner that the rule
of its synthesis can give, that is to say, can produce this a priori
intuition in every empirical example. But the existence of phenomena
cannot be known a priori, and although we could arrive by this path at
a conclusion of the fact of some existence, we could not cognize that
existence determinately, that is to say, we should be incapable of
anticipating in what respect the empirical intuition of it would be
distinguishable from that of others.

The two principles above mentioned, which I called mathematical, in
consideration of the fact of their authorizing the application of
mathematic phenomena, relate to these phenomena only in regard to their
possibility, and instruct us how phenomena, as far as regards their
intuition or the real in their perception, can be generated according
to the rules of a mathematical synthesis. Consequently, numerical
quantities, and with them the determination of a phenomenon as a
quantity, can be employed in the one case as well as in the other.
Thus, for example, out of 200,000 illuminations by the moon, I might
compose and give a priori, that is construct, the degree of our
sensations of the sun-light.* We may therefore entitle these two
principles constitutive.

[*Footnote: Kant’s meaning is: The two principles enunciated under the
heads of “Axioms of Intuition,” and “Anticipations of Perception,”
authorize the application to phenomena of determinations of size and
number, that is of mathematic. For example, I may compute the light of
the sun, and say that its quantity is a certain number of times greater
than that of the moon. In the same way, heat is measured by the
comparison of its different effects on water, &c., and on mercury in a

The case is very different with those principles whose province it is
to subject the existence of phenomena to rules a priori. For as
existence does not admit of being constructed, it is clear that they
must only concern the relations of existence and be merely regulative
principles. In this case, therefore, neither axioms nor anticipations
are to be thought of. Thus, if a perception is given us, in a certain
relation of time to other (although undetermined) perceptions, we
cannot then say a priori, what and how great (in quantity) the other
perception necessarily connected with the former is, but only how it is
connected, quoad its existence, in this given modus of time. Analogies
in philosophy mean something very different from that which they
represent in mathematics. In the latter they are formulae, which
enounce the equality of two relations of quantity, and are always
constitutive, so that if two terms of the proportion are given, the
third is also given, that is, can be constructed by the aid of these
formulae. But in philosophy, analogy is not the equality of two
quantitative but of two qualitative relations. In this case, from three
given terms, I can give a priori and cognize the relation to a fourth
member, but not this fourth term itself, although I certainly possess a
rule to guide me in the search for this fourth term in experience, and
a mark to assist me in discovering it. An analogy of experience is
therefore only a rule according to which unity of experience must arise
out of perceptions in respect to objects (phenomena) not as a
constitutive, but merely as a regulative principle. The same holds good
also of the postulates of empirical thought in general, which relate to
the synthesis of mere intuition (which concerns the form of phenomena),
the synthesis of perception (which concerns the matter of phenomena),
and the synthesis of experience (which concerns the relation of these
perceptions). For they are only regulative principles, and clearly
distinguishable from the mathematical, which are constitutive, not
indeed in regard to the certainty which both possess a priori, but in
the mode of evidence thereof, consequently also in the manner of

But what has been observed of all synthetical propositions, and must be
particularly remarked in this place, is this, that these analogies
possess significance and validity, not as principles of the
transcendental, but only as principles of the empirical use of the
understanding, and their truth can therefore be proved only as such,
and that consequently the phenomena must not be subjoined directly
under the categories, but only under their schemata. For if the objects
to which those principles must be applied were things in themselves, it
would be quite impossible to cognize aught concerning them
synthetically a priori. But they are nothing but phenomena; a complete
knowledge of which—a knowledge to which all principles a priori must at
last relate—is the only possible experience. It follows that these
principles can have nothing else for their aim than the conditions of
the empirical cognition in the unity of synthesis of phenomena. But
this synthesis is cogitated only in the schema of the pure conception
of the understanding, of whose unity, as that of a synthesis in
general, the category contains the function unrestricted by any
sensuous condition. These principles will therefore authorize us to
connect phenomena according to an analogy, with the logical and
universal unity of conceptions, and consequently to employ the
categories in the principles themselves; but in the application of them
to experience, we shall use only their schemata, as the key to their
proper application, instead of the categories, or rather the latter as
restricting conditions, under the title of “formulae” of the former.


Principle of the Permanence of Substance.

In all changes of phenomena, substance is permanent, and the quantum
thereof in nature is neither increased nor diminished.


All phenomena exist in time, wherein alone as substratum, that is, as
the permanent form of the internal intuition, coexistence and
succession can be represented. Consequently time, in which all changes
of phenomena must be cogitated, remains and changes not, because it is
that in which succession and coexistence can be represented only as
determinations thereof. Now, time in itself cannot be an object of
perception. It follows that in objects of perception, that is, in
phenomena, there must be found a substratum which represents time in
general, and in which all change or coexistence can be perceived by
means of the relation of phenomena to it. But the substratum of all
reality, that is, of all that pertains to the existence of things, is
substance; all that pertains to existence can be cogitated only as a
determination of substance. Consequently, the permanent, in relation to
which alone can all relations of time in phenomena be determined, is
substance in the world of phenomena, that is, the real in phenomena,
that which, as the substratum of all change, remains ever the same.
Accordingly, as this cannot change in existence, its quantity in nature
can neither be increased nor diminished.

Our apprehension of the manifold in a phenomenon is always successive,
is Consequently always changing. By it alone we could, therefore, never
determine whether this manifold, as an object of experience, is
coexistent or successive, unless it had for a foundation something
fixed and permanent, of the existence of which all succession and
coexistence are nothing but so many modes (modi of time). Only in the
permanent, then, are relations of time possible (for simultaneity and
succession are the only relations in time); that is to say, the
permanent is the substratum of our empirical representation of time
itself, in which alone all determination of time is possible.
Permanence is, in fact, just another expression for time, as the
abiding correlate of all existence of phenomena, and of all change, and
of all coexistence. For change does not affect time itself, but only
the phenomena in time (just as coexistence cannot be regarded as a
modus of time itself, seeing that in time no parts are coexistent, but
all successive). If we were to attribute succession to time itself, we
should be obliged to cogitate another time, in which this succession
would be possible. It is only by means of the permanent that existence
in different parts of the successive series of time receives a
quantity, which we entitle duration. For in mere succession, existence
is perpetually vanishing and recommencing, and therefore never has even
the least quantity. Without the permanent, then, no relation in time is
possible. Now, time in itself is not an object of perception;
consequently the permanent in phenomena must be regarded as the
substratum of all determination of time, and consequently also as the
condition of the possibility of all synthetical unity of perceptions,
that is, of experience; and all existence and all change in time can
only be regarded as a mode in the existence of that which abides
unchangeably. Therefore, in all phenomena, the permanent is the object
in itself, that is, the substance (phenomenon); but all that changes or
can change belongs only to the mode of the existence of this substance
or substances, consequently to its determinations.

I find that in all ages not only the philosopher, but even the common
understanding, has preposited this permanence as a substratum of all
change in phenomena; indeed, I am compelled to believe that they will
always accept this as an indubitable fact. Only the philosopher
expresses himself in a more precise and definite manner, when he says:
“In all changes in the world, the substance remains, and the accidents
alone are changeable.” But of this decidedly synthetical proposition, I
nowhere meet with even an attempt at proof; nay, it very rarely has the
good fortune to stand, as it deserves to do, at the head of the pure
and entirely a priori laws of nature. In truth, the statement that
substance is permanent, is tautological. For this very permanence is
the ground on which we apply the category of substance to the
phenomenon; and we should have been obliged to prove that in all
phenomena there is something permanent, of the existence of which the
changeable is nothing but a determination. But because a proof of this
nature cannot be dogmatical, that is, cannot be drawn from conceptions,
inasmuch as it concerns a synthetical proposition a priori, and as
philosophers never reflected that such propositions are valid only in
relation to possible experience, and therefore cannot be proved except
by means of a deduction of the possibility of experience, it is no
wonder that while it has served as the foundation of all experience
(for we feel the need of it in empirical cognition), it has never been
supported by proof.

A philosopher was asked: “What is the weight of smoke?” He answered:
“Subtract from the weight of the burnt wood the weight of the remaining
ashes, and you will have the weight of the smoke.” Thus he presumed it
to be incontrovertible that even in fire the matter (substance) does
not perish, but that only the form of it undergoes a change. In like
manner was the saying: “From nothing comes nothing,” only another
inference from the principle or permanence, or rather of the
ever-abiding existence of the true subject in phenomena. For if that in
the phenomenon which we call substance is to be the proper substratum
of all determination of time, it follows that all existence in past as
well as in future time, must be determinable by means of it alone.
Hence we are entitled to apply the term substance to a phenomenon, only
because we suppose its existence in all time, a notion which the word
permanence does not fully express, as it seems rather to be referable
to future time. However, the internal necessity perpetually to be, is
inseparably connected with the necessity always to have been, and so
the expression may stand as it is. “Gigni de nihilo nihil; in nihilum
nil posse reverti,”* are two propositions which the ancients never
parted, and which people nowadays sometimes mistakenly disjoin, because
they imagine that the propositions apply to objects as things in
themselves, and that the former might be inimical to the dependence
(even in respect of its substance also) of the world upon a supreme
cause. But this apprehension is entirely needless, for the question in
this case is only of phenomena in the sphere of experience, the unity
of which never could be possible, if we admitted the possibility that
new things (in respect of their substance) should arise. For in that
case, we should lose altogether that which alone can represent the
unity of time, to wit, the identity of the substratum, as that through
which alone all change possesses complete and thorough unity. This
permanence is, however, nothing but the manner in which we represent to
ourselves the existence of things in the phenomenal world.

[*Footnote: Persius, Satirae, iii.83-84.]

The determinations of a substance, which are only particular modes of
its existence, are called accidents. They are always real, because they
concern the existence of substance (negations are only determinations,
which express the non-existence of something in the substance). Now, if
to this real in the substance we ascribe a particular existence (for
example, to motion as an accident of matter), this existence is called
inherence, in contradistinction to the existence of substance, which we
call subsistence. But hence arise many misconceptions, and it would be
a more accurate and just mode of expression to designate the accident
only as the mode in which the existence of a substance is positively
determined. Meanwhile, by reason of the conditions of the logical
exercise of our understanding, it is impossible to avoid separating, as
it were, that which in the existence of a substance is subject to
change, whilst the substance remains, and regarding it in relation to
that which is properly permanent and radical. On this account, this
category of substance stands under the title of relation, rather
because it is the condition thereof than because it contains in itself
any relation.

Now, upon this notion of permanence rests the proper notion of the
conception change. Origin and extinction are not changes of that which
originates or becomes extinct. Change is but a mode of existence, which
follows on another mode of existence of the same object; hence all that
changes is permanent, and only the condition thereof changes. Now since
this mutation affects only determinations, which can have a beginning
or an end, we may say, employing an expression which seems somewhat
paradoxical: “Only the permanent (substance) is subject to change; the
mutable suffers no change, but rather alternation, that is, when
certain determinations cease, others begin.”

Change, when, cannot be perceived by us except in substances, and
origin or extinction in an absolute sense, that does not concern merely
a determination of the permanent, cannot be a possible perception, for
it is this very notion of the permanent which renders possible the
representation of a transition from one state into another, and from
non-being to being, which, consequently, can be empirically cognized
only as alternating determinations of that which is permanent. Grant
that a thing absolutely begins to be; we must then have a point of time
in which it was not. But how and by what can we fix and determine this
point of time, unless by that which already exists? For a void
time—preceding—is not an object of perception; but if we connect this
beginning with objects which existed previously, and which continue to
exist till the object in question in question begins to be, then the
latter can only be a determination of the former as the permanent. The
same holds good of the notion of extinction, for this presupposes the
empirical representation of a time, in which a phenomenon no longer

Substances (in the world of phenomena) are the substratum of all
determinations of time. The beginning of some, and the ceasing to be of
other substances, would utterly do away with the only condition of the
empirical unity of time; and in that case phenomena would relate to two
different times, in which, side by side, existence would pass; which is
absurd. For there is only one time in which all different times must be
placed, not as coexistent, but as successive.

Accordingly, permanence is a necessary condition under which alone
phenomena, as things or objects, are determinable in a possible
experience. But as regards the empirical criterion of this necessary
permanence, and with it of the substantiality of phenomena, we shall
find sufficient opportunity to speak in the sequel.


Principle of the Succession of Time According to the Law of Causality.
All changes take place according to the law of the connection of Cause
and Effect.


(That all phenomena in the succession of time are only changes, that
is, a successive being and non-being of the determinations of
substance, which is permanent; consequently that a being of substance
itself which follows on the non-being thereof, or a non-being of
substance which follows on the being thereof, in other words, that the
origin or extinction of substance itself, is impossible—all this has
been fully established in treating of the foregoing principle. This
principle might have been expressed as follows: “All alteration
(succession) of phenomena is merely change”; for the changes of
substance are not origin or extinction, because the conception of
change presupposes the same subject as existing with two opposite
determinations, and consequently as permanent. After this premonition,
we shall proceed to the proof.)

I perceive that phenomena succeed one another, that is to say, a state
of things exists at one time, the opposite of which existed in a former
state. In this case, then, I really connect together two perceptions in
time. Now connection is not an operation of mere sense and intuition,
but is the product of a synthetical faculty of imagination, which
determines the internal sense in respect of a relation of time. But
imagination can connect these two states in two ways, so that either
the one or the other may antecede in time; for time in itself cannot be
an object of perception, and what in an object precedes and what
follows cannot be empirically determined in relation to it. I am only
conscious, then, that my imagination places one state before and the
other after; not that the one state antecedes the other in the object.
In other words, the objective relation of the successive phenomena
remains quite undetermined by means of mere perception. Now in order
that this relation may be cognized as determined, the relation between
the two states must be so cogitated that it is thereby determined as
necessary, which of them must be placed before and which after, and not
conversely. But the conception which carries with it a necessity of
synthetical unity, can be none other than a pure conception of the
understanding which does not lie in mere perception; and in this case
it is the conception of “the relation of cause and effect,” the former
of which determines the latter in time, as its necessary consequence,
and not as something which might possibly antecede (or which might in
some cases not be perceived to follow). It follows that it is only
because we subject the sequence of phenomena, and consequently all
change, to the law of causality, that experience itself, that is,
empirical cognition of phenomena, becomes possible; and consequently,
that phenomena themselves, as objects of experience, are possible only
by virtue of this law.

Our apprehension of the manifold of phenomena is always successive. The
representations of parts succeed one another. Whether they succeed one
another in the object also, is a second point for reflection, which was
not contained in the former. Now we may certainly give the name of
object to everything, even to every representation, so far as we are
conscious thereof; but what this word may mean in the case of
phenomena, not merely in so far as they (as representations) are
objects, but only in so far as they indicate an object, is a question
requiring deeper consideration. In so far as they, regarded merely as
representations, are at the same time objects of consciousness, they
are not to be distinguished from apprehension, that is, reception into
the synthesis of imagination, and we must therefore say: “The manifold
of phenomena is always produced successively in the mind.” If phenomena
were things in themselves, no man would be able to conjecture from the
succession of our representations how this manifold is connected in the
object; for we have to do only with our representations. How things may
be in themselves, without regard to the representations through which
they affect us, is utterly beyond the sphere of our cognition. Now
although phenomena are not things in themselves, and are nevertheless
the only thing given to us to be cognized, it is my duty to show what
sort of connection in time belongs to the manifold in phenomena
themselves, while the representation of this manifold in apprehension
is always successive. For example, the apprehension of the manifold in
the phenomenon of a house which stands before me, is successive. Now
comes the question whether the manifold of this house is in itself
successive—which no one will be at all willing to grant. But, so soon
as I raise my conception of an object to the transcendental
signification thereof, I find that the house is not a thing in itself,
but only a phenomenon, that is, a representation, the transcendental
object of which remains utterly unknown. What then am I to understand
by the question: “How can the manifold be connected in the phenomenon
itself—not considered as a thing in itself, but merely as a
phenomenon?” Here that which lies in my successive apprehension is
regarded as representation, whilst the phenomenon which is given me,
notwithstanding that it is nothing more than a complex of these
representations, is regarded as the object thereof, with which my
conception, drawn from the representations of apprehension, must
harmonize. It is very soon seen that, as accordance of the cognition
with its object constitutes truth, the question now before us can only
relate to the formal conditions of empirical truth; and that the
phenomenon, in opposition to the representations of apprehension, can
only be distinguished therefrom as the object of them, if it is subject
to a rule which distinguishes it from every other apprehension, and
which renders necessary a mode of connection of the manifold. That in
the phenomenon which contains the condition of this necessary rule of
apprehension, is the object.

Let us now proceed to our task. That something happens, that is to say,
that something or some state exists which before was not, cannot be
empirically perceived, unless a phenomenon precedes, which does not
contain in itself this state. For a reality which should follow upon a
void time, in other words, a beginning, which no state of things
precedes, can just as little be apprehended as the void time itself.
Every apprehension of an event is therefore a perception which follows
upon another perception. But as this is the case with all synthesis of
apprehension, as I have shown above in the example of a house, my
apprehension of an event is not yet sufficiently distinguished from
other apprehensions. But I remark also that if in a phenomenon which
contains an occurrence, I call the antecedent state of my perception,
A, and the following state, B, the perception B can only follow A in
apprehension, and the perception A cannot follow B, but only precede
it. For example, I see a ship float down the stream of a river. My
perception of its place lower down follows upon my perception of its
place higher up the course of the river, and it is impossible that, in
the apprehension of this phenomenon, the vessel should be perceived
first below and afterwards higher up the stream. Here, therefore, the
order in the sequence of perceptions in apprehension is determined; and
by this order apprehension is regulated. In the former example, my
perceptions in the apprehension of a house might begin at the roof and
end at the foundation, or vice versa; or I might apprehend the manifold
in this empirical intuition, by going from left to right, and from
right to left. Accordingly, in the series of these perceptions, there
was no determined order, which necessitated my beginning at a certain
point, in order empirically to connect the manifold. But this rule is
always to be met with in the perception of that which happens, and it
makes the order of the successive perceptions in the apprehension of
such a phenomenon necessary.

I must, therefore, in the present case, deduce the subjective sequence
of apprehension from the objective sequence of phenomena, for otherwise
the former is quite undetermined, and one phenomenon is not
distinguishable from another. The former alone proves nothing as to the
connection of the manifold in an object, for it is quite arbitrary. The
latter must consist in the order of the manifold in a phenomenon,
according to which order the apprehension of one thing (that which
happens) follows that of another thing (which precedes), in conformity
with a rule. In this way alone can I be authorized to say of the
phenomenon itself, and not merely of my own apprehension, that a
certain order or sequence is to be found therein. That is, in other
words, I cannot arrange my apprehension otherwise than in this order.

In conformity with this rule, then, it is necessary that in that which
antecedes an event there be found the condition of a rule, according to
which in this event follows always and necessarily; but I cannot
reverse this and go back from the event, and determine (by
apprehension) that which antecedes it. For no phenomenon goes back from
the succeeding point of time to the preceding point, although it does
certainly relate to a preceding point of time; from a given time, on
the other hand, there is always a necessary progression to the
determined succeeding time. Therefore, because there certainly is
something that follows, I must of necessity connect it with something
else, which antecedes, and upon which it follows, in conformity with a
rule, that is necessarily, so that the event, as conditioned, affords
certain indication of a condition, and this condition determines the

Let us suppose that nothing precedes an event, upon which this event
must follow in conformity with a rule. All sequence of perception would
then exist only in apprehension, that is to say, would be merely
subjective, and it could not thereby be objectively determined what
thing ought to precede, and what ought to follow in perception. In such
a case, we should have nothing but a play of representations, which
would possess no application to any object. That is to say, it would
not be possible through perception to distinguish one phenomenon from
another, as regards relations of time; because the succession in the
act of apprehension would always be of the same sort, and therefore
there would be nothing in the phenomenon to determine the succession,
and to render a certain sequence objectively necessary. And, in this
case, I cannot say that two states in a phenomenon follow one upon the
other, but only that one apprehension follows upon another. But this is
merely subjective, and does not determine an object, and consequently
cannot be held to be cognition of an object—not even in the phenomenal

Accordingly, when we know in experience that something happens, we
always presuppose that something precedes, whereupon it follows in
conformity with a rule. For otherwise I could not say of the object
that it follows; because the mere succession in my apprehension, if it
be not determined by a rule in relation to something preceding, does
not authorize succession in the object. Only, therefore, in reference
to a rule, according to which phenomena are determined in their
sequence, that is, as they happen, by the preceding state, can I make
my subjective synthesis (of apprehension) objective, and it is only
under this presupposition that even the experience of an event is

No doubt it appears as if this were in thorough contradiction to all
the notions which people have hitherto entertained in regard to the
procedure of the human understanding. According to these opinions, it
is by means of the perception and comparison of similar consequences
following upon certain antecedent phenomena that the understanding is
led to the discovery of a rule, according to which certain events
always follow certain phenomena, and it is only by this process that we
attain to the conception of cause. Upon such a basis, it is clear that
this conception must be merely empirical, and the rule which it
furnishes us with—“Everything that happens must have a cause”—would be
just as contingent as experience itself. The universality and necessity
of the rule or law would be perfectly spurious attributes of it.
Indeed, it could not possess universal validity, inasmuch as it would
not in this case be a priori, but founded on deduction. But the same is
the case with this law as with other pure a priori representations
(e.g., space and time), which we can draw in perfect clearness and
completeness from experience, only because we had already placed them
therein, and by that means, and by that alone, had rendered experience
possible. Indeed, the logical clearness of this representation of a
rule, determining the series of events, is possible only when we have
made use thereof in experience. Nevertheless, the recognition of this
rule, as a condition of the synthetical unity of phenomena in time, was
the ground of experience itself and consequently preceded it a priori.

It is now our duty to show by an example that we never, even in
experience, attribute to an object the notion of succession or effect
(of an event—that is, the happening of something that did not exist
before), and distinguish it from the subjective succession of
apprehension, unless when a rule lies at the foundation, which compels
us to observe this order of perception in preference to any other, and
that, indeed, it is this necessity which first renders possible the
representation of a succession in the object.

We have representations within us, of which also we can be conscious.
But, however widely extended, however accurate and thoroughgoing this
consciousness may be, these representations are still nothing more than
representations, that is, internal determinations of the mind in this
or that relation of time. Now how happens it that to these
representations we should set an object, or that, in addition to their
subjective reality, as modifications, we should still further attribute
to them a certain unknown objective reality? It is clear that objective
significancy cannot consist in a relation to another representation (of
that which we desire to term object), for in that case the question
again arises: “How does this other representation go out of itself, and
obtain objective significancy over and above the subjective, which is
proper to it, as a determination of a state of mind?” If we try to
discover what sort of new property the relation to an object gives to
our subjective representations, and what new importance they thereby
receive, we shall find that this relation has no other effect than that
of rendering necessary the connection of our representations in a
certain manner, and of subjecting them to a rule; and that conversely,
it is only because a certain order is necessary in the relations of
time of our representations, that objective significancy is ascribed to

In the synthesis of phenomena, the manifold of our representations is
always successive. Now hereby is not represented an object, for by
means of this succession, which is common to all apprehension, no one
thing is distinguished from another. But so soon as I perceive or
assume that in this succession there is a relation to a state
antecedent, from which the representation follows in accordance with a
rule, so soon do I represent something as an event, or as a thing that
happens; in other words, I cognize an object to which I must assign a
certain determinate position in time, which cannot be altered, because
of the preceding state in the object. When, therefore, I perceive that
something happens, there is contained in this representation, in the
first place, the fact, that something antecedes; because, it is only in
relation to this that the phenomenon obtains its proper relation of
time, in other words, exists after an antecedent time, in which it did
not exist. But it can receive its determined place in time only by the
presupposition that something existed in the foregoing state, upon
which it follows inevitably and always, that is, in conformity with a
rule. From all this it is evident that, in the first place, I cannot
reverse the order of succession, and make that which happens precede
that upon which it follows; and that, in the second place, if the
antecedent state be posited, a certain determinate event inevitably and
necessarily follows. Hence it follows that there exists a certain order
in our representations, whereby the present gives a sure indication of
some previously existing state, as a correlate, though still
undetermined, of the existing event which is given—a correlate which
itself relates to the event as its consequence, conditions it, and
connects it necessarily with itself in the series of time.

If then it be admitted as a necessary law of sensibility, and
consequently a formal condition of all perception, that the preceding
necessarily determines the succeeding time (inasmuch as I cannot arrive
at the succeeding except through the preceding), it must likewise be an
indispensable law of empirical representation of the series of time
that the phenomena of the past determine all phenomena in the
succeeding time, and that the latter, as events, cannot take place,
except in so far as the former determine their existence in time, that
is to say, establish it according to a rule. For it is of course only
in phenomena that we can empirically cognize this continuity in the
connection of times.

For all experience and for the possibility of experience, understanding
is indispensable, and the first step which it takes in this sphere is
not to render the representation of objects clear, but to render the
representation of an object in general, possible. It does this by
applying the order of time to phenomena, and their existence. In other
words, it assigns to each phenomenon, as a consequence, a place in
relation to preceding phenomena, determined a priori in time, without
which it could not harmonize with time itself, which determines a place
a priori to all its parts. This determination of place cannot be
derived from the relation of phenomena to absolute time (for it is not
an object of perception); but, on the contrary, phenomena must
reciprocally determine the places in time of one another, and render
these necessary in the order of time. In other words, whatever follows
or happens, must follow in conformity with a universal rule upon that
which was contained in the foregoing state. Hence arises a series of
phenomena, which, by means of the understanding, produces and renders
necessary exactly the same order and continuous connection in the
series of our possible perceptions, as is found a priori in the form of
internal intuition (time), in which all our perceptions must have

That something happens, then, is a perception which belongs to a
possible experience, which becomes real only because I look upon the
phenomenon as determined in regard to its place in time, consequently
as an object, which can always be found by means of a rule in the
connected series of my perceptions. But this rule of the determination
of a thing according to succession in time is as follows: “In what
precedes may be found the condition, under which an event always (that
is, necessarily) follows.” From all this it is obvious that the
principle of cause and effect is the principle of possible experience,
that is, of objective cognition of phenomena, in regard to their
relations in the succession of time.

The proof of this fundamental proposition rests entirely on the
following momenta of argument. To all empirical cognition belongs the
synthesis of the manifold by the imagination, a synthesis which is
always successive, that is, in which the representations therein always
follow one another. But the order of succession in imagination is not
determined, and the series of successive representations may be taken
retrogressively as well as progressively. But if this synthesis is a
synthesis of apprehension (of the manifold of a given phenomenon), then
the order is determined in the object, or to speak more accurately,
there is therein an order of successive synthesis which determines an
object, and according to which something necessarily precedes, and when
this is posited, something else necessarily follows. If, then, my
perception is to contain the cognition of an event, that is, of
something which really happens, it must be an empirical judgement,
wherein we think that the succession is determined; that is, it
presupposes another phenomenon, upon which this event follows
necessarily, or in conformity with a rule. If, on the contrary, when I
posited the antecedent, the event did not necessarily follow, I should
be obliged to consider it merely as a subjective play of my
imagination, and if in this I represented to myself anything as
objective, I must look upon it as a mere dream. Thus, the relation of
phenomena (as possible perceptions), according to which that which
happens is, as to its existence, necessarily determined in time by
something which antecedes, in conformity with a rule—in other words,
the relation of cause and effect—is the condition of the objective
validity of our empirical judgements in regard to the sequence of
perceptions, consequently of their empirical truth, and therefore of
experience. The principle of the relation of causality in the
succession of phenomena is therefore valid for all objects of
experience, because it is itself the ground of the possibility of

Here, however, a difficulty arises, which must be resolved. The
principle of the connection of causality among phenomena is limited in
our formula to the succession thereof, although in practice we find
that the principle applies also when the phenomena exist together in
the same time, and that cause and effect may be simultaneous. For
example, there is heat in a room, which does not exist in the open air.
I look about for the cause, and find it to be the fire, Now the fire as
the cause is simultaneous with its effect, the heat of the room. In
this case, then, there is no succession as regards time, between cause
and effect, but they are simultaneous; and still the law holds good.
The greater part of operating causes in nature are simultaneous with
their effects, and the succession in time of the latter is produced
only because the cause cannot achieve the total of its effect in one
moment. But at the moment when the effect first arises, it is always
simultaneous with the causality of its cause, because, if the cause had
but a moment before ceased to be, the effect could not have arisen.
Here it must be specially remembered that we must consider the order of
time and not the lapse thereof. The relation remains, even though no
time has elapsed. The time between the causality of the cause and its
immediate effect may entirely vanish, and the cause and effect be thus
simultaneous, but the relation of the one to the other remains always
determinable according to time. If, for example, I consider a leaden
ball, which lies upon a cushion and makes a hollow in it, as a cause,
then it is simultaneous with the effect. But I distinguish the two
through the relation of time of the dynamical connection of both. For
if I lay the ball upon the cushion, then the hollow follows upon the
before smooth surface; but supposing the cushion has, from some cause
or another, a hollow, there does not thereupon follow a leaden ball.

Thus, the law of succession of time is in all instances the only
empirical criterion of effect in relation to the causality of the
antecedent cause. The glass is the cause of the rising of the water
above its horizontal surface, although the two phenomena are
contemporaneous. For, as soon as I draw some water with the glass from
a larger vessel, an effect follows thereupon, namely, the change of the
horizontal state which the water had in the large vessel into a
concave, which it assumes in the glass.

This conception of causality leads us to the conception of action; that
of action, to the conception of force; and through it, to the
conception of substance. As I do not wish this critical essay, the sole
purpose of which is to treat of the sources of our synthetical
cognition a priori, to be crowded with analyses which merely explain,
but do not enlarge the sphere of our conceptions, I reserve the
detailed explanation of the above conceptions for a future system of
pure reason. Such an analysis, indeed, executed with great
particularity, may already be found in well-known works on this
subject. But I cannot at present refrain from making a few remarks on
the empirical criterion of a substance, in so far as it seems to be
more evident and more easily recognized through the conception of
action than through that of the permanence of a phenomenon.

Where action (consequently activity and force) exists, substance also
must exist, and in it alone must be sought the seat of that fruitful
source of phenomena. Very well. But if we are called upon to explain
what we mean by substance, and wish to avoid the vice of reasoning in a
circle, the answer is by no means so easy. How shall we conclude
immediately from the action to the permanence of that which acts, this
being nevertheless an essential and peculiar criterion of substance
(phenomenon)? But after what has been said above, the solution of this
question becomes easy enough, although by the common mode of
procedure—merely analysing our conceptions—it would be quite
impossible. The conception of action indicates the relation of the
subject of causality to the effect. Now because all effect consists in
that which happens, therefore in the changeable, the last subject
thereof is the permanent, as the substratum of all that changes, that
is, substance. For according to the principle of causality, actions are
always the first ground of all change in phenomena and, consequently,
cannot be a property of a subject which itself changes, because if this
were the case, other actions and another subject would be necessary to
determine this change. From all this it results that action alone, as
an empirical criterion, is a sufficient proof of the presence of
substantiality, without any necessity on my part of endeavouring to
discover the permanence of substance by a comparison. Besides, by this
mode of induction we could not attain to the completeness which the
magnitude and strict universality of the conception requires. For that
the primary subject of the causality of all arising and passing away,
all origin and extinction, cannot itself (in the sphere of phenomena)
arise and pass away, is a sound and safe conclusion, a conclusion which
leads us to the conception of empirical necessity and permanence in
existence, and consequently to the conception of a substance as

When something happens, the mere fact of the occurrence, without regard
to that which occurs, is an object requiring investigation. The
transition from the non-being of a state into the existence of it,
supposing that this state contains no quality which previously existed
in the phenomenon, is a fact of itself demanding inquiry. Such an
event, as has been shown in No. A, does not concern substance (for
substance does not thus originate), but its condition or state. It is
therefore only change, and not origin from nothing. If this origin be
regarded as the effect of a foreign cause, it is termed creation, which
cannot be admitted as an event among phenomena, because the very
possibility of it would annihilate the unity of experience. If,
however, I regard all things not as phenomena, but as things in
themselves and objects of understanding alone, they, although
substances, may be considered as dependent, in respect of their
existence, on a foreign cause. But this would require a very different
meaning in the words, a meaning which could not apply to phenomena as
objects of possible experience.

How a thing can be changed, how it is possible that upon one state
existing in one point of time, an opposite state should follow in
another point of time—of this we have not the smallest conception a
priori. There is requisite for this the knowledge of real powers, which
can only be given empirically; for example, knowledge of moving forces,
or, in other words, of certain successive phenomena (as movements)
which indicate the presence of such forces. But the form of every
change, the condition under which alone it can take place as the coming
into existence of another state (be the content of the change, that is,
the state which is changed, what it may), and consequently the
succession of the states themselves can very well be considered a
priori, in relation to the law of causality and the conditions of

[*Footnote: It must be remarked that I do not speak of the change of
certain relations, but of the change of the state. Thus, when a body
moves in a uniform manner, it does not change its state (of motion);
but only when all motion increases or decreases.]

When a substance passes from one state, a, into another state, b, the
point of time in which the latter exists is different from, and
subsequent to that in which the former existed. In like manner, the
second state, as reality (in the phenomenon), differs from the first,
in which the reality of the second did not exist, as b from zero. That
is to say, if the state, b, differs from the state, a, only in respect
to quantity, the change is a coming into existence of b -a, which in
the former state did not exist, and in relation to which that state is
= O.

Now the question arises how a thing passes from one state = a, into
another state = b. Between two moments there is always a certain time,
and between two states existing in these moments there is always a
difference having a certain quantity (for all parts of phenomena are in
their turn quantities). Consequently, every transition from one state
into another is always effected in a time contained between two
moments, of which the first determines the state which leaves, and the
second determines the state into the thing passes. The thing leaves,
and the second determines the state into which the thing Both moments,
then, are limitations of the time of a change, consequently of the
intermediate state between both, and as such they belong to the total
of the change. Now every change has a cause, which evidences its
causality in the whole time during which the charge takes place. The
cause, therefore, does not produce the change all at once or in one
moment, but in a time, so that, as the time gradually increases from
the commencing instant, a, to its completion at b, in like manner also,
the quantity of the reality (b - a) is generated through the lesser
degrees which are contained between the first and last. All change is
therefore possible only through a continuous action of the causality,
which, in so far as it is uniform, we call a momentum. The change does
not consist of these momenta, but is generated or produced by them as
their effect.

Such is the law of the continuity of all change, the ground of which is
that neither time itself nor any phenomenon in time consists of parts
which are the smallest possible, but that, notwithstanding, the state
of a thing passes in the process of a change through all these parts,
as elements, to its second state. There is no smallest degree of
reality in a phenomenon, just as there is no smallest degree in the
quantity of time; and so the new state of reality grows up out of the
former state, through all the infinite degrees thereof, the differences
of which one from another, taken all together, are less than the
difference between o and a.

It is not our business to inquire here into the utility of this
principle in the investigation of nature. But how such a proposition,
which appears so greatly to extend our knowledge of nature, is possible
completely a priori, is indeed a question which deserves investigation,
although the first view seems to demonstrate the truth and reality of
the principle, and the question, how it is possible, may be considered
superfluous. For there are so many groundless pretensions to the
enlargement of our knowledge by pure reason that we must take it as a
general rule to be mistrustful of all such, and without a thoroughgoing
and radical deduction, to believe nothing of the sort even on the
clearest dogmatical evidence.

Every addition to our empirical knowledge, and every advance made in
the exercise of our perception, is nothing more than an extension of
the determination of the internal sense, that is to say, a progression
in time, be objects themselves what they may, phenomena, or pure
intuitions. This progression in time determines everything, and is
itself determined by nothing else. That is to say, the parts of the
progression exist only in time, and by means of the synthesis thereof,
and are not given antecedently to it. For this reason, every transition
in perception to anything which follows upon another in time, is a
determination of time by means of the production of this perception.
And as this determination of time is, always and in all its parts, a
quantity, the perception produced is to be considered as a quantity
which proceeds through all its degrees—no one of which is the smallest
possible—from zero up to its determined degree. From this we perceive
the possibility of cognizing a priori a law of changes—a law, however,
which concerns their form merely. We merely anticipate our own
apprehension, the formal condition of which, inasmuch as it is itself
to be found in the mind antecedently to all given phenomena, must
certainly be capable of being cognized a priori.

Thus, as time contains the sensuous condition a priori of the
possibility of a continuous progression of that which exists to that
which follows it, the understanding, by virtue of the unity of
apperception, contains the condition a priori of the possibility of a
continuous determination of the position in time of all phenomena, and
this by means of the series of causes and effects, the former of which
necessitate the sequence of the latter, and thereby render universally
and for all time, and by consequence, objectively, valid the empirical
cognition of the relations of time.


Principle of Coexistence, According to the Law of Reciprocity or

All substances, in so far as they can be perceived in space at the same
time, exist in a state of complete reciprocity of action.


Things are coexistent, when in empirical intuition the perception of
the one can follow upon the perception of the other, and vice
versa—which cannot occur in the succession of phenomena, as we have
shown in the explanation of the second principle. Thus I can perceive
the moon and then the earth, or conversely, first the earth and then
the moon; and for the reason that my perceptions of these objects can
reciprocally follow each other, I say, they exist contemporaneously.
Now coexistence is the existence of the manifold in the same time. But
time itself is not an object of perception; and therefore we cannot
conclude from the fact that things are placed in the same time, the
other fact, that the perception of these things can follow each other
reciprocally. The synthesis of the imagination in apprehension would
only present to us each of these perceptions as present in the subject
when the other is not present, and contrariwise; but would not show
that the objects are coexistent, that is to say, that, if the one
exists, the other also exists in the same time, and that this is
necessarily so, in order that the perceptions may be capable of
following each other reciprocally. It follows that a conception of the
understanding or category of the reciprocal sequence of the
determinations of phenomena (existing, as they do, apart from each
other, and yet contemporaneously), is requisite to justify us in saying
that the reciprocal succession of perceptions has its foundation in the
object, and to enable us to represent coexistence as objective. But
that relation of substances in which the one contains determinations
the ground of which is in the other substance, is the relation of
influence. And, when this influence is reciprocal, it is the relation
of community or reciprocity. Consequently the coexistence of substances
in space cannot be cognized in experience otherwise than under the
precondition of their reciprocal action. This is therefore the
condition of the possibility of things themselves as objects of

Things are coexistent, in so far as they exist in one and the same
time. But how can we know that they exist in one and the same time?
Only by observing that the order in the synthesis of apprehension of
the manifold is arbitrary and a matter of indifference, that is to say,
that it can proceed from A, through B, C, D, to E, or contrariwise from
E to A. For if they were successive in time (and in the order, let us
suppose, which begins with A), it is quite impossible for the
apprehension in perception to begin with E and go backwards to A,
inasmuch as A belongs to past time and, therefore, cannot be an object
of apprehension.

Let us assume that in a number of substances considered as phenomena
each is completely isolated, that is, that no one acts upon another.
Then I say that the coexistence of these cannot be an object of
possible perception and that the existence of one cannot, by any mode
of empirical synthesis, lead us to the existence of another. For we
imagine them in this case to be separated by a completely void space,
and thus perception, which proceeds from the one to the other in time,
would indeed determine their existence by means of a following
perception, but would be quite unable to distinguish whether the one
phenomenon follows objectively upon the first, or is coexistent with

Besides the mere fact of existence, then, there must be something by
means of which A determines the position of B in time and, conversely,
B the position of A; because only under this condition can substances
be empirically represented as existing contemporaneously. Now that
alone determines the position of another thing in time which is the
cause of it or of its determinations. Consequently every substance
(inasmuch as it can have succession predicated of it only in respect of
its determinations) must contain the causality of certain
determinations in another substance, and at the same time the effects
of the causality of the other in itself. That is to say, substances
must stand (mediately or immediately) in dynamical community with each
other, if coexistence is to be cognized in any possible experience.
But, in regard to objects of experience, that is absolutely necessary
without which the experience of these objects would itself be
impossible. Consequently it is absolutely necessary that all substances
in the world of phenomena, in so far as they are coexistent, stand in a
relation of complete community of reciprocal action to each other.

The word community has in our language [Footnote: German] two meanings,
and contains the two notions conveyed in the Latin communio and
commercium. We employ it in this place in the latter sense—that of a
dynamical community, without which even the community of place
(communio spatii) could not be empirically cognized. In our experiences
it is easy to observe that it is only the continuous influences in all
parts of space that can conduct our senses from one object to another;
that the light which plays between our eyes and the heavenly bodies
produces a mediating community between them and us, and thereby
evidences their coexistence with us; that we cannot empirically change
our position (perceive this change), unless the existence of matter
throughout the whole of space rendered possible the perception of the
positions we occupy; and that this perception can prove the
contemporaneous existence of these places only through their reciprocal
influence, and thereby also the coexistence of even the most remote
objects—although in this case the proof is only mediate. Without
community, every perception (of a phenomenon in space) is separated
from every other and isolated, and the chain of empirical
representations, that is, of experience, must, with the appearance of a
new object, begin entirely de novo, without the least connection with
preceding representations, and without standing towards these even in
the relation of time. My intention here is by no means to combat the
notion of empty space; for it may exist where our perceptions cannot
exist, inasmuch as they cannot reach thereto, and where, therefore, no
empirical perception of coexistence takes place. But in this case it is
not an object of possible experience.

The following remarks may be useful in the way of explanation. In the
mind, all phenomena, as contents of a possible experience, must exist
in community (communio) of apperception or consciousness, and in so far
as it is requisite that objects be represented as coexistent and
connected, in so far must they reciprocally determine the position in
time of each other and thereby constitute a whole. If this subjective
community is to rest upon an objective basis, or to be applied to
substances as phenomena, the perception of one substance must render
possible the perception of another, and conversely. For otherwise
succession, which is always found in perceptions as apprehensions,
would be predicated of external objects, and their representation of
their coexistence be thus impossible. But this is a reciprocal
influence, that is to say, a real community (commercium) of substances,
without which therefore the empirical relation of coexistence would be
a notion beyond the reach of our minds. By virtue of this commercium,
phenomena, in so far as they are apart from, and nevertheless in
connection with each other, constitute a compositum reale. Such
composita are possible in many different ways. The three dynamical
relations then, from which all others spring, are those of inherence,
consequence, and composition.

These, then, are the three analogies of experience. They are nothing
more than principles of the determination of the existence of phenomena
in time, according to the three modi of this determination; to wit, the
relation to time itself as a quantity (the quantity of existence, that
is, duration), the relation in time as a series or succession, finally,
the relation in time as the complex of all existence (simultaneity).
This unity of determination in regard to time is thoroughly dynamical;
that is to say, time is not considered as that in which experience
determines immediately to every existence its position; for this is
impossible, inasmuch as absolute time is not an object of perception,
by means of which phenomena can be connected with each other. On the
contrary, the rule of the understanding, through which alone the
existence of phenomena can receive synthetical unity as regards
relations of time, determines for every phenomenon its position in
time, and consequently a priori, and with validity for all and every

By nature, in the empirical sense of the word, we understand the
totality of phenomena connected, in respect of their existence,
according to necessary rules, that is, laws. There are therefore
certain laws (which are moreover a priori) which make nature possible;
and all empirical laws can exist only by means of experience, and by
virtue of those primitive laws through which experience itself becomes
possible. The purpose of the analogies is therefore to represent to us
the unity of nature in the connection of all phenomena under certain
exponents, the only business of which is to express the relation of
time (in so far as it contains all existence in itself) to the unity of
apperception, which can exist in synthesis only according to rules. The
combined expression of all is this: “All phenomena exist in one nature,
and must so exist, inasmuch as without this a priori unity, no unity of
experience, and consequently no determination of objects in experience,
is possible.”

As regards the mode of proof which we have employed in treating of
these transcendental laws of nature, and the peculiar character of we
must make one remark, which will at the same time be important as a
guide in every other attempt to demonstrate the truth of intellectual
and likewise synthetical propositions a priori. Had we endeavoured to
prove these analogies dogmatically, that is, from conceptions; that is
to say, had we employed this method in attempting to show that
everything which exists, exists only in that which is permanent—that
every thing or event presupposes the existence of something in a
preceding state, upon which it follows in conformity with a
rule—lastly, that in the manifold, which is coexistent, the states
coexist in connection with each other according to a rule, all our
labour would have been utterly in vain. For more conceptions of things,
analyse them as we may, cannot enable us to conclude from the existence
of one object to the existence of another. What other course was left
for us to pursue? This only, to demonstrate the possibility of
experience as a cognition in which at last all objects must be capable
of being presented to us, if the representation of them is to possess
any objective reality. Now in this third, this mediating term, the
essential form of which consists in the synthetical unity of the
apperception of all phenomena, we found a priori conditions of the
universal and necessary determination as to time of all existences in
the world of phenomena, without which the empirical determination
thereof as to time would itself be impossible, and we also discovered
rules of synthetical unity a priori, by means of which we could
anticipate experience. For want of this method, and from the fancy that
it was possible to discover a dogmatical proof of the synthetical
propositions which are requisite in the empirical employment of the
understanding, has it happened that a proof of the principle of
sufficient reason has been so often attempted, and always in vain. The
other two analogies nobody has ever thought of, although they have
always been silently employed by the mind,* because the guiding thread
furnished by the categories was wanting, the guide which alone can
enable us to discover every hiatus, both in the system of conceptions
and of principles.

[*Footnote: The unity of the universe, in which all phenomena to be
connected, is evidently a mere consequence of the admitted principle of
the community of all substances which are coexistent. For were
substances isolated, they could not as parts constitute a whole, and
were their connection (reciprocal action of the manifold) not necessary
from the very fact of coexistence, we could not conclude from the fact
of the latter as a merely ideal relation to the former as a real one.
We have, however, shown in its place that community is the proper
ground of the possibility of an empirical cognition of coexistence, and
that we may therefore properly reason from the latter to the former as
its condition.]


1. That which agrees with the formal conditions (intuition and
conception) of experience, is possible.

2. That which coheres with the material conditions of experience
(sensation), is real.

3. That whose coherence with the real is determined according to
universal conditions of experience is (exists) necessary.


The categories of modality possess this peculiarity, that they do not
in the least determine the object, or enlarge the conception to which
they are annexed as predicates, but only express its relation to the
faculty of cognition. Though my conception of a thing is in itself
complete, I am still entitled to ask whether the object of it is merely
possible, or whether it is also real, or, if the latter, whether it is
also necessary. But hereby the object itself is not more definitely
determined in thought, but the question is only in what relation it,
including all its determinations, stands to the understanding and its
employment in experience, to the empirical faculty of judgement, and to
the reason of its application to experience.

For this very reason, too, the categories of modality are nothing more
than explanations of the conceptions of possibility, reality, and
necessity, as employed in experience, and at the same time,
restrictions of all the categories to empirical use alone, not
authorizing the transcendental employment of them. For if they are to
have something more than a merely logical significance, and to be
something more than a mere analytical expression of the form of
thought, and to have a relation to things and their possibility,
reality, or necessity, they must concern possible experience and its
synthetical unity, in which alone objects of cognition can be given.

The postulate of the possibility of things requires also, that the
conception of the things agree with the formal conditions of our
experience in general. But this, that is to say, the objective form of
experience, contains all the kinds of synthesis which are requisite for
the cognition of objects. A conception which contains a synthesis must
be regarded as empty and, without reference to an object, if its
synthesis does not belong to experience—either as borrowed from it, and
in this case it is called an empirical conception, or such as is the
ground and a priori condition of experience (its form), and in this
case it is a pure conception, a conception which nevertheless belongs
to experience, inasmuch as its object can be found in this alone. For
where shall we find the criterion or character of the possibility of an
object which is cogitated by means of an a priori synthetical
conception, if not in the synthesis which constitutes the form of
empirical cognition of objects? That in such a conception no
contradiction exists is indeed a necessary logical condition, but very
far from being sufficient to establish the objective reality of the
conception, that is, the possibility of such an object as is thought in
the conception. Thus, in the conception of a figure which is contained
within two straight lines, there is no contradiction, for the
conceptions of two straight lines and of their junction contain no
negation of a figure. The impossibility in such a case does not rest
upon the conception in itself, but upon the construction of it in
space, that is to say, upon the conditions of space and its
determinations. But these have themselves objective reality, that is,
they apply to possible things, because they contain a priori the form
of experience in general.

And now we shall proceed to point out the extensive utility and
influence of this postulate of possibility. When I represent to myself
a thing that is permanent, so that everything in it which changes
belongs merely to its state or condition, from such a conception alone
I never can cognize that such a thing is possible. Or, if I represent
to myself something which is so constituted that, when it is posited,
something else follows always and infallibly, my thought contains no
self-contradiction; but whether such a property as causality is to be
found in any possible thing, my thought alone affords no means of
judging. Finally, I can represent to myself different things
(substances) which are so constituted that the state or condition of
one causes a change in the state of the other, and reciprocally; but
whether such a relation is a property of things cannot be perceived
from these conceptions, which contain a merely arbitrary synthesis.
Only from the fact, therefore, that these conceptions express a priori
the relations of perceptions in every experience, do we know that they
possess objective reality, that is, transcendental truth; and that
independent of experience, though not independent of all relation to
form of an experience in general and its synthetical unity, in which
alone objects can be empirically cognized.

But when we fashion to ourselves new conceptions of substances, forces,
action, and reaction, from the material presented to us by perception,
without following the example of experience in their connection, we
create mere chimeras, of the possibility of which we cannot discover
any criterion, because we have not taken experience for our
instructress, though we have borrowed the conceptions from her. Such
fictitious conceptions derive their character of possibility not, like
the categories, a priori, as conceptions on which all experience
depends, but only, a posteriori, as conceptions given by means of
experience itself, and their possibility must either be cognized a
posteriori and empirically, or it cannot be cognized at all. A
substance which is permanently present in space, yet without filling it
(like that tertium quid between matter and the thinking subject which
some have tried to introduce into metaphysics), or a peculiar
fundamental power of the mind of intuiting the future by anticipation
(instead of merely inferring from past and present events), or,
finally, a power of the mind to place itself in community of thought
with other men, however distant they may be—these are conceptions the
possibility of which has no ground to rest upon. For they are not based
upon experience and its known laws; and, without experience, they are a
merely arbitrary conjunction of thoughts, which, though containing no
internal contradiction, has no claim to objective reality, neither,
consequently, to the possibility of such an object as is thought in
these conceptions. As far as concerns reality, it is self-evident that
we cannot cogitate such a possibility in concreto without the aid of
experience; because reality is concerned only with sensation, as the
matter of experience, and not with the form of thought, with which we
can no doubt indulge in shaping fancies.

But I pass by everything which derives its possibility from reality in
experience, and I purpose treating here merely of the possibility of
things by means of a priori conceptions. I maintain, then, that the
possibility of things is not derived from such conceptions per se, but
only when considered as formal and objective conditions of an
experience in general.

It seems, indeed, as if the possibility of a triangle could be cognized
from the conception of it alone (which is certainly independent of
experience); for we can certainly give to the conception a
corresponding object completely a priori, that is to say, we can
construct it. But as a triangle is only the form of an object, it must
remain a mere product of the imagination, and the possibility of the
existence of an object corresponding to it must remain doubtful, unless
we can discover some other ground, unless we know that the figure can
be cogitated under the conditions upon which all objects of experience
rest. Now, the facts that space is a formal condition a priori of
external experience, that the formative synthesis, by which we
construct a triangle in imagination, is the very same as that we employ
in the apprehension of a phenomenon for the purpose of making an
empirical conception of it, are what alone connect the notion of the
possibility of such a thing, with the conception of it. In the same
manner, the possibility of continuous quantities, indeed of quantities
in general, for the conceptions of them are without exception
synthetical, is never evident from the conceptions in themselves, but
only when they are considered as the formal conditions of the
determination of objects in experience. And where, indeed, should we
look for objects to correspond to our conceptions, if not in
experience, by which alone objects are presented to us? It is, however,
true that without antecedent experience we can cognize and characterize
the possibility of things, relatively to the formal conditions, under
which something is determined in experience as an object, consequently,
completely a priori. But still this is possible only in relation to
experience and within its limits.

The postulate concerning the cognition of the reality of things
requires perception, consequently conscious sensation, not indeed
immediately, that is, of the object itself, whose existence is to be
cognized, but still that the object have some connection with a real
perception, in accordance with the analogies of experience, which
exhibit all kinds of real connection in experience.

From the mere conception of a thing it is impossible to conclude its
existence. For, let the conception be ever so complete, and containing
a statement of all the determinations of the thing, the existence of it
has nothing to do with all this, but only with thew question whether
such a thing is given, so that the perception of it can in every case
precede the conception. For the fact that the conception of it precedes
the perception, merely indicates the possibility of its existence; it
is perception which presents matter to the conception, that is the sole
criterion of reality. Prior to the perception of the thing, however,
and therefore comparatively a priori, we are able to cognize its
existence, provided it stands in connection with some perceptions
according to the principles of the empirical conjunction of these, that
is, in conformity with the analogies of perception. For, in this case,
the existence of the supposed thing is connected with our perception in
a possible experience, and we are able, with the guidance of these
analogies, to reason in the series of possible perceptions from a thing
which we do really perceive to the thing we do not perceive. Thus, we
cognize the existence of a magnetic matter penetrating all bodies from
the perception of the attraction of the steel-filings by the magnet,
although the constitution of our organs renders an immediate perception
of this matter impossible for us. For, according to the laws of
sensibility and the connected context of our perceptions, we should in
an experience come also on an immediate empirical intuition of this
matter, if our senses were more acute—but this obtuseness has no
influence upon and cannot alter the form of possible experience in
general. Our knowledge of the existence of things reaches as far as our
perceptions, and what may be inferred from them according to empirical
laws, extend. If we do not set out from experience, or do not proceed
according to the laws of the empirical connection of phenomena, our
pretensions to discover the existence of a thing which we do not
immediately perceive are vain. Idealism, however, brings forward
powerful objections to these rules for proving existence mediately.
This is, therefore, the proper place for its refutation.


Idealism—I mean material idealism—is the theory which declares the
existence of objects in space without us to be either () doubtful and
indemonstrable, or (2) false and impossible. The first is the
problematical idealism of Descartes, who admits the undoubted certainty
of only one empirical assertion (assertio), to wit, “I am.” The second
is the dogmatical idealism of Berkeley, who maintains that space,
together with all the objects of which it is the inseparable condition,
is a thing which is in itself impossible, and that consequently the
objects in space are mere products of the imagination. The dogmatical
theory of idealism is unavoidable, if we regard space as a property of
things in themselves; for in that case it is, with all to which it
serves as condition, a nonentity. But the foundation for this kind of
idealism we have already destroyed in the transcendental aesthetic.
Problematical idealism, which makes no such assertion, but only alleges
our incapacity to prove the existence of anything besides ourselves by
means of immediate experience, is a theory rational and evidencing a
thorough and philosophical mode of thinking, for it observes the rule
not to form a decisive judgement before sufficient proof be shown. The
desired proof must therefore demonstrate that we have experience of
external things, and not mere fancies. For this purpose, we must prove,
that our internal and, to Descartes, indubitable experience is itself
possible only under the previous assumption of external experience.


The simple but empirically determined consciousness of my own existence
proves the existence of external objects in space.


I am conscious of my own existence as determined in time. All
determination in regard to time presupposes the existence of something
permanent in perception. But this permanent something cannot be
something in me, for the very reason that my existence in time is
itself determined by this permanent something. It follows that the
perception of this permanent existence is possible only through a thing
without me and not through the mere representation of a thing without
me. Consequently, the determination of my existence in time is possible
only through the existence of real things external to me. Now,
consciousness in time is necessarily connected with the consciousness
of the possibility of this determination in time. Hence it follows that
consciousness in time is necessarily connected also with the existence
of things without me, inasmuch as the existence of these things is the
condition of determination in time. That is to say, the consciousness
of my own existence is at the same time an immediate consciousness of
the existence of other things without me.

Remark I. The reader will observe, that in the foregoing proof the game
which idealism plays is retorted upon itself, and with more justice. It
assumed that the only immediate experience is internal and that from
this we can only infer the existence of external things. But, as always
happens, when we reason from given effects to determined causes,
idealism has reasoned with too much haste and uncertainty, for it is
quite possible that the cause of our representations may lie in
ourselves, and that we ascribe it falsely to external things. But our
proof shows that external experience is properly immediate,* that only
by virtue of it—not, indeed, the consciousness of our own existence,
but certainly the determination of our existence in time, that is,
internal experience—is possible. It is true, that the representation “I
am,” which is the expression of the consciousness which can accompany
all my thoughts, is that which immediately includes the existence of a
subject. But in this representation we cannot find any knowledge of the
subject, and therefore also no empirical knowledge, that is,
experience. For experience contains, in addition to the thought of
something existing, intuition, and in this case it must be internal
intuition, that is, time, in relation to which the subject must be
determined. But the existence of external things is absolutely
requisite for this purpose, so that it follows that internal experience
is itself possible only mediately and through external experience.

[*Footnote: The immediate consciousness of the existence of external
things is, in the preceding theorem, not presupposed, but proved, by
the possibility of this consciousness understood by us or not. The
question as to the possibility of it would stand thus: “Have we an
internal sense, but no external sense, and is our belief in external
perception a mere delusion?” But it is evident that, in order merely to
fancy to ourselves anything as external, that is, to present it to the
sense in intuition we must already possess an external sense, and must
thereby distinguish immediately the mere receptivity of an external
intuition from the spontaneity which characterizes every act of
imagination. For merely to imagine also an external sense, would
annihilate the faculty of intuition itself which is to be determined by
the imagination.]

Remark II. Now with this view all empirical use of our faculty of
cognition in the determination of time is in perfect accordance. Its
truth is supported by the fact that it is possible to perceive a
determination of time only by means of a change in external relations
(motion) to the permanent in space (for example, we become aware of the
sun’s motion by observing the changes of his relation to the objects of
this earth). But this is not all. We find that we possess nothing
permanent that can correspond and be submitted to the conception of a
substance as intuition, except matter. This idea of permanence is not
itself derived from external experience, but is an a priori necessary
condition of all determination of time, consequently also of the
internal sense in reference to our own existence, and that through the
existence of external things. In the representation “I,” the
consciousness of myself is not an intuition, but a merely intellectual
representation produced by the spontaneous activity of a thinking
subject. It follows, that this “i” has not any predicate of intuition,
which, in its character of permanence, could serve as correlate to the
determination of time in the internal sense—in the same way as
impenetrability is the correlate of matter as an empirical intuition.

Remark III. From the fact that the existence of external things is a
necessary condition of the possibility of a determined consciousness of
ourselves, it does not follow that every intuitive representation of
external things involves the existence of these things, for their
representations may very well be the mere products of the imagination
(in dreams as well as in madness); though, indeed, these are themselves
created by the reproduction of previous external perceptions, which, as
has been shown, are possible only through the reality of external
objects. The sole aim of our remarks has, however, been to prove that
internal experience in general is possible only through external
experience in general. Whether this or that supposed experience be
purely imaginary must be discovered from its particular determinations
and by comparing these with the criteria of all real experience.

Finally, as regards the third postulate, it applies to material
necessity in existence, and not to merely formal and logical necessity
in the connection of conceptions. Now as we cannot cognize completely a
priori the existence of any object of sense, though we can do so
comparatively a priori, that is, relatively to some other previously
given existence—a cognition, however, which can only be of such an
existence as must be contained in the complex of experience, of which
the previously given perception is a part—the necessity of existence
can never be cognized from conceptions, but always, on the contrary,
from its connection with that which is an object of perception. But the
only existence cognized, under the condition of other given phenomena,
as necessary, is the existence of effects from given causes in
conformity with the laws of causality. It is consequently not the
necessity of the existence of things (as substances), but the necessity
of the state of things that we cognize, and that not immediately, but
by means of the existence of other states given in perception,
according to empirical laws of causality. Hence it follows that the
criterion of necessity is to be found only in the law of possible
experience—that everything which happens is determined a priori in the
phenomenon by its cause. Thus we cognize only the necessity of effects
in nature, the causes of which are given us. Moreover, the criterion of
necessity in existence possesses no application beyond the field of
possible experience, and even in this it is not valid of the existence
of things as substances, because these can never be considered as
empirical effects, or as something that happens and has a beginning.
Necessity, therefore, regards only the relations of phenomena according
to the dynamical law of causality, and the possibility grounded
thereon, of reasoning from some given existence (of a cause) a priori
to another existence (of an effect). “Everything that happens is
hypothetically necessary,” is a principle which subjects the changes
that take place in the world to a law, that is, to a rule of necessary
existence, without which nature herself could not possibly exist. Hence
the proposition, “Nothing happens by blind chance (in mundo non datur
casus),” is an a priori law of nature. The case is the same with the
proposition, “Necessity in nature is not blind,” that is, it is
conditioned, consequently intelligible necessity (non datur fatum).
Both laws subject the play of change to “a nature of things (as
phenomena),” or, which is the same thing, to the unity of the
understanding, and through the understanding alone can changes belong
to an experience, as the synthetical unity of phenomena. Both belong to
the class of dynamical principles. The former is properly a consequence
of the principle of causality—one of the analogies of experience. The
latter belongs to the principles of modality, which to the
determination of causality adds the conception of necessity, which is
itself, however, subject to a rule of the understanding. The principle
of continuity forbids any leap in the series of phenomena regarded as
changes (in mundo non datur saltus); and likewise, in the complex of
all empirical intuitions in space, any break or hiatus between two
phenomena (non datur hiatus)—for we can so express the principle, that
experience can admit nothing which proves the existence of a vacuum, or
which even admits it as a part of an empirical synthesis. For, as
regards a vacuum or void, which we may cogitate as out and beyond the
field of possible experience (the world), such a question cannot come
before the tribunal of mere understanding, which decides only upon
questions that concern the employment of given phenomena for the
construction of empirical cognition. It is rather a problem for ideal
reason, which passes beyond the sphere of a possible experience and
aims at forming a judgement of that which surrounds and circumscribes
it, and the proper place for the consideration of it is the
transcendental dialectic. These four propositions, “In mundo non datur
hiatus, non datur saltus, non datur casus, non datur fatum,” as well as
all principles of transcendental origin, we could very easily exhibit
in their proper order, that is, in conformity with the order of the
categories, and assign to each its proper place. But the already
practised reader will do this for himself, or discover the clue to such
an arrangement. But the combined result of all is simply this, to admit
into the empirical synthesis nothing which might cause a break in or be
foreign to the understanding and the continuous connection of all
phenomena, that is, the unity of the conceptions of the understanding.
For in the understanding alone is the unity of experience, in which all
perceptions must have their assigned place, possible.

Whether the field of possibility be greater than that of reality, and
whether the field of the latter be itself greater than that of
necessity, are interesting enough questions, and quite capable of
synthetic solution, questions, however, which come under the
jurisdiction of reason alone. For they are tantamount to asking whether
all things as phenomena do without exception belong to the complex and
connected whole of a single experience, of which every given perception
is a part which therefore cannot be conjoined with any other
phenomena—or, whether my perceptions can belong to more than one
possible experience? The understanding gives to experience, according
to the subjective and formal conditions, of sensibility as well as of
apperception, the rules which alone make this experience possible.
Other forms of intuition besides those of space and time, other forms
of understanding besides the discursive forms of thought, or of
cognition by means of conceptions, we can neither imagine nor make
intelligible to ourselves; and even if we could, they would still not
belong to experience, which is the only mode of cognition by which
objects are presented to us. Whether other perceptions besides those
which belong to the total of our possible experience, and consequently
whether some other sphere of matter exists, the understanding has no
power to decide, its proper occupation being with the synthesis of that
which is given. Moreover, the poverty of the usual arguments which go
to prove the existence of a vast sphere of possibility, of which all
that is real (every object of experience) is but a small part, is very
remarkable. “All real is possible”; from this follows naturally,
according to the logical laws of conversion, the particular
proposition: “Some possible is real.” Now this seems to be equivalent
to: “Much is possible that is not real.” No doubt it does seem as if we
ought to consider the sum of the possible to be greater than that of
the real, from the fact that something must be added to the former to
constitute the latter. But this notion of adding to the possible is
absurd. For that which is not in the sum of the possible, and
consequently requires to be added to it, is manifestly impossible. In
addition to accordance with the formal conditions of experience, the
understanding requires a connection with some perception; but that
which is connected with this perception is real, even although it is
not immediately perceived. But that another series of phenomena, in
complete coherence with that which is given in perception, consequently
more than one all-embracing experience is possible, is an inference
which cannot be concluded from the data given us by experience, and
still less without any data at all. That which is possible only under
conditions which are themselves merely possible, is not possible in any
respect. And yet we can find no more certain ground on which to base
the discussion of the question whether the sphere of possibility is
wider than that of experience.

I have merely mentioned these questions, that in treating of the
conception of the understanding, there might be no omission of anything
that, in the common opinion, belongs to them. In reality, however, the
notion of absolute possibility (possibility which is valid in every
respect) is not a mere conception of the understanding, which can be
employed empirically, but belongs to reason alone, which passes the
bounds of all empirical use of the understanding. We have, therefore,
contented ourselves with a merely critical remark, leaving the subject
to be explained in the sequel.

Before concluding this fourth section, and at the same time the system
of all principles of the pure understanding, it seems proper to mention
the reasons which induced me to term the principles of modality
postulates. This expression I do not here use in the sense which some
more recent philosophers, contrary to its meaning with mathematicians,
to whom the word properly belongs, attach to it—that of a proposition,
namely, immediately certain, requiring neither deduction nor proof. For
if, in the case of synthetical propositions, however evident they may
be, we accord to them without deduction, and merely on the strength of
their own pretensions, unqualified belief, all critique of the
understanding is entirely lost; and, as there is no want of bold
pretensions, which the common belief (though for the philosopher this
is no credential) does not reject, the understanding lies exposed to
every delusion and conceit, without the power of refusing its assent to
those assertions, which, though illegitimate, demand acceptance as
veritable axioms. When, therefore, to the conception of a thing an a
priori determination is synthetically added, such a proposition must
obtain, if not a proof, at least a deduction of the legitimacy of its

The principles of modality are, however, not objectively synthetical,
for the predicates of possibility, reality, and necessity do not in the
least augment the conception of that of which they are affirmed,
inasmuch as they contribute nothing to the representation of the
object. But as they are, nevertheless, always synthetical, they are so
merely subjectively. That is to say, they have a reflective power, and
apply to the conception of a thing, of which, in other respects, they
affirm nothing, the faculty of cognition in which the conception
originates and has its seat. So that if the conception merely agree
with the formal conditions of experience, its object is called
possible; if it is in connection with perception, and determined
thereby, the object is real; if it is determined according to
conceptions by means of the connection of perceptions, the object is
called necessary. The principles of modality therefore predicate of a
conception nothing more than the procedure of the faculty of cognition
which generated it. Now a postulate in mathematics is a practical
proposition which contains nothing but the synthesis by which we
present an object to ourselves, and produce the conception of it, for
example—“With a given line, to describe a circle upon a plane, from a
given point”; and such a proposition does not admit of proof, because
the procedure, which it requires, is exactly that by which alone it is
possible to generate the conception of such a figure. With the same
right, accordingly, can we postulate the principles of modality,
because they do not augment* the conception of a thing but merely
indicate the manner in which it is connected with the faculty of

[*Footnote: When I think the reality of a thing, I do really think more
than the possibility, but not in the thing; for that can never contain
more in reality than was contained in its complete possibility. But
while the notion of possibility is merely the notion of a position of
thing in relation to the understanding (its empirical use), reality is
the conjunction of the thing with perception.]


It is very remarkable that we cannot perceive the possibility of a
thing from the category alone, but must always have an intuition, by
which to make evident the objective reality of the pure conception of
the understanding. Take, for example, the categories of relation. How
(1) a thing can exist only as a subject, and not as a mere
determination of other things, that is, can be substance; or how (2),
because something exists, some other thing must exist, consequently how
a thing can be a cause; or how (3), when several things exist, from the
fact that one of these things exists, some consequence to the others
follows, and reciprocally, and in this way a community of substances
can be possible—are questions whose solution cannot be obtained from
mere conceptions. The very same is the case with the other categories;
for example, how a thing can be of the same sort with many others, that
is, can be a quantity, and so on. So long as we have not intuition we
cannot know whether we do really think an object by the categories, and
where an object can anywhere be found to cohere with them, and thus the
truth is established, that the categories are not in themselves
cognitions, but mere forms of thought for the construction of
cognitions from given intuitions. For the same reason is it true that
from categories alone no synthetical proposition can be made. For
example: “In every existence there is substance,” that is, something
that can exist only as a subject and not as mere predicate; or,
“Everything is a quantity”—to construct propositions such as these, we
require something to enable us to go out beyond the given conception
and connect another with it. For the same reason the attempt to prove a
synthetical proposition by means of mere conceptions, for example:
“Everything that exists contingently has a cause,” has never succeeded.
We could never get further than proving that, without this relation to
conceptions, we could not conceive the existence of the contingent,
that is, could not a priori through the understanding cognize the
existence of such a thing; but it does not hence follow that this is
also the condition of the possibility of the thing itself that is said
to be contingent. If, accordingly; we look back to our proof of the
principle of causality, we shall find that we were able to prove it as
valid only of objects of possible experience, and, indeed, only as
itself the principle of the possibility of experience, Consequently of
the cognition of an object given in empirical intuition, and not from
mere conceptions. That, however, the proposition: “Everything that is
contingent must have a cause,” is evident to every one merely from
conceptions, is not to be denied. But in this case the conception of
the contingent is cogitated as involving not the category of modality
(as that the non-existence of which can be conceived) but that of
relation (as that which can exist only as the consequence of something
else), and so it is really an identical proposition: “That which can
exist only as a consequence, has a cause.” In fact, when we have to
give examples of contingent existence, we always refer to changes, and
not merely to the possibility of conceiving the opposite.* But change
is an event, which, as such, is possible only through a cause, and
considered per se its non-existence is therefore possible, and we
become cognizant of its contingency from the fact that it can exist
only as the effect of a cause. Hence, if a thing is assumed to be
contingent, it is an analytical proposition to say, it has a cause.

[*Footnote: We can easily conceive the non-existence of matter; but the
ancients did not thence infer its contingency. But even the alternation
of the existence and non-existence of a given state in a thing, in
which all change consists, by no means proves the contingency of that
state—the ground of proof being the reality of its opposite. For
example, a body is in a state of rest after motion, but we cannot infer
the contingency of the motion from the fact that the former is the
opposite of the latter. For this opposite is merely a logical and not a
real opposite to the other. If we wish to demonstrate the contingency
of the motion, what we ought to prove is that, instead of the motion
which took place in the preceding point of time, it was possible for
the body to have been then in rest, not, that it is afterwards in rest;
for in this case, both opposites are perfectly consistent with each

But it is still more remarkable that, to understand the possibility of
things according to the categories and thus to demonstrate the
objective reality of the latter, we require not merely intuitions, but
external intuitions. If, for example, we take the pure conceptions of
relation, we find that (1) for the purpose of presenting to the
conception of substance something permanent in intuition corresponding
thereto and thus of demonstrating the objective reality of this
conception, we require an intuition (of matter) in space, because space
alone is permanent and determines things as such, while time, and with
it all that is in the internal sense, is in a state of continual flow;
(2) in order to represent change as the intuition corresponding to the
conception of causality, we require the representation of motion as
change in space; in fact, it is through it alone that changes, the
possibility of which no pure understanding can perceive, are capable of
being intuited. Change is the connection of determinations
contradictorily opposed to each other in the existence of one and the
same thing. Now, how it is possible that out of a given state one quite
opposite to it in the same thing should follow, reason without an
example can not only not conceive, but cannot even make intelligible
without intuition; and this intuition is the motion of a point in
space; the existence of which in different spaces (as a consequence of
opposite determinations) alone makes the intuition of change possible.
For, in order to make even internal change cognitable, we require to
represent time, as the form of the internal sense, figuratively by a
line, and the internal change by the drawing of that line (motion), and
consequently are obliged to employ external intuition to be able to
represent the successive existence of ourselves in different states.
The proper ground of this fact is that all change to be perceived as
change presupposes something permanent in intuition, while in the
internal sense no permanent intuition is to be found. Lastly, the
objective possibility of the category of community cannot be conceived
by mere reason, and consequently its objective reality cannot be
demonstrated without an intuition, and that external in space. For how
can we conceive the possibility of community, that is, when several
substances exist, that some effect on the existence of the one follows
from the existence of the other, and reciprocally, and therefore that,
because something exists in the latter, something else must exist in
the former, which could not be understood from its own existence alone?
For this is the very essence of community—which is inconceivable as a
property of things which are perfectly isolated. Hence, Leibnitz, in
attributing to the substances of the world—as cogitated by the
understanding alone—a community, required the mediating aid of a
divinity; for, from their existence, such a property seemed to him with
justice inconceivable. But we can very easily conceive the possibility
of community (of substances as phenomena) if we represent them to
ourselves as in space, consequently in external intuition. For external
intuition contains in itself a priori formal external relations, as the
conditions of the possibility of the real relations of action and
reaction, and therefore of the possibility of community. With the same
ease can it be demonstrated, that the possibility of things as
quantities, and consequently the objective reality of the category of
quantity, can be grounded only in external intuition, and that by its
means alone is the notion of quantity appropriated by the internal
sense. But I must avoid prolixity, and leave the task of illustrating
this by examples to the reader’s own reflection.

The above remarks are of the greatest importance, not only for the
confirmation of our previous confutation of idealism, but still more
when the subject of self-cognition by mere internal consciousness and
the determination of our own nature without the aid of external
empirical intuitions is under discussion, for the indication of the
grounds of the possibility of such a cognition.

The result of the whole of this part of the analytic of principles is,
therefore: “All principles of the pure understanding are nothing more
than a priori principles of the possibility of experience, and to
experience alone do all a priori synthetical propositions apply and
relate”; indeed, their possibility itself rests entirely on this

 Chapter III Of the Ground of the Division of all Objects into
 Phenomena and Noumena

We have now not only traversed the region of the pure understanding and
carefully surveyed every part of it, but we have also measured it, and
assigned to everything therein its proper place. But this land is an
island, and enclosed by nature herself within unchangeable limits. It
is the land of truth (an attractive word), surrounded by a wide and
stormy ocean, the region of illusion, where many a fog-bank, many an
iceberg, seems to the mariner, on his voyage of discovery, a new
country, and, while constantly deluding him with vain hopes, engages
him in dangerous adventures, from which he never can desist, and which
yet he never can bring to a termination. But before venturing upon this
sea, in order to explore it in its whole extent, and to arrive at a
certainty whether anything is to be discovered there, it will not be
without advantage if we cast our eyes upon the chart of the land that
we are about to leave, and to ask ourselves, firstly, whether we cannot
rest perfectly contented with what it contains, or whether we must not
of necessity be contented with it, if we can find nowhere else a solid
foundation to build upon; and, secondly, by what title we possess this
land itself, and how we hold it secure against all hostile claims?
Although, in the course of our analytic, we have already given
sufficient answers to these questions, yet a summary recapitulation of
these solutions may be useful in strengthening our conviction, by
uniting in one point the momenta of the arguments.

We have seen that everything which the understanding draws from itself,
without borrowing from experience, it nevertheless possesses only for
the behoof and use of experience. The principles of the pure
understanding, whether constitutive a priori (as the mathematical
principles), or merely regulative (as the dynamical), contain nothing
but the pure schema, as it were, of possible experience. For experience
possesses its unity from the synthetical unity which the understanding,
originally and from itself, imparts to the synthesis of the imagination
in relation to apperception, and in a priori relation to and agreement
with which phenomena, as data for a possible cognition, must stand. But
although these rules of the understanding are not only a priori true,
but the very source of all truth, that is, of the accordance of our
cognition with objects, and on this ground, that they contain the basis
of the possibility of experience, as the ensemble of all cognition, it
seems to us not enough to propound what is true—we desire also to be
told what we want to know. If, then, we learn nothing more by this
critical examination than what we should have practised in the merely
empirical use of the understanding, without any such subtle inquiry,
the presumption is that the advantage we reap from it is not worth the
labour bestowed upon it. It may certainly be answered that no rash
curiosity is more prejudicial to the enlargement of our knowledge than
that which must know beforehand the utility of this or that piece of
information which we seek, before we have entered on the needful
investigations, and before one could form the least conception of its
utility, even though it were placed before our eyes. But there is one
advantage in such transcendental inquiries which can be made
comprehensible to the dullest and most reluctant learner—this, namely,
that the understanding which is occupied merely with empirical
exercise, and does not reflect on the sources of its own cognition, may
exercise its functions very well and very successfully, but is quite
unable to do one thing, and that of very great importance, to
determine, namely, the bounds that limit its employment, and to know
what lies within or without its own sphere. This purpose can be
obtained only by such profound investigations as we have instituted.
But if it cannot distinguish whether certain questions lie within its
horizon or not, it can never be sure either as to its claims or
possessions, but must lay its account with many humiliating
corrections, when it transgresses, as it unavoidably will, the limits
of its own territory, and loses itself in fanciful opinions and
blinding illusions.

That the understanding, therefore, cannot make of its a priori
principles, or even of its conceptions, other than an empirical use, is
a proposition which leads to the most important results. A
transcendental use is made of a conception in a fundamental proposition
or principle, when it is referred to things in general and considered
as things in themselves; an empirical use, when it is referred merely
to phenomena, that is, to objects of a possible experience. That the
latter use of a conception is the only admissible one is evident from
the reasons following. For every conception are requisite, firstly, the
logical form of a conception (of thought) general; and, secondly, the
possibility of presenting to this an object to which it may apply.
Failing this latter, it has no sense, and utterly void of content,
although it may contain the logical function for constructing a
conception from certain data. Now, object cannot be given to a
conception otherwise than by intuition, and, even if a pure intuition
antecedent to the object is a priori possible, this pure intuition can
itself obtain objective validity only from empirical intuition, of
which it is itself but the form. All conceptions, therefore, and with
them all principles, however high the degree of their a priori
possibility, relate to empirical intuitions, that is, to data towards a
possible experience. Without this they possess no objective validity,
but are mere play of imagination or of understanding with images or
notions. Let us take, for example, the conceptions of mathematics, and
first in its pure intuitions. “Space has three dimensions”—“Between two
points there can be only one straight line,” etc. Although all these
principles, and the representation of the object with which this
science occupies itself, are generated in the mind entirely a priori,
they would nevertheless have no significance if we were not always able
to exhibit their significance in and by means of phenomena (empirical
objects). Hence it is requisite that an abstract conception be made
sensuous, that is, that an object corresponding to it in intuition be
forthcoming, otherwise the conception remains, as we say, without
sense, that is, without meaning. Mathematics fulfils this requirement
by the construction of the figure, which is a phenomenon evident to the
senses. The same science finds support and significance in number; this
in its turn finds it in the fingers, or in counters, or in lines and
points. The conception itself is always produced a priori, together
with the synthetical principles or formulas from such conceptions; but
the proper employment of them, and their application to objects, can
exist nowhere but in experience, the possibility of which, as regards
its form, they contain a priori.

That this is also the case with all of the categories and the
principles based upon them is evident from the fact that we cannot
render intelligible the possibility of an object corresponding to them
without having recourse to the conditions of sensibility, consequently,
to the form of phenomena, to which, as their only proper objects, their
use must therefore be confined, inasmuch as, if this condition is
removed, all significance, that is, all relation to an object,
disappears, and no example can be found to make it comprehensible what
sort of things we ought to think under such conceptions.

The conception of quantity cannot be explained except by saying that it
is the determination of a thing whereby it can be cogitated how many
times one is placed in it. But this “how many times” is based upon
successive repetition, consequently upon time and the synthesis of the
homogeneous therein. Reality, in contradistinction to negation, can be
explained only by cogitating a time which is either filled therewith or
is void. If I leave out the notion of permanence (which is existence in
all time), there remains in the conception of substance nothing but the
logical notion of subject, a notion of which I endeavour to realize by
representing to myself something that can exist only as a subject. But
not only am I perfectly ignorant of any conditions under which this
logical prerogative can belong to a thing, I can make nothing out of
the notion, and draw no inference from it, because no object to which
to apply the conception is determined, and we consequently do not know
whether it has any meaning at all. In like manner, if I leave out the
notion of time, in which something follows upon some other thing in
conformity with a rule, I can find nothing in the pure category, except
that there is a something of such a sort that from it a conclusion may
be drawn as to the existence of some other thing. But in this case it
would not only be impossible to distinguish between a cause and an
effect, but, as this power to draw conclusions requires conditions of
which I am quite ignorant, the conception is not determined as to the
mode in which it ought to apply to an object. The so-called principle:
“Everything that is contingent has a cause,” comes with a gravity and
self-assumed authority that seems to require no support from without.
But, I ask, what is meant by contingent? The answer is that the
non-existence of which is possible. But I should like very well to know
by what means this possibility of non-existence is to be cognized, if
we do not represent to ourselves a succession in the series of
phenomena, and in this succession an existence which follows a
non-existence, or conversely, consequently, change. For to say, that
the non-existence of a thing is not self-contradictory is a lame appeal
to a logical condition, which is no doubt a necessary condition of the
existence of the conception, but is far from being sufficient for the
real objective possibility of non-existence. I can annihilate in
thought every existing substance without self-contradiction, but I
cannot infer from this their objective contingency in existence, that
is to say, the possibility of their non-existence in itself. As regards
the category of community, it may easily be inferred that, as the pure
categories of substance and causality are incapable of a definition and
explanation sufficient to determine their object without the aid of
intuition, the category of reciprocal causality in the relation of
substances to each other (commercium) is just as little susceptible
thereof. Possibility, existence, and necessity nobody has ever yet been
able to explain without being guilty of manifest tautology, when the
definition has been drawn entirely from the pure understanding. For the
substitution of the logical possibility of the conception—the condition
of which is that it be not self-contradictory, for the transcendental
possibility of things—the condition of which is that there be an object
corresponding to the conception, is a trick which can only deceive the

[*Footnote: In one word, to none of these conceptions belongs a
corresponding object, and consequently their real possibility cannot be
demonstrated, if we take away sensuous intuition—the only intuition
which we possess—and there then remains nothing but the logical
possibility, that is, the fact that the conception or thought is
possible—which, however, is not the question; what we want to know
being, whether it relates to an object and thus possesses any meaning.]

It follows incontestably, that the pure conceptions of the
understanding are incapable of transcendental, and must always be of
empirical use alone, and that the principles of the pure understanding
relate only to the general conditions of a possible experience, to
objects of the senses, and never to things in general, apart from the
mode in which we intuite them.

Transcendental analytic has accordingly this important result, to wit,
that the understanding is competent effect nothing a priori, except the
anticipation of the form of a possible experience in general, and that,
as that which is not phenomenon cannot be an object of experience, it
can never overstep the limits of sensibility, within which alone
objects are presented to us. Its principles are merely principles of
the exposition of phenomena, and the proud name of an ontology, which
professes to present synthetical cognitions a priori of things in
general in a systematic doctrine, must give place to the modest title
of analytic of the pure understanding.

Thought is the act of referring a given intuition to an object. If the
mode of this intuition is unknown to us, the object is merely
transcendental, and the conception of the understanding is employed
only transcendentally, that is, to produce unity in the thought of a
manifold in general. Now a pure category, in which all conditions of
sensuous intuition—as the only intuition we possess—are abstracted,
does not determine an object, but merely expresses the thought of an
object in general, according to different modes. Now, to employ a
conception, the function of judgement is required, by which an object
is subsumed under the conception, consequently the at least formal
condition, under which something can be given in intuition. Failing
this condition of judgement (schema), subsumption is impossible; for
there is in such a case nothing given, which may be subsumed under the
conception. The merely transcendental use of the categories is
therefore, in fact, no use at all and has no determined, or even, as
regards its form, determinable object. Hence it follows that the pure
category is incompetent to establish a synthetical a priori principle,
and that the principles of the pure understanding are only of empirical
and never of transcendental use, and that beyond the sphere of possible
experience no synthetical a priori principles are possible.

It may be advisable, therefore, to express ourselves thus. The pure
categories, apart from the formal conditions of sensibility, have a
merely transcendental meaning, but are nevertheless not of
transcendental use, because this is in itself impossible, inasmuch as
all the conditions of any employment or use of them (in judgements) are
absent, to wit, the formal conditions of the subsumption of an object
under these conceptions. As, therefore, in the character of pure
categories, they must be employed empirically, and cannot be employed
transcendentally, they are of no use at all, when separated from
sensibility, that is, they cannot be applied to an object. They are
merely the pure form of the employment of the understanding in respect
of objects in general and of thought, without its being at the same
time possible to think or to determine any object by their means. But
there lurks at the foundation of this subject an illusion which it is
very difficult to avoid. The categories are not based, as regards their
origin, upon sensibility, like the forms of intuition, space, and time;
they seem, therefore, to be capable of an application beyond the sphere
of sensuous objects. But this is not the case. They are nothing but
mere forms of thought, which contain only the logical faculty of
uniting a priori in consciousness the manifold given in intuition.
Apart, then, from the only intuition possible for us, they have still
less meaning than the pure sensuous forms, space and time, for through
them an object is at least given, while a mode of connection of the
manifold, when the intuition which alone gives the manifold is wanting,
has no meaning at all. At the same time, when we designate certain
objects as phenomena or sensuous existences, thus distinguishing our
mode of intuiting them from their own nature as things in themselves,
it is evident that by this very distinction we as it were place the
latter, considered in this their own nature, although we do not so
intuite them, in opposition to the former, or, on the other hand, we do
so place other possible things, which are not objects of our senses,
but are cogitated by the understanding alone, and call them
intelligible existences (noumena). Now the question arises whether the
pure conceptions of our understanding do possess significance in
respect of these latter, and may possibly be a mode of cognizing them.

But we are met at the very commencement with an ambiguity, which may
easily occasion great misapprehension. The understanding, when it terms
an object in a certain relation phenomenon, at the same time forms out
of this relation a representation or notion of an object in itself, and
hence believes that it can form also conceptions of such objects. Now
as the understanding possesses no other fundamental conceptions besides
the categories, it takes for granted that an object considered as a
thing in itself must be capable of being thought by means of these pure
conceptions, and is thereby led to hold the perfectly undetermined
conception of an intelligible existence, a something out of the sphere
of our sensibility, for a determinate conception of an existence which
we can cognize in some way or other by means of the understanding.

If, by the term noumenon, we understand a thing so far as it is not an
object of our sensuous intuition, thus making abstraction of our mode
of intuiting it, this is a noumenon in the negative sense of the word.
But if we understand by it an object of a non-sensuous intuition, we in
this case assume a peculiar mode of intuition, an intellectual
intuition, to wit, which does not, however, belong to us, of the very
possibility of which we have no notion—and this is a noumenon in the
positive sense.

The doctrine of sensibility is also the doctrine of noumena in the
negative sense, that is, of things which the understanding is obliged
to cogitate apart from any relation to our mode of intuition,
consequently not as mere phenomena, but as things in themselves. But
the understanding at the same time comprehends that it cannot employ
its categories for the consideration of things in themselves, because
these possess significance only in relation to the unity of intuitions
in space and time, and that they are competent to determine this unity
by means of general a priori connecting conceptions only on account of
the pure ideality of space and time. Where this unity of time is not to
be met with, as is the case with noumena, the whole use, indeed the
whole meaning of the categories is entirely lost, for even the
possibility of things to correspond to the categories is in this case
incomprehensible. On this point, I need only refer the reader to what I
have said at the commencement of the General Remark appended to the
foregoing chapter. Now, the possibility of a thing can never be proved
from the fact that the conception of it is not self-contradictory, but
only by means of an intuition corresponding to the conception. If,
therefore, we wish to apply the categories to objects which cannot be
regarded as phenomena, we must have an intuition different from the
sensuous, and in this case the objects would be a noumena in the
positive sense of the word. Now, as such an intuition, that is, an
intellectual intuition, is no part of our faculty of cognition, it is
absolutely impossible for the categories to possess any application
beyond the limits of experience. It may be true that there are
intelligible existences to which our faculty of sensuous intuition has
no relation, and cannot be applied, but our conceptions of the
understanding, as mere forms of thought for our sensuous intuition, do
not extend to these. What, therefore, we call noumenon must be
understood by us as such in a negative sense.

If I take away from an empirical intuition all thought (by means of the
categories), there remains no cognition of any object; for by means of
mere intuition nothing is cogitated, and, from the existence of such or
such an affection of sensibility in me, it does not follow that this
affection or representation has any relation to an object without me.
But if I take away all intuition, there still remains the form of
thought, that is, the mode of determining an object for the manifold of
a possible intuition. Thus the categories do in some measure really
extend further than sensuous intuition, inasmuch as they think objects
in general, without regard to the mode (of sensibility) in which these
objects are given. But they do not for this reason apply to and
determine a wider sphere of objects, because we cannot assume that such
can be given, without presupposing the possibility of another than the
sensuous mode of intuition, a supposition we are not justified in

I call a conception problematical which contains in itself no
contradiction, and which is connected with other cognitions as a
limitation of given conceptions, but whose objective reality cannot be
cognized in any manner. The conception of a noumenon, that is, of a
thing which must be cogitated not as an object of sense, but as a thing
in itself (solely through the pure understanding), is not
self-contradictory, for we are not entitled to maintain that
sensibility is the only possible mode of intuition. Nay, further, this
conception is necessary to restrain sensuous intuition within the
bounds of phenomena, and thus to limit the objective validity of
sensuous cognition; for things in themselves, which lie beyond its
province, are called noumena for the very purpose of indicating that
this cognition does not extend its application to all that the
understanding thinks. But, after all, the possibility of such noumena
is quite incomprehensible, and beyond the sphere of phenomena, all is
for us a mere void; that is to say, we possess an understanding whose
province does problematically extend beyond this sphere, but we do not
possess an intuition, indeed, not even the conception of a possible
intuition, by means of which objects beyond the region of sensibility
could be given us, and in reference to which the understanding might be
employed assertorically. The conception of a noumenon is therefore
merely a limitative conception and therefore only of negative use. But
it is not an arbitrary or fictitious notion, but is connected with the
limitation of sensibility, without, however, being capable of
presenting us with any positive datum beyond this sphere.

The division of objects into phenomena and noumena, and of the world
into a mundus sensibilis and intelligibilis is therefore quite
inadmissible in a positive sense, although conceptions do certainly
admit of such a division; for the class of noumena have no determinate
object corresponding to them, and cannot therefore possess objective
validity. If we abandon the senses, how can it be made conceivable that
the categories (which are the only conceptions that could serve as
conceptions for noumena) have any sense or meaning at all, inasmuch as
something more than the mere unity of thought, namely, a possible
intuition, is requisite for their application to an object? The
conception of a noumenon, considered as merely problematical, is,
however, not only admissible, but, as a limitative conception of
sensibility, absolutely necessary. But, in this case, a noumenon is not
a particular intelligible object for our understanding; on the
contrary, the kind of understanding to which it could belong is itself
a problem, for we cannot form the most distant conception of the
possibility of an understanding which should cognize an object, not
discursively by means of categories, but intuitively in a non-sensuous
intuition. Our understanding attains in this way a sort of negative
extension. That is to say, it is not limited by, but rather limits,
sensibility, by giving the name of noumena to things, not considered as
phenomena, but as things in themselves. But it at the same time
prescribes limits to itself, for it confesses itself unable to cognize
these by means of the categories, and hence is compelled to cogitate
them merely as an unknown something.

I find, however, in the writings of modern authors, an entirely
different use of the expressions, mundus sensibilis and intelligibilis,
which quite departs from the meaning of the ancients—an acceptation in
which, indeed, there is to be found no difficulty, but which at the
same time depends on mere verbal quibbling. According to this meaning,
some have chosen to call the complex of phenomena, in so far as it is
intuited, mundus sensibilis, but in so far as the connection thereof is
cogitated according to general laws of thought, mundus intelligibilis.
Astronomy, in so far as we mean by the word the mere observation of the
starry heaven, may represent the former; a system of astronomy, such as
the Copernican or Newtonian, the latter. But such twisting of words is
a mere sophistical subterfuge, to avoid a difficult question, by
modifying its meaning to suit our own convenience. To be sure,
understanding and reason are employed in the cognition of phenomena;
but the question is, whether these can be applied when the object is
not a phenomenon and in this sense we regard it if it is cogitated as
given to the understanding alone, and not to the senses. The question
therefore is whether, over and above the empirical use of the
understanding, a transcendental use is possible, which applies to the
noumenon as an object. This question we have answered in the negative.

When therefore we say, the senses represent objects as they appear, the
understanding as they are, the latter statement must not be understood
in a transcendental, but only in an empirical signification, that is,
as they must be represented in the complete connection of phenomena,
and not according to what they may be, apart from their relation to
possible experience, consequently not as objects of the pure
understanding. For this must ever remain unknown to us. Nay, it is also
quite unknown to us whether any such transcendental or extraordinary
cognition is possible under any circumstances, at least, whether it is
possible by means of our categories. Understanding and sensibility,
with us, can determine objects only in conjunction. If we separate
them, we have intuitions without conceptions, or conceptions without
intuitions; in both cases, representations, which we cannot apply to
any determinate object.

If, after all our inquiries and explanations, any one still hesitates
to abandon the mere transcendental use of the categories, let him
attempt to construct with them a synthetical proposition. It would, of
course, be unnecessary for this purpose to construct an analytical
proposition, for that does not extend the sphere of the understanding,
but, being concerned only about what is cogitated in the conception
itself, it leaves it quite undecided whether the conception has any
relation to objects, or merely indicates the unity of thought—complete
abstraction being made of the modi in which an object may be given: in
such a proposition, it is sufficient for the understanding to know what
lies in the conception—to what it applies is to it indifferent. The
attempt must therefore be made with a synthetical and so-called
transcendental principle, for example: “Everything that exists, exists
as substance,” or, “Everything that is contingent exists as an effect
of some other thing, viz., of its cause.” Now I ask, whence can the
understanding draw these synthetical propositions, when the conceptions
contained therein do not relate to possible experience but to things in
themselves (noumena)? Where is to be found the third term, which is
always requisite PURE site in a synthetical proposition, which may
connect in the same proposition conceptions which have no logical
(analytical) connection with each other? The proposition never will be
demonstrated, nay, more, the possibility of any such pure assertion
never can be shown, without making reference to the empirical use of
the understanding, and thus, ipso facto, completely renouncing pure and
non-sensuous judgement. Thus the conception of pure and merely
intelligible objects is completely void of all principles of its
application, because we cannot imagine any mode in which they might be
given, and the problematical thought which leaves a place open for them
serves only, like a void space, to limit the use of empirical
principles, without containing at the same time any other object of
cognition beyond their sphere.


Of the Equivocal Nature or Amphiboly of the Conceptions of Reflection
from the Confusion of the Transcendental with the Empirical use of the

Reflection (reflexio) is not occupied about objects themselves, for the
purpose of directly obtaining conceptions of them, but is that state of
the mind in which we set ourselves to discover the subjective
conditions under which we obtain conceptions. It is the consciousness
of the relation of given representations to the different sources or
faculties of cognition, by which alone their relation to each other can
be rightly determined. The first question which occurs in considering
our representations is to what faculty of cognition do they belong? To
the understanding or to the senses? Many judgements are admitted to be
true from mere habit or inclination; but, because reflection neither
precedes nor follows, it is held to be a judgement that has its origin
in the understanding. All judgements do not require examination, that
is, investigation into the grounds of their truth. For, when they are
immediately certain (for example: “Between two points there can be only
one straight line”), no better or less mediate test of their truth can
be found than that which they themselves contain and express. But all
judgement, nay, all comparisons require reflection, that is, a
distinction of the faculty of cognition to which the given conceptions
belong. The act whereby I compare my representations with the faculty
of cognition which originates them, and whereby I distinguish whether
they are compared with each other as belonging to the pure
understanding or to sensuous intuition, I term transcendental
reflection. Now, the relations in which conceptions can stand to each
other are those of identity and difference, agreement and opposition,
of the internal and external, finally, of the determinable and the
determining (matter and form). The proper determination of these
relations rests on the question, to what faculty of cognition they
subjectively belong, whether to sensibility or understanding? For, on
the manner in which we solve this question depends the manner in which
we must cogitate these relations.

Before constructing any objective judgement, we compare the conceptions
that are to be placed in the judgement, and observe whether there
exists identity (of many representations in one conception), if a
general judgement is to be constructed, or difference, if a particular;
whether there is agreement when affirmative; and opposition when
negative judgements are to be constructed, and so on. For this reason
we ought to call these conceptions, conceptions of comparison
(conceptus comparationis). But as, when the question is not as to the
logical form, but as to the content of conceptions, that is to say,
whether the things themselves are identical or different, in agreement
or opposition, and so on, the things can have a twofold relation to our
faculty of cognition, to wit, a relation either to sensibility or to
the understanding, and as on this relation depends their relation to
each other, transcendental reflection, that is, the relation of given
representations to one or the other faculty of cognition, can alone
determine this latter relation. Thus we shall not be able to discover
whether the things are identical or different, in agreement or
opposition, etc., from the mere conception of the things by means of
comparison (comparatio), but only by distinguishing the mode of
cognition to which they belong, in other words, by means of
transcendental reflection. We may, therefore, with justice say, that
logical reflection is mere comparison, for in it no account is taken of
the faculty of cognition to which the given conceptions belong, and
they are consequently, as far as regards their origin, to be treated as
homogeneous; while transcendental reflection (which applies to the
objects themselves) contains the ground of the possibility of objective
comparison of representations with each other, and is therefore very
different from the former, because the faculties of cognition to which
they belong are not even the same. Transcendental reflection is a duty
which no one can neglect who wishes to establish an a priori judgement
upon things. We shall now proceed to fulfil this duty, and thereby
throw not a little light on the question as to the determination of the
proper business of the understanding.

1. Identity and Difference. When an object is presented to us several
times, but always with the same internal determinations (qualitas et
quantitas), it, if an object of pure understanding, is always the same,
not several things, but only one thing (numerica identitas); but if a
phenomenon, we do not concern ourselves with comparing the conception
of the thing with the conception of some other, but, although they may
be in this respect perfectly the same, the difference of place at the
same time is a sufficient ground for asserting the numerical difference
of these objects (of sense). Thus, in the case of two drops of water,
we may make complete abstraction of all internal difference (quality
and quantity), and, the fact that they are intuited at the same time in
different places, is sufficient to justify us in holding them to be
numerically different. Leibnitz regarded phenomena as things in
themselves, consequently as intelligibilia, that is, objects of pure
understanding (although, on account of the confused nature of their
representations, he gave them the name of phenomena), and in this case
his principle of the indiscernible (principium identatis
indiscernibilium) is not to be impugned. But, as phenomena are objects
of sensibility, and, as the understanding, in respect of them, must be
employed empirically and not purely or transcendentally, plurality and
numerical difference are given by space itself as the condition of
external phenomena. For one part of space, although it may be perfectly
similar and equal to another part, is still without it, and for this
reason alone is different from the latter, which is added to it in
order to make up a greater space. It follows that this must hold good
of all things that are in the different parts of space at the same
time, however similar and equal one may be to another.

2. Agreement and Opposition. When reality is represented by the pure
understanding (realitas noumenon), opposition between realities is
incogitable—such a relation, that is, that when these realities are
connected in one subject, they annihilate the effects of each other and
may be represented in the formula 3 -3 = 0. On the other hand, the real
in a phenomenon (realitas phaenomenon) may very well be in mutual
opposition, and, when united in the same subject, the one may
completely or in part annihilate the effect or consequence of the
other; as in the case of two moving forces in the same straight line
drawing or impelling a point in opposite directions, or in the case of
a pleasure counterbalancing a certain amount of pain.

3. The Internal and External. In an object of the pure understanding,
only that is internal which has no relation (as regards its existence)
to anything different from itself. On the other hand, the internal
determinations of a substantia phaenomenon in space are nothing but
relations, and it is itself nothing more than a complex of mere
relations. Substance in space we are cognizant of only through forces
operative in it, either drawing others towards itself (attraction), or
preventing others from forcing into itself (repulsion and
impenetrability). We know no other properties that make up the
conception of substance phenomenal in space, and which we term matter.
On the other hand, as an object of the pure understanding, every
substance must have internal determination and forces. But what other
internal attributes of such an object can I think than those which my
internal sense presents to me? That, to wit, which in either itself
thought, or something analogous to it. Hence Leibnitz, who looked upon
things as noumena, after denying them everything like external
relation, and therefore also composition or combination, declared that
all substances, even the component parts of matter, were simple
substances with powers of representation, in one word, monads.

4. Matter and Form. These two conceptions lie at the foundation of all
other reflection, so inseparably are they connected with every mode of
exercising the understanding. The former denotes the determinable in
general, the second its determination, both in a transcendental sense,
abstraction being made of every difference in that which is given, and
of the mode in which it is determined. Logicians formerly termed the
universal, matter, the specific difference of this or that part of the
universal, form. In a judgement one may call the given conceptions
logical matter (for the judgement), the relation of these to each other
(by means of the copula), the form of the judgement. In an object, the
composite parts thereof (essentialia) are the matter; the mode in which
they are connected in the object, the form. In respect to things in
general, unlimited reality was regarded as the matter of all
possibility, the limitation thereof (negation) as the form, by which
one thing is distinguished from another according to transcendental
conceptions. The understanding demands that something be given (at
least in the conception), in order to be able to determine it in a
certain manner. Hence, in a conception of the pure understanding, the
matter precedes the form, and for this reason Leibnitz first assumed
the existence of things (monads) and of an internal power of
representation in them, in order to found upon this their external
relation and the community their state (that is, of their
representations). Hence, with him, space and time were possible—the
former through the relation of substances, the latter through the
connection of their determinations with each other, as causes and
effects. And so would it really be, if the pure understanding were
capable of an immediate application to objects, and if space and time
were determinations of things in themselves. But being merely sensuous
intuitions, in which we determine all objects solely as phenomena, the
form of intuition (as a subjective property of sensibility) must
antecede all matter (sensations), consequently space and time must
antecede all phenomena and all data of experience, and rather make
experience itself possible. But the intellectual philosopher could not
endure that the form should precede the things themselves and determine
their possibility; an objection perfectly correct, if we assume that we
intuite things as they are, although with confused representation. But
as sensuous intuition is a peculiar subjective condition, which is a
priori at the foundation of all perception, and the form of which is
primitive, the form must be given per se, and so far from matter (or
the things themselves which appear) lying at the foundation of
experience (as we must conclude, if we judge by mere conceptions), the
very possibility of itself presupposes, on the contrary, a given formal
intuition (space and time).


Let me be allowed to term the position which we assign to a conception
either in the sensibility or in the pure understanding, the
transcendental place. In this manner, the appointment of the position
which must be taken by each conception according to the difference in
its use, and the directions for determining this place to all
conceptions according to rules, would be a transcendental topic, a
doctrine which would thoroughly shield us from the surreptitious
devices of the pure understanding and the delusions which thence arise,
as it would always distinguish to what faculty of cognition each
conception properly belonged. Every conception, every title, under
which many cognitions rank together, may be called a logical place.
Upon this is based the logical topic of Aristotle, of which teachers
and rhetoricians could avail themselves, in order, under certain titles
of thought, to observe what would best suit the matter they had to
treat, and thus enable themselves to quibble and talk with fluency and
an appearance of profundity.

Transcendental topic, on the contrary, contains nothing more than the
above-mentioned four titles of all comparison and distinction, which
differ from categories in this respect, that they do not represent the
object according to that which constitutes its conception (quantity,
reality), but set forth merely the comparison of representations, which
precedes our conceptions of things. But this comparison requires a
previous reflection, that is, a determination of the place to which the
representations of the things which are compared belong, whether, to
wit, they are cogitated by the pure understanding, or given by

Conceptions may be logically compared without the trouble of inquiring
to what faculty their objects belong, whether as noumena, to the
understanding, or as phenomena, to sensibility. If, however, we wish to
employ these conceptions in respect of objects, previous transcendental
reflection is necessary. Without this reflection I should make a very
unsafe use of these conceptions, and construct pretended synthetical
propositions which critical reason cannot acknowledge and which are
based solely upon a transcendental amphiboly, that is, upon a
substitution of an object of pure understanding for a phenomenon.

For want of this doctrine of transcendental topic, and consequently
deceived by the amphiboly of the conceptions of reflection, the
celebrated Leibnitz constructed an intellectual system of the world, or
rather, believed himself competent to cognize the internal nature of
things, by comparing all objects merely with the understanding and the
abstract formal conceptions of thought. Our table of the conceptions of
reflection gives us the unexpected advantage of being able to exhibit
the distinctive peculiarities of his system in all its parts, and at
the same time of exposing the fundamental principle of this peculiar
mode of thought, which rested upon naught but a misconception. He
compared all things with each other merely by means of conceptions, and
naturally found no other differences than those by which the
understanding distinguishes its pure conceptions one from another. The
conditions of sensuous intuition, which contain in themselves their own
means of distinction, he did not look upon as primitive, because
sensibility was to him but a confused mode of representation and not
any particular source of representations. A phenomenon was for him the
representation of the thing in itself, although distinguished from
cognition by the understanding only in respect of the logical form—the
former with its usual want of analysis containing, according to him, a
certain mixture of collateral representations in its conception of a
thing, which it is the duty of the understanding to separate and
distinguish. In one word, Leibnitz intellectualized phenomena, just as
Locke, in his system of noogony (if I may be allowed to make use of
such expressions), sensualized the conceptions of the understanding,
that is to say, declared them to be nothing more than empirical or
abstract conceptions of reflection. Instead of seeking in the
understanding and sensibility two different sources of representations,
which, however, can present us with objective judgements of things only
in conjunction, each of these great men recognized but one of these
faculties, which, in their opinion, applied immediately to things in
themselves, the other having no duty but that of confusing or arranging
the representations of the former.

Accordingly, the objects of sense were compared by Leibnitz as things
in general merely in the understanding.

1st. He compares them in regard to their identity or difference—as
judged by the understanding. As, therefore, he considered merely the
conceptions of objects, and not their position in intuition, in which
alone objects can be given, and left quite out of sight the
transcendental locale of these conceptions—whether, that is, their
object ought to be classed among phenomena, or among things in
themselves, it was to be expected that he should extend the application
of the principle of indiscernibles, which is valid solely of
conceptions of things in general, to objects of sense (mundus
phaenomenon), and that he should believe that he had thereby
contributed in no small degree to extend our knowledge of nature. In
truth, if I cognize in all its inner determinations a drop of water as
a thing in itself, I cannot look upon one drop as different from
another, if the conception of the one is completely identical with that
of the other. But if it is a phenomenon in space, it has a place not
merely in the understanding (among conceptions), but also in sensuous
external intuition (in space), and in this case, the physical locale is
a matter of indifference in regard to the internal determinations of
things, and one place, B, may contain a thing which is perfectly
similar and equal to another in a place, A, just as well as if the two
things were in every respect different from each other. Difference of
place without any other conditions, makes the plurality and distinction
of objects as phenomena, not only possible in itself, but even
necessary. Consequently, the above so-called law is not a law of
nature. It is merely an analytical rule for the comparison of things by
means of mere conceptions.

2nd. The principle: “Realities (as simple affirmations) never logically
contradict each other,” is a proposition perfectly true respecting the
relation of conceptions, but, whether as regards nature, or things in
themselves (of which we have not the slightest conception), is without
any the least meaning. For real opposition, in which A -B is = 0,
exists everywhere, an opposition, that is, in which one reality united
with another in the same subject annihilates the effects of the other—a
fact which is constantly brought before our eyes by the different
antagonistic actions and operations in nature, which, nevertheless, as
depending on real forces, must be called realitates phaenomena. General
mechanics can even present us with the empirical condition of this
opposition in an a priori rule, as it directs its attention to the
opposition in the direction of forces—a condition of which the
transcendental conception of reality can tell us nothing. Although M.
Leibnitz did not announce this proposition with precisely the pomp of a
new principle, he yet employed it for the establishment of new
propositions, and his followers introduced it into their
Leibnitzio-Wolfian system of philosophy. According to this principle,
for example, all evils are but consequences of the limited nature of
created beings, that is, negations, because these are the only opposite
of reality. (In the mere conception of a thing in general this is
really the case, but not in things as phenomena.) In like manner, the
upholders of this system deem it not only possible, but natural also,
to connect and unite all reality in one being, because they acknowledge
no other sort of opposition than that of contradiction (by which the
conception itself of a thing is annihilated), and find themselves
unable to conceive an opposition of reciprocal destruction, so to
speak, in which one real cause destroys the effect of another, and the
conditions of whose representation we meet with only in sensibility.

3rd. The Leibnitzian monadology has really no better foundation than on
this philosopher’s mode of falsely representing the difference of the
internal and external solely in relation to the understanding.
Substances, in general, must have something inward, which is therefore
free from external relations, consequently from that of composition
also. The simple—that which can be represented by a unit—is therefore
the foundation of that which is internal in things in themselves. The
internal state of substances cannot therefore consist in place, shape,
contact, or motion, determinations which are all external relations,
and we can ascribe to them no other than that whereby we internally
determine our faculty of sense itself, that is to say, the state of
representation. Thus, then, were constructed the monads, which were to
form the elements of the universe, the active force of which consists
in representation, the effects of this force being thus entirely
confined to themselves.

For the same reason, his view of the possible community of substances
could not represent it but as a predetermined harmony, and by no means
as a physical influence. For inasmuch as everything is occupied only
internally, that is, with its own representations, the state of the
representations of one substance could not stand in active and living
connection with that of another, but some third cause operating on all
without exception was necessary to make the different states correspond
with one another. And this did not happen by means of assistance
applied in each particular case (systema assistentiae), but through the
unity of the idea of a cause occupied and connected with all
substances, in which they necessarily receive, according to the
Leibnitzian school, their existence and permanence, consequently also
reciprocal correspondence, according to universal laws.

4th. This philosopher’s celebrated doctrine of space and time, in which
he intellectualized these forms of sensibility, originated in the same
delusion of transcendental reflection. If I attempt to represent by the
mere understanding, the external relations of things, I can do so only
by employing the conception of their reciprocal action, and if I wish
to connect one state of the same thing with another state, I must avail
myself of the notion of the order of cause and effect. And thus
Leibnitz regarded space as a certain order in the community of
substances, and time as the dynamical sequence of their states. That
which space and time possess proper to themselves and independent of
things, he ascribed to a necessary confusion in our conceptions of
them, whereby that which is a mere form of dynamical relations is held
to be a self-existent intuition, antecedent even to things themselves.
Thus space and time were the intelligible form of the connection of
things (substances and their states) in themselves. But things were
intelligible substances (substantiae noumena). At the same time, he
made these conceptions valid of phenomena, because he did not allow to
sensibility a peculiar mode of intuition, but sought all, even the
empirical representation of objects, in the understanding, and left to
sense naught but the despicable task of confusing and disarranging the
representations of the former.

But even if we could frame any synthetical proposition concerning
things in themselves by means of the pure understanding (which is
impossible), it could not apply to phenomena, which do not represent
things in themselves. In such a case I should be obliged in
transcendental reflection to compare my conceptions only under the
conditions of sensibility, and so space and time would not be
determinations of things in themselves, but of phenomena. What things
may be in themselves, I know not and need not know, because a thing is
never presented to me otherwise than as a phenomenon.

I must adopt the same mode of procedure with the other conceptions of
reflection. Matter is substantia phaenomenon. That in it which is
internal I seek to discover in all parts of space which it occupies,
and in all the functions and operations it performs, and which are
indeed never anything but phenomena of the external sense. I cannot
therefore find anything that is absolutely, but only what is
comparatively internal, and which itself consists of external
relations. The absolutely internal in matter, and as it should be
according to the pure understanding, is a mere chimera, for matter is
not an object for the pure understanding. But the transcendental
object, which is the foundation of the phenomenon which we call matter,
is a mere nescio quid, the nature of which we could not understand,
even though someone were found able to tell us. For we can understand
nothing that does not bring with it something in intuition
corresponding to the expressions employed. If, by the complaint of
being unable to perceive the internal nature of things, it is meant
that we do not comprehend by the pure understanding what the things
which appear to us may be in themselves, it is a silly and unreasonable
complaint; for those who talk thus really desire that we should be able
to cognize, consequently to intuite, things without senses, and
therefore wish that we possessed a faculty of cognition perfectly
different from the human faculty, not merely in degree, but even as
regards intuition and the mode thereof, so that thus we should not be
men, but belong to a class of beings, the possibility of whose
existence, much less their nature and constitution, we have no means of
cognizing. By observation and analysis of phenomena we penetrate into
the interior of nature, and no one can say what progress this knowledge
may make in time. But those transcendental questions which pass beyond
the limits of nature, we could never answer, even although all nature
were laid open to us, because we have not the power of observing our
own mind with any other intuition than that of our internal sense. For
herein lies the mystery of the origin and source of our faculty of
sensibility. Its application to an object, and the transcendental
ground of this unity of subjective and objective, lie too deeply
concealed for us, who cognize ourselves only through the internal
sense, consequently as phenomena, to be able to discover in our
existence anything but phenomena, the non-sensuous cause of which we at
the same time earnestly desire to penetrate to.

The great utility of this critique of conclusions arrived at by the
processes of mere reflection consists in its clear demonstration of the
nullity of all conclusions respecting objects which are compared with
each other in the understanding alone, while it at the same time
confirms what we particularly insisted on, namely, that, although
phenomena are not included as things in themselves among the objects of
the pure understanding, they are nevertheless the only things by which
our cognition can possess objective reality, that is to say, which give
us intuitions to correspond with our conceptions.

When we reflect in a purely logical manner, we do nothing more than
compare conceptions in our understanding, to discover whether both have
the same content, whether they are self-contradictory or not, whether
anything is contained in either conception, which of the two is given,
and which is merely a mode of thinking that given. But if I apply these
conceptions to an object in general (in the transcendental sense),
without first determining whether it is an object of sensuous or
intellectual intuition, certain limitations present themselves, which
forbid us to pass beyond the conceptions and render all empirical use
of them impossible. And thus these limitations prove that the
representation of an object as a thing in general is not only
insufficient, but, without sensuous determination and independently of
empirical conditions, self-contradictory; that we must therefore make
abstraction of all objects, as in logic, or, admitting them, must think
them under conditions of sensuous intuition; that, consequently, the
intelligible requires an altogether peculiar intuition, which we do not
possess, and in the absence of which it is for us nothing; while, on
the other hand phenomena cannot be objects in themselves. For, when I
merely think things in general, the difference in their external
relations cannot constitute a difference in the things themselves; on
the contrary, the former presupposes the latter, and if the conception
of one of two things is not internally different from that of the
other, I am merely thinking the same thing in different relations.
Further, by the addition of one affirmation (reality) to the other, the
positive therein is really augmented, and nothing is abstracted or
withdrawn from it; hence the real in things cannot be in contradiction
with or opposition to itself—and so on.

The true use of the conceptions of reflection in the employment of the
understanding has, as we have shown, been so misconceived by Leibnitz,
one of the most acute philosophers of either ancient or modern times,
that he has been misled into the construction of a baseless system of
intellectual cognition, which professes to determine its objects
without the intervention of the senses. For this reason, the exposition
of the cause of the amphiboly of these conceptions, as the origin of
these false principles, is of great utility in determining with
certainty the proper limits of the understanding.

It is right to say whatever is affirmed or denied of the whole of a
conception can be affirmed or denied of any part of it (dictum de omni
et nullo); but it would be absurd so to alter this logical proposition
as to say whatever is not contained in a general conception is likewise
not contained in the particular conceptions which rank under it; for
the latter are particular conceptions, for the very reason that their
content is greater than that which is cogitated in the general
conception. And yet the whole intellectual system of Leibnitz is based
upon this false principle, and with it must necessarily fall to the
ground, together with all the ambiguous principles in reference to the
employment of the understanding which have thence originated.

Leibnitz’s principle of the identity of indiscernibles or
indistinguishables is really based on the presupposition that, if in
the conception of a thing a certain distinction is not to be found, it
is also not to be met with in things themselves; that, consequently,
all things are completely identical (numero eadem) which are not
distinguishable from each other (as to quality or quantity) in our
conceptions of them. But, as in the mere conception of anything
abstraction has been made of many necessary conditions of intuition,
that of which abstraction has been made is rashly held to be
non-existent, and nothing is attributed to the thing but what is
contained in its conception.

The conception of a cubic foot of space, however I may think it, is in
itself completely identical. But two cubic feet in space are
nevertheless distinct from each other from the sole fact of their being
in different places (they are numero diversa); and these places are
conditions of intuition, wherein the object of this conception is
given, and which do not belong to the conception, but to the faculty of
sensibility. In like manner, there is in the conception of a thing no
contradiction when a negative is not connected with an affirmative; and
merely affirmative conceptions cannot, in conjunction, produce any
negation. But in sensuous intuition, wherein reality (take for example,
motion) is given, we find conditions (opposite directions)—of which
abstraction has been made in the conception of motion in general—which
render possible a contradiction or opposition (not indeed of a logical
kind)—and which from pure positives produce zero = 0. We are therefore
not justified in saying that all reality is in perfect agreement and
harmony, because no contradiction is discoverable among its
conceptions.* According to mere conceptions, that which is internal is
the substratum of all relations or external determinations. When,
therefore, I abstract all conditions of intuition, and confine myself
solely to the conception of a thing in general, I can make abstraction
of all external relations, and there must nevertheless remain a
conception of that which indicates no relation, but merely internal
determinations. Now it seems to follow that in everything (substance)
there is something which is absolutely internal and which antecedes all
external determinations, inasmuch as it renders them possible; and that
therefore this substratum is something which does not contain any
external relations and is consequently simple (for corporeal things are
never anything but relations, at least of their parts external to each
other); and, inasmuch as we know of no other absolutely internal
determinations than those of the internal sense, this substratum is not
only simple, but also, analogously with our internal sense, determined
through representations, that is to say, all things are properly
monads, or simple beings endowed with the power of representation. Now
all this would be perfectly correct, if the conception of a thing were
the only necessary condition of the presentation of objects of external
intuition. It is, on the contrary, manifest that a permanent phenomenon
in space (impenetrable extension) can contain mere relations, and
nothing that is absolutely internal, and yet be the primary substratum
of all external perception. By mere conceptions I cannot think anything
external, without, at the same time, thinking something internal, for
the reason that conceptions of relations presuppose given things, and
without these are impossible. But, as an intuition there is something
(that is, space, which, with all it contains, consists of purely
formal, or, indeed, real relations) which is not found in the mere
conception of a thing in general, and this presents to us the
substratum which could not be cognized through conceptions alone, I
cannot say: because a thing cannot be represented by mere conceptions
without something absolutely internal, there is also, in the things
themselves which are contained under these conceptions, and in their
intuition nothing external to which something absolutely internal does
not serve as the foundation. For, when we have made abstraction of all
the conditions of intuition, there certainly remains in the mere
conception nothing but the internal in general, through which alone the
external is possible. But this necessity, which is grounded upon
abstraction alone, does not obtain in the case of things themselves, in
so far as they are given in intuition with such determinations as
express mere relations, without having anything internal as their
foundation; for they are not things of a thing of which we can neither
for they are not things in themselves, but only phenomena. What we
cognize in matter is nothing but relations (what we call its internal
determinations are but comparatively internal). But there are some
self-subsistent and permanent, through which a determined object is
given. That I, when abstraction is made of these relations, have
nothing more to think, does not destroy the conception of a thing as
phenomenon, nor the conception of an object in abstracto, but it does
away with the possibility of an object that is determinable according
to mere conceptions, that is, of a noumenon. It is certainly startling
to hear that a thing consists solely of relations; but this thing is
simply a phenomenon, and cannot be cogitated by means of the mere
categories: it does itself consist in the mere relation of something in
general to the senses. In the same way, we cannot cogitate relations of
things in abstracto, if we commence with conceptions alone, in any
other manner than that one is the cause of determinations in the other;
for that is itself the conception of the understanding or category of
relation. But, as in this case we make abstraction of all intuition, we
lose altogether the mode in which the manifold determines to each of
its parts its place, that is, the form of sensibility (space); and yet
this mode antecedes all empirical causality.

[*Footnote: If any one wishes here to have recourse to the usual
subterfuge, and to say, that at least realitates noumena cannot be in
opposition to each other, it will be requisite for him to adduce an
example of this pure and non-sensuous reality, that it may be
understood whether the notion represents something or nothing. But an
example cannot be found except in experience, which never presents to
us anything more than phenomena; and thus the proposition means nothing
more than that the conception which contains only affirmatives does not
contain anything negative—a proposition nobody ever doubted.]

If by intelligible objects we understand things which can be thought by
means of the pure categories, without the need of the schemata of
sensibility, such objects are impossible. For the condition of the
objective use of all our conceptions of understanding is the mode of
our sensuous intuition, whereby objects are given; and, if we make
abstraction of the latter, the former can have no relation to an
object. And even if we should suppose a different kind of intuition
from our own, still our functions of thought would have no use or
signification in respect thereof. But if we understand by the term,
objects of a non-sensuous intuition, in respect of which our categories
are not valid, and of which we can accordingly have no knowledge
(neither intuition nor conception), in this merely negative sense
noumena must be admitted. For this is no more than saying that our mode
of intuition is not applicable to all things, but only to objects of
our senses, that consequently its objective validity is limited, and
that room is therefore left for another kind of intuition, and thus
also for things that may be objects of it. But in this sense the
conception of a noumenon is problematical, that is to say, it is the
notion of that it that it is possible, nor that it is impossible,
inasmuch as we do not know of any mode of intuition besides the
sensuous, or of any other sort of conceptions than the categories—a
mode of intuition and a kind of conception neither of which is
applicable to a non-sensuous object. We are on this account incompetent
to extend the sphere of our objects of thought beyond the conditions of
our sensibility, and to assume the existence of objects of pure
thought, that is, of noumena, inasmuch as these have no true positive
signification. For it must be confessed of the categories that they are
not of themselves sufficient for the cognition of things in themselves
and, without the data of sensibility, are mere subjective forms of the
unity of the understanding. Thought is certainly not a product of the
senses, and in so far is not limited by them, but it does not therefore
follow that it may be employed purely and without the intervention of
sensibility, for it would then be without reference to an object. And
we cannot call a noumenon an object of pure thought; for the
representation thereof is but the problematical conception of an object
for a perfectly different intuition and a perfectly different
understanding from ours, both of which are consequently themselves
problematical. The conception of a noumenon is therefore not the
conception of an object, but merely a problematical conception
inseparably connected with the limitation of our sensibility. That is
to say, this conception contains the answer to the question: “Are there
objects quite unconnected with, and independent of, our intuition?”—a
question to which only an indeterminate answer can be given. That
answer is: “Inasmuch as sensuous intuition does not apply to all things
without distinction, there remains room for other and different
objects.” The existence of these problematical objects is therefore not
absolutely denied, in the absence of a determinate conception of them,
but, as no category is valid in respect of them, neither must they be
admitted as objects for our understanding.

Understanding accordingly limits sensibility, without at the same time
enlarging its own field. While, moreover, it forbids sensibility to
apply its forms and modes to things in themselves and restricts it to
the sphere of phenomena, it cogitates an object in itself, only,
however, as a transcendental object, which is the cause of a phenomenon
(consequently not itself a phenomenon), and which cannot be thought
either as a quantity or as reality, or as substance (because these
conceptions always require sensuous forms in which to determine an
object)—an object, therefore, of which we are quite unable to say
whether it can be met with in ourselves or out of us, whether it would
be annihilated together with sensibility, or, if this were taken away,
would continue to exist. If we wish to call this object a noumenon,
because the representation of it is non-sensuous, we are at liberty to
do so. But as we can apply to it none of the conceptions of our
understanding, the representation is for us quite void, and is
available only for the indication of the limits of our sensuous
intuition, thereby leaving at the same time an empty space, which we
are competent to fill by the aid neither of possible experience, nor of
the pure understanding.

The critique of the pure understanding, accordingly, does not permit us
to create for ourselves a new field of objects beyond those which are
presented to us as phenomena, and to stray into intelligible worlds;
nay, it does not even allow us to endeavour to form so much as a
conception of them. The specious error which leads to this—and which is
a perfectly excusable one—lies in the fact that the employment of the
understanding, contrary to its proper purpose and destination, is made
transcendental, and objects, that is, possible intuitions, are made to
regulate themselves according to conceptions, instead of the
conceptions arranging themselves according to the intuitions, on which
alone their own objective validity rests. Now the reason of this again
is that apperception, and with it thought, antecedes all possible
determinate arrangement of representations. Accordingly we think
something in general and determine it on the one hand sensuously, but,
on the other, distinguish the general and in abstracto represented
object from this particular mode of intuiting it. In this case there
remains a mode of determining the object by mere thought, which is
really but a logical form without content, which, however, seems to us
to be a mode of the existence of the object in itself (noumenon),
without regard to intuition which is limited to our senses.

Before ending this transcendental analytic, we must make an addition,
which, although in itself of no particular importance, seems to be
necessary to the completeness of the system. The highest conception,
with which a transcendental philosophy commonly begins, is the division
into possible and impossible. But as all division presupposes a divided
conception, a still higher one must exist, and this is the conception
of an object in general—problematically understood and without its
being decided whether it is something or nothing. As the categories are
the only conceptions which apply to objects in general, the
distinguishing of an object, whether it is something or nothing, must
proceed according to the order and direction of the categories.

1. To the categories of quantity, that is, the conceptions of all,
many, and one, the conception which annihilates all, that is, the
conception of none, is opposed. And thus the object of a conception, to
which no intuition can be found to correspond, is = nothing. That is,
it is a conception without an object (ens rationis), like noumena,
which cannot be considered possible in the sphere of reality, though
they must not therefore be held to be impossible—or like certain new
fundamental forces in matter, the existence of which is cogitable
without contradiction, though, as examples from experience are not
forthcoming, they must not be regarded as possible.

2. Reality is something; negation is nothing, that is, a conception of
the absence of an object, as cold, a shadow (nihil privativum).

3. The mere form of intuition, without substance, is in itself no
object, but the merely formal condition of an object (as phenomenon),
as pure space and pure time. These are certainly something, as forms of
intuition, but are not themselves objects which are intuited (ens

4. The object of a conception which is self-contradictory, is nothing,
because the conception is nothing—is impossible, as a figure composed
of two straight lines (nihil negativum).

The table of this division of the conception of nothing (the
corresponding division of the conception of something does not require
special description) must therefore be arranged as follows:

                      NOTHING AS

                        1 As Empty Conception without object, _ens
                        rationis_ 2                               3
                        Empty object of               Empty intuition a
                        conception,                without object,
                        _nihil privativum              ens imaginarium_
                        4 Empty object without conception, _nihil

We see that the ens rationis is distinguished from the nihil negativum
or pure nothing by the consideration that the former must not be
reckoned among possibilities, because it is a mere fiction—though not
self-contradictory, while the latter is completely opposed to all
possibility, inasmuch as the conception annihilates itself. Both,
however, are empty conceptions. On the other hand, the nihil privativum
and ens imaginarium are empty data for conceptions. If light be not
given to the senses, we cannot represent to ourselves darkness, and if
extended objects are not perceived, we cannot represent space. Neither
the negation, nor the mere form of intuition can, without something
real, be an object.




 I. Of Transcendental Illusory Appearance

We termed dialectic in general a logic of appearance. This does not
signify a doctrine of probability; for probability is truth, only
cognized upon insufficient grounds, and though the information it gives
us is imperfect, it is not therefore deceitful. Hence it must not be
separated from the analytical part of logic. Still less must phenomenon
and appearance be held to be identical. For truth or illusory
appearance does not reside in the object, in so far as it is intuited,
but in the judgement upon the object, in so far as it is thought. It
is, therefore, quite correct to say that the senses do not err, not
because they always judge correctly, but because they do not judge at
all. Hence truth and error, consequently also, illusory appearance as
the cause of error, are only to be found in a judgement, that is, in
the relation of an object to our understanding. In a cognition which
completely harmonizes with the laws of the understanding, no error can
exist. In a representation of the senses—as not containing any
judgement—there is also no error. But no power of nature can of itself
deviate from its own laws. Hence neither the understanding per se
(without the influence of another cause), nor the senses per se, would
fall into error; the former could not, because, if it acts only
according to its own laws, the effect (the judgement) must necessarily
accord with these laws. But in accordance with the laws of the
understanding consists the formal element in all truth. In the senses
there is no judgement—neither a true nor a false one. But, as we have
no source of cognition besides these two, it follows that error is
caused solely by the unobserved influence of the sensibility upon the
understanding. And thus it happens that the subjective grounds of a
judgement and are confounded with the objective, and cause them to
deviate from their proper determination,* just as a body in motion
would always of itself proceed in a straight line, but if another
impetus gives to it a different direction, it will then start off into
a curvilinear line of motion. To distinguish the peculiar action of the
understanding from the power which mingles with it, it is necessary to
consider an erroneous judgement as the diagonal between two forces,
that determine the judgement in two different directions, which, as it
were, form an angle, and to resolve this composite operation into the
simple ones of the understanding and the sensibility. In pure a priori
judgements this must be done by means of transcendental reflection,
whereby, as has been already shown, each representation has its place
appointed in the corresponding faculty of cognition, and consequently
the influence of the one faculty upon the other is made apparent.

[*Footnote: Sensibility, subjected to the understanding, as the object
upon which the understanding employs its functions, is the source of
real cognitions. But, in so far as it exercises an influence upon the
action of the understanding and determines it to judgement, sensibility
is itself the cause of error.]

It is not at present our business to treat of empirical illusory
appearance (for example, optical illusion), which occurs in the
empirical application of otherwise correct rules of the understanding,
and in which the judgement is misled by the influence of imagination.
Our purpose is to speak of transcendental illusory appearance, which
influences principles—that are not even applied to experience, for in
this case we should possess a sure test of their correctness—but which
leads us, in disregard of all the warnings of criticism, completely
beyond the empirical employment of the categories and deludes us with
the chimera of an extension of the sphere of the pure understanding. We
shall term those principles the application of which is confined
entirely within the limits of possible experience, immanent; those, on
the other hand, which transgress these limits, we shall call
transcendent principles. But by these latter I do not understand
principles of the transcendental use or misuse of the categories, which
is in reality a mere fault of the judgement when not under due
restraint from criticism, and therefore not paying sufficient attention
to the limits of the sphere in which the pure understanding is allowed
to exercise its functions; but real principles which exhort us to break
down all those barriers, and to lay claim to a perfectly new field of
cognition, which recognizes no line of demarcation. Thus transcendental
and transcendent are not identical terms. The principles of the pure
understanding, which we have already propounded, ought to be of
empirical and not of transcendental use, that is, they are not
applicable to any object beyond the sphere of experience. A principle
which removes these limits, nay, which authorizes us to overstep them,
is called transcendent. If our criticism can succeed in exposing the
illusion in these pretended principles, those which are limited in
their employment to the sphere of experience may be called, in
opposition to the others, immanent principles of the pure

Logical illusion, which consists merely in the imitation of the form of
reason (the illusion in sophistical syllogisms), arises entirely from a
want of due attention to logical rules. So soon as the attention is
awakened to the case before us, this illusion totally disappears.
Transcendental illusion, on the contrary, does not cease to exist, even
after it has been exposed, and its nothingness clearly perceived by
means of transcendental criticism. Take, for example, the illusion in
the proposition: “The world must have a beginning in time.” The cause
of this is as follows. In our reason, subjectively considered as a
faculty of human cognition, there exist fundamental rules and maxims of
its exercise, which have completely the appearance of objective
principles. Now from this cause it happens that the subjective
necessity of a certain connection of our conceptions, is regarded as an
objective necessity of the determination of things in themselves. This
illusion it is impossible to avoid, just as we cannot avoid perceiving
that the sea appears to be higher at a distance than it is near the
shore, because we see the former by means of higher rays than the
latter, or, which is a still stronger case, as even the astronomer
cannot prevent himself from seeing the moon larger at its rising than
some time afterwards, although he is not deceived by this illusion.

Transcendental dialectic will therefore content itself with exposing
the illusory appearance in transcendental judgements, and guarding us
against it; but to make it, as in the case of logical illusion,
entirely disappear and cease to be illusion is utterly beyond its
power. For we have here to do with a natural and unavoidable illusion,
which rests upon subjective principles and imposes these upon us as
objective, while logical dialectic, in the detection of sophisms, has
to do merely with an error in the logical consequence of the
propositions, or with an artificially constructed illusion, in
imitation of the natural error. There is, therefore, a natural and
unavoidable dialectic of pure reason—not that in which the bungler,
from want of the requisite knowledge, involves himself, nor that which
the sophist devises for the purpose of misleading, but that which is an
inseparable adjunct of human reason, and which, even after its
illusions have been exposed, does not cease to deceive, and continually
to lead reason into momentary errors, which it becomes necessary
continually to remove.

 II. Of Pure Reason as the Seat of Transcendental Illusory Appearance


All our knowledge begins with sense, proceeds thence to understanding,
and ends with reason, beyond which nothing higher can be discovered in
the human mind for elaborating the matter of intuition and subjecting
it to the highest unity of thought. At this stage of our inquiry it is
my duty to give an explanation of this, the highest faculty of
cognition, and I confess I find myself here in some difficulty. Of
reason, as of the understanding, there is a merely formal, that is,
logical use, in which it makes abstraction of all content of cognition;
but there is also a real use, inasmuch as it contains in itself the
source of certain conceptions and principles, which it does not borrow
either from the senses or the understanding. The former faculty has
been long defined by logicians as the faculty of mediate conclusion in
contradistinction to immediate conclusions (consequentiae immediatae);
but the nature of the latter, which itself generates conceptions, is
not to be understood from this definition. Now as a division of reason
into a logical and a transcendental faculty presents itself here, it
becomes necessary to seek for a higher conception of this source of
cognition which shall comprehend both conceptions. In this we may
expect, according to the analogy of the conceptions of the
understanding, that the logical conception will give us the key to the
transcendental, and that the table of the functions of the former will
present us with the clue to the conceptions of reason.

In the former part of our transcendental logic, we defined the
understanding to be the faculty of rules; reason may be distinguished
from understanding as the faculty of principles.

The term principle is ambiguous, and commonly signifies merely a
cognition that may be employed as a principle, although it is not in
itself, and as regards its proper origin, entitled to the distinction.
Every general proposition, even if derived from experience by the
process of induction, may serve as the major in a syllogism; but it is
not for that reason a principle. Mathematical axioms (for example,
there can be only one straight line between two points) are general a
priori cognitions, and are therefore rightly denominated principles,
relatively to the cases which can be subsumed under them. But I cannot
for this reason say that I cognize this property of a straight line
from principles—I cognize it only in pure intuition.

Cognition from principles, then, is that cognition in which I cognize
the particular in the general by means of conceptions. Thus every
syllogism is a form of the deduction of a cognition from a principle.
For the major always gives a conception, through which everything that
is subsumed under the condition thereof is cognized according to a
principle. Now as every general cognition may serve as the major in a
syllogism, and the understanding presents us with such general a priori
propositions, they may be termed principles, in respect of their
possible use.

But if we consider these principles of the pure understanding in
relation to their origin, we shall find them to be anything rather than
cognitions from conceptions. For they would not even be possible a
priori, if we could not rely on the assistance of pure intuition (in
mathematics), or on that of the conditions of a possible experience.
That everything that happens has a cause, cannot be concluded from the
general conception of that which happens; on the contrary the principle
of causality instructs us as to the mode of obtaining from that which
happens a determinate empirical conception.

Synthetical cognitions from conceptions the understanding cannot
supply, and they alone are entitled to be called principles. At the
same time, all general propositions may be termed comparative

It has been a long-cherished wish—that (who knows how late), may one
day, be happily accomplished—that the principles of the endless variety
of civil laws should be investigated and exposed; for in this way alone
can we find the secret of simplifying legislation. But in this case,
laws are nothing more than limitations of our freedom upon conditions
under which it subsists in perfect harmony with itself; they
consequently have for their object that which is completely our own
work, and of which we ourselves may be the cause by means of these
conceptions. But how objects as things in themselves—how the nature of
things is subordinated to principles and is to be determined, according
to conceptions, is a question which it seems well nigh impossible to
answer. Be this, however, as it may—for on this point our investigation
is yet to be made—it is at least manifest from what we have said that
cognition from principles is something very different from cognition by
means of the understanding, which may indeed precede other cognitions
in the form of a principle, but in itself—in so far as it is
synthetical—is neither based upon mere thought, nor contains a general
proposition drawn from conceptions alone.

The understanding may be a faculty for the production of unity of
phenomena by virtue of rules; the reason is a faculty for the
production of unity of rules (of the understanding) under principles.
Reason, therefore, never applies directly to experience, or to any
sensuous object; its object is, on the contrary, the understanding, to
the manifold cognition of which it gives a unity a priori by means of
conceptions—a unity which may be called rational unity, and which is of
a nature very different from that of the unity produced by the

The above is the general conception of the faculty of reason, in so far
as it has been possible to make it comprehensible in the absence of
examples. These will be given in the sequel.


A distinction is commonly made between that which is immediately
cognized and that which is inferred or concluded. That in a figure
which is bounded by three straight lines there are three angles, is an
immediate cognition; but that these angles are together equal to two
right angles, is an inference or conclusion. Now, as we are constantly
employing this mode of thought and have thus become quite accustomed to
it, we no longer remark the above distinction, and, as in the case of
the so-called deceptions of sense, consider as immediately perceived,
what has really been inferred. In every reasoning or syllogism, there
is a fundamental proposition, afterwards a second drawn from it, and
finally the conclusion, which connects the truth in the first with the
truth in the second—and that infallibly. If the judgement concluded is
so contained in the first proposition that it can be deduced from it
without the meditation of a third notion, the conclusion is called
immediate (consequentia immediata); I prefer the term conclusion of the
understanding. But if, in addition to the fundamental cognition, a
second judgement is necessary for the production of the conclusion, it
is called a conclusion of the reason. In the proposition: All men are
mortal, are contained the propositions: Some men are mortal, Nothing
that is not mortal is a man, and these are therefore immediate
conclusions from the first. On the other hand, the proposition: all the
learned are mortal, is not contained in the main proposition (for the
conception of a learned man does not occur in it), and it can be
deduced from the main proposition only by means of a mediating

In every syllogism I first cogitate a rule (the major) by means of the
understanding. In the next place I subsume a cognition under the
condition of the rule (and this is the minor) by means of the
judgement. And finally I determine my cognition by means of the
predicate of the rule (this is the conclusio), consequently, I
determine it a priori by means of the reason. The relations, therefore,
which the major proposition, as the rule, represents between a
cognition and its condition, constitute the different kinds of
syllogisms. These are just threefold—analogously with all judgements,
in so far as they differ in the mode of expressing the relation of a
cognition in the understanding—namely, categorical, hypothetical, and

When as often happens, the conclusion is a judgement which may follow
from other given judgements, through which a perfectly different object
is cogitated, I endeavour to discover in the understanding whether the
assertion in this conclusion does not stand under certain conditions
according to a general rule. If I find such a condition, and if the
object mentioned in the conclusion can be subsumed under the given
condition, then this conclusion follows from a rule which is also valid
for other objects of cognition. From this we see that reason endeavours
to subject the great variety of the cognitions of the understanding to
the smallest possible number of principles (general conditions), and
thus to produce in it the highest unity.


Can we isolate reason, and, if so, is it in this case a peculiar source
of conceptions and judgements which spring from it alone, and through
which it can be applied to objects; or is it merely a subordinate
faculty, whose duty it is to give a certain form to given cognitions—a
form which is called logical, and through which the cognitions of the
understanding are subordinated to each other, and lower rules to higher
(those, to wit, whose condition comprises in its sphere the condition
of the others), in so far as this can be done by comparison? This is
the question which we have at present to answer. Manifold variety of
rules and unity of principles is a requirement of reason, for the
purpose of bringing the understanding into complete accordance with
itself, just as understanding subjects the manifold content of
intuition to conceptions, and thereby introduces connection into it.
But this principle prescribes no law to objects, and does not contain
any ground of the possibility of cognizing or of determining them as
such, but is merely a subjective law for the proper arrangement of the
content of the understanding. The purpose of this law is, by a
comparison of the conceptions of the understanding, to reduce them to
the smallest possible number, although, at the same time, it does not
justify us in demanding from objects themselves such a uniformity as
might contribute to the convenience and the enlargement of the sphere
of the understanding, or in expecting that it will itself thus receive
from them objective validity. In one word, the question is: “does
reason in itself, that is, does pure reason contain a priori
synthetical principles and rules, and what are those principles?”

The formal and logical procedure of reason in syllogisms gives us
sufficient information in regard to the ground on which the
transcendental principle of reason in its pure synthetical cognition
will rest.

1. Reason, as observed in the syllogistic process, is not applicable to
intuitions, for the purpose of subjecting them to rules—for this is the
province of the understanding with its categories—but to conceptions
and judgements. If pure reason does apply to objects and the intuition
of them, it does so not immediately, but mediately—through the
understanding and its judgements, which have a direct relation to the
senses and their intuition, for the purpose of determining their
objects. The unity of reason is therefore not the unity of a possible
experience, but is essentially different from this unity, which is that
of the understanding. That everything which happens has a cause, is not
a principle cognized and prescribed by reason. This principle makes the
unity of experience possible and borrows nothing from reason, which,
without a reference to possible experience, could never have produced
by means of mere conceptions any such synthetical unity.

2. Reason, in its logical use, endeavours to discover the general
condition of its judgement (the conclusion), and a syllogism is itself
nothing but a judgement by means of the subsumption of its condition
under a general rule (the major). Now as this rule may itself be
subjected to the same process of reason, and thus the condition of the
condition be sought (by means of a prosyllogism) as long as the process
can be continued, it is very manifest that the peculiar principle of
reason in its logical use is to find for the conditioned cognition of
the understanding the unconditioned whereby the unity of the former is

But this logical maxim cannot be a principle of pure reason, unless we
admit that, if the conditioned is given, the whole series of conditions
subordinated to one another—a series which is consequently itself
unconditioned—is also given, that is, contained in the object and its

But this principle of pure reason is evidently synthetical; for,
analytically, the conditioned certainly relates to some condition, but
not to the unconditioned. From this principle also there must originate
different synthetical propositions, of which the pure understanding is
perfectly ignorant, for it has to do only with objects of a possible
experience, the cognition and synthesis of which is always conditioned.
The unconditioned, if it does really exist, must be especially
considered in regard to the determinations which distinguish it from
whatever is conditioned, and will thus afford us material for many a
priori synthetical propositions.

The principles resulting from this highest principle of pure reason
will, however, be transcendent in relation to phenomena, that is to
say, it will be impossible to make any adequate empirical use of this
principle. It is therefore completely different from all principles of
the understanding, the use made of which is entirely immanent, their
object and purpose being merely the possibility of experience. Now our
duty in the transcendental dialectic is as follows. To discover whether
the principle that the series of conditions (in the synthesis of
phenomena, or of thought in general) extends to the unconditioned is
objectively true, or not; what consequences result therefrom affecting
the empirical use of the understanding, or rather whether there exists
any such objectively valid proposition of reason, and whether it is
not, on the contrary, a merely logical precept which directs us to
ascend perpetually to still higher conditions, to approach completeness
in the series of them, and thus to introduce into our cognition the
highest possible unity of reason. We must ascertain, I say, whether
this requirement of reason has not been regarded, by a
misunderstanding, as a transcendental principle of pure reason, which
postulates a thorough completeness in the series of conditions in
objects themselves. We must show, moreover, the misconceptions and
illusions that intrude into syllogisms, the major proposition of which
pure reason has supplied—a proposition which has perhaps more of the
character of a petitio than of a postulatum—and that proceed from
experience upwards to its conditions. The solution of these problems is
our task in transcendental dialectic, which we are about to expose even
at its source, that lies deep in human reason. We shall divide it into
two parts, the first of which will treat of the transcendent
conceptions of pure reason, the second of transcendent and dialectical


The conceptions of pure reason—we do not here speak of the possibility
of them—are not obtained by reflection, but by inference or conclusion.
The conceptions of understanding are also cogitated a priori
antecedently to experience, and render it possible; but they contain
nothing but the unity of reflection upon phenomena, in so far as these
must necessarily belong to a possible empirical consciousness. Through
them alone are cognition and the determination of an object possible.
It is from them, accordingly, that we receive material for reasoning,
and antecedently to them we possess no a priori conceptions of objects
from which they might be deduced, On the other hand, the sole basis of
their objective reality consists in the necessity imposed on them, as
containing the intellectual form of all experience, of restricting
their application and influence to the sphere of experience.

But the term, conception of reason, or rational conception, itself
indicates that it does not confine itself within the limits of
experience, because its object-matter is a cognition, of which every
empirical cognition is but a part—nay, the whole of possible experience
may be itself but a part of it—a cognition to which no actual
experience ever fully attains, although it does always pertain to it.
The aim of rational conceptions is the comprehension, as that of the
conceptions of understanding is the understanding of perceptions. If
they contain the unconditioned, they relate to that to which all
experience is subordinate, but which is never itself an object of
experience—that towards which reason tends in all its conclusions from
experience, and by the standard of which it estimates the degree of
their empirical use, but which is never itself an element in an
empirical synthesis. If, notwithstanding, such conceptions possess
objective validity, they may be called conceptus ratiocinati
(conceptions legitimately concluded); in cases where they do not, they
have been admitted on account of having the appearance of being
correctly concluded, and may be called conceptus ratiocinantes
(sophistical conceptions). But as this can only be sufficiently
demonstrated in that part of our treatise which relates to the
dialectical conclusions of reason, we shall omit any consideration of
it in this place. As we called the pure conceptions of the
understanding categories, we shall also distinguish those of pure
reason by a new name and call them transcendental ideas. These terms,
however, we must in the first place explain and justify.

 Section I—Of Ideas in General

Despite the great wealth of words which European languages possess, the
thinker finds himself often at a loss for an expression exactly suited
to his conception, for want of which he is unable to make himself
intelligible either to others or to himself. To coin new words is a
pretension to legislation in language which is seldom successful; and,
before recourse is taken to so desperate an expedient, it is advisable
to examine the dead and learned languages, with the hope and the
probability that we may there meet with some adequate expression of the
notion we have in our minds. In this case, even if the original meaning
of the word has become somewhat uncertain, from carelessness or want of
caution on the part of the authors of it, it is always better to adhere
to and confirm its proper meaning—even although it may be doubtful
whether it was formerly used in exactly this sense—than to make our
labour vain by want of sufficient care to render ourselves

For this reason, when it happens that there exists only a single word
to express a certain conception, and this word, in its usual
acceptation, is thoroughly adequate to the conception, the accurate
distinction of which from related conceptions is of great importance,
we ought not to employ the expression improvidently, or, for the sake
of variety and elegance of style, use it as a synonym for other cognate
words. It is our duty, on the contrary, carefully to preserve its
peculiar signification, as otherwise it easily happens that when the
attention of the reader is no longer particularly attracted to the
expression, and it is lost amid the multitude of other words of very
different import, the thought which it conveyed, and which it alone
conveyed, is lost with it.

Plato employed the expression idea in a way that plainly showed he
meant by it something which is never derived from the senses, but which
far transcends even the conceptions of the understanding (with which
Aristotle occupied himself), inasmuch as in experience nothing
perfectly corresponding to them could be found. Ideas are, according to
him, archetypes of things themselves, and not merely keys to possible
experiences, like the categories. In his view they flow from the
highest reason, by which they have been imparted to human reason,
which, however, exists no longer in its original state, but is obliged
with great labour to recall by reminiscence—which is called
philosophy—the old but now sadly obscured ideas. I will not here enter
upon any literary investigation of the sense which this sublime
philosopher attached to this expression. I shall content myself with
remarking that it is nothing unusual, in common conversation as well as
in written works, by comparing the thoughts which an author has
delivered upon a subject, to understand him better than he understood
himself inasmuch as he may not have sufficiently determined his
conception, and thus have sometimes spoken, nay even thought, in
opposition to his own opinions.

Plato perceived very clearly that our faculty of cognition has the
feeling of a much higher vocation than that of merely spelling out
phenomena according to synthetical unity, for the purpose of being able
to read them as experience, and that our reason naturally raises itself
to cognitions far too elevated to admit of the possibility of an object
given by experience corresponding to them—cognitions which are
nevertheless real, and are not mere phantoms of the brain.

This philosopher found his ideas especially in all that is practical,*
that is, which rests upon freedom, which in its turn ranks under
cognitions that are the peculiar product of reason. He who would derive
from experience the conceptions of virtue, who would make (as many have
really done) that, which at best can but serve as an imperfectly
illustrative example, a model for or the formation of a perfectly
adequate idea on the subject, would in fact transform virtue into a
nonentity changeable according to time and circumstance and utterly
incapable of being employed as a rule. On the contrary, every one is
conscious that, when any one is held up to him as a model of virtue, he
compares this so-called model with the true original which he possesses
in his own mind and values him according to this standard. But this
standard is the idea of virtue, in relation to which all possible
objects of experience are indeed serviceable as examples—proofs of the
practicability in a certain degree of that which the conception of
virtue demands—but certainly not as archetypes. That the actions of man
will never be in perfect accordance with all the requirements of the
pure ideas of reason, does not prove the thought to be chimerical. For
only through this idea are all judgements as to moral merit or demerit
possible; it consequently lies at the foundation of every approach to
moral perfection, however far removed from it the obstacles in human
nature—indeterminable as to degree—may keep us.

[*Footnote: He certainly extended the application of his conception to
speculative cognitions also, provided they were given pure and
completely a priori, nay, even to mathematics, although this science
cannot possess an object otherwhere than in Possible experience. I
cannot follow him in this, and as little can I follow him in his
mystical deduction of these ideas, or in his hypostatization of them;
although, in truth, the elevated and exaggerated language which he
employed in describing them is quite capable of an interpretation more
subdued and more in accordance with fact and the nature of things.]

The Platonic Republic has become proverbial as an example—and a
striking one—of imaginary perfection, such as can exist only in the
brain of the idle thinker; and Brucker ridicules the philosopher for
maintaining that a prince can never govern well, unless he is
participant in the ideas. But we should do better to follow up this
thought and, where this admirable thinker leaves us without assistance,
employ new efforts to place it in clearer light, rather than carelessly
fling it aside as useless, under the very miserable and pernicious
pretext of impracticability. A constitution of the greatest possible
human freedom according to laws, by which the liberty of every
individual can consist with the liberty of every other (not of the
greatest possible happiness, for this follows necessarily from the
former), is, to say the least, a necessary idea, which must be placed
at the foundation not only of the first plan of the constitution of a
state, but of all its laws. And, in this, it not necessary at the
outset to take account of the obstacles which lie in our way—obstacles
which perhaps do not necessarily arise from the character of human
nature, but rather from the previous neglect of true ideas in
legislation. For there is nothing more pernicious and more unworthy of
a philosopher, than the vulgar appeal to a so-called adverse
experience, which indeed would not have existed, if those institutions
had been established at the proper time and in accordance with ideas;
while, instead of this, conceptions, crude for the very reason that
they have been drawn from experience, have marred and frustrated all
our better views and intentions. The more legislation and government
are in harmony with this idea, the more rare do punishments become and
thus it is quite reasonable to maintain, as Plato did, that in a
perfect state no punishments at all would be necessary. Now although a
perfect state may never exist, the idea is not on that account the less
just, which holds up this maximum as the archetype or standard of a
constitution, in order to bring legislative government always nearer
and nearer to the greatest possible perfection. For at what precise
degree human nature must stop in its progress, and how wide must be the
chasm which must necessarily exist between the idea and its
realization, are problems which no one can or ought to determine—and
for this reason, that it is the destination of freedom to overstep all
assigned limits between itself and the idea.

But not only in that wherein human reason is a real causal agent and
where ideas are operative causes (of actions and their objects), that
is to say, in the region of ethics, but also in regard to nature
herself, Plato saw clear proofs of an origin from ideas. A plant, and
animal, the regular order of nature—probably also the disposition of
the whole universe—give manifest evidence that they are possible only
by means of and according to ideas; that, indeed, no one creature,
under the individual conditions of its existence, perfectly harmonizes
with the idea of the most perfect of its kind—just as little as man
with the idea of humanity, which nevertheless he bears in his soul as
the archetypal standard of his actions; that, notwithstanding, these
ideas are in the highest sense individually, unchangeably, and
completely determined, and are the original causes of things; and that
the totality of connected objects in the universe is alone fully
adequate to that idea. Setting aside the exaggerations of expression in
the writings of this philosopher, the mental power exhibited in this
ascent from the ectypal mode of regarding the physical world to the
architectonic connection thereof according to ends, that is, ideas, is
an effort which deserves imitation and claims respect. But as regards
the principles of ethics, of legislation, and of religion, spheres in
which ideas alone render experience possible, although they never
attain to full expression therein, he has vindicated for himself a
position of peculiar merit, which is not appreciated only because it is
judged by the very empirical rules, the validity of which as principles
is destroyed by ideas. For as regards nature, experience presents us
with rules and is the source of truth, but in relation to ethical laws
experience is the parent of illusion, and it is in the highest degree
reprehensible to limit or to deduce the laws which dictate what I ought
to do, from what is done.

We must, however, omit the consideration of these important subjects,
the development of which is in reality the peculiar duty and dignity of
philosophy, and confine ourselves for the present to the more humble
but not less useful task of preparing a firm foundation for those
majestic edifices of moral science. For this foundation has been
hitherto insecure from the many subterranean passages which reason in
its confident but vain search for treasures has made in all directions.
Our present duty is to make ourselves perfectly acquainted with the
transcendental use made of pure reason, its principles and ideas, that
we may be able properly to determine and value its influence and real
worth. But before bringing these introductory remarks to a close, I beg
those who really have philosophy at heart—and their number is but
small—if they shall find themselves convinced by the considerations
following as well as by those above, to exert themselves to preserve to
the expression idea its original signification, and to take care that
it be not lost among those other expressions by which all sorts of
representations are loosely designated—that the interests of science
may not thereby suffer. We are in no want of words to denominate
adequately every mode of representation, without the necessity of
encroaching upon terms which are proper to others. The following is a
graduated list of them. The genus is representation in general
(representatio). Under it stands representation with consciousness
(perceptio). A perception which relates solely to the subject as a
modification of its state, is a sensation (sensatio), an objective
perception is a cognition (cognitio). A cognition is either an
intuition or a conception (intuitus vel conceptus). The former has an
immediate relation to the object and is singular and individual; the
latter has but a mediate relation, by means of a characteristic mark
which may be common to several things. A conception is either empirical
or pure. A pure conception, in so far as it has its origin in the
understanding alone, and is not the conception of a pure sensuous
image, is called notio. A conception formed from notions, which
transcends the possibility of experience, is an idea, or a conception
of reason. To one who has accustomed himself to these distinctions, it
must be quite intolerable to hear the representation of the colour red
called an idea. It ought not even to be called a notion or conception
of understanding.

 Section II. Of Transcendental Ideas

Transcendental analytic showed us how the mere logical form of our
cognition can contain the origin of pure conceptions a priori,
conceptions which represent objects antecedently to all experience, or
rather, indicate the synthetical unity which alone renders possible an
empirical cognition of objects. The form of judgements—converted into a
conception of the synthesis of intuitions—produced the categories which
direct the employment of the understanding in experience. This
consideration warrants us to expect that the form of syllogisms, when
applied to synthetical unity of intuitions, following the rule of the
categories, will contain the origin of particular a priori conceptions,
which we may call pure conceptions of reason or transcendental ideas,
and which will determine the use of the understanding in the totality
of experience according to principles.

The function of reason in arguments consists in the universality of a
cognition according to conceptions, and the syllogism itself is a
judgement which is determined a priori in the whole extent of its
condition. The proposition: “Caius is mortal,” is one which may be
obtained from experience by the aid of the understanding alone; but my
wish is to find a conception which contains the condition under which
the predicate of this judgement is given—in this case, the conception
of man—and after subsuming under this condition, taken in its whole
extent (all men are mortal), I determine according to it the cognition
of the object thought, and say: “Caius is mortal.”

Hence, in the conclusion of a syllogism we restrict a predicate to a
certain object, after having thought it in the major in its whole
extent under a certain condition. This complete quantity of the extent
in relation to such a condition is called universality (universalitas).
To this corresponds totality (universitas) of conditions in the
synthesis of intuitions. The transcendental conception of reason is
therefore nothing else than the conception of the totality of the
conditions of a given conditioned. Now as the unconditioned alone
renders possible totality of conditions, and, conversely, the totality
of conditions is itself always unconditioned; a pure rational
conception in general can be defined and explained by means of the
conception of the unconditioned, in so far as it contains a basis for
the synthesis of the conditioned.

To the number of modes of relation which the understanding cogitates by
means of the categories, the number of pure rational conceptions will
correspond. We must therefore seek for, first, an unconditioned of the
categorical synthesis in a subject; secondly, of the hypothetical
synthesis of the members of a series; thirdly, of the disjunctive
synthesis of parts in a system.

There are exactly the same number of modes of syllogisms, each of which
proceeds through prosyllogisms to the unconditioned—one to the subject
which cannot be employed as predicate, another to the presupposition
which supposes nothing higher than itself, and the third to an
aggregate of the members of the complete division of a conception.
Hence the pure rational conceptions of totality in the synthesis of
conditions have a necessary foundation in the nature of human reason—at
least as modes of elevating the unity of the understanding to the
unconditioned. They may have no valid application, corresponding to
their transcendental employment, in concreto, and be thus of no greater
utility than to direct the understanding how, while extending them as
widely as possible, to maintain its exercise and application in perfect
consistence and harmony.

But, while speaking here of the totality of conditions and of the
unconditioned as the common title of all conceptions of reason, we
again light upon an expression which we find it impossible to dispense
with, and which nevertheless, owing to the ambiguity attaching to it
from long abuse, we cannot employ with safety. The word absolute is one
of the few words which, in its original signification, was perfectly
adequate to the conception it was intended to convey—a conception which
no other word in the same language exactly suits, and the loss—or,
which is the same thing, the incautious and loose employment—of which
must be followed by the loss of the conception itself. And, as it is a
conception which occupies much of the attention of reason, its loss
would be greatly to the detriment of all transcendental philosophy. The
word absolute is at present frequently used to denote that something
can be predicated of a thing considered in itself and intrinsically. In
this sense absolutely possible would signify that which is possible in
itself (interne)—which is, in fact, the least that one can predicate of
an object. On the other hand, it is sometimes employed to indicate that
a thing is valid in all respects—for example, absolute sovereignty.
Absolutely possible would in this sense signify that which is possible
in all relations and in every respect; and this is the most that can be
predicated of the possibility of a thing. Now these significations do
in truth frequently coincide. Thus, for example, that which is
intrinsically impossible, is also impossible in all relations, that is,
absolutely impossible. But in most cases they differ from each other
toto caelo, and I can by no means conclude that, because a thing is in
itself possible, it is also possible in all relations, and therefore
absolutely. Nay, more, I shall in the sequel show that absolute
necessity does not by any means depend on internal necessity, and that,
therefore, it must not be considered as synonymous with it. Of an
opposite which is intrinsically impossible, we may affirm that it is in
all respects impossible, and that, consequently, the thing itself, of
which this is the opposite, is absolutely necessary; but I cannot
reason conversely and say, the opposite of that which is absolutely
necessary is intrinsically impossible, that is, that the absolute
necessity of things is an internal necessity. For this internal
necessity is in certain cases a mere empty word with which the least
conception cannot be connected, while the conception of the necessity
of a thing in all relations possesses very peculiar determinations. Now
as the loss of a conception of great utility in speculative science
cannot be a matter of indifference to the philosopher, I trust that the
proper determination and careful preservation of the expression on
which the conception depends will likewise be not indifferent to him.

In this enlarged signification, then, shall I employ the word absolute,
in opposition to that which is valid only in some particular respect;
for the latter is restricted by conditions, the former is valid without
any restriction whatever.

Now the transcendental conception of reason has for its object nothing
else than absolute totality in the synthesis of conditions and does not
rest satisfied till it has attained to the absolutely, that is, in all
respects and relations, unconditioned. For pure reason leaves to the
understanding everything that immediately relates to the object of
intuition or rather to their synthesis in imagination. The former
restricts itself to the absolute totality in the employment of the
conceptions of the understanding and aims at carrying out the
synthetical unity which is cogitated in the category, even to the
unconditioned. This unity may hence be called the rational unity of
phenomena, as the other, which the category expresses, may be termed
the unity of the understanding. Reason, therefore, has an immediate
relation to the use of the understanding, not indeed in so far as the
latter contains the ground of possible experience (for the conception
of the absolute totality of conditions is not a conception that can be
employed in experience, because no experience is unconditioned), but
solely for the purpose of directing it to a certain unity, of which the
understanding has no conception, and the aim of which is to collect
into an absolute whole all acts of the understanding. Hence the
objective employment of the pure conceptions of reason is always
transcendent, while that of the pure conceptions of the understanding
must, according to their nature, be always immanent, inasmuch as they
are limited to possible experience.

I understand by idea a necessary conception of reason, to which no
corresponding object can be discovered in the world of sense.
Accordingly, the pure conceptions of reason at present under
consideration are transcendental ideas. They are conceptions of pure
reason, for they regard all empirical cognition as determined by means
of an absolute totality of conditions. They are not mere fictions, but
natural and necessary products of reason, and have hence a necessary
relation to the whole sphere of the exercise of the understanding. And,
finally, they are transcendent, and overstep the limits of all
experiences, in which, consequently, no object can ever be presented
that would be perfectly adequate to a transcendental idea. When we use
the word idea, we say, as regards its object (an object of the pure
understanding), a great deal, but as regards its subject (that is, in
respect of its reality under conditions of experience), exceedingly
little, because the idea, as the conception of a maximum, can never be
completely and adequately presented in concreto. Now, as in the merely
speculative employment of reason the latter is properly the sole aim,
and as in this case the approximation to a conception, which is never
attained in practice, is the same thing as if the conception were
non-existent—it is commonly said of the conception of this kind, “it is
only an idea.” So we might very well say, “the absolute totality of all
phenomena is only an idea,” for, as we never can present an adequate
representation of it, it remains for us a problem incapable of
solution. On the other hand, as in the practical use of the
understanding we have only to do with action and practice according to
rules, an idea of pure reason can always be given really in concreto,
although only partially, nay, it is the indispensable condition of all
practical employment of reason. The practice or execution of the idea
is always limited and defective, but nevertheless within indeterminable
boundaries, consequently always under the influence of the conception
of an absolute perfection. And thus the practical idea is always in the
highest degree fruitful, and in relation to real actions indispensably
necessary. In the idea, pure reason possesses even causality and the
power of producing that which its conception contains. Hence we cannot
say of wisdom, in a disparaging way, “it is only an idea.” For, for the
very reason that it is the idea of the necessary unity of all possible
aims, it must be for all practical exertions and endeavours the
primitive condition and rule—a rule which, if not constitutive, is at
least limitative.

Now, although we must say of the transcendental conceptions of reason,
“they are only ideas,” we must not, on this account, look upon them as
superfluous and nugatory. For, although no object can be determined by
them, they can be of great utility, unobserved and at the basis of the
edifice of the understanding, as the canon for its extended and
self-consistent exercise—a canon which, indeed, does not enable it to
cognize more in an object than it would cognize by the help of its own
conceptions, but which guides it more securely in its cognition. Not to
mention that they perhaps render possible a transition from our
conceptions of nature and the non-ego to the practical conceptions, and
thus produce for even ethical ideas keeping, so to speak, and
connection with the speculative cognitions of reason. The explication
of all this must be looked for in the sequel.

But setting aside, in conformity with our original purpose, the
consideration of the practical ideas, we proceed to contemplate reason
in its speculative use alone, nay, in a still more restricted sphere,
to wit, in the transcendental use; and here must strike into the same
path which we followed in our deduction of the categories. That is to
say, we shall consider the logical form of the cognition of reason,
that we may see whether reason may not be thereby a source of
conceptions which enables us to regard objects in themselves as
determined synthetically a priori, in relation to one or other of the
functions of reason.

Reason, considered as the faculty of a certain logical form of
cognition, is the faculty of conclusion, that is, of mediate
judgement—by means of the subsumption of the condition of a possible
judgement under the condition of a given judgement. The given judgement
is the general rule (major). The subsumption of the condition of
another possible judgement under the condition of the rule is the
minor. The actual judgement, which enounces the assertion of the rule
in the subsumed case, is the conclusion (conclusio). The rule
predicates something generally under a certain condition. The condition
of the rule is satisfied in some particular case. It follows that what
was valid in general under that condition must also be considered as
valid in the particular case which satisfies this condition. It is very
plain that reason attains to a cognition, by means of acts of the
understanding which constitute a series of conditions. When I arrive at
the proposition, “All bodies are changeable,” by beginning with the
more remote cognition (in which the conception of body does not appear,
but which nevertheless contains the condition of that conception), “All
compound is changeable,” by proceeding from this to a less remote
cognition, which stands under the condition of the former, “Bodies are
compound,” and hence to a third, which at length connects for me the
remote cognition (changeable) with the one before me, “Consequently,
bodies are changeable”—I have arrived at a cognition (conclusion)
through a series of conditions (premisses). Now every series, whose
exponent (of the categorical or hypothetical judgement) is given, can
be continued; consequently the same procedure of reason conducts us to
the ratiocinatio polysyllogistica, which is a series of syllogisms,
that can be continued either on the side of the conditions (per
prosyllogismos) or of the conditioned (per episyllogismos) to an
indefinite extent.

But we very soon perceive that the chain or series of prosyllogisms,
that is, of deduced cognitions on the side of the grounds or conditions
of a given cognition, in other words, the ascending series of
syllogisms must have a very different relation to the faculty of reason
from that of the descending series, that is, the progressive procedure
of reason on the side of the conditioned by means of episyllogisms.
For, as in the former case the cognition (conclusio) is given only as
conditioned, reason can attain to this cognition only under the
presupposition that all the members of the series on the side of the
conditions are given (totality in the series of premisses), because
only under this supposition is the judgement we may be considering
possible a priori; while on the side of the conditioned or the
inferences, only an incomplete and becoming, and not a presupposed or
given series, consequently only a potential progression, is cogitated.
Hence, when a cognition is contemplated as conditioned, reason is
compelled to consider the series of conditions in an ascending line as
completed and given in their totality. But if the very same condition
is considered at the same time as the condition of other cognitions,
which together constitute a series of inferences or consequences in a
descending line, reason may preserve a perfect indifference, as to how
far this progression may extend a parte posteriori, and whether the
totality of this series is possible, because it stands in no need of
such a series for the purpose of arriving at the conclusion before it,
inasmuch as this conclusion is sufficiently guaranteed and determined
on grounds a parte priori. It may be the case, that upon the side of
the conditions the series of premisses has a first or highest
condition, or it may not possess this, and so be a parte priori
unlimited; but it must, nevertheless, contain totality of conditions,
even admitting that we never could succeed in completely apprehending
it; and the whole series must be unconditionally true, if the
conditioned, which is considered as an inference resulting from it, is
to be held as true. This is a requirement of reason, which announces
its cognition as determined a priori and as necessary, either in
itself—and in this case it needs no grounds to rest upon—or, if it is
deduced, as a member of a series of grounds, which is itself
unconditionally true.

 Section III. System of Transcendental Ideas

We are not at present engaged with a logical dialectic, which makes
complete abstraction of the content of cognition and aims only at
unveiling the illusory appearance in the form of syllogisms. Our
subject is transcendental dialectic, which must contain, completely a
priori, the origin of certain cognitions drawn from pure reason, and
the origin of certain deduced conceptions, the object of which cannot
be given empirically and which therefore lie beyond the sphere of the
faculty of understanding. We have observed, from the natural relation
which the transcendental use of our cognition, in syllogisms as well as
in judgements, must have to the logical, that there are three kinds of
dialectical arguments, corresponding to the three modes of conclusion,
by which reason attains to cognitions on principles; and that in all it
is the business of reason to ascend from the conditioned synthesis,
beyond which the understanding never proceeds, to the unconditioned
which the understanding never can reach.

Now the most general relations which can exist in our representations
are: 1st, the relation to the subject; 2nd, the relation to objects,
either as phenomena, or as objects of thought in general. If we connect
this subdivision with the main division, all the relations of our
representations, of which we can form either a conception or an idea,
are threefold: 1. The relation to the subject; 2. The relation to the
manifold of the object as a phenomenon; 3. The relation to all things
in general.

Now all pure conceptions have to do in general with the synthetical
unity of representations; conceptions of pure reason (transcendental
ideas), on the other hand, with the unconditional synthetical unity of
all conditions. It follows that all transcendental ideas arrange
themselves in three classes, the first of which contains the absolute
(unconditioned) unity of the thinking subject, the second the absolute
unity of the series of the conditions of a phenomenon, the third the
absolute unity of the condition of all objects of thought in general.

The thinking subject is the object-matter of Psychology; the sum total
of all phenomena (the world) is the object-matter of Cosmology; and the
thing which contains the highest condition of the possibility of all
that is cogitable (the being of all beings) is the object-matter of all
Theology. Thus pure reason presents us with the idea of a
transcendental doctrine of the soul (psychologia rationalis), of a
transcendental science of the world (cosmologia rationalis), and
finally of a transcendental doctrine of God (theologia
transcendentalis). Understanding cannot originate even the outline of
any of these sciences, even when connected with the highest logical use
of reason, that is, all cogitable syllogisms—for the purpose of
proceeding from one object (phenomenon) to all others, even to the
utmost limits of the empirical synthesis. They are, on the contrary,
pure and genuine products, or problems, of pure reason.

What modi of the pure conceptions of reason these transcendental ideas
are will be fully exposed in the following chapter. They follow the
guiding thread of the categories. For pure reason never relates
immediately to objects, but to the conceptions of these contained in
the understanding. In like manner, it will be made manifest in the
detailed explanation of these ideas—how reason, merely through the
synthetical use of the same function which it employs in a categorical
syllogism, necessarily attains to the conception of the absolute unity
of the thinking subject—how the logical procedure in hypothetical ideas
necessarily produces the idea of the absolutely unconditioned in a
series of given conditions, and finally—how the mere form of the
disjunctive syllogism involves the highest conception of a being of all
beings: a thought which at first sight seems in the highest degree

An objective deduction, such as we were able to present in the case of
the categories, is impossible as regards these transcendental ideas.
For they have, in truth, no relation to any object, in experience, for
the very reason that they are only ideas. But a subjective deduction of
them from the nature of our reason is possible, and has been given in
the present chapter.

It is easy to perceive that the sole aim of pure reason is the absolute
totality of the synthesis on the side of the conditions, and that it
does not concern itself with the absolute completeness on the Part of
the conditioned. For of the former alone does she stand in need, in
order to preposit the whole series of conditions, and thus present them
to the understanding a priori. But if we once have a completely (and
unconditionally) given condition, there is no further necessity, in
proceeding with the series, for a conception of reason; for the
understanding takes of itself every step downward, from the condition
to the conditioned. Thus the transcendental ideas are available only
for ascending in the series of conditions, till we reach the
unconditioned, that is, principles. As regards descending to the
conditioned, on the other hand, we find that there is a widely
extensive logical use which reason makes of the laws of the
understanding, but that a transcendental use thereof is impossible; and
that when we form an idea of the absolute totality of such a synthesis,
for example, of the whole series of all future changes in the world,
this idea is a mere ens rationis, an arbitrary fiction of thought, and
not a necessary presupposition of reason. For the possibility of the
conditioned presupposes the totality of its conditions, but not of its
consequences. Consequently, this conception is not a transcendental
idea—and it is with these alone that we are at present occupied.

Finally, it is obvious that there exists among the transcendental ideas
a certain connection and unity, and that pure reason, by means of them,
collects all its cognitions into one system. From the cognition of self
to the cognition of the world, and through these to the supreme being,
the progression is so natural, that it seems to resemble the logical
march of reason from the premisses to the conclusion.* Now whether
there lies unobserved at the foundation of these ideas an analogy of
the same kind as exists between the logical and transcendental
procedure of reason, is another of those questions, the answer to which
we must not expect till we arrive at a more advanced stage in our
inquiries. In this cursory and preliminary view, we have, meanwhile,
reached our aim. For we have dispelled the ambiguity which attached to
the transcendental conceptions of reason, from their being commonly
mixed up with other conceptions in the systems of philosophers, and not
properly distinguished from the conceptions of the understanding; we
have exposed their origin and, thereby, at the same time their
determinate number, and presented them in a systematic connection, and
have thus marked out and enclosed a definite sphere for pure reason.

[*Footnote: The science of Metaphysics has for the proper object of its
inquiries only three grand ideas: GOD, FREEDOM, and IMMORTALITY, and it
aims at showing, that the second conception, conjoined with the first,
must lead to the third, as a necessary conclusion. All the other
subjects with which it occupies itself, are merely means for the
attainment and realization of these ideas. It does not require these
ideas for the construction of a science of nature, but, on the
contrary, for the purpose of passing beyond the sphere of nature. A
complete insight into and comprehension of them would render Theology,
Ethics, and, through the conjunction of both, Religion, solely
dependent on the speculative faculty of reason. In a systematic
representation of these ideas the above-mentioned arrangement—the
synthetical one—would be the most suitable; but in the investigation
which must necessarily precede it, the analytical, which reverses this
arrangement, would be better adapted to our purpose, as in it we should
proceed from that which experience immediately presents to
us—psychology, to cosmology, and thence to theology.]


It may be said that the object of a merely transcendental idea is
something of which we have no conception, although the idea may be a
necessary product of reason according to its original laws. For, in
fact, a conception of an object that is adequate to the idea given by
reason, is impossible. For such an object must be capable of being
presented and intuited in a Possible experience. But we should express
our meaning better, and with less risk of being misunderstood, if we
said that we can have no knowledge of an object, which perfectly
corresponds to an idea, although we may possess a problematical
conception thereof.

Now the transcendental (subjective) reality at least of the pure
conceptions of reason rests upon the fact that we are led to such ideas
by a necessary procedure of reason. There must therefore be syllogisms
which contain no empirical premisses, and by means of which we conclude
from something that we do know, to something of which we do not even
possess a conception, to which we, nevertheless, by an unavoidable
illusion, ascribe objective reality. Such arguments are, as regards
their result, rather to be termed sophisms than syllogisms, although
indeed, as regards their origin, they are very well entitled to the
latter name, inasmuch as they are not fictions or accidental products
of reason, but are necessitated by its very nature. They are sophisms,
not of men, but of pure reason herself, from which the Wisest cannot
free himself. After long labour he may be able to guard against the
error, but he can never be thoroughly rid of the illusion which
continually mocks and misleads him.

Of these dialectical arguments there are three kinds, corresponding to
the number of the ideas which their conclusions present. In the
argument or syllogism of the first class, I conclude, from the
transcendental conception of the subject contains no manifold, the
absolute unity of the subject itself, of which I cannot in this manner
attain to a conception. This dialectical argument I shall call the
transcendental paralogism. The second class of sophistical arguments is
occupied with the transcendental conception of the absolute totality of
the series of conditions for a given phenomenon, and I conclude, from
the fact that I have always a self-contradictory conception of the
unconditioned synthetical unity of the series upon one side, the truth
of the opposite unity, of which I have nevertheless no conception. The
condition of reason in these dialectical arguments, I shall term the
antinomy of pure reason. Finally, according to the third kind of
sophistical argument, I conclude, from the totality of the conditions
of thinking objects in general, in so far as they can be given, the
absolute synthetical unity of all conditions of the possibility of
things in general; that is, from things which I do not know in their
mere transcendental conception, I conclude a being of all beings which
I know still less by means of a transcendental conception, and of whose
unconditioned necessity I can form no conception whatever. This
dialectical argument I shall call the ideal of pure reason.

 Chapter I. Of the Paralogisms of Pure Reason

The logical paralogism consists in the falsity of an argument in
respect of its form, be the content what it may. But a transcendental
paralogism has a transcendental foundation, and concludes falsely,
while the form is correct and unexceptionable. In this manner the
paralogism has its foundation in the nature of human reason, and is the
parent of an unavoidable, though not insoluble, mental illusion.

We now come to a conception which was not inserted in the general list
of transcendental conceptions, and yet must be reckoned with them, but
at the same time without in the least altering, or indicating a
deficiency in that table. This is the conception, or, if the term is
preferred, the judgement, “I think.” But it is readily perceived that
this thought is as it were the vehicle of all conceptions in general,
and consequently of transcendental conceptions also, and that it is
therefore regarded as a transcendental conception, although it can have
no peculiar claim to be so ranked, inasmuch as its only use is to
indicate that all thought is accompanied by consciousness. At the same
time, pure as this conception is from empirical content (impressions of
the senses), it enables us to distinguish two different kinds of
objects. “I,” as thinking, am an object of the internal sense, and am
called soul. That which is an object of the external senses is called
body. Thus the expression, “I,” as a thinking being, designates the
object-matter of psychology, which may be called “the rational doctrine
of the soul,” inasmuch as in this science I desire to know nothing of
the soul but what, independently of all experience (which determines me
in concreto), may be concluded from this conception “I,” in so far as
it appears in all thought.

Now, the rational doctrine of the soul is really an undertaking of this
kind. For if the smallest empirical element of thought, if any
particular perception of my internal state, were to be introduced among
the grounds of cognition of this science, it would not be a rational,
but an empirical doctrine of the soul. We have thus before us a
pretended science, raised upon the single proposition, “I think,” whose
foundation or want of foundation we may very properly, and agreeably
with the nature of a transcendental philosophy, here examine. It ought
not to be objected that in this proposition, which expresses the
perception of one’s self, an internal experience is asserted, and that
consequently the rational doctrine of the soul which is founded upon
it, is not pure, but partly founded upon an empirical principle. For
this internal perception is nothing more than the mere apperception, “I
think,” which in fact renders all transcendental conceptions possible,
in which we say, “I think substance, cause, etc.” For internal
experience in general and its possibility, or perception in general,
and its relation to other perceptions, unless some particular
distinction or determination thereof is empirically given, cannot be
regarded as empirical cognition, but as cognition of the empirical, and
belongs to the investigation of the possibility of every experience,
which is certainly transcendental. The smallest object of experience
(for example, only pleasure or pain), that should be included in the
general representation of self-consciousness, would immediately change
the rational into an empirical psychology.

“I think” is therefore the only text of rational psychology, from which
it must develop its whole system. It is manifest that this thought,
when applied to an object (myself), can contain nothing but
transcendental predicates thereof; because the least empirical
predicate would destroy the purity of the science and its independence
of all experience.

But we shall have to follow here the guidance of the categories—only,
as in the present case a thing, “I,” as thinking being, is at first
given, we shall—not indeed change the order of the categories as it
stands in the table—but begin at the category of substance, by which at
the a thing in itself is represented and proceeds backwards through the
series. The topic of the rational doctrine of the soul, from which
everything else it may contain must be deduced, is accordingly as

            1                          2 The Soul is SUBSTANCE       As
            regards its quality it is SIMPLE

                      3 As regards the different times in which it
                      exists, it is numerically identical, that is
                      UNITY, not Plurality.

                       4 It is in relation to possible objects in

[*Footnote: The reader, who may not so easily perceive the
psychological sense of these expressions, taken here in their
transcendental abstraction, and cannot guess why the latter attribute
of the soul belongs to the category of existence, will find the
expressions sufficiently explained and justified in the sequel. I have,
moreover, to apologize for the Latin terms which have been employed,
instead of their German synonyms, contrary to the rules of correct
writing. But I judged it better to sacrifice elegance to perspicuity.]

From these elements originate all the conceptions of pure psychology,
by combination alone, without the aid of any other principle. This
substance, merely as an object of the internal sense, gives the
conception of Immateriality; as simple substance, that of
Incorruptibility; its identity, as intellectual substance, gives the
conception of Personality; all these three together, Spirituality. Its
relation to objects in space gives us the conception of connection
(commercium) with bodies. Thus it represents thinking substance as the
principle of life in matter, that is, as a soul (anima), and as the
ground of Animality; and this, limited and determined by the conception
of spirituality, gives us that of Immortality.

Now to these conceptions relate four paralogisms of a transcendental
psychology, which is falsely held to be a science of pure reason,
touching the nature of our thinking being. We can, however, lay at the
foundation of this science nothing but the simple and in itself
perfectly contentless representation “i” which cannot even be called a
conception, but merely a consciousness which accompanies all
conceptions. By this “I,” or “He,” or “It,” who or which thinks,
nothing more is represented than a transcendental subject of thought =
x, which is cognized only by means of the thoughts that are its
predicates, and of which, apart from these, we cannot form the least
conception. Hence in a perpetual circle, inasmuch as we must always
employ it, in order to frame any judgement respecting it. And this
inconvenience we find it impossible to rid ourselves of, because
consciousness in itself is not so much a representation distinguishing
a particular object, as a form of representation in general, in so far
as it may be termed cognition; for in and by cognition alone do I think

It must, however, appear extraordinary at first sight that the
condition under which I think, and which is consequently a property of
my subject, should be held to be likewise valid for every existence
which thinks, and that we can presume to base upon a seemingly
empirical proposition a judgement which is apodeictic and universal, to
wit, that everything which thinks is constituted as the voice of my
consciousness declares it to be, that is, as a self-conscious being.
The cause of this belief is to be found in the fact that we necessarily
attribute to things a priori all the properties which constitute
conditions under which alone we can cogitate them. Now I cannot obtain
the least representation of a thinking being by means of external
experience, but solely through self-consciousness. Such objects are
consequently nothing more than the transference of this consciousness
of mine to other things which can only thus be represented as thinking
beings. The proposition, “I think,” is, in the present case, understood
in a problematical sense, not in so far as it contains a perception of
an existence (like the Cartesian “Cogito, ergo sum”),[Footnote: “I
think, therefore I am.”] but in regard to its mere possibility—for the
purpose of discovering what properties may be inferred from so simple a
proposition and predicated of the subject of it.

If at the foundation of our pure rational cognition of thinking beings
there lay more than the mere Cogito—if we could likewise call in aid
observations on the play of our thoughts, and the thence derived
natural laws of the thinking self, there would arise an empirical
psychology which would be a kind of physiology of the internal sense
and might possibly be capable of explaining the phenomena of that
sense. But it could never be available for discovering those properties
which do not belong to possible experience (such as the quality of
simplicity), nor could it make any apodeictic enunciation on the nature
of thinking beings: it would therefore not be a rational psychology.

Now, as the proposition “I think” (in the problematical sense) contains
the form of every judgement in general and is the constant
accompaniment of all the categories, it is manifest that conclusions
are drawn from it only by a transcendental employment of the
understanding. This use of the understanding excludes all empirical
elements; and we cannot, as has been shown above, have any favourable
conception beforehand of its procedure. We shall therefore follow with
a critical eye this proposition through all the predicaments of pure
psychology; but we shall, for brevity’s sake, allow this examination to
proceed in an uninterrupted connection.

Before entering on this task, however, the following general remark may
help to quicken our attention to this mode of argument. It is not
merely through my thinking that I cognize an object, but only through
my determining a given intuition in relation to the unity of
consciousness in which all thinking consists. It follows that I cognize
myself, not through my being conscious of myself as thinking, but only
when I am conscious of the intuition of myself as determined in
relation to the function of thought. All the modi of self-consciousness
in thought are hence not conceptions of objects (conceptions of the
understanding—categories); they are mere logical functions, which do
not present to thought an object to be cognized, and cannot therefore
present my Self as an object. Not the consciousness of the determining,
but only that of the determinable self, that is, of my internal
intuition (in so far as the manifold contained in it can be connected
conformably with the general condition of the unity of apperception in
thought), is the object.

1. In all judgements I am the determining subject of that relation
which constitutes a judgement. But that the I which thinks, must be
considered as in thought always a subject, and as a thing which cannot
be a predicate to thought, is an apodeictic and identical proposition.
But this proposition does not signify that I, as an object, am, for
myself, a self-subsistent being or substance. This latter statement—an
ambitious one—requires to be supported by data which are not to be
discovered in thought; and are perhaps (in so far as I consider the
thinking self merely as such) not to be discovered in the thinking self
at all.

2. That the I or Ego of apperception, and consequently in all thought,
is singular or simple, and cannot be resolved into a plurality of
subjects, and therefore indicates a logically simple subject—this is
self-evident from the very conception of an Ego, and is consequently an
analytical proposition. But this is not tantamount to declaring that
the thinking Ego is a simple substance—for this would be a synthetical
proposition. The conception of substance always relates to intuitions,
which with me cannot be other than sensuous, and which consequently lie
completely out of the sphere of the understanding and its thought: but
to this sphere belongs the affirmation that the Ego is simple in
thought. It would indeed be surprising, if the conception of
“substance,” which in other cases requires so much labour to
distinguish from the other elements presented by intuition—so much
trouble, too, to discover whether it can be simple (as in the case of
the parts of matter)—should be presented immediately to me, as if by
revelation, in the poorest mental representation of all.

3. The proposition of the identity of my Self amidst all the manifold
representations of which I am conscious, is likewise a proposition
lying in the conceptions themselves, and is consequently analytical.
But this identity of the subject, of which I am conscious in all its
representations, does not relate to or concern the intuition of the
subject, by which it is given as an object. This proposition cannot
therefore enounce the identity of the person, by which is understood
the consciousness of the identity of its own substance as a thinking
being in all change and variation of circumstances. To prove this, we
should require not a mere analysis of the proposition, but synthetical
judgements based upon a given intuition.

4. I distinguish my own existence, as that of a thinking being, from
that of other things external to me—among which my body also is
reckoned. This is also an analytical proposition, for other things are
exactly those which I think as different or distinguished from myself.
But whether this consciousness of myself is possible without things
external to me; and whether therefore I can exist merely as a thinking
being (without being man)—cannot be known or inferred from this

Thus we have gained nothing as regards the cognition of myself as
object, by the analysis of the consciousness of my Self in thought. The
logical exposition of thought in general is mistaken for a metaphysical
determination of the object.

Our Critique would be an investigation utterly superfluous, if there
existed a possibility of proving a priori, that all thinking beings are
in themselves simple substances, as such, therefore, possess the
inseparable attribute of personality, and are conscious of their
existence apart from and unconnected with matter. For we should thus
have taken a step beyond the world of sense, and have penetrated into
the sphere of noumena; and in this case the right could not be denied
us of extending our knowledge in this sphere, of establishing
ourselves, and, under a favouring star, appropriating to ourselves
possessions in it. For the proposition: “Every thinking being, as such,
is simple substance,” is an a priori synthetical proposition; because
in the first place it goes beyond the conception which is the subject
of it, and adds to the mere notion of a thinking being the mode of its
existence, and in the second place annexes a predicate (that of
simplicity) to the latter conception—a predicate which it could not
have discovered in the sphere of experience. It would follow that a
priori synthetical propositions are possible and legitimate, not only,
as we have maintained, in relation to objects of possible experience,
and as principles of the possibility of this experience itself, but are
applicable to things in themselves—an inference which makes an end of
the whole of this Critique, and obliges us to fall back on the old mode
of metaphysical procedure. But indeed the danger is not so great, if we
look a little closer into the question.

There lurks in the procedure of rational Psychology a paralogism, which
is represented in the following syllogism:

That which cannot be cogitated otherwise than as subject, does not
exist otherwise than as subject, and is therefore substance.

A thinking being, considered merely as such, cannot be cogitated
otherwise than as subject.

Therefore it exists also as such, that is, as substance.

In the major we speak of a being that can be cogitated generally and in
every relation, consequently as it may be given in intuition. But in
the minor we speak of the same being only in so far as it regards
itself as subject, relatively to thought and the unity of
consciousness, but not in relation to intuition, by which it is
presented as an object to thought. Thus the conclusion is here arrived
at by a Sophisma figurae dictionis.*

[*Footnote: Thought is taken in the two premisses in two totally
different senses. In the major it is considered as relating and
applying to objects in general, consequently to objects of intuition
also. In the minor, we understand it as relating merely to
self-consciousness. In this sense, we do not cogitate an object, but
merely the relation to the self-consciousness of the subject, as the
form of thought. In the former premiss we speak of things which cannot
be cogitated otherwise than as subjects. In the second, we do not speak
of things, but of thought (all objects being abstracted), in which the
Ego is always the subject of consciousness. Hence the conclusion cannot
be, “I cannot exist otherwise than as subject”; but only “I can, in
cogitating my existence, employ my Ego only as the subject of the
judgement.” But this is an identical proposition, and throws no light
on the mode of my existence.]

That this famous argument is a mere paralogism, will be plain to any
one who will consider the general remark which precedes our exposition
of the principles of the pure understanding, and the section on
noumena. For it was there proved that the conception of a thing, which
can exist per se—only as a subject and never as a predicate, possesses
no objective reality; that is to say, we can never know whether there
exists any object to correspond to the conception; consequently, the
conception is nothing more than a conception, and from it we derive no
proper knowledge. If this conception is to indicate by the term
substance, an object that can be given, if it is to become a cognition,
we must have at the foundation of the cognition a permanent intuition,
as the indispensable condition of its objective reality. For through
intuition alone can an object be given. But in internal intuition there
is nothing permanent, for the Ego is but the consciousness of my
thought. If then, we appeal merely to thought, we cannot discover the
necessary condition of the application of the conception of
substance—that is, of a subject existing per se—to the subject as a
thinking being. And thus the conception of the simple nature of
substance, which is connected with the objective reality of this
conception, is shown to be also invalid, and to be, in fact, nothing
more than the logical qualitative unity of self-consciousness in
thought; whilst we remain perfectly ignorant whether the subject is
composite or not.

Refutation of the Argument of Mendelssohn for the Substantiality or
Permanence of the Soul.

This acute philosopher easily perceived the insufficiency of the common
argument which attempts to prove that the soul—it being granted that it
is a simple being—cannot perish by dissolution or decomposition; he saw
it is not impossible for it to cease to be by extinction, or
disappearance. He endeavoured to prove in his Phaedo, that the soul
cannot be annihilated, by showing that a simple being cannot cease to
exist. Inasmuch as, he said, a simple existence cannot diminish, nor
gradually lose portions of its being, and thus be by degrees reduced to
nothing (for it possesses no parts, and therefore no multiplicity),
between the moment in which it is, and the moment in which it is not,
no time can be discovered—which is impossible. But this philosopher did
not consider that, granting the soul to possess this simple nature,
which contains no parts external to each other and consequently no
extensive quantity, we cannot refuse to it any less than to any other
being, intensive quantity, that is, a degree of reality in regard to
all its faculties, nay, to all that constitutes its existence. But this
degree of reality can become less and less through an infinite series
of smaller degrees. It follows, therefore, that this supposed
substance—this thing, the permanence of which is not assured in any
other way, may, if not by decomposition, by gradual loss (remissio) of
its powers (consequently by elanguescence, if I may employ this
expression), be changed into nothing. For consciousness itself has
always a degree, which may be lessened.* Consequently the faculty of
being conscious may be diminished; and so with all other faculties. The
permanence of the soul, therefore, as an object of the internal sense,
remains undemonstrated, nay, even indemonstrable. Its permanence in
life is evident, per se, inasmuch as the thinking being (as man) is to
itself, at the same time, an object of the external senses. But this
does not authorize the rational psychologist to affirm, from mere
conceptions, its permanence beyond life.*

[*Footnote: Clearness is not, as logicians maintain, the consciousness
of a representation. For a certain degree of consciousness, which may
not, however, be sufficient for recollection, is to be met with in many
dim representations. For without any consciousness at all, we should
not be able to recognize any difference in the obscure representations
we connect; as we really can do with many conceptions, such as those of
right and justice, and those of the musician, who strikes at once
several notes in improvising a piece of music. But a representation is
clear, in which our consciousness is sufficient for the consciousness
of the difference of this representation from others. If we are only
conscious that there is a difference, but are not conscious of the
difference—that is, what the difference is—the representation must be
termed obscure. There is, consequently, an infinite series of degrees
of consciousness down to its entire disappearance.]

*[2]Footnote: There are some who think they have done enough to
establish a new possibility in the mode of the existence of souls, when
they have shown that there is no contradiction in their hypotheses on
this subject. Such are those who affirm the possibility of thought—of
which they have no other knowledge than what they derive from its use
in connecting empirical intuitions presented in this our human
life—after this life has ceased. But it is very easy to embarrass them
by the introduction of counter-possibilities, which rest upon quite as
good a foundation. Such, for example, is the possibility of the
division of a simple substance into several substances; and conversely,
of the coalition of several into one simple substance. For, although
divisibility presupposes composition, it does not necessarily require a
composition of substances, but only of the degrees (of the several
faculties) of one and the same substance. Now we can cogitate all the
powers and faculties of the soul—even that of consciousness—as
diminished by one half, the substance still remaining. In the same way
we can represent to ourselves without contradiction, this obliterated
half as preserved, not in the soul, but without it; and we can believe
that, as in this case every thing that is real in the soul, and has a
degree—consequently its entire existence—has been halved, a particular
substance would arise out of the soul. For the multiplicity, which has
been divided, formerly existed, but not as a multiplicity of
substances, but of every reality as the quantum of existence in it; and
the unity of substance was merely a mode of existence, which by this
division alone has been transformed into a plurality of subsistence. In
the same manner several simple substances might coalesce into one,
without anything being lost except the plurality of subsistence,
inasmuch as the one substance would contain the degree of reality of
all the former substances. Perhaps, indeed, the simple substances,
which appear under the form of matter, might (not indeed by a
mechanical or chemical influence upon each other, but by an unknown
influence, of which the former would be but the phenomenal appearance),
by means of such a dynamical division of the parent-souls, as intensive
quantities, produce other souls, while the former repaired the loss
thus sustained with new matter of the same sort. I am far from allowing
any value to such chimeras; and the principles of our analytic have
clearly proved that no other than an empirical use of the
categories—that of substance, for example—is possible. But if the
rationalist is bold enough to construct, on the mere authority of the
faculty of thought—without any intuition, whereby an object is given—a
self-subsistent being, merely because the unity of apperception in
thought cannot allow him to believe it a composite being, instead of
declaring, as he ought to do, that he is unable to explain the
possibility of a thinking nature; what ought to hinder the materialist,
with as complete an independence of experience, to employ the principle
of the rationalist in a directly opposite manner—still preserving the
formal unity required by his opponent?]

If, now, we take the above propositions—as they must be accepted as
valid for all thinking beings in the system of rational psychology—in
synthetical connection, and proceed, from the category of relation,
with the proposition: “All thinking beings are, as such, substances,”
backwards through the series, till the circle is completed; we come at
last to their existence, of which, in this system of rational
psychology, substances are held to be conscious, independently of
external things; nay, it is asserted that, in relation to the
permanence which is a necessary characteristic of substance, they can
of themselves determine external things. It follows that idealism—at
least problematical idealism, is perfectly unavoidable in this
rationalistic system. And, if the existence of outward things is not
held to be requisite to the determination of the existence of a
substance in time, the existence of these outward things at all, is a
gratuitous assumption which remains without the possibility of a proof.

But if we proceed analytically—the “I think” as a proposition
containing in itself an existence as given, consequently modality being
the principle—and dissect this proposition, in order to ascertain its
content, and discover whether and how this Ego determines its existence
in time and space without the aid of anything external; the
propositions of rationalistic psychology would not begin with the
conception of a thinking being, but with a reality, and the properties
of a thinking being in general would be deduced from the mode in which
this reality is cogitated, after everything empirical had been
abstracted; as is shown in the following table:

                        1 I think,

            2                             3 as Subject,              as
            simple Subject,

                        4 as identical Subject, in every state of my

Now, inasmuch as it is not determined in this second proposition,
whether I can exist and be cogitated only as subject, and not also as a
predicate of another being, the conception of a subject is here taken
in a merely logical sense; and it remains undetermined, whether
substance is to be cogitated under the conception or not. But in the
third proposition, the absolute unity of apperception—the simple Ego in
the representation to which all connection and separation, which
constitute thought, relate, is of itself important; even although it
presents us with no information about the constitution or subsistence
of the subject. Apperception is something real, and the simplicity of
its nature is given in the very fact of its possibility. Now in space
there is nothing real that is at the same time simple; for points,
which are the only simple things in space, are merely limits, but not
constituent parts of space. From this follows the impossibility of a
definition on the basis of materialism of the constitution of my Ego as
a merely thinking subject. But, because my existence is considered in
the first proposition as given, for it does not mean, “Every thinking
being exists” (for this would be predicating of them absolute
necessity), but only, “I exist thinking”; the proposition is quite
empirical, and contains the determinability of my existence merely in
relation to my representations in time. But as I require for this
purpose something that is permanent, such as is not given in internal
intuition; the mode of my existence, whether as substance or as
accident, cannot be determined by means of this simple
self-consciousness. Thus, if materialism is inadequate to explain the
mode in which I exist, spiritualism is likewise as insufficient; and
the conclusion is that we are utterly unable to attain to any knowledge
of the constitution of the soul, in so far as relates to the
possibility of its existence apart from external objects.

And, indeed, how should it be possible, merely by the aid of the unity
of consciousness—which we cognize only for the reason that it is
indispensable to the possibility of experience—to pass the bounds of
experience (our existence in this life); and to extend our cognition to
the nature of all thinking beings by means of the empirical—but in
relation to every sort of intuition, perfectly
undetermined—proposition, “I think”?

There does not then exist any rational psychology as a doctrine
furnishing any addition to our knowledge of ourselves. It is nothing
more than a discipline, which sets impassable limits to speculative
reason in this region of thought, to prevent it, on the one hand, from
throwing itself into the arms of a soulless materialism, and, on the
other, from losing itself in the mazes of a baseless spiritualism. It
teaches us to consider this refusal of our reason to give any
satisfactory answer to questions which reach beyond the limits of this
our human life, as a hint to abandon fruitless speculation; and to
direct, to a practical use, our knowledge of ourselves—which, although
applicable only to objects of experience, receives its principles from
a higher source, and regulates its procedure as if our destiny reached
far beyond the boundaries of experience and life.

From all this it is evident that rational psychology has its origin in
a mere misunderstanding. The unity of consciousness, which lies at the
basis of the categories, is considered to be an intuition of the
subject as an object; and the category of substance is applied to the
intuition. But this unity is nothing more than the unity in thought, by
which no object is given; to which therefore the category of
substance—which always presupposes a given intuition—cannot be applied.
Consequently, the subject cannot be cognized. The subject of the
categories cannot, therefore, for the very reason that it cogitates
these, frame any conception of itself as an object of the categories;
for, to cogitate these, it must lay at the foundation its own pure
self-consciousness—the very thing that it wishes to explain and
describe. In like manner, the subject, in which the representation of
time has its basis, cannot determine, for this very reason, its own
existence in time. Now, if the latter is impossible, the former, as an
attempt to determine itself by means of the categories as a thinking
being in general, is no less so.*

[*Footnote: The “I think” is, as has been already stated, an empirical
proposition, and contains the proposition, “I exist.” But I cannot say,
“Everything, which thinks, exists”; for in this case the property of
thought would constitute all beings possessing it, necessary beings.
Hence my existence cannot be considered as an inference from the
proposition, “I think,” as Descartes maintained—because in this case
the major premiss, “Everything, which thinks, exists,” must precede—but
the two propositions are identical. The proposition, “I think,”
expresses an undetermined empirical intuition, that perception (proving
consequently that sensation, which must belong to sensibility, lies at
the foundation of this proposition); but it precedes experience, whose
province it is to determine an object of perception by means of the
categories in relation to time; and existence in this proposition is
not a category, as it does not apply to an undetermined given object,
but only to one of which we have a conception, and about which we wish
to know whether it does or does not exist, out of, and apart from this
conception. An undetermined perception signifies here merely something
real that has been given, only, however, to thought in general—but not
as a phenomenon, nor as a thing in itself (noumenon), but only as
something that really exists, and is designated as such in the
proposition, “I think.” For it must be remarked that, when I call the
proposition, “I think,” an empirical proposition, I do not thereby mean
that the Ego in the proposition is an empirical representation; on the
contrary, it is purely intellectual, because it belongs to thought in
general. But without some empirical representation, which presents to
the mind material for thought, the mental act, “I think,” would not
take place; and the empirical is only the condition of the application
or employment of the pure intellectual faculty.]

Thus, then, appears the vanity of the hope of establishing a cognition
which is to extend its rule beyond the limits of experience—a cognition
which is one of the highest interests of humanity; and thus is proved
the futility of the attempt of speculative philosophy in this region of
thought. But, in this interest of thought, the severity of criticism
has rendered to reason a not unimportant service, by the demonstration
of the impossibility of making any dogmatical affirmation concerning an
object of experience beyond the boundaries of experience. She has thus
fortified reason against all affirmations of the contrary. Now, this
can be accomplished in only two ways. Either our proposition must be
proved apodeictically; or, if this is unsuccessful, the sources of this
inability must be sought for, and, if these are discovered to exist in
the natural and necessary limitation of our reason, our opponents must
submit to the same law of renunciation and refrain from advancing
claims to dogmatic assertion.

But the right, say rather the necessity to admit a future life, upon
principles of the practical conjoined with the speculative use of
reason, has lost nothing by this renunciation; for the merely
speculative proof has never had any influence upon the common reason of
men. It stands upon the point of a hair, so that even the schools have
been able to preserve it from falling only by incessantly discussing it
and spinning it like a top; and even in their eyes it has never been
able to present any safe foundation for the erection of a theory. The
proofs which have been current among men, preserve their value
undiminished; nay, rather gain in clearness and unsophisticated power,
by the rejection of the dogmatical assumptions of speculative reason.
For reason is thus confined within her own peculiar province—the
arrangement of ends or aims, which is at the same time the arrangement
of nature; and, as a practical faculty, without limiting itself to the
latter, it is justified in extending the former, and with it our own
existence, beyond the boundaries of experience and life. If we turn our
attention to the analogy of the nature of living beings in this world,
in the consideration of which reason is obliged to accept as a
principle that no organ, no faculty, no appetite is useless, and that
nothing is superfluous, nothing disproportionate to its use, nothing
unsuited to its end; but that, on the contrary, everything is perfectly
conformed to its destination in life—we shall find that man, who alone
is the final end and aim of this order, is still the only animal that
seems to be excepted from it. For his natural gifts—not merely as
regards the talents and motives that may incite him to employ them, but
especially the moral law in him—stretch so far beyond all mere earthly
utility and advantage, that he feels himself bound to prize the mere
consciousness of probity, apart from all advantageous consequences—even
the shadowy gift of posthumous fame—above everything; and he is
conscious of an inward call to constitute himself, by his conduct in
this world—without regard to mere sublunary interests—the citizen of a
better. This mighty, irresistible proof—accompanied by an
ever-increasing knowledge of the conformability to a purpose in
everything we see around us, by the conviction of the boundless
immensity of creation, by the consciousness of a certain
illimitableness in the possible extension of our knowledge, and by a
desire commensurate therewith—remains to humanity, even after the
theoretical cognition of ourselves has failed to establish the
necessity of an existence after death.

Conclusion of the Solution of the Psychological Paralogism.

The dialectical illusion in rational psychology arises from our
confounding an idea of reason (of a pure intelligence) with the
conception—in every respect undetermined—of a thinking being in
general. I cogitate myself in behalf of a possible experience, at the
same time making abstraction of all actual experience; and infer
therefrom that I can be conscious of myself apart from experience and
its empirical conditions. I consequently confound the possible
abstraction of my empirically determined existence with the supposed
consciousness of a possible separate existence of my thinking self; and
I believe that I cognize what is substantial in myself as a
transcendental subject, when I have nothing more in thought than the
unity of consciousness, which lies at the basis of all determination of

The task of explaining the community of the soul with the body does not
properly belong to the psychology of which we are here speaking;
because it proposes to prove the personality of the soul apart from
this communion (after death), and is therefore transcendent in the
proper sense of the word, although occupying itself with an object of
experience—only in so far, however, as it ceases to be an object of
experience. But a sufficient answer may be found to the question in our
system. The difficulty which lies in the execution of this task
consists, as is well known, in the presupposed heterogeneity of the
object of the internal sense (the soul) and the objects of the external
senses; inasmuch as the formal condition of the intuition of the one is
time, and of that of the other space also. But if we consider that both
kinds of objects do not differ internally, but only in so far as the
one appears externally to the other—consequently, that what lies at the
basis of phenomena, as a thing in itself, may not be heterogeneous;
this difficulty disappears. There then remains no other difficulty than
is to be found in the question—how a community of substances is
possible; a question which lies out of the region of psychology, and
which the reader, after what in our analytic has been said of primitive
forces and faculties, will easily judge to be also beyond the region of
human cognition.


On the Transition from Rational Psychology to Cosmology.

The proposition, “I think,” or, “I exist thinking,” is an empirical
proposition. But such a proposition must be based on empirical
intuition, and the object cogitated as a phenomenon; and thus our
theory appears to maintain that the soul, even in thought, is merely a
phenomenon; and in this way our consciousness itself, in fact, abuts
upon nothing.

Thought, per se, is merely the purely spontaneous logical function
which operates to connect the manifold of a possible intuition; and it
does not represent the subject of consciousness as a phenomenon—for
this reason alone, that it pays no attention to the question whether
the mode of intuiting it is sensuous or intellectual. I therefore do
not represent myself in thought either as I am, or as I appear to
myself; I merely cogitate myself as an object in general, of the mode
of intuiting which I make abstraction. When I represent myself as the
subject of thought, or as the ground of thought, these modes of
representation are not related to the categories of substance or of
cause; for these are functions of thought applicable only to our
sensuous intuition. The application of these categories to the Ego
would, however, be necessary, if I wished to make myself an object of
knowledge. But I wish to be conscious of myself only as thinking; in
what mode my Self is given in intuition, I do not consider, and it may
be that I, who think, am a phenomenon—although not in so far as I am a
thinking being; but in the consciousness of myself in mere thought I am
a being, though this consciousness does not present to me any property
of this being as material for thought.

But the proposition, “I think,” in so far as it declares, “I exist
thinking,” is not the mere representation of a logical function. It
determines the subject (which is in this case an object also) in
relation to existence; and it cannot be given without the aid of the
internal sense, whose intuition presents to us an object, not as a
thing in itself, but always as a phenomenon. In this proposition there
is therefore something more to be found than the mere spontaneity of
thought; there is also the receptivity of intuition, that is, my
thought of myself applied to the empirical intuition of myself. Now, in
this intuition the thinking self must seek the conditions of the
employment of its logical functions as categories of substance, cause,
and so forth; not merely for the purpose of distinguishing itself as an
object in itself by means of the representation “I,” but also for the
purpose of determining the mode of its existence, that is, of cognizing
itself as noumenon. But this is impossible, for the internal empirical
intuition is sensuous, and presents us with nothing but phenomenal
data, which do not assist the object of pure consciousness in its
attempt to cognize itself as a separate existence, but are useful only
as contributions to experience.

But, let it be granted that we could discover, not in experience, but
in certain firmly-established a priori laws of the use of pure
reason—laws relating to our existence, authority to consider ourselves
as legislating a priori in relation to our own existence and as
determining this existence; we should, on this supposition, find
ourselves possessed of a spontaneity, by which our actual existence
would be determinable, without the aid of the conditions of empirical
intuition. We should also become aware that in the consciousness of our
existence there was an a priori content, which would serve to determine
our own existence—an existence only sensuously determinable—relatively,
however, to a certain internal faculty in relation to an intelligible

But this would not give the least help to the attempts of rational
psychology. For this wonderful faculty, which the consciousness of the
moral law in me reveals, would present me with a principle of the
determination of my own existence which is purely intellectual—but by
what predicates? By none other than those which are given in sensuous
intuition. Thus I should find myself in the same position in rational
psychology which I formerly occupied, that is to say, I should find
myself still in need of sensuous intuitions, in order to give
significance to my conceptions of substance and cause, by means of
which alone I can possess a knowledge of myself: but these intuitions
can never raise me above the sphere of experience. I should be
justified, however, in applying these conceptions, in regard to their
practical use, which is always directed to objects of experience—in
conformity with their analogical significance when employed
theoretically—to freedom and its subject. At the same time, I should
understand by them merely the logical functions of subject and
predicate, of principle and consequence, in conformity with which all
actions are so determined, that they are capable of being explained
along with the laws of nature, conformably to the categories of
substance and cause, although they originate from a very different
principle. We have made these observations for the purpose of guarding
against misunderstanding, to which the doctrine of our intuition of
self as a phenomenon is exposed. We shall have occasion to perceive
their utility in the sequel.

 Chapter II. The Antinomy of Pure Reason

We showed in the introduction to this part of our work, that all
transcendental illusion of pure reason arose from dialectical
arguments, the schema of which logic gives us in its three formal
species of syllogisms—just as the categories find their logical schema
in the four functions of all judgements. The first kind of these
sophistical arguments related to the unconditioned unity of the
subjective conditions of all representations in general (of the subject
or soul), in correspondence with the categorical syllogisms, the major
of which, as the principle, enounces the relation of a predicate to a
subject. The second kind of dialectical argument will therefore be
concerned, following the analogy with hypothetical syllogisms, with the
unconditioned unity of the objective conditions in the phenomenon; and,
in this way, the theme of the third kind to be treated of in the
following chapter will be the unconditioned unity of the objective
conditions of the possibility of objects in general.

But it is worthy of remark that the transcendental paralogism produced
in the mind only a one-third illusion, in regard to the idea of the
subject of our thought; and the conceptions of reason gave no ground to
maintain the contrary proposition. The advantage is completely on the
side of Pneumatism; although this theory itself passes into naught, in
the crucible of pure reason.

Very different is the case when we apply reason to the objective
synthesis of phenomena. Here, certainly, reason establishes, with much
plausibility, its principle of unconditioned unity; but it very soon
falls into such contradictions that it is compelled, in relation to
cosmology, to renounce its pretensions.

For here a new phenomenon of human reason meets us—a perfectly natural
antithetic, which does not require to be sought for by subtle
sophistry, but into which reason of itself unavoidably falls. It is
thereby preserved, to be sure, from the slumber of a fancied
conviction—which a merely one-sided illusion produces; but it is at the
same time compelled, either, on the one hand, to abandon itself to a
despairing scepticism, or, on the other, to assume a dogmatical
confidence and obstinate persistence in certain assertions, without
granting a fair hearing to the other side of the question. Either is
the death of a sound philosophy, although the former might perhaps
deserve the title of the euthanasia of pure reason.

Before entering this region of discord and confusion, which the
conflict of the laws of pure reason (antinomy) produces, we shall
present the reader with some considerations, in explanation and
justification of the method we intend to follow in our treatment of
this subject. I term all transcendental ideas, in so far as they relate
to the absolute totality in the synthesis of phenomena, cosmical
conceptions; partly on account of this unconditioned totality, on which
the conception of the world-whole is based—a conception, which is
itself an idea—partly because they relate solely to the synthesis of
phenomena—the empirical synthesis; while, on the other hand, the
absolute totality in the synthesis of the conditions of all possible
things gives rise to an ideal of pure reason, which is quite distinct
from the cosmical conception, although it stands in relation with it.
Hence, as the paralogisms of pure reason laid the foundation for a
dialectical psychology, the antinomy of pure reason will present us
with the transcendental principles of a pretended pure (rational)
cosmology—not, however, to declare it valid and to appropriate it,
but—as the very term of a conflict of reason sufficiently indicates, to
present it as an idea which cannot be reconciled with phenomena and

 Section I. System of Cosmological Ideas

That We may be able to enumerate with systematic precision these ideas
according to a principle, we must remark, in the first place, that it
is from the understanding alone that pure and transcendental
conceptions take their origin; that the reason does not properly give
birth to any conception, but only frees the conception of the
understanding from the unavoidable limitation of a possible experience,
and thus endeavours to raise it above the empirical, though it must
still be in connection with it. This happens from the fact that, for a
given conditioned, reason demands absolute totality on the side of the
conditions (to which the understanding submits all phenomena), and thus
makes of the category a transcendental idea. This it does that it may
be able to give absolute completeness to the empirical synthesis, by
continuing it to the unconditioned (which is not to be found in
experience, but only in the idea). Reason requires this according to
the principle: If the conditioned is given the whole of the conditions,
and consequently the absolutely unconditioned, is also given, whereby
alone the former was possible. First, then, the transcendental ideas
are properly nothing but categories elevated to the unconditioned; and
they may be arranged in a table according to the titles of the latter.
But, secondly, all the categories are not available for this purpose,
but only those in which the synthesis constitutes a series—of
conditions subordinated to, not co-ordinated with, each other. Absolute
totality is required of reason only in so far as concerns the ascending
series of the conditions of a conditioned; not, consequently, when the
question relates to the descending series of consequences, or to the
aggregate of the co-ordinated conditions of these consequences. For, in
relation to a given conditioned, conditions are presupposed and
considered to be given along with it. On the other hand, as the
consequences do not render possible their conditions, but rather
presuppose them—in the consideration of the procession of consequences
(or in the descent from the given condition to the conditioned), we may
be quite unconcerned whether the series ceases or not; and their
totality is not a necessary demand of reason.

Thus we cogitate—and necessarily—a given time completely elapsed up to
a given moment, although that time is not determinable by us. But as
regards time future, which is not the condition of arriving at the
present, in order to conceive it; it is quite indifferent whether we
consider future time as ceasing at some point, or as prolonging itself
to infinity. Take, for example, the series m, n, o, in which n is given
as conditioned in relation to m, but at the same time as the condition
of o, and let the series proceed upwards from the conditioned n to m
(l, k, i, etc.), and also downwards from the condition n to the
conditioned o (p, q, r, etc.)—I must presuppose the former series, to
be able to consider n as given, and n is according to reason (the
totality of conditions) possible only by means of that series. But its
possibility does not rest on the following series o, p, q, r, which for
this reason cannot be regarded as given, but only as capable of being
given (dabilis).

I shall term the synthesis of the series on the side of the
conditions—from that nearest to the given phenomenon up to the more
remote—regressive; that which proceeds on the side of the conditioned,
from the immediate consequence to the more remote, I shall call the
progressive synthesis. The former proceeds in antecedentia, the latter
in consequentia. The cosmological ideas are therefore occupied with the
totality of the regressive synthesis, and proceed in antecedentia, not
in consequentia. When the latter takes place, it is an arbitrary and
not a necessary problem of pure reason; for we require, for the
complete understanding of what is given in a phenomenon, not the
consequences which succeed, but the grounds or principles which

In order to construct the table of ideas in correspondence with the
table of categories, we take first the two primitive quanta of all our
intuitions, time and space. Time is in itself a series (and the formal
condition of all series), and hence, in relation to a given present, we
must distinguish a priori in it the antecedentia as conditions (time
past) from the consequentia (time future). Consequently, the
transcendental idea of the absolute totality of the series of the
conditions of a given conditioned, relates merely to all past time.
According to the idea of reason, the whole past time, as the condition
of the given moment, is necessarily cogitated as given. But, as regards
space, there exists in it no distinction between progressus and
regressus; for it is an aggregate and not a series—its parts existing
together at the same time. I can consider a given point of time in
relation to past time only as conditioned, because this given moment
comes into existence only through the past time rather through the
passing of the preceding time. But as the parts of space are not
subordinated, but co-ordinated to each other, one part cannot be the
condition of the possibility of the other; and space is not in itself,
like time, a series. But the synthesis of the manifold parts of
space—(the syntheses whereby we apprehend space)—is nevertheless
successive; it takes place, therefore, in time, and contains a series.
And as in this series of aggregated spaces (for example, the feet in a
rood), beginning with a given portion of space, those which continue to
be annexed form the condition of the limits of the former—the
measurement of a space must also be regarded as a synthesis of the
series of the conditions of a given conditioned. It differs, however,
in this respect from that of time, that the side of the conditioned is
not in itself distinguishable from the side of the condition; and,
consequently, regressus and progressus in space seem to be identical.
But, inasmuch as one part of space is not given, but only limited, by
and through another, we must also consider every limited space as
conditioned, in so far as it presupposes some other space as the
condition of its limitation, and so on. As regards limitation,
therefore, our procedure in space is also a regressus, and the
transcendental idea of the absolute totality of the synthesis in a
series of conditions applies to space also; and I am entitled to demand
the absolute totality of the phenomenal synthesis in space as well as
in time. Whether my demand can be satisfied is a question to be
answered in the sequel.

Secondly, the real in space—that is, matter—is conditioned. Its
internal conditions are its parts, and the parts of parts its remote
conditions; so that in this case we find a regressive synthesis, the
absolute totality of which is a demand of reason. But this cannot be
obtained otherwise than by a complete division of parts, whereby the
real in matter becomes either nothing or that which is not matter, that
is to say, the simple. Consequently we find here also a series of
conditions and a progress to the unconditioned.

Thirdly, as regards the categories of a real relation between
phenomena, the category of substance and its accidents is not suitable
for the formation of a transcendental idea; that is to say, reason has
no ground, in regard to it, to proceed regressively with conditions.
For accidents (in so far as they inhere in a substance) are
co-ordinated with each other, and do not constitute a series. And, in
relation to substance, they are not properly subordinated to it, but
are the mode of existence of the substance itself. The conception of
the substantial might nevertheless seem to be an idea of the
transcendental reason. But, as this signifies nothing more than the
conception of an object in general, which subsists in so far as we
cogitate in it merely a transcendental subject without any predicates;
and as the question here is of an unconditioned in the series of
phenomena—it is clear that the substantial can form no member thereof.
The same holds good of substances in community, which are mere
aggregates and do not form a series. For they are not subordinated to
each other as conditions of the possibility of each other; which,
however, may be affirmed of spaces, the limits of which are never
determined in themselves, but always by some other space. It is,
therefore, only in the category of causality that we can find a series
of causes to a given effect, and in which we ascend from the latter, as
the conditioned, to the former as the conditions, and thus answer the
question of reason.

Fourthly, the conceptions of the possible, the actual, and the
necessary do not conduct us to any series—excepting only in so far as
the contingent in existence must always be regarded as conditioned, and
as indicating, according to a law of the understanding, a condition,
under which it is necessary to rise to a higher, till in the totality
of the series, reason arrives at unconditioned necessity.

There are, accordingly, only four cosmological ideas, corresponding
with the four titles of the categories. For we can select only such as
necessarily furnish us with a series in the synthesis of the manifold.

                      1 The absolute Completeness of the COMPOSITION of
                      the given totality of all phenomena.

                      2 The absolute Completeness of the DIVISION of
                      given totality in a phenomenon.

                       3 The absolute Completeness of the ORIGINATION
                       of a phenomenon.

                       4 The absolute Completeness of the DEPENDENCE of
                       the EXISTENCE of what is changeable in a

We must here remark, in the first place, that the idea of absolute
totality relates to nothing but the exposition of phenomena, and
therefore not to the pure conception of a totality of things. Phenomena
are here, therefore, regarded as given, and reason requires the
absolute completeness of the conditions of their possibility, in so far
as these conditions constitute a series—consequently an absolutely
(that is, in every respect) complete synthesis, whereby a phenomenon
can be explained according to the laws of the understanding.

Secondly, it is properly the unconditioned alone that reason seeks in
this serially and regressively conducted synthesis of conditions. It
wishes, to speak in another way, to attain to completeness in the
series of premisses, so as to render it unnecessary to presuppose
others. This unconditioned is always contained in the absolute totality
of the series, when we endeavour to form a representation of it in
thought. But this absolutely complete synthesis is itself but an idea;
for it is impossible, at least before hand, to know whether any such
synthesis is possible in the case of phenomena. When we represent all
existence in thought by means of pure conceptions of the understanding,
without any conditions of sensuous intuition, we may say with justice
that for a given conditioned the whole series of conditions
subordinated to each other is also given; for the former is only given
through the latter. But we find in the case of phenomena a particular
limitation of the mode in which conditions are given, that is, through
the successive synthesis of the manifold of intuition, which must be
complete in the regress. Now whether this completeness is sensuously
possible, is a problem. But the idea of it lies in the reason—be it
possible or impossible to connect with the idea adequate empirical
conceptions. Therefore, as in the absolute totality of the regressive
synthesis of the manifold in a phenomenon (following the guidance of
the categories, which represent it as a series of conditions to a given
conditioned) the unconditioned is necessarily contained—it being still
left unascertained whether and how this totality exists; reason sets
out from the idea of totality, although its proper and final aim is the
unconditioned—of the whole series, or of a part thereof.

This unconditioned may be cogitated—either as existing only in the
entire series, all the members of which therefore would be without
exception conditioned and only the totality absolutely
unconditioned—and in this case the regressus is called infinite; or the
absolutely unconditioned is only a part of the series, to which the
other members are subordinated, but which Is not itself submitted to
any other condition.* In the former case the series is a parte priori
unlimited (without beginning), that is, infinite, and nevertheless
completely given. But the regress in it is never completed, and can
only be called potentially infinite. In the second case there exists a
first in the series. This first is called, in relation to past time,
the beginning of the world; in relation to space, the limit of the
world; in relation to the parts of a given limited whole, the simple;
in relation to causes, absolute spontaneity (liberty); and in relation
to the existence of changeable things, absolute physical necessity.

[*Footnote: The absolute totality of the series of conditions to a
given conditioned is always unconditioned; because beyond it there
exist no other conditions, on which it might depend. But the absolute
totality of such a series is only an idea, or rather a problematical
conception, the possibility of which must be investigated—particularly
in relation to the mode in which the unconditioned, as the
transcendental idea which is the real subject of inquiry, may be
contained therein.]

We possess two expressions, world and nature, which are generally
interchanged. The first denotes the mathematical total of all phenomena
and the totality of their synthesis—in its progress by means of
composition, as well as by division. And the world is termed nature,*
when it is regarded as a dynamical whole—when our attention is not
directed to the aggregation in space and time, for the purpose of
cogitating it as a quantity, but to the unity in the existence of
phenomena. In this case the condition of that which happens is called a
cause; the unconditioned causality of the cause in a phenomenon is
termed liberty; the conditioned cause is called in a more limited sense
a natural cause. The conditioned in existence is termed contingent, and
the unconditioned necessary. The unconditioned necessity of phenomena
may be called natural necessity.

[*Footnote: Nature, understood adjective (formaliter), signifies the
complex of the determinations of a thing, connected according to an
internal principle of causality. On the other hand, we understand by
nature, substantive (materialiter), the sum total of phenomena, in so
far as they, by virtue of an internal principle of causality, are
connected with each other throughout. In the former sense we speak of
the nature of liquid matter, of fire, etc., and employ the word only
adjective; while, if speaking of the objects of nature, we have in our
minds the idea of a subsisting whole.]

The ideas which we are at present engaged in discussing I have called
cosmological ideas; partly because by the term world is understood the
entire content of all phenomena, and our ideas are directed solely to
the unconditioned among phenomena; partly also, because world, in the
transcendental sense, signifies the absolute totality of the content of
existing things, and we are directing our attention only to the
completeness of the synthesis—although, properly, only in regression.
In regard to the fact that these ideas are all transcendent, and,
although they do not transcend phenomena as regards their mode, but are
concerned solely with the world of sense (and not with noumena),
nevertheless carry their synthesis to a degree far above all possible
experience—it still seems to me that we can, with perfect propriety,
designate them cosmical conceptions. As regards the distinction between
the mathematically and the dynamically unconditioned which is the aim
of the regression of the synthesis, I should call the two former, in a
more limited signification, cosmical conceptions, the remaining two
transcendent physical conceptions. This distinction does not at present
seem to be of particular importance, but we shall afterwards find it to
be of some value.

 Section II. Antithetic of Pure Reason

Thetic is the term applied to every collection of dogmatical
propositions. By antithetic I do not understand dogmatical assertions
of the opposite, but the self-contradiction of seemingly dogmatical
cognitions (thesis cum antithesis), in none of which we can discover
any decided superiority. Antithetic is not, therefore, occupied with
one-sided statements, but is engaged in considering the contradictory
nature of the general cognitions of reason and its causes.
Transcendental antithetic is an investigation into the antinomy of pure
reason, its causes and result. If we employ our reason not merely in
the application of the principles of the understanding to objects of
experience, but venture with it beyond these boundaries, there arise
certain sophistical propositions or theorems. These assertions have the
following peculiarities: They can find neither confirmation nor
confutation in experience; and each is in itself not only
self-consistent, but possesses conditions of its necessity in the very
nature of reason—only that, unluckily, there exist just as valid and
necessary grounds for maintaining the contrary proposition.

The questions which naturally arise in the consideration of this
dialectic of pure reason, are therefore: 1st. In what propositions is
pure reason unavoidably subject to an antinomy? 2nd. What are the
causes of this antinomy? 3rd. Whether and in what way can reason free
itself from this self-contradiction?

A dialectical proposition or theorem of pure reason must, according to
what has been said, be distinguishable from all sophistical
propositions, by the fact that it is not an answer to an arbitrary
question, which may be raised at the mere pleasure of any person, but
to one which human reason must necessarily encounter in its progress.
In the second place, a dialectical proposition, with its opposite, does
not carry the appearance of a merely artificial illusion, which
disappears as soon as it is investigated, but a natural and unavoidable
illusion, which, even when we are no longer deceived by it, continues
to mock us and, although rendered harmless, can never be completely

This dialectical doctrine will not relate to the unity of understanding
in empirical conceptions, but to the unity of reason in pure ideas. The
conditions of this doctrine are—inasmuch as it must, as a synthesis
according to rules, be conformable to the understanding, and at the
same time as the absolute unity of the synthesis, to the reason—that,
if it is adequate to the unity of reason, it is too great for the
understanding, if according with the understanding, it is too small for
the reason. Hence arises a mutual opposition, which cannot be avoided,
do what we will.

These sophistical assertions of dialectic open, as it were, a
battle-field, where that side obtains the victory which has been
permitted to make the attack, and he is compelled to yield who has been
unfortunately obliged to stand on the defensive. And hence, champions
of ability, whether on the right or on the wrong side, are certain to
carry away the crown of victory, if they only take care to have the
right to make the last attack, and are not obliged to sustain another
onset from their opponent. We can easily believe that this arena has
been often trampled by the feet of combatants, that many victories have
been obtained on both sides, but that the last victory, decisive of the
affair between the contending parties, was won by him who fought for
the right, only if his adversary was forbidden to continue the tourney.
As impartial umpires, we must lay aside entirely the consideration
whether the combatants are fighting for the right or for the wrong
side, for the true or for the false, and allow the combat to be first
decided. Perhaps, after they have wearied more than injured each other,
they will discover the nothingness of their cause of quarrel and part
good friends.

This method of watching, or rather of originating, a conflict of
assertions, not for the purpose of finally deciding in favour of either
side, but to discover whether the object of the struggle is not a mere
illusion, which each strives in vain to reach, but which would be no
gain even when reached—this procedure, I say, may be termed the
sceptical method. It is thoroughly distinct from scepticism—the
principle of a technical and scientific ignorance, which undermines the
foundations of all knowledge, in order, if possible, to destroy our
belief and confidence therein. For the sceptical method aims at
certainty, by endeavouring to discover in a conflict of this kind,
conducted honestly and intelligently on both sides, the point of
misunderstanding; just as wise legislators derive, from the
embarrassment of judges in lawsuits, information in regard to the
defective and ill-defined parts of their statutes. The antinomy which
reveals itself in the application of laws, is for our limited wisdom
the best criterion of legislation. For the attention of reason, which
in abstract speculation does not easily become conscious of its errors,
is thus roused to the momenta in the determination of its principles.

But this sceptical method is essentially peculiar to transcendental
philosophy, and can perhaps be dispensed with in every other field of
investigation. In mathematics its use would be absurd; because in it no
false assertions can long remain hidden, inasmuch as its demonstrations
must always proceed under the guidance of pure intuition, and by means
of an always evident synthesis. In experimental philosophy, doubt and
delay may be very useful; but no misunderstanding is possible, which
cannot be easily removed; and in experience means of solving the
difficulty and putting an end to the dissension must at last be found,
whether sooner or later. Moral philosophy can always exhibit its
principles, with their practical consequences, in concreto—at least in
possible experiences, and thus escape the mistakes and ambiguities of
abstraction. But transcendental propositions, which lay claim to
insight beyond the region of possible experience, cannot, on the one
hand, exhibit their abstract synthesis in any a priori intuition, nor,
on the other, expose a lurking error by the help of experience.
Transcendental reason, therefore, presents us with no other criterion
than that of an attempt to reconcile such assertions, and for this
purpose to permit a free and unrestrained conflict between them. And
this we now proceed to arrange.*

[*Footnote: The antinomies stand in the order of the four
transcendental ideas above detailed.]


The world has a beginning in time, and is also limited in regard to


Granted that the world has no beginning in time; up to every given
moment of time, an eternity must have elapsed, and therewith passed
away an infinite series of successive conditions or states of things in
the world. Now the infinity of a series consists in the fact that it
never can be completed by means of a successive synthesis. It follows
that an infinite series already elapsed is impossible and that,
consequently, a beginning of the world is a necessary condition of its
existence. And this was the first thing to be proved.

As regards the second, let us take the opposite for granted. In this
case, the world must be an infinite given total of coexistent things.
Now we cannot cogitate the dimensions of a quantity, which is not given
within certain limits of an intuition,* in any other way than by means
of the synthesis of its parts, and the total of such a quantity only by
means of a completed synthesis, or the repeated addition of unity to
itself. Accordingly, to cogitate the world, which fills all spaces, as
a whole, the successive synthesis of the parts of an infinite world
must be looked upon as completed, that is to say, an infinite time must
be regarded as having elapsed in the enumeration of all co-existing
things; which is impossible. For this reason an infinite aggregate of
actual things cannot be considered as a given whole, consequently, not
as a contemporaneously given whole. The world is consequently, as
regards extension in space, not infinite, but enclosed in limits. And
this was the second thing to be proved.

[*Footnote: We may consider an undetermined quantity as a whole, when
it is enclosed within limits, although we cannot construct or ascertain
its totality by measurement, that is, by the successive synthesis of
its parts. For its limits of themselves determine its completeness as a


The world has no beginning, and no limits in space, but is, in relation
both to time and space, infinite.


For let it be granted that it has a beginning. A beginning is an
existence which is preceded by a time in which the thing does not
exist. On the above supposition, it follows that there must have been a
time in which the world did not exist, that is, a void time. But in a
void time the origination of a thing is impossible; because no part of
any such time contains a distinctive condition of being, in preference
to that of non-being (whether the supposed thing originate of itself,
or by means of some other cause). Consequently, many series of things
may have a beginning in the world, but the world itself cannot have a
beginning, and is, therefore, in relation to past time, infinite.

As regards the second statement, let us first take the opposite for
granted—that the world is finite and limited in space; it follows that
it must exist in a void space, which is not limited. We should
therefore meet not only with a relation of things in space, but also a
relation of things to space. Now, as the world is an absolute whole,
out of and beyond which no object of intuition, and consequently no
correlate to which can be discovered, this relation of the world to a
void space is merely a relation to no object. But such a relation, and
consequently the limitation of the world by void space, is nothing.
Consequently, the world, as regards space, is not limited, that is, it
is infinite in regard to extension.*

*Footnote: Space is merely the form of external intuition (formal
intuition), and not a real object which can be externally perceived.
Space, prior to all things which determine it (fill or limit it), or,
rather, which present an empirical intuition conformable to it, is,
under the title of absolute space, nothing but the mere possibility of
external phenomena, in so far as they either exist in themselves, or
can annex themselves to given intuitions. Empirical intuition is
therefore not a composition of phenomena and space (of perception and
empty intuition). The one is not the correlate of the other in a
synthesis, but they are vitally connected in the same empirical
intuition, as matter and form. If we wish to set one of these two apart
from the other—space from phenomena—there arise all sorts of empty
determinations of external intuition, which are very far from being
possible perceptions. For example, motion or rest of the world in an
infinite empty space, or a determination of the mutual relation of
both, cannot possibly be perceived, and is therefore merely the
predicate of a notional entity.]


In bringing forward these conflicting arguments, I have not been on the
search for sophisms, for the purpose of availing myself of special
pleading, which takes advantage of the carelessness of the opposite
party, appeals to a misunderstood statute, and erects its unrighteous
claims upon an unfair interpretation. Both proofs originate fairly from
the nature of the case, and the advantage presented by the mistakes of
the dogmatists of both parties has been completely set aside.

The thesis might also have been unfairly demonstrated, by the
introduction of an erroneous conception of the infinity of a given
quantity. A quantity is infinite, if a greater than itself cannot
possibly exist. The quantity is measured by the number of given
units—which are taken as a standard—contained in it. Now no number can
be the greatest, because one or more units can always be added. It
follows that an infinite given quantity, consequently an infinite world
(both as regards time and extension) is impossible. It is, therefore,
limited in both respects. In this manner I might have conducted my
proof; but the conception given in it does not agree with the true
conception of an infinite whole. In this there is no representation of
its quantity, it is not said how large it is; consequently its
conception is not the conception of a maximum. We cogitate in it merely
its relation to an arbitrarily assumed unit, in relation to which it is
greater than any number. Now, just as the unit which is taken is
greater or smaller, the infinite will be greater or smaller; but the
infinity, which consists merely in the relation to this given unit,
must remain always the same, although the absolute quantity of the
whole is not thereby cognized.

The true (transcendental) conception of infinity is: that the
successive synthesis of unity in the measurement of a given quantum can
never be completed.* Hence it follows, without possibility of mistake,
that an eternity of actual successive states up to a given (the
present) moment cannot have elapsed, and that the world must therefore
have a beginning.

[*Footnote: The quantum in this sense contains a congeries of given
units, which is greater than any number—and this is the mathematical
conception of the infinite.]

In regard to the second part of the thesis, the difficulty as to an
infinite and yet elapsed series disappears; for the manifold of a world
infinite in extension is contemporaneously given. But, in order to
cogitate the total of this manifold, as we cannot have the aid of
limits constituting by themselves this total in intuition, we are
obliged to give some account of our conception, which in this case
cannot proceed from the whole to the determined quantity of the parts,
but must demonstrate the possibility of a whole by means of a
successive synthesis of the parts. But as this synthesis must
constitute a series that cannot be completed, it is impossible for us
to cogitate prior to it, and consequently not by means of it, a
totality. For the conception of totality itself is in the present case
the representation of a completed synthesis of the parts; and this
completion, and consequently its conception, is impossible.


The proof in favour of the infinity of the cosmical succession and the
cosmical content is based upon the consideration that, in the opposite
case, a void time and a void space must constitute the limits of the
world. Now I am not unaware, that there are some ways of escaping this
conclusion. It may, for example, be alleged, that a limit to the world,
as regards both space and time, is quite possible, without at the same
time holding the existence of an absolute time before the beginning of
the world, or an absolute space extending beyond the actual world—which
is impossible. I am quite well satisfied with the latter part of this
opinion of the philosophers of the Leibnitzian school. Space is merely
the form of external intuition, but not a real object which can itself
be externally intuited; it is not a correlate of phenomena, it is the
form of phenomena itself. Space, therefore, cannot be regarded as
absolutely and in itself something determinative of the existence of
things, because it is not itself an object, but only the form of
possible objects. Consequently, things, as phenomena, determine space;
that is to say, they render it possible that, of all the possible
predicates of space (size and relation), certain may belong to reality.
But we cannot affirm the converse, that space, as something
self-subsistent, can determine real things in regard to size or shape,
for it is in itself not a real thing. Space (filled or void)* may
therefore be limited by phenomena, but phenomena cannot be limited by
an empty space without them. This is true of time also. All this being
granted, it is nevertheless indisputable, that we must assume these two
nonentities, void space without and void time before the world, if we
assume the existence of cosmical limits, relatively to space or time.

[*Footnote: It is evident that what is meant here is, that empty space,
in so far as it is limited by phenomena—space, that is, within the
world—does not at least contradict transcendental principles, and may
therefore, as regards them, be admitted, although its possibility
cannot on that account be affirmed.]

For, as regards the subterfuge adopted by those who endeavour to evade
the consequence—that, if the world is limited as to space and time, the
infinite void must determine the existence of actual things in regard
to their dimensions—it arises solely from the fact that instead of a
sensuous world, an intelligible world—of which nothing is known—is
cogitated; instead of a real beginning (an existence, which is preceded
by a period in which nothing exists), an existence which presupposes no
other condition than that of time; and, instead of limits of extension,
boundaries of the universe. But the question relates to the mundus
phaenomenon, and its quantity; and in this case we cannot make
abstraction of the conditions of sensibility, without doing away with
the essential reality of this world itself. The world of sense, if it
is limited, must necessarily lie in the infinite void. If this, and
with it space as the a priori condition of the possibility of
phenomena, is left out of view, the whole world of sense disappears. In
our problem is this alone considered as given. The mundus
intelligibilis is nothing but the general conception of a world, in
which abstraction has been made of all conditions of intuition, and in
relation to which no synthetical proposition—either affirmative or
negative—is possible.


Every composite substance in the world consists of simple parts; and
there exists nothing that is not either itself simple, or composed of
simple parts.


For, grant that composite substances do not consist of simple parts; in
this case, if all combination or composition were annihilated in
thought, no composite part, and (as, by the supposition, there do not
exist simple parts) no simple part would exist. Consequently, no
substance; consequently, nothing would exist. Either, then, it is
impossible to annihilate composition in thought; or, after such
annihilation, there must remain something that subsists without
composition, that is, something that is simple. But in the former case
the composite could not itself consist of substances, because with
substances composition is merely a contingent relation, apart from
which they must still exist as self-subsistent beings. Now, as this
case contradicts the supposition, the second must contain the
truth—that the substantial composite in the world consists of simple

It follows, as an immediate inference, that the things in the world are
all, without exception, simple beings—that composition is merely an
external condition pertaining to them—and that, although we never can
separate and isolate the elementary substances from the state of
composition, reason must cogitate these as the primary subjects of all
composition, and consequently, as prior thereto—and as simple


No composite thing in the world consists of simple parts; and there
does not exist in the world any simple substance.


Let it be supposed that a composite thing (as substance) consists of
simple parts. Inasmuch as all external relation, consequently all
composition of substances, is possible only in space; the space,
occupied by that which is composite, must consist of the same number of
parts as is contained in the composite. But space does not consist of
simple parts, but of spaces. Therefore, every part of the composite
must occupy a space. But the absolutely primary parts of what is
composite are simple. It follows that what is simple occupies a space.
Now, as everything real that occupies a space, contains a manifold the
parts of which are external to each other, and is consequently
composite—and a real composite, not of accidents (for these cannot
exist external to each other apart from substance), but of
substances—it follows that the simple must be a substantial composite,
which is self-contradictory.

The second proposition of the antithesis—that there exists in the world
nothing that is simple—is here equivalent to the following: The
existence of the absolutely simple cannot be demonstrated from any
experience or perception either external or internal; and the
absolutely simple is a mere idea, the objective reality of which cannot
be demonstrated in any possible experience; it is consequently, in the
exposition of phenomena, without application and object. For, let us
take for granted that an object may be found in experience for this
transcendental idea; the empirical intuition of such an object must
then be recognized to contain absolutely no manifold with its parts
external to each other, and connected into unity. Now, as we cannot
reason from the non-consciousness of such a manifold to the
impossibility of its existence in the intuition of an object, and as
the proof of this impossibility is necessary for the establishment and
proof of absolute simplicity; it follows that this simplicity cannot be
inferred from any perception whatever. As, therefore, an absolutely
simple object cannot be given in any experience, and the world of sense
must be considered as the sum total of all possible experiences:
nothing simple exists in the world.

This second proposition in the antithesis has a more extended aim than
the first. The first merely banishes the simple from the intuition of
the composite; while the second drives it entirely out of nature. Hence
we were unable to demonstrate it from the conception of a given object
of external intuition (of the composite), but we were obliged to prove
it from the relation of a given object to a possible experience in


When I speak of a whole, which necessarily consists of simple parts, I
understand thereby only a substantial whole, as the true composite;
that is to say, I understand that contingent unity of the manifold
which is given as perfectly isolated (at least in thought), placed in
reciprocal connection, and thus constituted a unity. Space ought not to
be called a compositum but a totum, for its parts are possible in the
whole, and not the whole by means of the parts. It might perhaps be
called a compositum ideale, but not a compositum reale. But this is of
no importance. As space is not a composite of substances (and not even
of real accidents), if I abstract all composition therein—nothing, not
even a point, remains; for a point is possible only as the limit of a
space—consequently of a composite. Space and time, therefore, do not
consist of simple parts. That which belongs only to the condition or
state of a substance, even although it possesses a quantity (motion or
change, for example), likewise does not consist of simple parts. That
is to say, a certain degree of change does not originate from the
addition of many simple changes. Our inference of the simple from the
composite is valid only of self-subsisting things. But the accidents of
a state are not self-subsistent. The proof, then, for the necessity of
the simple, as the component part of all that is substantial and
composite, may prove a failure, and the whole case of this thesis be
lost, if we carry the proposition too far, and wish to make it valid of
everything that is composite without distinction—as indeed has really
now and then happened. Besides, I am here speaking only of the simple,
in so far as it is necessarily given in the composite—the latter being
capable of solution into the former as its component parts. The proper
signification of the word monas (as employed by Leibnitz) ought to
relate to the simple, given immediately as simple substance (for
example, in consciousness), and not as an element of the composite. As
an clement, the term atomus would be more appropriate. And as I wish to
prove the existence of simple substances, only in relation to, and as
the elements of, the composite, I might term the antithesis of the
second Antinomy, transcendental Atomistic. But as this word has long
been employed to designate a particular theory of corporeal phenomena
(moleculae), and thus presupposes a basis of empirical conceptions, I
prefer calling it the dialectical principle of Monadology.


Against the assertion of the infinite subdivisibility of matter whose
ground of proof is purely mathematical, objections have been alleged by
the Monadists. These objections lay themselves open, at first sight, to
suspicion, from the fact that they do not recognize the clearest
mathematical proofs as propositions relating to the constitution of
space, in so far as it is really the formal condition of the
possibility of all matter, but regard them merely as inferences from
abstract but arbitrary conceptions, which cannot have any application
to real things. Just as if it were possible to imagine another mode of
intuition than that given in the primitive intuition of space; and just
as if its a priori determinations did not apply to everything, the
existence of which is possible, from the fact alone of its filling
space. If we listen to them, we shall find ourselves required to
cogitate, in addition to the mathematical point, which is simple—not,
however, a part, but a mere limit of space—physical points, which are
indeed likewise simple, but possess the peculiar property, as parts of
space, of filling it merely by their aggregation. I shall not repeat
here the common and clear refutations of this absurdity, which are to
be found everywhere in numbers: every one knows that it is impossible
to undermine the evidence of mathematics by mere discursive
conceptions; I shall only remark that, if in this case philosophy
endeavours to gain an advantage over mathematics by sophistical
artifices, it is because it forgets that the discussion relates solely
to Phenomena and their conditions. It is not sufficient to find the
conception of the simple for the pure conception of the composite, but
we must discover for the intuition of the composite (matter), the
intuition of the simple. Now this, according to the laws of
sensibility, and consequently in the case of objects of sense, is
utterly impossible. In the case of a whole composed of substances,
which is cogitated solely by the pure understanding, it may be
necessary to be in possession of the simple before composition is
possible. But this does not hold good of the Totum substantiale
phaenomenon, which, as an empirical intuition in space, possesses the
necessary property of containing no simple part, for the very reason
that no part of space is simple. Meanwhile, the Monadists have been
subtle enough to escape from this difficulty, by presupposing intuition
and the dynamical relation of substances as the condition of the
possibility of space, instead of regarding space as the condition of
the possibility of the objects of external intuition, that is, of
bodies. Now we have a conception of bodies only as phenomena, and, as
such, they necessarily presuppose space as the condition of all
external phenomena. The evasion is therefore in vain; as, indeed, we
have sufficiently shown in our Aesthetic. If bodies were things in
themselves, the proof of the Monadists would be unexceptionable.

The second dialectical assertion possesses the peculiarity of having
opposed to it a dogmatical proposition, which, among all such
sophistical statements, is the only one that undertakes to prove in the
case of an object of experience, that which is properly a
transcendental idea—the absolute simplicity of substance. The
proposition is that the object of the internal sense, the thinking Ego,
is an absolute simple substance. Without at present entering upon this
subject—as it has been considered at length in a former chapter—I shall
merely remark that, if something is cogitated merely as an object,
without the addition of any synthetical determination of its
intuition—as happens in the case of the bare representation, I—it is
certain that no manifold and no composition can be perceived in such a
representation. As, moreover, the predicates whereby I cogitate this
object are merely intuitions of the internal sense, there cannot be
discovered in them anything to prove the existence of a manifold whose
parts are external to each other, and, consequently, nothing to prove
the existence of real composition. Consciousness, therefore, is so
constituted that, inasmuch as the thinking subject is at the same time
its own object, it cannot divide itself—although it can divide its
inhering determinations. For every object in relation to itself is
absolute unity. Nevertheless, if the subject is regarded externally, as
an object of intuition, it must, in its character of phenomenon,
possess the property of composition. And it must always be regarded in
this manner, if we wish to know whether there is or is not contained in
it a manifold whose parts are external to each other.


Causality according to the laws of nature, is not the only causality
operating to originate the phenomena of the world. A causality of
freedom is also necessary to account fully for these phenomena.


Let it be supposed, that there is no other kind of causality than that
according to the laws of nature. Consequently, everything that happens
presupposes a previous condition, which it follows with absolute
certainty, in conformity with a rule. But this previous condition must
itself be something that has happened (that has arisen in time, as it
did not exist before), for, if it has always been in existence, its
consequence or effect would not thus originate for the first time, but
would likewise have always existed. The causality, therefore, of a
cause, whereby something happens, is itself a thing that has happened.
Now this again presupposes, in conformity with the law of nature, a
previous condition and its causality, and this another anterior to the
former, and so on. If, then, everything happens solely in accordance
with the laws of nature, there cannot be any real first beginning of
things, but only a subaltern or comparative beginning. There cannot,
therefore, be a completeness of series on the side of the causes which
originate the one from the other. But the law of nature is that nothing
can happen without a sufficient a priori determined cause. The
proposition therefore—if all causality is possible only in accordance
with the laws of nature—is, when stated in this unlimited and general
manner, self-contradictory. It follows that this cannot be the only
kind of causality.

From what has been said, it follows that a causality must be admitted,
by means of which something happens, without its cause being determined
according to necessary laws by some other cause preceding. That is to
say, there must exist an absolute spontaneity of cause, which of itself
originates a series of phenomena which proceeds according to natural
laws—consequently transcendental freedom, without which even in the
course of nature the succession of phenomena on the side of causes is
never complete.


There is no such thing as freedom, but everything in the world happens
solely according to the laws of nature.


Granted, that there does exist freedom in the transcendental sense, as
a peculiar kind of causality, operating to produce events in the
world—a faculty, that is to say, of originating a state, and
consequently a series of consequences from that state. In this case,
not only the series originated by this spontaneity, but the
determination of this spontaneity itself to the production of the
series, that is to say, the causality itself must have an absolute
commencement, such that nothing can precede to determine this action
according to unvarying laws. But every beginning of action presupposes
in the acting cause a state of inaction; and a dynamically primal
beginning of action presupposes a state, which has no connection—as
regards causality—with the preceding state of the cause—which does not,
that is, in any wise result from it. Transcendental freedom is
therefore opposed to the natural law of cause and effect, and such a
conjunction of successive states in effective causes is destructive of
the possibility of unity in experience and for that reason not to be
found in experience—is consequently a mere fiction of thought.

We have, therefore, nothing but nature to which we must look for
connection and order in cosmical events. Freedom—independence of the
laws of nature—is certainly a deliverance from restraint, but it is
also a relinquishing of the guidance of law and rule. For it cannot be
alleged that, instead of the laws of nature, laws of freedom may be
introduced into the causality of the course of nature. For, if freedom
were determined according to laws, it would be no longer freedom, but
merely nature. Nature, therefore, and transcendental freedom are
distinguishable as conformity to law and lawlessness. The former
imposes upon understanding the difficulty of seeking the origin of
events ever higher and higher in the series of causes, inasmuch as
causality is always conditioned thereby; while it compensates this
labour by the guarantee of a unity complete and in conformity with law.
The latter, on the contrary, holds out to the understanding the promise
of a point of rest in the chain of causes, by conducting it to an
unconditioned causality, which professes to have the power of
spontaneous origination, but which, in its own utter blindness,
deprives it of the guidance of rules, by which alone a completely
connected experience is possible.


The transcendental idea of freedom is far from constituting the entire
content of the psychological conception so termed, which is for the
most part empirical. It merely presents us with the conception of
spontaneity of action, as the proper ground for imputing freedom to the
cause of a certain class of objects. It is, however, the true
stumbling-stone to philosophy, which meets with unconquerable
difficulties in the way of its admitting this kind of unconditioned
causality. That element in the question of the freedom of the will,
which has for so long a time placed speculative reason in such
perplexity, is properly only transcendental, and concerns the question,
whether there must be held to exist a faculty of spontaneous
origination of a series of successive things or states. How such a
faculty is possible is not a necessary inquiry; for in the case of
natural causality itself, we are obliged to content ourselves with the
a priori knowledge that such a causality must be presupposed, although
we are quite incapable of comprehending how the being of one thing is
possible through the being of another, but must for this information
look entirely to experience. Now we have demonstrated this necessity of
a free first beginning of a series of phenomena, only in so far as it
is required for the comprehension of an origin of the world, all
following states being regarded as a succession according to laws of
nature alone. But, as there has thus been proved the existence of a
faculty which can of itself originate a series in time—although we are
unable to explain how it can exist—we feel ourselves authorized to
admit, even in the midst of the natural course of events, a beginning,
as regards causality, of different successions of phenomena, and at the
same time to attribute to all substances a faculty of free action. But
we ought in this case not to allow ourselves to fall into a common
misunderstanding, and to suppose that, because a successive series in
the world can only have a comparatively first beginning—another state
or condition of things always preceding—an absolutely first beginning
of a series in the course of nature is impossible. For we are not
speaking here of an absolutely first beginning in relation to time, but
as regards causality alone. When, for example, I, completely of my own
free will, and independently of the necessarily determinative influence
of natural causes, rise from my chair, there commences with this event,
including its material consequences in infinitum, an absolutely new
series; although, in relation to time, this event is merely the
continuation of a preceding series. For this resolution and act of mine
do not form part of the succession of effects in nature, and are not
mere continuations of it; on the contrary, the determining causes of
nature cease to operate in reference to this event, which certainly
succeeds the acts of nature, but does not proceed from them. For these
reasons, the action of a free agent must be termed, in regard to
causality, if not in relation to time, an absolutely primal beginning
of a series of phenomena.

The justification of this need of reason to rest upon a free act as the
first beginning of the series of natural causes is evident from the
fact, that all philosophers of antiquity (with the exception of the
Epicurean school) felt themselves obliged, when constructing a theory
of the motions of the universe, to accept a prime mover, that is, a
freely acting cause, which spontaneously and prior to all other causes
evolved this series of states. They always felt the need of going
beyond mere nature, for the purpose of making a first beginning


The assertor of the all-sufficiency of nature in regard to causality
(transcendental Physiocracy), in opposition to the doctrine of freedom,
would defend his view of the question somewhat in the following manner.
He would say, in answer to the sophistical arguments of the opposite
party: If you do not accept a mathematical first, in relation to time,
you have no need to seek a dynamical first, in regard to causality. Who
compelled you to imagine an absolutely primal condition of the world,
and therewith an absolute beginning of the gradually progressing
successions of phenomena—and, as some foundation for this fancy of
yours, to set bounds to unlimited nature? Inasmuch as the substances in
the world have always existed—at least the unity of experience renders
such a supposition quite necessary—there is no difficulty in believing
also, that the changes in the conditions of these substances have
always existed; and, consequently, that a first beginning, mathematical
or dynamical, is by no means required. The possibility of such an
infinite derivation, without any initial member from which all the
others result, is certainly quite incomprehensible. But, if you are
rash enough to deny the enigmatical secrets of nature for this reason,
you will find yourselves obliged to deny also the existence of many
fundamental properties of natural objects (such as fundamental forces),
which you can just as little comprehend; and even the possibility of so
simple a conception as that of change must present to you insuperable
difficulties. For if experience did not teach you that it was real, you
never could conceive a priori the possibility of this ceaseless
sequence of being and non-being.

But if the existence of a transcendental faculty of freedom is
granted—a faculty of originating changes in the world—this faculty must
at least exist out of and apart from the world; although it is
certainly a bold assumption, that, over and above the complete content
of all possible intuitions, there still exists an object which cannot
be presented in any possible perception. But, to attribute to
substances in the world itself such a faculty, is quite inadmissible;
for, in this case; the connection of phenomena reciprocally determining
and determined according to general laws, which is termed nature, and
along with it the criteria of empirical truth, which enable us to
distinguish experience from mere visionary dreaming, would almost
entirely disappear. In proximity with such a lawless faculty of
freedom, a system of nature is hardly cogitable; for the laws of the
latter would be continually subject to the intrusive influences of the
former, and the course of phenomena, which would otherwise proceed
regularly and uniformly, would become thereby confused and


There exists either in, or in connection with the world—either as a
part of it, or as the cause of it—an absolutely necessary being.


The world of sense, as the sum total of all phenomena, contains a
series of changes. For, without such a series, the mental
representation of the series of time itself, as the condition of the
possibility of the sensuous world, could not be presented to us.* But
every change stands under its condition, which precedes it in time and
renders it necessary. Now the existence of a given condition
presupposes a complete series of conditions up to the absolutely
unconditioned, which alone is absolutely necessary. It follows that
something that is absolutely necessary must exist, if change exists as
its consequence. But this necessary thing itself belongs to the
sensuous world. For suppose it to exist out of and apart from it, the
series of cosmical changes would receive from it a beginning, and yet
this necessary cause would not itself belong to the world of sense. But
this is impossible. For, as the beginning of a series in time is
determined only by that which precedes it in time, the supreme
condition of the beginning of a series of changes must exist in the
time in which this series itself did not exist; for a beginning
supposes a time preceding, in which the thing that begins to be was not
in existence. The causality of the necessary cause of changes, and
consequently the cause itself, must for these reasons belong to
time—and to phenomena, time being possible only as the form of
phenomena. Consequently, it cannot be cogitated as separated from the
world of sense—the sum total of all phenomena. There is, therefore,
contained in the world, something that is absolutely necessary—whether
it be the whole cosmical series itself, or only a part of it.

[*Footnote: Objectively, time, as the formal condition of the
possibility of change, precedes all changes; but subjectively, and in
consciousness, the representation of time, like every other, is given
solely by occasion of perception.]


An absolutely necessary being does not exist, either in the world, or
out of it—as its cause.


Grant that either the world itself is necessary, or that there is
contained in it a necessary existence. Two cases are possible. First,
there must either be in the series of cosmical changes a beginning,
which is unconditionally necessary, and therefore uncaused—which is at
variance with the dynamical law of the determination of all phenomena
in time; or, secondly, the series itself is without beginning, and,
although contingent and conditioned in all its parts, is nevertheless
absolutely necessary and unconditioned as a whole—which is
self-contradictory. For the existence of an aggregate cannot be
necessary, if no single part of it possesses necessary existence.

Grant, on the other band, that an absolutely necessary cause exists out
of and apart from the world. This cause, as the highest member in the
series of the causes of cosmical changes, must originate or begin* the
existence of the latter and their series. In this case it must also
begin to act, and its causality would therefore belong to time, and
consequently to the sum total of phenomena, that is, to the world. It
follows that the cause cannot be out of the world; which is
contradictory to the hypothesis. Therefore, neither in the world, nor
out of it (but in causal connection with it), does there exist any
absolutely necessary being.

[*Footnote: The word begin is taken in two senses. The first is
active—the cause being regarded as beginning a series of conditions as
its effect (infit). The second is passive—the causality in the cause
itself beginning to operate (fit). I reason here from the first to the


To demonstrate the existence of a necessary being, I cannot be
permitted in this place to employ any other than the cosmological
argument, which ascends from the conditioned in phenomena to the
unconditioned in conception—the unconditioned being considered the
necessary condition of the absolute totality of the series. The proof,
from the mere idea of a supreme being, belongs to another principle of
reason and requires separate discussion.

The pure cosmological proof demonstrates the existence of a necessary
being, but at the same time leaves it quite unsettled, whether this
being is the world itself, or quite distinct from it. To establish the
truth of the latter view, principles are requisite, which are not
cosmological and do not proceed in the series of phenomena. We should
require to introduce into our proof conceptions of contingent
beings—regarded merely as objects of the understanding, and also a
principle which enables us to connect these, by means of mere
conceptions, with a necessary being. But the proper place for all such
arguments is a transcendent philosophy, which has unhappily not yet
been established.

But, if we begin our proof cosmologically, by laying at the foundation
of it the series of phenomena, and the regress in it according to
empirical laws of causality, we are not at liberty to break off from
this mode of demonstration and to pass over to something which is not
itself a member of the series. The condition must be taken in exactly
the same signification as the relation of the conditioned to its
condition in the series has been taken, for the series must conduct us
in an unbroken regress to this supreme condition. But if this relation
is sensuous, and belongs to the possible empirical employment of
understanding, the supreme condition or cause must close the regressive
series according to the laws of sensibility and consequently, must
belong to the series of time. It follows that this necessary existence
must be regarded as the highest member of the cosmical series.

Certain philosophers have, nevertheless, allowed themselves the liberty
of making such a saltus (metabasis eis allo gonos). From the changes in
the world they have concluded their empirical contingency, that is,
their dependence on empirically-determined causes, and they thus
admitted an ascending series of empirical conditions: and in this they
are quite right. But as they could not find in this series any primal
beginning or any highest member, they passed suddenly from the
empirical conception of contingency to the pure category, which
presents us with a series—not sensuous, but intellectual—whose
completeness does certainly rest upon the existence of an absolutely
necessary cause. Nay, more, this intellectual series is not tied to any
sensuous conditions; and is therefore free from the condition of time,
which requires it spontaneously to begin its causality in time. But
such a procedure is perfectly inadmissible, as will be made plain from
what follows.

In the pure sense of the categories, that is contingent the
contradictory opposite of which is possible. Now we cannot reason from
empirical contingency to intellectual. The opposite of that which is
changed—the opposite of its state—is actual at another time, and is
therefore possible. Consequently, it is not the contradictory opposite
of the former state. To be that, it is necessary that, in the same time
in which the preceding state existed, its opposite could have existed
in its place; but such a cognition is not given us in the mere
phenomenon of change. A body that was in motion = A, comes into a state
of rest = non-A. Now it cannot be concluded from the fact that a state
opposite to the state A follows it, that the contradictory opposite of
A is possible; and that A is therefore contingent. To prove this, we
should require to know that the state of rest could have existed in the
very same time in which the motion took place. Now we know nothing more
than that the state of rest was actual in the time that followed the
state of motion; consequently, that it was also possible. But motion at
one time, and rest at another time, are not contradictorily opposed to
each other. It follows from what has been said that the succession of
opposite determinations, that is, change, does not demonstrate the fact
of contingency as represented in the conceptions of the pure
understanding; and that it cannot, therefore, conduct us to the fact of
the existence of a necessary being. Change proves merely empirical
contingency, that is to say, that the new state could not have existed
without a cause, which belongs to the preceding time. This cause—even
although it is regarded as absolutely necessary—must be presented to us
in time, and must belong to the series of phenomena.


The difficulties which meet us, in our attempt to rise through the
series of phenomena to the existence of an absolutely necessary supreme
cause, must not originate from our inability to establish the truth of
our mere conceptions of the necessary existence of a thing. That is to
say, our objections not be ontological, but must be directed against
the causal connection with a series of phenomena of a condition which
is itself unconditioned. In one word, they must be cosmological and
relate to empirical laws. We must show that the regress in the series
of causes (in the world of sense) cannot conclude with an empirically
unconditioned condition, and that the cosmological argument from the
contingency of the cosmical state—a contingency alleged to arise from
change—does not justify us in accepting a first cause, that is, a prime
originator of the cosmical series.

The reader will observe in this antinomy a very remarkable contrast.
The very same grounds of proof which established in the thesis the
existence of a supreme being, demonstrated in the antithesis—and with
equal strictness—the non-existence of such a being. We found, first,
that a necessary being exists, because the whole time past contains the
series of all conditions, and with it, therefore, the unconditioned
(the necessary); secondly, that there does not exist any necessary
being, for the same reason, that the whole time past contains the
series of all conditions—which are themselves, therefore, in the
aggregate, conditioned. The cause of this seeming incongruity is as
follows. We attend, in the first argument, solely to the absolute
totality of the series of conditions, the one of which determines the
other in time, and thus arrive at a necessary unconditioned. In the
second, we consider, on the contrary, the contingency of everything
that is determined in the series of time—for every event is preceded by
a time, in which the condition itself must be determined as
conditioned—and thus everything that is unconditioned or absolutely
necessary disappears. In both, the mode of proof is quite in accordance
with the common procedure of human reason, which often falls into
discord with itself, from considering an object from two different
points of view. Herr von Mairan regarded the controversy between two
celebrated astronomers, which arose from a similar difficulty as to the
choice of a proper standpoint, as a phenomenon of sufficient importance
to warrant a separate treatise on the subject. The one concluded: the
moon revolves on its own axis, because it constantly presents the same
side to the earth; the other declared that the moon does not revolve on
its own axis, for the same reason. Both conclusions were perfectly
correct, according to the point of view from which the motions of the
moon were considered.

 Section III. Of the Interest of Reason in these Self-contradictions

We have thus completely before us the dialectical procedure of the
cosmological ideas. No possible experience can present us with an
object adequate to them in extent. Nay, more, reason itself cannot
cogitate them as according with the general laws of experience. And yet
they are not arbitrary fictions of thought. On the contrary, reason, in
its uninterrupted progress in the empirical synthesis, is necessarily
conducted to them, when it endeavours to free from all conditions and
to comprehend in its unconditioned totality that which can only be
determined conditionally in accordance with the laws of experience.
These dialectical propositions are so many attempts to solve four
natural and unavoidable problems of reason. There are neither more, nor
can there be less, than this number, because there are no other series
of synthetical hypotheses, limiting a priori the empirical synthesis.

The brilliant claims of reason striving to extend its dominion beyond
the limits of experience, have been represented above only in dry
formulae, which contain merely the grounds of its pretensions. They
have, besides, in conformity with the character of a transcendental
philosophy, been freed from every empirical element; although the full
splendour of the promises they hold out, and the anticipations they
excite, manifests itself only when in connection with empirical
cognitions. In the application of them, however, and in the advancing
enlargement of the employment of reason, while struggling to rise from
the region of experience and to soar to those sublime ideas, philosophy
discovers a value and a dignity, which, if it could but make good its
assertions, would raise it far above all other departments of human
knowledge—professing, as it does, to present a sure foundation for our
highest hopes and the ultimate aims of all the exertions of reason. The
questions: whether the world has a beginning and a limit to its
extension in space; whether there exists anywhere, or perhaps, in my
own thinking Self, an indivisible and indestructible unity—or whether
nothing but what is divisible and transitory exists; whether I am a
free agent, or, like other beings, am bound in the chains of nature and
fate; whether, finally, there is a supreme cause of the world, or all
our thought and speculation must end with nature and the order of
external things—are questions for the solution of which the
mathematician would willingly exchange his whole science; for in it
there is no satisfaction for the highest aspirations and most ardent
desires of humanity. Nay, it may even be said that the true value of
mathematics—that pride of human reason—consists in this: that she
guides reason to the knowledge of nature—in her greater as well as in
her less manifestations—in her beautiful order and regularity—guides
her, moreover, to an insight into the wonderful unity of the moving
forces in the operations of nature, far beyond the expectations of a
philosophy building only on experience; and that she thus encourages
philosophy to extend the province of reason beyond all experience, and
at the same time provides it with the most excellent materials for
supporting its investigations, in so far as their nature admits, by
adequate and accordant intuitions.

Unfortunately for speculation—but perhaps fortunately for the practical
interests of humanity—reason, in the midst of her highest
anticipations, finds herself hemmed in by a press of opposite and
contradictory conclusions, from which neither her honour nor her safety
will permit her to draw back. Nor can she regard these conflicting
trains of reasoning with indifference as mere passages at arms, still
less can she command peace; for in the subject of the conflict she has
a deep interest. There is no other course left open to her than to
reflect with herself upon the origin of this disunion in reason—whether
it may not arise from a mere misunderstanding. After such an inquiry,
arrogant claims would have to be given up on both sides; but the
sovereignty of reason over understanding and sense would be based upon
a sure foundation.

We shall at present defer this radical inquiry and, in the meantime,
consider for a little what side in the controversy we should most
willingly take, if we were obliged to become partisans at all. As, in
this case, we leave out of sight altogether the logical criterion of
truth, and merely consult our own interest in reference to the
question, these considerations, although inadequate to settle the
question of right in either party, will enable us to comprehend how
those who have taken part in the struggle, adopt the one view rather
than the other—no special insight into the subject, however, having
influenced their choice. They will, at the same time, explain to us
many other things by the way—for example, the fiery zeal on the one
side and the cold maintenance of their cause on the other; why the one
party has met with the warmest approbations, and the other has always
been repulsed by irreconcilable prejudices.

There is one thing, however, that determines the proper point of view,
from which alone this preliminary inquiry can be instituted and carried
on with the proper completeness—and that is the comparison of the
principles from which both sides, thesis and antithesis, proceed. My
readers would remark in the propositions of the antithesis a complete
uniformity in the mode of thought and a perfect unity of principle. Its
principle was that of pure empiricism, not only in the explication of
the phenomena in the world, but also in the solution of the
transcendental ideas, even of that of the universe itself. The
affirmations of the thesis, on the contrary, were based, in addition to
the empirical mode of explanation employed in the series of phenomena,
on intellectual propositions; and its principles were in so far not
simple. I shall term the thesis, in view of its essential
characteristic, the dogmatism of pure reason.

On the side of Dogmatism, or of the thesis, therefore, in the
determination of the cosmological ideas, we find:

1. A practical interest, which must be very dear to every
right-thinking man. That the word has a beginning—that the nature of my
thinking self is simple, and therefore indestructible—that I am a free
agent, and raised above the compulsion of nature and her laws—and,
finally, that the entire order of things, which form the world, is
dependent upon a Supreme Being, from whom the whole receives unity and
connection—these are so many foundation-stones of morality and
religion. The antithesis deprives us of all these supports—or, at
least, seems so to deprive us.

2. A speculative interest of reason manifests itself on this side. For,
if we take the transcendental ideas and employ them in the manner which
the thesis directs, we can exhibit completely a priori the entire chain
of conditions, and understand the derivation of the
conditioned—beginning from the unconditioned. This the antithesis does
not do; and for this reason does not meet with so welcome a reception.
For it can give no answer to our question respecting the conditions of
its synthesis—except such as must be supplemented by another question,
and so on to infinity. According to it, we must rise from a given
beginning to one still higher; every part conducts us to a still
smaller one; every event is preceded by another event which is its
cause; and the conditions of existence rest always upon other and still
higher conditions, and find neither end nor basis in some
self-subsistent thing as the primal being.

3. This side has also the advantage of popularity; and this constitutes
no small part of its claim to favour. The common understanding does not
find the least difficulty in the idea of the unconditioned beginning of
all synthesis—accustomed, as it is, rather to follow our consequences
than to seek for a proper basis for cognition. In the conception of an
absolute first, moreover—the possibility of which it does not inquire
into—it is highly gratified to find a firmly-established point of
departure for its attempts at theory; while in the restless and
continuous ascent from the conditioned to the condition, always with
one foot in the air, it can find no satisfaction.

On the side of the antithesis, or Empiricism, in the determination of
the cosmological ideas:

1. We cannot discover any such practical interest arising from pure
principles of reason as morality and religion present. On the contrary,
pure empiricism seems to empty them of all their power and influence.
If there does not exist a Supreme Being distinct from the world—if the
world is without beginning, consequently without a Creator—if our wills
are not free, and the soul is divisible and subject to corruption just
like matter—the ideas and principles of morality lose all validity and
fall with the transcendental ideas which constituted their theoretical

2. But empiricism, in compensation, holds out to reason, in its
speculative interests, certain important advantages, far exceeding any
that the dogmatist can promise us. For, when employed by the
empiricist, understanding is always upon its proper ground of
investigation—the field of possible experience, the laws of which it
can explore, and thus extend its cognition securely and with clear
intelligence without being stopped by limits in any direction. Here can
it and ought it to find and present to intuition its proper object—not
only in itself, but in all its relations; or, if it employ conceptions,
upon this ground it can always present the corresponding images in
clear and unmistakable intuitions. It is quite unnecessary for it to
renounce the guidance of nature, to attach itself to ideas, the objects
of which it cannot know; because, as mere intellectual entities, they
cannot be presented in any intuition. On the contrary, it is not even
permitted to abandon its proper occupation, under the pretence that it
has been brought to a conclusion (for it never can be), and to pass
into the region of idealizing reason and transcendent conceptions,
which it is not required to observe and explore the laws of nature, but
merely to think and to imagine—secure from being contradicted by facts,
because they have not been called as witnesses, but passed by, or
perhaps subordinated to the so-called higher interests and
considerations of pure reason.

Hence the empiricist will never allow himself to accept any epoch of
nature for the first—the absolutely primal state; he will not believe
that there can be limits to his outlook into her wide domains, nor pass
from the objects of nature, which he can satisfactorily explain by
means of observation and mathematical thought—which he can determine
synthetically in intuition, to those which neither sense nor
imagination can ever present in concreto; he will not concede the
existence of a faculty in nature, operating independently of the laws
of nature—a concession which would introduce uncertainty into the
procedure of the understanding, which is guided by necessary laws to
the observation of phenomena; nor, finally, will he permit himself to
seek a cause beyond nature, inasmuch as we know nothing but it, and
from it alone receive an objective basis for all our conceptions and
instruction in the unvarying laws of things.

In truth, if the empirical philosopher had no other purpose in the
establishment of his antithesis than to check the presumption of a
reason which mistakes its true destination, which boasts of its insight
and its knowledge, just where all insight and knowledge cease to exist,
and regards that which is valid only in relation to a practical
interest, as an advancement of the speculative interests of the mind
(in order, when it is convenient for itself, to break the thread of our
physical investigations, and, under pretence of extending our
cognition, connect them with transcendental ideas, by means of which we
really know only that we know nothing)—if, I say, the empiricist rested
satisfied with this benefit, the principle advanced by him would be a
maxim recommending moderation in the pretensions of reason and modesty
in its affirmations, and at the same time would direct us to the right
mode of extending the province of the understanding, by the help of the
only true teacher, experience. In obedience to this advice,
intellectual hypotheses and faith would not be called in aid of our
practical interests; nor should we introduce them under the pompous
titles of science and insight. For speculative cognition cannot find an
objective basis any other where than in experience; and, when we
overstep its limits our synthesis, which requires ever new cognitions
independent of experience, has no substratum of intuition upon which to

But if—as often happens—empiricism, in relation to ideas, becomes
itself dogmatic and boldly denies that which is above the sphere of its
phenomenal cognition, it falls itself into the error of intemperance—an
error which is here all the more reprehensible, as thereby the
practical interest of reason receives an irreparable injury.

And this constitutes the opposition between Epicureanism* and

[*Footnote: It is, however, still a matter of doubt whether Epicurus
ever propounded these principles as directions for the objective
employment of the understanding. If, indeed, they were nothing more
than maxims for the speculative exercise of reason, he gives evidence
therein a more genuine philosophic spirit than any of the philosophers
of antiquity. That, in the explanation of phenomena, we must proceed as
if the field of inquiry had neither limits in space nor commencement in
time; that we must be satisfied with the teaching of experience in
reference to the material of which the world is posed; that we must not
look for any other mode of the origination of events than that which is
determined by the unalterable laws of nature; and finally, that we not
employ the hypothesis of a cause distinct from the world to account for
a phenomenon or for the world itself—are principles for the extension
of speculative philosophy, and the discovery of the true sources of the
principles of morals, which, however little conformed to in the present
day, are undoubtedly correct. At the same time, any one desirous of
ignoring, in mere speculation, these dogmatical propositions, need not
for that reason be accused of denying them.]

Both Epicurus and Plato assert more in their systems than they know.
The former encourages and advances science—although to the prejudice of
the practical; the latter presents us with excellent principles for the
investigation of the practical, but, in relation to everything
regarding which we can attain to speculative cognition, permits reason
to append idealistic explanations of natural phenomena, to the great
injury of physical investigation.

3. In regard to the third motive for the preliminary choice of a party
in this war of assertions, it seems very extraordinary that empiricism
should be utterly unpopular. We should be inclined to believe that the
common understanding would receive it with pleasure—promising as it
does to satisfy it without passing the bounds of experience and its
connected order; while transcendental dogmatism obliges it to rise to
conceptions which far surpass the intelligence and ability of the most
practised thinkers. But in this, in truth, is to be found its real
motive. For the common understanding thus finds itself in a situation
where not even the most learned can have the advantage of it. If it
understands little or nothing about these transcendental conceptions,
no one can boast of understanding any more; and although it may not
express itself in so scholastically correct a manner as others, it can
busy itself with reasoning and arguments without end, wandering among
mere ideas, about which one can always be very eloquent, because we
know nothing about them; while, in the observation and investigation of
nature, it would be forced to remain dumb and to confess its utter
ignorance. Thus indolence and vanity form of themselves strong
recommendations of these principles. Besides, although it is a hard
thing for a philosopher to assume a principle, of which he can give to
himself no reasonable account, and still more to employ conceptions,
the objective reality of which cannot be established, nothing is more
usual with the common understanding. It wants something which will
allow it to go to work with confidence. The difficulty of even
comprehending a supposition does not disquiet it, because—not knowing
what comprehending means—it never even thinks of the supposition it may
be adopting as a principle; and regards as known that with which it has
become familiar from constant use. And, at last, all speculative
interests disappear before the practical interests which it holds dear;
and it fancies that it understands and knows what its necessities and
hopes incite it to assume or to believe. Thus the empiricism of
transcendentally idealizing reason is robbed of all popularity; and,
however prejudicial it may be to the highest practical principles,
there is no fear that it will ever pass the limits of the schools, or
acquire any favour or influence in society or with the multitude.

Human reason is by nature architectonic. That is to say, it regards all
cognitions as parts of a possible system, and hence accepts only such
principles as at least do not incapacitate a cognition to which we may
have attained from being placed along with others in a general system.
But the propositions of the antithesis are of a character which renders
the completion of an edifice of cognitions impossible. According to
these, beyond one state or epoch of the world there is always to be
found one more ancient; in every part always other parts themselves
divisible; preceding every event another, the origin of which must
itself be sought still higher; and everything in existence is
conditioned, and still not dependent on an unconditioned and primal
existence. As, therefore, the antithesis will not concede the existence
of a first beginning which might be available as a foundation, a
complete edifice of cognition, in the presence of such hypothesis, is
utterly impossible. Thus the architectonic interest of reason, which
requires a unity—not empirical, but a priori and rational—forms a
natural recommendation for the assertions of the thesis in our

But if any one could free himself entirely from all considerations of
interest, and weigh without partiality the assertions of reason,
attending only to their content, irrespective of the consequences which
follow from them; such a person, on the supposition that he knew no
other way out of the confusion than to settle the truth of one or other
of the conflicting doctrines, would live in a state of continual
hesitation. Today, he would feel convinced that the human will is free;
to-morrow, considering the indissoluble chain of nature, he would look
on freedom as a mere illusion and declare nature to be all-in-all. But,
if he were called to action, the play of the merely speculative reason
would disappear like the shapes of a dream, and practical interest
would dictate his choice of principles. But, as it well befits a
reflective and inquiring being to devote certain periods of time to the
examination of its own reason—to divest itself of all partiality, and
frankly to communicate its observations for the judgement and opinion
of others; so no one can be blamed for, much less prevented from,
placing both parties on their trial, with permission to end themselves,
free from intimidation, before intimidation, before a sworn jury of
equal condition with themselves—the condition of weak and fallible men.

 Section IV. Of the necessity imposed upon Pure Reason of presenting a
 Solution of its Transcendental Problems

To avow an ability to solve all problems and to answer all questions
would be a profession certain to convict any philosopher of extravagant
boasting and self-conceit, and at once to destroy the confidence that
might otherwise have been reposed in him. There are, however, sciences
so constituted that every question arising within their sphere must
necessarily be capable of receiving an answer from the knowledge
already possessed, for the answer must be received from the same
sources whence the question arose. In such sciences it is not allowable
to excuse ourselves on the plea of necessary and unavoidable ignorance;
a solution is absolutely requisite. The rule of right and wrong must
help us to the knowledge of what is right or wrong in all possible
cases; otherwise, the idea of obligation or duty would be utterly null,
for we cannot have any obligation to that which we cannot know. On the
other hand, in our investigations of the phenomena of nature, much must
remain uncertain, and many questions continue insoluble; because what
we know of nature is far from being sufficient to explain all the
phenomena that are presented to our observation. Now the question is:
Whether there is in transcendental philosophy any question, relating to
an object presented to pure reason, which is unanswerable by this
reason; and whether we must regard the subject of the question as quite
uncertain, so far as our knowledge extends, and must give it a place
among those subjects, of which we have just so much conception as is
sufficient to enable us to raise a question—faculty or materials
failing us, however, when we attempt an answer.

Now I maintain that, among all speculative cognition, the peculiarity
of transcendental philosophy is that there is no question, relating to
an object presented to pure reason, which is insoluble by this reason;
and that the profession of unavoidable ignorance—the problem being
alleged to be beyond the reach of our faculties—cannot free us from the
obligation to present a complete and satisfactory answer. For the very
conception which enables us to raise the question must give us the
power of answering it; inasmuch as the object, as in the case of right
and wrong, is not to be discovered out of the conception.

But, in transcendental philosophy, it is only the cosmological
questions to which we can demand a satisfactory answer in relation to
the constitution of their object; and the philosopher is not permitted
to avail himself of the pretext of necessary ignorance and impenetrable
obscurity. These questions relate solely to the cosmological ideas. For
the object must be given in experience, and the question relates to the
adequateness of the object to an idea. If the object is transcendental
and therefore itself unknown; if the question, for example, is whether
the object—the something, the phenomenon of which (internal—in
ourselves) is thought—that is to say, the soul, is in itself a simple
being; or whether there is a cause of all things, which is absolutely
necessary—in such cases we are seeking for our idea an object, of which
we may confess that it is unknown to us, though we must not on that
account assert that it is impossible.* The cosmological ideas alone
posses the peculiarity that we can presuppose the object of them and
the empirical synthesis requisite for the conception of that object to
be given; and the question, which arises from these ideas, relates
merely to the progress of this synthesis, in so far as it must contain
absolute totality—which, however, is not empirical, as it cannot be
given in any experience. Now, as the question here is solely in regard
to a thing as the object of a possible experience and not as a thing in
itself, the answer to the transcendental cosmological question need not
be sought out of the idea, for the question does not regard an object
in itself. The question in relation to a possible experience is not,
“What can be given in an experience in concreto” but “what is contained
in the idea, to which the empirical synthesis must approximate.” The
question must therefore be capable of solution from the idea alone. For
the idea is a creation of reason itself, which therefore cannot
disclaim the obligation to answer or refer us to the unknown object.

[*Footnote: The question, “What is the constitution of a transcendental
object?” is unanswerable—we are unable to say what it is; but we can
perceive that the question itself is nothing; because it does not
relate to any object that can be presented to us. For this reason, we
must consider all the questions raised in transcendental psychology as
answerable and as really answered; for they relate to the
transcendental subject of all internal phenomena, which is not itself
phenomenon and consequently not given as an object, in which, moreover,
none of the categories—and it is to them that the question is properly
directed—find any conditions of its application. Here, therefore, is a
case where no answer is the only proper answer. For a question
regarding the constitution of a something which cannot be cogitated by
any determined predicate, being completely beyond the sphere of objects
and experience, is perfectly null and void.]

It is not so extraordinary, as it at first sight appears, that a
science should demand and expect satisfactory answers to all the
questions that may arise within its own sphere (questiones domesticae),
although, up to a certain time, these answers may not have been
discovered. There are, in addition to transcendental philosophy, only
two pure sciences of reason; the one with a speculative, the other with
a practical content—pure mathematics and pure ethics. Has any one ever
heard it alleged that, from our complete and necessary ignorance of the
conditions, it is uncertain what exact relation the diameter of a
circle bears to the circle in rational or irrational numbers? By the
former the sum cannot be given exactly, by the latter only
approximately; and therefore we decide that the impossibility of a
solution of the question is evident. Lambert presented us with a
demonstration of this. In the general principles of morals there can be
nothing uncertain, for the propositions are either utterly without
meaning, or must originate solely in our rational conceptions. On the
other hand, there must be in physical science an infinite number of
conjectures, which can never become certainties; because the phenomena
of nature are not given as objects dependent on our conceptions. The
key to the solution of such questions cannot, therefore, be found in
our conceptions, or in pure thought, but must lie without us and for
that reason is in many cases not to be discovered; and consequently a
satisfactory explanation cannot be expected. The questions of
transcendental analytic, which relate to the deduction of our pure
cognition, are not to be regarded as of the same kind as those
mentioned above; for we are not at present treating of the certainty of
judgements in relation to the origin of our conceptions, but only of
that certainty in relation to objects.

We cannot, therefore, escape the responsibility of at least a critical
solution of the questions of reason, by complaints of the limited
nature of our faculties, and the seemingly humble confession that it is
beyond the power of our reason to decide, whether the world has existed
from all eternity or had a beginning—whether it is infinitely extended,
or enclosed within certain limits—whether anything in the world is
simple, or whether everything must be capable of infinite
divisibility—whether freedom can originate phenomena, or whether
everything is absolutely dependent on the laws and order of nature—and,
finally, whether there exists a being that is completely unconditioned
and necessary, or whether the existence of everything is conditioned
and consequently dependent on something external to itself, and
therefore in its own nature contingent. For all these questions relate
to an object, which can be given nowhere else than in thought. This
object is the absolutely unconditioned totality of the synthesis of
phenomena. If the conceptions in our minds do not assist us to some
certain result in regard to these problems, we must not defend
ourselves on the plea that the object itself remains hidden from and
unknown to us. For no such thing or object can be given—it is not to be
found out of the idea in our minds. We must seek the cause of our
failure in our idea itself, which is an insoluble problem and in regard
to which we obstinately assume that there exists a real object
corresponding and adequate to it. A clear explanation of the dialectic
which lies in our conception, will very soon enable us to come to a
satisfactory decision in regard to such a question.

The pretext that we are unable to arrive at certainty in regard to
these problems may be met with this question, which requires at least a
plain answer: “From what source do the ideas originate, the solution of
which involves you in such difficulties? Are you seeking for an
explanation of certain phenomena; and do you expect these ideas to give
you the principles or the rules of this explanation?” Let it be
granted, that all nature was laid open before you; that nothing was hid
from your senses and your consciousness. Still, you could not cognize
in concreto the object of your ideas in any experience. For what is
demanded is not only this full and complete intuition, but also a
complete synthesis and the consciousness of its absolute totality; and
this is not possible by means of any empirical cognition. It follows
that your question—your idea—is by no means necessary for the
explanation of any phenomenon; and the idea cannot have been in any
sense given by the object itself. For such an object can never be
presented to us, because it cannot be given by any possible experience.
Whatever perceptions you may attain to, you are still surrounded by
conditions—in space, or in time—and you cannot discover anything
unconditioned; nor can you decide whether this unconditioned is to be
placed in an absolute beginning of the synthesis, or in an absolute
totality of the series without beginning. A whole, in the empirical
signification of the term, is always merely comparative. The absolute
whole of quantity (the universe), of division, of derivation, of the
condition of existence, with the question—whether it is to be produced
by finite or infinite synthesis, no possible experience can instruct us
concerning. You will not, for example, be able to explain the phenomena
of a body in the least degree better, whether you believe it to consist
of simple, or of composite parts; for a simple phenomenon—and just as
little an infinite series of composition—can never be presented to your
perception. Phenomena require and admit of explanation, only in so far
as the conditions of that explanation are given in perception; but the
sum total of that which is given in phenomena, considered as an
absolute whole, is itself a perception—and we cannot therefore seek for
explanations of this whole beyond itself, in other perceptions. The
explanation of this whole is the proper object of the transcendental
problems of pure reason.

Although, therefore, the solution of these problems is unattainable
through experience, we must not permit ourselves to say that it is
uncertain how the object of our inquiries is constituted. For the
object is in our own mind and cannot be discovered in experience; and
we have only to take care that our thoughts are consistent with each
other, and to avoid falling into the amphiboly of regarding our idea as
a representation of an object empirically given, and therefore to be
cognized according to the laws of experience. A dogmatical solution is
therefore not only unsatisfactory but impossible. The critical
solution, which may be a perfectly certain one, does not consider the
question objectively, but proceeds by inquiring into the basis of the
cognition upon which the question rests.

 Section V. Sceptical Exposition of the Cosmological Problems presented
 in the four Transcendental Ideas

We should be quite willing to desist from the demand of a dogmatical
answer to our questions, if we understood beforehand that, be the
answer what it may, it would only serve to increase our ignorance, to
throw us from one incomprehensibility into another, from one obscurity
into another still greater, and perhaps lead us into irreconcilable
contradictions. If a dogmatical affirmative or negative answer is
demanded, is it at all prudent to set aside the probable grounds of a
solution which lie before us and to take into consideration what
advantage we shall gain, if the answer is to favour the one side or the
other? If it happens that in both cases the answer is mere nonsense, we
have in this an irresistible summons to institute a critical
investigation of the question, for the purpose of discovering whether
it is based on a groundless presupposition and relates to an idea, the
falsity of which would be more easily exposed in its application and
consequences than in the mere representation of its content. This is
the great utility of the sceptical mode of treating the questions
addressed by pure reason to itself. By this method we easily rid
ourselves of the confusions of dogmatism, and establish in its place a
temperate criticism, which, as a genuine cathartic, will successfully
remove the presumptuous notions of philosophy and their consequence—the
vain pretension to universal science.

If, then, I could understand the nature of a cosmological idea and
perceive, before I entered on the discussion of the subject at all,
that, whatever side of the question regarding the unconditioned of the
regressive synthesis of phenomena it favoured—it must either be too
great or too small for every conception of the understanding—I would be
able to comprehend how the idea, which relates to an object of
experience—an experience which must be adequate to and in accordance
with a possible conception of the understanding—must be completely void
and without significance, inasmuch as its object is inadequate,
consider it as we may. And this is actually the case with all
cosmological conceptions, which, for the reason above mentioned,
involve reason, so long as it remains attached to them, in an
unavoidable antinomy. For suppose:

First, that the world has no beginning—in this case it is too large for
our conception; for this conception, which consists in a successive
regress, cannot overtake the whole eternity that has elapsed. Grant
that it has a beginning, it is then too small for the conception of the
understanding. For, as a beginning presupposes a time preceding, it
cannot be unconditioned; and the law of the empirical employment of the
understanding imposes the necessity of looking for a higher condition
of time; and the world is, therefore, evidently too small for this law.

The same is the case with the double answer to the question regarding
the extent, in space, of the world. For, if it is infinite and
unlimited, it must be too large for every possible empirical
conception. If it is finite and limited, we have a right to ask: “What
determines these limits?” Void space is not a self-subsistent correlate
of things, and cannot be a final condition—and still less an empirical
condition, forming a part of a possible experience. For how can we have
any experience or perception of an absolute void? But the absolute
totality of the empirical synthesis requires that the unconditioned be
an empirical conception. Consequently, a finite world is too small for
our conception.

Secondly, if every phenomenon (matter) in space consists of an infinite
number of parts, the regress of the division is always too great for
our conception; and if the division of space must cease with some
member of the division (the simple), it is too small for the idea of
the unconditioned. For the member at which we have discontinued our
division still admits a regress to many more parts contained in the

Thirdly, suppose that every event in the world happens in accordance
with the laws of nature; the causality of a cause must itself be an
event and necessitates a regress to a still higher cause, and
consequently the unceasing prolongation of the series of conditions a
parte priori. Operative nature is therefore too large for every
conception we can form in the synthesis of cosmical events.

If we admit the existence of spontaneously produced events, that is, of
free agency, we are driven, in our search for sufficient reasons, on an
unavoidable law of nature and are compelled to appeal to the empirical
law of causality, and we find that any such totality of connection in
our synthesis is too small for our necessary empirical conception.

Fourthly, if we assume the existence of an absolutely necessary
being—whether it be the world or something in the world, or the cause
of the world—we must place it in a time at an infinite distance from
any given moment; for, otherwise, it must be dependent on some other
and higher existence. Such an existence is, in this case, too large for
our empirical conception, and unattainable by the continued regress of
any synthesis.

But if we believe that everything in the world—be it condition or
conditioned—is contingent; every given existence is too small for our
conception. For in this case we are compelled to seek for some other
existence upon which the former depends.

We have said that in all these cases the cosmological idea is either
too great or too small for the empirical regress in a synthesis, and
consequently for every possible conception of the understanding. Why
did we not express ourselves in a manner exactly the reverse of this
and, instead of accusing the cosmological idea of over stepping or of
falling short of its true aim, possible experience, say that, in the
first case, the empirical conception is always too small for the idea,
and in the second too great, and thus attach the blame of these
contradictions to the empirical regress? The reason is this. Possible
experience can alone give reality to our conceptions; without it a
conception is merely an idea, without truth or relation to an object.
Hence a possible empirical conception must be the standard by which we
are to judge whether an idea is anything more than an idea and fiction
of thought, or whether it relates to an object in the world. If we say
of a thing that in relation to some other thing it is too large or too
small, the former is considered as existing for the sake of the latter,
and requiring to be adapted to it. Among the trivial subjects of
discussion in the old schools of dialectics was this question: “If a
ball cannot pass through a hole, shall we say that the ball is too
large or the hole too small?” In this case it is indifferent what
expression we employ; for we do not know which exists for the sake of
the other. On the other hand, we cannot say: “The man is too long for
his coat”; but: “The coat is too short for the man.”

We are thus led to the well-founded suspicion that the cosmological
ideas, and all the conflicting sophistical assertions connected with
them, are based upon a false and fictitious conception of the mode in
which the object of these ideas is presented to us; and this suspicion
will probably direct us how to expose the illusion that has so long led
us astray from the truth.

 Section VI. Transcendental Idealism as the Key to theSolution of Pure
 Cosmological Dialectic

In the transcendental aesthetic we proved that everything intuited in
space and time, all objects of a possible experience, are nothing but
phenomena, that is, mere representations; and that these, as presented
to us—as extended bodies, or as series of changes—have no
self-subsistent existence apart from human thought. This doctrine I
call Transcendental Idealism.* The realist in the transcendental sense
regards these modifications of our sensibility, these mere
representations, as things subsisting in themselves.

[*Footnote: I have elsewhere termed this theory formal idealism, to
distinguish it from material idealism, which doubts or denies the
existence of external things. To avoid ambiguity, it seems advisable in
many cases to employ this term instead of that mentioned in the text.]

It would be unjust to accuse us of holding the long-decried theory of
empirical idealism, which, while admitting the reality of space,
denies, or at least doubts, the existence of bodies extended in it, and
thus leaves us without a sufficient criterion of reality and illusion.
The supporters of this theory find no difficulty in admitting the
reality of the phenomena of the internal sense in time; nay, they go
the length of maintaining that this internal experience is of itself a
sufficient proof of the real existence of its object as a thing in

Transcendental idealism allows that the objects of external
intuition—as intuited in space, and all changes in time—as represented
by the internal sense, are real. For, as space is the form of that
intuition which we call external, and, without objects in space, no
empirical representation could be given us, we can and ought to regard
extended bodies in it as real. The case is the same with
representations in time. But time and space, with all phenomena
therein, are not in themselves things. They are nothing but
representations and cannot exist out of and apart from the mind. Nay,
the sensuous internal intuition of the mind (as the object of
consciousness), the determination of which is represented by the
succession of different states in time, is not the real, proper self,
as it exists in itself—not the transcendental subject—but only a
phenomenon, which is presented to the sensibility of this, to us,
unknown being. This internal phenomenon cannot be admitted to be a
self-subsisting thing; for its condition is time, and time cannot be
the condition of a thing in itself. But the empirical truth of
phenomena in space and time is guaranteed beyond the possibility of
doubt, and sufficiently distinguished from the illusion of dreams or
fancy—although both have a proper and thorough connection in an
experience according to empirical laws. The objects of experience then
are not things in themselves, but are given only in experience, and
have no existence apart from and independently of experience. That
there may be inhabitants in the moon, although no one has ever observed
them, must certainly be admitted; but this assertion means only, that
we may in the possible progress of experience discover them at some
future time. For that which stands in connection with a perception
according to the laws of the progress of experience is real. They are
therefore really existent, if they stand in empirical connection with
my actual or real consciousness, although they are not in themselves
real, that is, apart from the progress of experience.

There is nothing actually given—we can be conscious of nothing as real,
except a perception and the empirical progression from it to other
possible perceptions. For phenomena, as mere representations, are real
only in perception; and perception is, in fact, nothing but the reality
of an empirical representation, that is, a phenomenon. To call a
phenomenon a real thing prior to perception means either that we must
meet with this phenomenon in the progress of experience, or it means
nothing at all. For I can say only of a thing in itself that it exists
without relation to the senses and experience. But we are speaking here
merely of phenomena in space and time, both of which are determinations
of sensibility, and not of things in themselves. It follows that
phenomena are not things in themselves, but are mere representations,
which if not given in us—in perception—are non-existent.

The faculty of sensuous intuition is properly a receptivity—a capacity
of being affected in a certain manner by representations, the relation
of which to each other is a pure intuition of space and time—the pure
forms of sensibility. These representations, in so far as they are
connected and determinable in this relation (in space and time)
according to laws of the unity of experience, are called objects. The
non-sensuous cause of these representations is completely unknown to us
and hence cannot be intuited as an object. For such an object could not
be represented either in space or in time; and without these conditions
intuition or representation is impossible. We may, at the same time,
term the non-sensuous cause of phenomena the transcendental object—but
merely as a mental correlate to sensibility, considered as a
receptivity. To this transcendental object we may attribute the whole
connection and extent of our possible perceptions, and say that it is
given and exists in itself prior to all experience. But the phenomena,
corresponding to it, are not given as things in themselves, but in
experience alone. For they are mere representations, receiving from
perceptions alone significance and relation to a real object, under the
condition that this or that perception—indicating an object—is in
complete connection with all others in accordance with the rules of the
unity of experience. Thus we can say: “The things that really existed
in past time are given in the transcendental object of experience.” But
these are to me real objects, only in so far as I can represent to my
own mind, that a regressive series of possible perceptions—following
the indications of history, or the footsteps of cause and effect—in
accordance with empirical laws—that, in one word, the course of the
world conducts us to an elapsed series of time as the condition of the
present time. This series in past time is represented as real, not in
itself, but only in connection with a possible experience. Thus, when I
say that certain events occurred in past time, I merely assert the
possibility of prolonging the chain of experience, from the present
perception, upwards to the conditions that determine it according to

If I represent to myself all objects existing in all space and time, I
do not thereby place these in space and time prior to all experience;
on the contrary, such a representation is nothing more than the notion
of a possible experience, in its absolute completeness. In experience
alone are those objects, which are nothing but representations, given.
But, when I say they existed prior to my experience, this means only
that I must begin with the perception present to me and follow the
track indicated until I discover them in some part or region of
experience. The cause of the empirical condition of this
progression—and consequently at what member therein I must stop, and at
what point in the regress I am to find this member—is transcendental,
and hence necessarily incognizable. But with this we have not to do;
our concern is only with the law of progression in experience, in which
objects, that is, phenomena, are given. It is a matter of indifference,
whether I say, “I may in the progress of experience discover stars, at
a hundred times greater distance than the most distant of those now
visible,” or, “Stars at this distance may be met in space, although no
one has, or ever will discover them.” For, if they are given as things
in themselves, without any relation to possible experience, they are
for me non-existent, consequently, are not objects, for they are not
contained in the regressive series of experience. But, if these
phenomena must be employed in the construction or support of the
cosmological idea of an absolute whole, and when we are discussing a
question that oversteps the limits of possible experience, the proper
distinction of the different theories of the reality of sensuous
objects is of great importance, in order to avoid the illusion which
must necessarily arise from the misinterpretation of our empirical

 Section VII. Critical Solution of the Cosmological Problem

The antinomy of pure reason is based upon the following dialectical
argument: “If that which is conditioned is given, the whole series of
its conditions is also given; but sensuous objects are given as
conditioned; consequently...” This syllogism, the major of which seems
so natural and evident, introduces as many cosmological ideas as there
are different kinds of conditions in the synthesis of phenomena, in so
far as these conditions constitute a series. These ideas require
absolute totality in the series, and thus place reason in inextricable
embarrassment. Before proceeding to expose the fallacy in this
dialectical argument, it will be necessary to have a correct
understanding of certain conceptions that appear in it.

In the first place, the following proposition is evident, and
indubitably certain: “If the conditioned is given, a regress in the
series of all its conditions is thereby imperatively required.” For the
very conception of a conditioned is a conception of something related
to a condition, and, if this condition is itself conditioned, to
another condition—and so on through all the members of the series. This
proposition is, therefore, analytical and has nothing to fear from
transcendental criticism. It is a logical postulate of reason: to
pursue, as far as possible, the connection of a conception with its

If, in the second place, both the conditioned and the condition are
things in themselves, and if the former is given, not only is the
regress to the latter requisite, but the latter is really given with
the former. Now, as this is true of all the members of the series, the
entire series of conditions, and with them the unconditioned, is at the
same time given in the very fact of the conditioned, the existence of
which is possible only in and through that series, being given. In this
case, the synthesis of the conditioned with its condition, is a
synthesis of the understanding merely, which represents things as they
are, without regarding whether and how we can cognize them. But if I
have to do with phenomena, which, in their character of mere
representations, are not given, if I do not attain to a cognition of
them (in other words, to themselves, for they are nothing more than
empirical cognitions), I am not entitled to say: “If the conditioned is
given, all its conditions (as phenomena) are also given.” I cannot,
therefore, from the fact of a conditioned being given, infer the
absolute totality of the series of its conditions. For phenomena are
nothing but an empirical synthesis in apprehension or perception, and
are therefore given only in it. Now, in speaking of phenomena it does
not follow that, if the conditioned is given, the synthesis which
constitutes its empirical condition is also thereby given and
presupposed; such a synthesis can be established only by an actual
regress in the series of conditions. But we are entitled to say in this
case that a regress to the conditions of a conditioned, in other words,
that a continuous empirical synthesis is enjoined; that, if the
conditions are not given, they are at least required; and that we are
certain to discover the conditions in this regress.

We can now see that the major, in the above cosmological syllogism,
takes the conditioned in the transcendental signification which it has
in the pure category, while the minor speaks of it in the empirical
signification which it has in the category as applied to phenomena.
There is, therefore, a dialectical fallacy in the syllogism—a sophisma
figurae dictionis. But this fallacy is not a consciously devised one,
but a perfectly natural illusion of the common reason of man. For, when
a thing is given as conditioned, we presuppose in the major its
conditions and their series, unperceived, as it were, and unseen;
because this is nothing more than the logical requirement of complete
and satisfactory premisses for a given conclusion. In this case, time
is altogether left out in the connection of the conditioned with the
condition; they are supposed to be given in themselves, and
contemporaneously. It is, moreover, just as natural to regard phenomena
(in the minor) as things in themselves and as objects presented to the
pure understanding, as in the major, in which complete abstraction was
made of all conditions of intuition. But it is under these conditions
alone that objects are given. Now we overlooked a remarkable
distinction between the conceptions. The synthesis of the conditioned
with its condition, and the complete series of the latter (in the
major) are not limited by time, and do not contain the conception of
succession. On the contrary, the empirical synthesis and the series of
conditions in the phenomenal world—subsumed in the minor—are
necessarily successive and given in time alone. It follows that I
cannot presuppose in the minor, as I did in the major, the absolute
totality of the synthesis and of the series therein represented; for in
the major all the members of the series are given as things in
themselves—without any limitations or conditions of time, while in the
minor they are possible only in and through a successive regress, which
cannot exist, except it be actually carried into execution in the world
of phenomena.

After this proof of the viciousness of the argument commonly employed
in maintaining cosmological assertions, both parties may now be justly
dismissed, as advancing claims without grounds or title. But the
process has not been ended by convincing them that one or both were in
the wrong and had maintained an assertion which was without valid
grounds of proof. Nothing seems to be clearer than that, if one
maintains: “The world has a beginning,” and another: “The world has no
beginning,” one of the two must be right. But it is likewise clear
that, if the evidence on both sides is equal, it is impossible to
discover on what side the truth lies; and the controversy continues,
although the parties have been recommended to peace before the tribunal
of reason. There remains, then, no other means of settling the question
than to convince the parties, who refute each other with such
conclusiveness and ability, that they are disputing about nothing, and
that a transcendental illusion has been mocking them with visions of
reality where there is none. The mode of adjusting a dispute which
cannot be decided upon its own merits, we shall now proceed to lay
before our readers.

Zeno of Elea, a subtle dialectician, was severely reprimanded by Plato
as a sophist, who, merely from the base motive of exhibiting his skill
in discussion, maintained and subverted the same proposition by
arguments as powerful and convincing on the one side as on the other.
He maintained, for example, that God (who was probably nothing more, in
his view, than the world) is neither finite nor infinite, neither in
motion nor in rest, neither similar nor dissimilar to any other thing.
It seemed to those philosophers who criticized his mode of discussion
that his purpose was to deny completely both of two self-contradictory
propositions—which is absurd. But I cannot believe that there is any
justice in this accusation. The first of these propositions I shall
presently consider in a more detailed manner. With regard to the
others, if by the word of God he understood merely the Universe, his
meaning must have been—that it cannot be permanently present in one
place—that is, at rest—nor be capable of changing its place—that is, of
moving—because all places are in the universe, and the universe itself
is, therefore, in no place. Again, if the universe contains in itself
everything that exists, it cannot be similar or dissimilar to any other
thing, because there is, in fact, no other thing with which it can be
compared. If two opposite judgements presuppose a contingent
impossible, or arbitrary condition, both—in spite of their opposition
(which is, however, not properly or really a contradiction)—fall away;
because the condition, which ensured the validity of both, has itself

If we say: “Everybody has either a good or a bad smell,” we have
omitted a third possible judgement—it has no smell at all; and thus
both conflicting statements may be false. If we say: “It is either
good-smelling or not good-smelling (vel suaveolens vel
non-suaveolens),” both judgements are contradictorily opposed; and the
contradictory opposite of the former judgement—some bodies are not
good-smelling—embraces also those bodies which have no smell at all. In
the preceding pair of opposed judgements (per disparata), the
contingent condition of the conception of body (smell) attached to both
conflicting statements, instead of having been omitted in the latter,
which is consequently not the contradictory opposite of the former.

If, accordingly, we say: “The world is either infinite in extension, or
it is not infinite (non est infinitus)”; and if the former proposition
is false, its contradictory opposite—the world is not infinite—must be
true. And thus I should deny the existence of an infinite, without,
however affirming the existence of a finite world. But if we construct
our proposition thus: “The world is either infinite or finite
(non-infinite),” both statements may be false. For, in this case, we
consider the world as per se determined in regard to quantity, and
while, in the one judgement, we deny its infinite and consequently,
perhaps, its independent existence; in the other, we append to the
world, regarded as a thing in itself, a certain determination—that of
finitude; and the latter may be false as well as the former, if the
world is not given as a thing in itself, and thus neither as finite nor
as infinite in quantity. This kind of opposition I may be allowed to
term dialectical; that of contradictories may be called analytical
opposition. Thus then, of two dialectically opposed judgements both may
be false, from the fact, that the one is not a mere contradictory of
the other, but actually enounces more than is requisite for a full and
complete contradiction.

When we regard the two propositions—“The world is infinite in
quantity,” and, “The world is finite in quantity,” as contradictory
opposites, we are assuming that the world—the complete series of
phenomena—is a thing in itself. For it remains as a permanent quantity,
whether I deny the infinite or the finite regress in the series of its
phenomena. But if we dismiss this assumption—this transcendental
illusion—and deny that it is a thing in itself, the contradictory
opposition is metamorphosed into a merely dialectical one; and the
world, as not existing in itself—independently of the regressive series
of my representations—exists in like manner neither as a whole which is
infinite nor as a whole which is finite in itself. The universe exists
for me only in the empirical regress of the series of phenomena and not
per se. If, then, it is always conditioned, it is never completely or
as a whole; and it is, therefore, not an unconditioned whole and does
not exist as such, either with an infinite, or with a finite quantity.

What we have here said of the first cosmological idea—that of the
absolute totality of quantity in phenomena—applies also to the others.
The series of conditions is discoverable only in the regressive
synthesis itself, and not in the phenomenon considered as a thing in
itself—given prior to all regress. Hence I am compelled to say: “The
aggregate of parts in a given phenomenon is in itself neither finite
nor infinite; and these parts are given only in the regressive
synthesis of decomposition—a synthesis which is never given in absolute
completeness, either as finite, or as infinite.” The same is the case
with the series of subordinated causes, or of the conditioned up to the
unconditioned and necessary existence, which can never be regarded as
in itself, ind in its totality, either as finite or as infinite;
because, as a series of subordinate representations, it subsists only
in the dynamical regress and cannot be regarded as existing previously
to this regress, or as a self-subsistent series of things.

Thus the antinomy of pure reason in its cosmological ideas disappears.
For the above demonstration has established the fact that it is merely
the product of a dialectical and illusory opposition, which arises from
the application of the idea of absolute totality—admissible only as a
condition of things in themselves—to phenomena, which exist only in our
representations, and—when constituting a series—in a successive
regress. This antinomy of reason may, however, be really profitable to
our speculative interests, not in the way of contributing any
dogmatical addition, but as presenting to us another material support
in our critical investigations. For it furnishes us with an indirect
proof of the transcendental ideality of phenomena, if our minds were
not completely satisfied with the direct proof set forth in the
Trancendental Aesthetic. The proof would proceed in the following
dilemma. If the world is a whole existing in itself, it must be either
finite or infinite. But it is neither finite nor infinite—as has been
shown, on the one side, by the thesis, on the other, by the antithesis.
Therefore the world—the content of all phenomena—is not a whole
existing in itself. It follows that phenomena are nothing, apart from
our representations. And this is what we mean by transcendental

This remark is of some importance. It enables us to see that the proofs
of the fourfold antinomy are not mere sophistries—are not fallacious,
but grounded on the nature of reason, and valid—under the supposition
that phenomena are things in themselves. The opposition of the
judgements which follow makes it evident that a fallacy lay in the
initial supposition, and thus helps us to discover the true
constitution of objects of sense. This transcendental dialectic does
not favour scepticism, although it presents us with a triumphant
demonstration of the advantages of the sceptical method, the great
utility of which is apparent in the antinomy, where the arguments of
reason were allowed to confront each other in undiminished force. And
although the result of these conflicts of reason is not what we
expected—although we have obtained no positive dogmatical addition to
metaphysical science—we have still reaped a great advantage in the
correction of our judgements on these subjects of thought.

 Section VIII. Regulative Principle of Pure Reason in relation to the
 Cosmological Ideas

The cosmological principle of totality could not give us any certain
knowledge in regard to the maximum in the series of conditions in the
world of sense, considered as a thing in itself. The actual regress in
the series is the only means of approaching this maximum. This
principle of pure reason, therefore, may still be considered as
valid—not as an axiom enabling us to cogitate totality in the object as
actual, but as a problem for the understanding, which requires it to
institute and to continue, in conformity with the idea of totality in
the mind, the regress in the series of the conditions of a given
conditioned. For in the world of sense, that is, in space and time,
every condition which we discover in our investigation of phenomena is
itself conditioned; because sensuous objects are not things in
themselves (in which case an absolutely unconditioned might be reached
in the progress of cognition), but are merely empirical representations
the conditions of which must always be found in intuition. The
principle of reason is therefore properly a mere rule—prescribing a
regress in the series of conditions for given phenomena, and
prohibiting any pause or rest on an absolutely unconditioned. It is,
therefore, not a principle of the possibility of experience or of the
empirical cognition of sensuous objects—consequently not a principle of
the understanding; for every experience is confined within certain
proper limits determined by the given intuition. Still less is it a
constitutive principle of reason authorizing us to extend our
conception of the sensuous world beyond all possible experience. It is
merely a principle for the enlargement and extension of experience as
far as is possible for human faculties. It forbids us to consider any
empirical limits as absolute. It is, hence, a principle of reason,
which, as a rule, dictates how we ought to proceed in our empirical
regress, but is unable to anticipate or indicate prior to the empirical
regress what is given in the object itself. I have termed it for this
reason a regulative principle of reason; while the principle of the
absolute totality of the series of conditions, as existing in itself
and given in the object, is a constitutive cosmological principle. This
distinction will at once demonstrate the falsehood of the constitutive
principle, and prevent us from attributing (by a transcendental
subreptio) objective reality to an idea, which is valid only as a rule.

In order to understand the proper meaning of this rule of pure reason,
we must notice first that it cannot tell us what the object is, but
only how the empirical regress is to be proceeded with in order to
attain to the complete conception of the object. If it gave us any
information in respect to the former statement, it would be a
constitutive principle—a principle impossible from the nature of pure
reason. It will not therefore enable us to establish any such
conclusions as: “The series of conditions for a given conditioned is in
itself finite,” or, “It is infinite.” For, in this case, we should be
cogitating in the mere idea of absolute totality, an object which is
not and cannot be given in experience; inasmuch as we should be
attributing a reality objective and independent of the empirical
synthesis, to a series of phenomena. This idea of reason cannot then be
regarded as valid—except as a rule for the regressive synthesis in the
series of conditions, according to which we must proceed from the
conditioned, through all intermediate and subordinate conditions, up to
the unconditioned; although this goal is unattained and unattainable.
For the absolutely unconditioned cannot be discovered in the sphere of

We now proceed to determine clearly our notion of a synthesis which can
never be complete. There are two terms commonly employed for this
purpose. These terms are regarded as expressions of different and
distinguishable notions, although the ground of the distinction has
never been clearly exposed. The term employed by the mathematicians is
progressus in infinitum. The philosophers prefer the expression
progressus in indefinitum. Without detaining the reader with an
examination of the reasons for such a distinction, or with remarks on
the right or wrong use of the terms, I shall endeavour clearly to
determine these conceptions, so far as is necessary for the purpose in
this Critique.

We may, with propriety, say of a straight line, that it may be produced
to infinity. In this case the distinction between a progressus in
infinitum and a progressus in indefinitum is a mere piece of subtlety.
For, although when we say, “Produce a straight line,” it is more
correct to say in indefinitum than in infinitum; because the former
means, “Produce it as far as you please,” the second, “You must not
cease to produce it”; the expression in infinitum is, when we are
speaking of the power to do it, perfectly correct, for we can always
make it longer if we please—on to infinity. And this remark holds good
in all cases, when we speak of a progressus, that is, an advancement
from the condition to the conditioned; this possible advancement always
proceeds to infinity. We may proceed from a given pair in the
descending line of generation from father to son, and cogitate a
never-ending line of descendants from it. For in such a case reason
does not demand absolute totality in the series, because it does not
presuppose it as a condition and as given (datum), but merely as
conditioned, and as capable of being given (dabile).

Very different is the case with the problem: “How far the regress,
which ascends from the given conditioned to the conditions, must
extend”; whether I can say: “It is a regress in infinitum,” or only “in
indefinitum”; and whether, for example, setting out from the human
beings at present alive in the world, I may ascend in the series of
their ancestors, in infinitum—mr whether all that can be said is, that
so far as I have proceeded, I have discovered no empirical ground for
considering the series limited, so that I am justified, and indeed,
compelled to search for ancestors still further back, although I am not
obliged by the idea of reason to presuppose them.

My answer to this question is: “If the series is given in empirical
intuition as a whole, the regress in the series of its internal
conditions proceeds in infinitum; but, if only one member of the series
is given, from which the regress is to proceed to absolute totality,
the regress is possible only in indefinitum.” For example, the division
of a portion of matter given within certain limits—of a body, that
is—proceeds in infinitum. For, as the condition of this whole is its
part, and the condition of the part a part of the part, and so on, and
as in this regress of decomposition an unconditioned indivisible member
of the series of conditions is not to be found; there are no reasons or
grounds in experience for stopping in the division, but, on the
contrary, the more remote members of the division are actually and
empirically given prior to this division. That is to say, the division
proceeds to infinity. On the other hand, the series of ancestors of any
given human being is not given, in its absolute totality, in any
experience, and yet the regress proceeds from every genealogical member
of this series to one still higher, and does not meet with any
empirical limit presenting an absolutely unconditioned member of the
series. But as the members of such a series are not contained in the
empirical intuition of the whole, prior to the regress, this regress
does not proceed to infinity, but only in indefinitum, that is, we are
called upon to discover other and higher members, which are themselves
always conditioned.

In neither case—the regressus in infinitum, nor the regressus in
indefinitum, is the series of conditions to be considered as actually
infinite in the object itself. This might be true of things in
themselves, but it cannot be asserted of phenomena, which, as
conditions of each other, are only given in the empirical regress
itself. Hence, the question no longer is, “What is the quantity of this
series of conditions in itself—is it finite or infinite?” for it is
nothing in itself; but, “How is the empirical regress to be commenced,
and how far ought we to proceed with it?” And here a signal distinction
in the application of this rule becomes apparent. If the whole is given
empirically, it is possible to recede in the series of its internal
conditions to infinity. But if the whole is not given, and can only be
given by and through the empirical regress, I can only say: “It is
possible to infinity, to proceed to still higher conditions in the
series.” In the first case, I am justified in asserting that more
members are empirically given in the object than I attain to in the
regress (of decomposition). In the second case, I am justified only in
saying, that I can always proceed further in the regress, because no
member of the series is given as absolutely conditioned, and thus a
higher member is possible, and an inquiry with regard to it is
necessary. In the one case it is necessary to find other members of the
series, in the other it is necessary to inquire for others, inasmuch as
experience presents no absolute limitation of the regress. For, either
you do not possess a perception which absolutely limits your empirical
regress, and in this case the regress cannot be regarded as complete;
or, you do possess such a limitative perception, in which case it is
not a part of your series (for that which limits must be distinct from
that which is limited by it), and it is incumbent you to continue your
regress up to this condition, and so on.

These remarks will be placed in their proper light by their application
in the following section.

 Section IX. Of the Empirical Use of the Regulative Principle of Reason
 with regard to the Cosmological Ideas

We have shown that no transcendental use can be made either of the
conceptions of reason or of understanding. We have shown, likewise,
that the demand of absolute totality in the series of conditions in the
world of sense arises from a transcendental employment of reason,
resting on the opinion that phenomena are to be regarded as things in
themselves. It follows that we are not required to answer the question
respecting the absolute quantity of a series—whether it is in itself
limited or unlimited. We are only called upon to determine how far we
must proceed in the empirical regress from condition to condition, in
order to discover, in conformity with the rule of reason, a full and
correct answer to the questions proposed by reason itself.

This principle of reason is hence valid only as a rule for the
extension of a possible experience—its invalidity as a principle
constitutive of phenomena in themselves having been sufficiently
demonstrated. And thus, too, the antinomial conflict of reason with
itself is completely put an end to; inasmuch as we have not only
presented a critical solution of the fallacy lurking in the opposite
statements of reason, but have shown the true meaning of the ideas
which gave rise to these statements. The dialectical principle of
reason has, therefore, been changed into a doctrinal principle. But in
fact, if this principle, in the subjective signification which we have
shown to be its only true sense, may be guaranteed as a principle of
the unceasing extension of the employment of our understanding, its
influence and value are just as great as if it were an axiom for the a
priori determination of objects. For such an axiom could not exert a
stronger influence on the extension and rectification of our knowledge,
otherwise than by procuring for the principles of the understanding the
most widely expanded employment in the field of experience.

 I. Solution of the Cosmological Idea of the Totality of the
 Composition of Phenomena in the Universe

Here, as well as in the case of the other cosmological problems, the
ground of the regulative principle of reason is the proposition that in
our empirical regress no experience of an absolute limit, and
consequently no experience of a condition, which is itself absolutely
unconditioned, is discoverable. And the truth of this proposition
itself rests upon the consideration that such an experience must
represent to us phenomena as limited by nothing or the mere void, on
which our continued regress by means of perception must abut—which is

Now this proposition, which declares that every condition attained in
the empirical regress must itself be considered empirically
conditioned, contains the rule in terminis, which requires me, to
whatever extent I may have proceeded in the ascending series, always to
look for some higher member in the series—whether this member is to
become known to me through experience, or not.

Nothing further is necessary, then, for the solution of the first
cosmological problem, than to decide, whether, in the regress to the
unconditioned quantity of the universe (as regards space and time),
this never limited ascent ought to be called a regressus in infinitum
or indefinitum.

The general representation which we form in our minds of the series of
all past states or conditions of the world, or of all the things which
at present exist in it, is itself nothing more than a possible
empirical regress, which is cogitated—although in an undetermined
manner—in the mind, and which gives rise to the conception of a series
of conditions for a given object.* Now I have a conception of the
universe, but not an intuition—that is, not an intuition of it as a
whole. Thus I cannot infer the magnitude of the regress from the
quantity or magnitude of the world, and determine the former by means
of the latter; on the contrary, I must first of all form a conception
of the quantity or magnitude of the world from the magnitude of the
empirical regress. But of this regress I know nothing more than that I
ought to proceed from every given member of the series of conditions to
one still higher. But the quantity of the universe is not thereby
determined, and we cannot affirm that this regress proceeds in
infinitum. Such an affirmation would anticipate the members of the
series which have not yet been reached, and represent the number of
them as beyond the grasp of any empirical synthesis; it would
consequently determine the cosmical quantity prior to the regress
(although only in a negative manner)—which is impossible. For the world
is not given in its totality in any intuition: consequently, its
quantity cannot be given prior to the regress. It follows that we are
unable to make any declaration respecting the cosmical quantity in
itself—not even that the regress in it is a regress in infinitum; we
must only endeavour to attain to a conception of the quantity of the
universe, in conformity with the rule which determines the empirical
regress in it. But this rule merely requires us never to admit an
absolute limit to our series—how far soever we may have proceeded in
it, but always, on the contrary, to subordinate every phenomenon to
some other as its condition, and consequently to proceed to this higher
phenomenon. Such a regress is, therefore, the regressus in indefinitum,
which, as not determining a quantity in the object, is clearly
distinguishable from the regressus in infinitum.

[*Footnote: The cosmical series can neither be greater nor smaller than
the possible empirical regress, upon which its conception is based. And
as this regress cannot be a determinate infinite regress, still less a
determinate finite (absolutely limited), it is evident that we cannot
regard the world as either finite or infinite, because the regress,
which gives us the representation of the world, is neither finite nor

It follows from what we have said that we are not justified in
declaring the world to be infinite in space, or as regards past time.
For this conception of an infinite given quantity is empirical; but we
cannot apply the conception of an infinite quantity to the world as an
object of the senses. I cannot say, “The regress from a given
perception to everything limited either in space or time, proceeds in
infinitum,” for this presupposes an infinite cosmical quantity; neither
can I say, “It is finite,” for an absolute limit is likewise impossible
in experience. It follows that I am not entitled to make any assertion
at all respecting the whole object of experience—the world of sense; I
must limit my declarations to the rule according to which experience or
empirical knowledge is to be attained.

To the question, therefore, respecting the cosmical quantity, the first
and negative answer is: “The world has no beginning in time, and no
absolute limit in space.”

For, in the contrary case, it would be limited by a void time on the
one hand, and by a void space on the other. Now, since the world, as a
phenomenon, cannot be thus limited in itself for a phenomenon is not a
thing in itself; it must be possible for us to have a perception of
this limitation by a void time and a void space. But such a
perception—such an experience is impossible; because it has no content.
Consequently, an absolute cosmical limit is empirically, and therefore
absolutely, impossible.*

[*Footnote: The reader will remark that the proof presented above is
very different from the dogmatical demonstration given in the
antithesis of the first antinomy. In that demonstration, it was taken
for granted that the world is a thing in itself—given in its totality
prior to all regress, and a determined position in space and time was
denied to it—if it was not considered as occupying all time and all
space. Hence our conclusion differed from that given above; for we
inferred in the antithesis the actual infinity of the world.]

From this follows the affirmative answer: “The regress in the series of
phenomena—as a determination of the cosmical quantity, proceeds in
indefinitum.” This is equivalent to saying: “The world of sense has no
absolute quantity, but the empirical regress (through which alone the
world of sense is presented to us on the side of its conditions) rests
upon a rule, which requires it to proceed from every member of the
series, as conditioned, to one still more remote (whether through
personal experience, or by means of history, or the chain of cause and
effect), and not to cease at any point in this extension of the
possible empirical employment of the understanding.” And this is the
proper and only use which reason can make of its principles.

The above rule does not prescribe an unceasing regress in one kind of
phenomena. It does not, for example, forbid us, in our ascent from an
individual human being through the line of his ancestors, to expect
that we shall discover at some point of the regress a primeval pair, or
to admit, in the series of heavenly bodies, a sun at the farthest
possible distance from some centre. All that it demands is a perpetual
progress from phenomena to phenomena, even although an actual
perception is not presented by them (as in the case of our perceptions
being so weak as that we are unable to become conscious of them), since
they, nevertheless, belong to possible experience.

Every beginning is in time, and all limits to extension are in space.
But space and time are in the world of sense. Consequently phenomena in
the world are conditionally limited, but the world itself is not
limited, either conditionally or unconditionally.

For this reason, and because neither the world nor the cosmical series
of conditions to a given conditioned can be completely given, our
conception of the cosmical quantity is given only in and through the
regress and not prior to it—in a collective intuition. But the regress
itself is really nothing more than the determining of the cosmical
quantity, and cannot therefore give us any determined conception of
it—still less a conception of a quantity which is, in relation to a
certain standard, infinite. The regress does not, therefore, proceed to
infinity (an infinity given), but only to an indefinite extent, for or
the of presenting to us a quantity—realized only in and through the
regress itself.

 II. Solution of the Cosmological Idea of the Totality of the Division
 of a Whole given in Intuition

When I divide a whole which is given in intuition, I proceed from a
conditioned to its conditions. The division of the parts of the whole
(subdivisio or decompositio) is a regress in the series of these
conditions. The absolute totality of this series would be actually
attained and given to the mind, if the regress could arrive at simple
parts. But if all the parts in a continuous decomposition are
themselves divisible, the division, that is to say, the regress,
proceeds from the conditioned to its conditions in infinitum; because
the conditions (the parts) are themselves contained in the conditioned,
and, as the latter is given in a limited intuition, the former are all
given along with it. This regress cannot, therefore, be called a
regressus in indefinitum, as happened in the case of the preceding
cosmological idea, the regress in which proceeded from the conditioned
to the conditions not given contemporaneously and along with it, but
discoverable only through the empirical regress. We are not, however,
entitled to affirm of a whole of this kind, which is divisible in
infinitum, that it consists of an infinite number of parts. For,
although all the parts are contained in the intuition of the whole, the
whole division is not contained therein. The division is contained only
in the progressing decomposition—in the regress itself, which is the
condition of the possibility and actuality of the series. Now, as this
regress is infinite, all the members (parts) to which it attains must
be contained in the given whole as an aggregate. But the complete
series of division is not contained therein. For this series, being
infinite in succession and always incomplete, cannot represent an
infinite number of members, and still less a composition of these
members into a whole.

To apply this remark to space. Every limited part of space presented to
intuition is a whole, the parts of which are always spaces—to whatever
extent subdivided. Every limited space is hence divisible to infinity.

Let us again apply the remark to an external phenomenon enclosed in
limits, that is, a body. The divisibility of a body rests upon the
divisibility of space, which is the condition of the possibility of the
body as an extended whole. A body is consequently divisible to
infinity, though it does not, for that reason, consist of an infinite
number of parts.

It certainly seems that, as a body must be cogitated as substance in
space, the law of divisibility would not be applicable to it as
substance. For we may and ought to grant, in the case of space, that
division or decomposition, to any extent, never can utterly annihilate
composition (that is to say, the smallest part of space must still
consist of spaces); otherwise space would entirely cease to exist—which
is impossible. But, the assertion on the other band that when all
composition in matter is annihilated in thought, nothing remains, does
not seem to harmonize with the conception of substance, which must be
properly the subject of all composition and must remain, even after the
conjunction of its attributes in space—which constituted a body—is
annihilated in thought. But this is not the case with substance in the
phenomenal world, which is not a thing in itself cogitated by the pure
category. Phenomenal substance is not an absolute subject; it is merely
a permanent sensuous image, and nothing more than an intuition, in
which the unconditioned is not to be found.

But, although this rule of progress to infinity is legitimate and
applicable to the subdivision of a phenomenon, as a mere occupation or
filling of space, it is not applicable to a whole consisting of a
number of distinct parts and constituting a quantum discretum—that is
to say, an organized body. It cannot be admitted that every part in an
organized whole is itself organized, and that, in analysing it to
infinity, we must always meet with organized parts; although we may
allow that the parts of the matter which we decompose in infinitum, may
be organized. For the infinity of the division of a phenomenon in space
rests altogether on the fact that the divisibility of a phenomenon is
given only in and through this infinity, that is, an undetermined
number of parts is given, while the parts themselves are given and
determined only in and through the subdivision; in a word, the infinity
of the division necessarily presupposes that the whole is not already
divided in se. Hence our division determines a number of parts in the
whole—a number which extends just as far as the actual regress in the
division; while, on the other hand, the very notion of a body organized
to infinity represents the whole as already and in itself divided. We
expect, therefore, to find in it a determinate, but at the same time,
infinite, number of parts—which is self-contradictory. For we should
thus have a whole containing a series of members which could not be
completed in any regress—which is infinite, and at the same time
complete in an organized composite. Infinite divisibility is applicable
only to a quantum continuum, and is based entirely on the infinite
divisibility of space, But in a quantum discretum the multitude of
parts or units is always determined, and hence always equal to some
number. To what extent a body may be organized, experience alone can
inform us; and although, so far as our experience of this or that body
has extended, we may not have discovered any inorganic part, such parts
must exist in possible experience. But how far the transcendental
division of a phenomenon must extend, we cannot know from experience—it
is a question which experience cannot answer; it is answered only by
the principle of reason which forbids us to consider the empirical
regress, in the analysis of extended body, as ever absolutely complete.

Concluding Remark on the Solution of the Transcendental Mathematical
Ideas—and Introductory to the Solution of the Dynamical Ideas.

We presented the antinomy of pure reason in a tabular form, and we
endeavoured to show the ground of this self-contradiction on the part
of reason, and the only means of bringing it to a conclusion—namely, by
declaring both contradictory statements to be false. We represented in
these antinomies the conditions of phenomena as belonging to the
conditioned according to relations of space and time—which is the usual
supposition of the common understanding. In this respect, all
dialectical representations of totality, in the series of conditions to
a given conditioned, were perfectly homogeneous. The condition was
always a member of the series along with the conditioned, and thus the
homogeneity of the whole series was assured. In this case the regress
could never be cogitated as complete; or, if this was the case, a
member really conditioned was falsely regarded as a primal member,
consequently as unconditioned. In such an antinomy, therefore, we did
not consider the object, that is, the conditioned, but the series of
conditions belonging to the object, and the magnitude of that series.
And thus arose the difficulty—a difficulty not to be settled by any
decision regarding the claims of the two parties, but simply by cutting
the knot—by declaring the series proposed by reason to be either too
long or too short for the understanding, which could in neither case
make its conceptions adequate with the ideas.

But we have overlooked, up to this point, an essential difference
existing between the conceptions of the understanding which reason
endeavours to raise to the rank of ideas—two of these indicating a
mathematical, and two a dynamical synthesis of phenomena. Hitherto, it
was necessary to signalize this distinction; for, just as in our
general representation of all transcendental ideas, we considered them
under phenomenal conditions, so, in the two mathematical ideas, our
discussion is concerned solely with an object in the world of
phenomena. But as we are now about to proceed to the consideration of
the dynamical conceptions of the understanding, and their adequateness
with ideas, we must not lose sight of this distinction. We shall find
that it opens up to us an entirely new view of the conflict in which
reason is involved. For, while in the first two antinomies, both
parties were dismissed, on the ground of having advanced statements
based upon false hypothesis; in the present case the hope appears of
discovering a hypothesis which may be consistent with the demands of
reason, and, the judge completing the statement of the grounds of
claim, which both parties had left in an unsatisfactory state, the
question may be settled on its own merits, not by dismissing the
claimants, but by a comparison of the arguments on both sides. If we
consider merely their extension, and whether they are adequate with
ideas, the series of conditions may be regarded as all homogeneous. But
the conception of the understanding which lies at the basis of these
ideas, contains either a synthesis of the homogeneous (presupposed in
every quantity—in its composition as well as in its division) or of the
heterogeneous, which is the case in the dynamical synthesis of cause
and effect, as well as of the necessary and the contingent.

Thus it happens that in the mathematical series of phenomena no other
than a sensuous condition is admissible—a condition which is itself a
member of the series; while the dynamical series of sensuous conditions
admits a heterogeneous condition, which is not a member of the series,
but, as purely intelligible, lies out of and beyond it. And thus reason
is satisfied, and an unconditioned placed at the head of the series of
phenomena, without introducing confusion into or discontinuing it,
contrary to the principles of the understanding.

Now, from the fact that the dynamical ideas admit a condition of
phenomena which does not form a part of the series of phenomena, arises
a result which we should not have expected from an antinomy. In former
cases, the result was that both contradictory dialectical statements
were declared to be false. In the present case, we find the conditioned
in the dynamical series connected with an empirically unconditioned,
but non-sensuous condition; and thus satisfaction is done to the
understanding on the one hand and to the reason on the other.* While,
moreover, the dialectical arguments for unconditioned totality in mere
phenomena fall to the ground, both propositions of reason may be shown
to be true in their proper signification. This could not happen in the
case of the cosmological ideas which demanded a mathematically
unconditioned unity; for no condition could be placed at the head of
the series of phenomena, except one which was itself a phenomenon and
consequently a member of the series.

[*Footnote: For the understanding cannot admit among phenomena a
condition which is itself empirically unconditioned. But if it is
possible to cogitate an intelligible condition—one which is not a
member of the series of phenomena—for a conditioned phenomenon, without
breaking the series of empirical conditions, such a condition may be
admissible as empirically unconditioned, and the empirical regress
continue regular, unceasing, and intact.]

 III. Solution of the Cosmological Idea of the Totality of the
 Deduction of Cosmical Events from their Causes

There are only two modes of causality cogitable—the causality of nature
or of freedom. The first is the conjunction of a particular state with
another preceding it in the world of sense, the former following the
latter by virtue of a law. Now, as the causality of phenomena is
subject to conditions of time, and the preceding state, if it had
always existed, could not have produced an effect which would make its
first appearance at a particular time, the causality of a cause must
itself be an effect—must itself have begun to be, and therefore,
according to the principle of the understanding, itself requires a

We must understand, on the contrary, by the term freedom, in the
cosmological sense, a faculty of the spontaneous origination of a
state; the causality of which, therefore, is not subordinated to
another cause determining it in time. Freedom is in this sense a pure
transcendental idea, which, in the first place, contains no empirical
element; the object of which, in the second place, cannot be given or
determined in any experience, because it is a universal law of the very
possibility of experience, that everything which happens must have a
cause, that consequently the causality of a cause, being itself
something that has happened, must also have a cause. In this view of
the case, the whole field of experience, how far soever it may extend,
contains nothing that is not subject to the laws of nature. But, as we
cannot by this means attain to an absolute totality of conditions in
reference to the series of causes and effects, reason creates the idea
of a spontaneity, which can begin to act of itself, and without any
external cause determining it to action, according to the natural law
of causality.

It is especially remarkable that the practical conception of freedom is
based upon the transcendental idea, and that the question of the
possibility of the former is difficult only as it involves the
consideration of the truth of the latter. Freedom, in the practical
sense, is the independence of the will of coercion by sensuous
impulses. A will is sensuous, in so far as it is pathologically
affected (by sensuous impulses); it is termed animal (arbitrium
brutum), when it is pathologically necessitated. The human will is
certainly an arbitrium sensitivum, not brutum, but liberum; because
sensuousness does not necessitate its action, a faculty existing in man
of self-determination, independently of all sensuous coercion.

It is plain that, if all causality in the world of sense were
natural—and natural only—every event would be determined by another
according to necessary laws, and that, consequently, phenomena, in so
far as they determine the will, must necessitate every action as a
natural effect from themselves; and thus all practical freedom would
fall to the ground with the transcendental idea. For the latter
presupposes that although a certain thing has not happened, it ought to
have happened, and that, consequently, its phenomenal cause was not so
powerful and determinative as to exclude the causality of our will—a
causality capable of producing effects independently of and even in
opposition to the power of natural causes, and capable, consequently,
of spontaneously originating a series of events.

Here, too, we find it to be the case, as we generally found in the
self-contradictions and perplexities of a reason which strives to pass
the bounds of possible experience, that the problem is properly not
physiological, but transcendental. The question of the possibility of
freedom does indeed concern psychology; but, as it rests upon
dialectical arguments of pure reason, its solution must engage the
attention of transcendental philosophy. Before attempting this
solution, a task which transcendental philosophy cannot decline, it
will be advisable to make a remark with regard to its procedure in the
settlement of the question.

If phenomena were things in themselves, and time and space forms of the
existence of things, condition and conditioned would always be members
of the same series; and thus would arise in the present case the
antinomy common to all transcendental ideas—that their series is either
too great or too small for the understanding. The dynamical ideas,
which we are about to discuss in this and the following section,
possess the peculiarity of relating to an object, not considered as a
quantity, but as an existence; and thus, in the discussion of the
present question, we may make abstraction of the quantity of the series
of conditions, and consider merely the dynamical relation of the
condition to the conditioned. The question, then, suggests itself,
whether freedom is possible; and, if it is, whether it can consist with
the universality of the natural law of causality; and, consequently,
whether we enounce a proper disjunctive proposition when we say: “Every
effect must have its origin either in nature or in freedom,” or whether
both cannot exist together in the same event in different relations.
The principle of an unbroken connection between all events in the
phenomenal world, in accordance with the unchangeable laws of nature,
is a well-established principle of transcendental analytic which admits
of no exception. The question, therefore, is: “Whether an effect,
determined according to the laws of nature, can at the same time be
produced by a free agent, or whether freedom and nature mutually
exclude each other?” And here, the common but fallacious hypothesis of
the absolute reality of phenomena manifests its injurious influence in
embarrassing the procedure of reason. For if phenomena are things in
themselves, freedom is impossible. In this case, nature is the complete
and all-sufficient cause of every event; and condition and conditioned,
cause and effect are contained in the same series, and necessitated by
the same law. If, on the contrary, phenomena are held to be, as they
are in fact, nothing more than mere representations, connected with
each other in accordance with empirical laws, they must have a ground
which is not phenomenal. But the causality of such an intelligible
cause is not determined or determinable by phenomena; although its
effects, as phenomena, must be determined by other phenomenal
existences. This cause and its causality exist therefore out of and
apart from the series of phenomena; while its effects do exist and are
discoverable in the series of empirical conditions. Such an effect may
therefore be considered to be free in relation to its intelligible
cause, and necessary in relation to the phenomena from which it is a
necessary consequence—a distinction which, stated in this perfectly
general and abstract manner, must appear in the highest degree subtle
and obscure. The sequel will explain. It is sufficient, at present, to
remark that, as the complete and unbroken connection of phenomena is an
unalterable law of nature, freedom is impossible—on the supposition
that phenomena are absolutely real. Hence those philosophers who adhere
to the common opinion on this subject can never succeed in reconciling
the ideas of nature and freedom.

Possibility of Freedom in Harmony with the Universal Law of Natural

That element in a sensuous object which is not itself sensuous, I may
be allowed to term intelligible. If, accordingly, an object which must
be regarded as a sensuous phenomenon possesses a faculty which is not
an object of sensuous intuition, but by means of which it is capable of
being the cause of phenomena, the causality of an object or existence
of this kind may be regarded from two different points of view. It may
be considered to be intelligible, as regards its action—the action of a
thing which is a thing in itself, and sensuous, as regards its
effects—the effects of a phenomenon belonging to the sensuous world. We
should accordingly, have to form both an empirical and an intellectual
conception of the causality of such a faculty or power—both, however,
having reference to the same effect. This twofold manner of cogitating
a power residing in a sensuous object does not run counter to any of
the conceptions which we ought to form of the world of phenomena or of
a possible experience. Phenomena—not being things in themselves—must
have a transcendental object as a foundation, which determines them as
mere representations; and there seems to be no reason why we should not
ascribe to this transcendental object, in addition to the property of
self-phenomenization, a causality whose effects are to be met with in
the world of phenomena, although it is not itself a phenomenon. But
every effective cause must possess a character, that is to say, a law
of its causality, without which it would cease to be a cause. In the
above case, then, every sensuous object would possess an empirical
character, which guaranteed that its actions, as phenomena, stand in
complete and harmonious connection, conformably to unvarying natural
laws, with all other phenomena, and can be deduced from these, as
conditions, and that they do thus, in connection with these, constitute
a series in the order of nature. This sensuous object must, in the
second place, possess an intelligible character, which guarantees it to
be the cause of those actions, as phenomena, although it is not itself
a phenomenon nor subordinate to the conditions of the world of sense.
The former may be termed the character of the thing as a phenomenon,
the latter the character of the thing as a thing in itself.

Now this active subject would, in its character of intelligible
subject, be subordinate to no conditions of time, for time is only a
condition of phenomena, and not of things in themselves. No action
would begin or cease to be in this subject; it would consequently be
free from the law of all determination of time—the law of change,
namely, that everything which happens must have a cause in the
phenomena of a preceding state. In one word, the causality of the
subject, in so far as it is intelligible, would not form part of the
series of empirical conditions which determine and necessitate an event
in the world of sense. Again, this intelligible character of a thing
cannot be immediately cognized, because we can perceive nothing but
phenomena, but it must be capable of being cogitated in harmony with
the empirical character; for we always find ourselves compelled to
place, in thought, a transcendental object at the basis of phenomena
although we can never know what this object is in itself.

In virtue of its empirical character, this subject would at the same
time be subordinate to all the empirical laws of causality, and, as a
phenomenon and member of the sensuous world, its effects would have to
be accounted for by a reference to preceding phenomena. Eternal
phenomena must be capable of influencing it; and its actions, in
accordance with natural laws, must explain to us how its empirical
character, that is, the law of its causality, is to be cognized in and
by means of experience. In a word, all requisites for a complete and
necessary determination of these actions must be presented to us by

In virtue of its intelligible character, on the other hand (although we
possess only a general conception of this character), the subject must
be regarded as free from all sensuous influences, and from all
phenomenal determination. Moreover, as nothing happens in this
subject—for it is a noumenon, and there does not consequently exist in
it any change, demanding the dynamical determination of time, and for
the same reason no connection with phenomena as causes—this active
existence must in its actions be free from and independent of natural
necessity, for or necessity exists only in the world of phenomena. It
would be quite correct to say that it originates or begins its effects
in the world of sense from itself, although the action productive of
these effects does not begin in itself. We should not be in this case
affirming that these sensuous effects began to exist of themselves,
because they are always determined by prior empirical conditions—by
virtue of the empirical character, which is the phenomenon of the
intelligible character—and are possible only as constituting a
continuation of the series of natural causes. And thus nature and
freedom, each in the complete and absolute signification of these
terms, can exist, without contradiction or disagreement, in the same

Exposition of the Cosmological Idea of Freedom in Harmony with the
Universal Law of Natural Necessity.

I have thought it advisable to lay before the reader at first merely a
sketch of the solution of this transcendental problem, in order to
enable him to form with greater ease a clear conception of the course
which reason must adopt in the solution. I shall now proceed to exhibit
the several momenta of this solution, and to consider them in their

The natural law that everything which happens must have a cause, that
the causality of this cause, that is, the action of the cause (which
cannot always have existed, but must be itself an event, for it
precedes in time some effect which it has originated), must have itself
a phenomenal cause, by which it is determined and, and, consequently,
all events are empirically determined in an order of nature—this law, I
say, which lies at the foundation of the possibility of experience, and
of a connected system of phenomena or nature is a law of the
understanding, from which no departure, and to which no exception, can
be admitted. For to except even a single phenomenon from its operation
is to exclude it from the sphere of possible experience and thus to
admit it to be a mere fiction of thought or phantom of the brain.

Thus we are obliged to acknowledge the existence of a chain of causes,
in which, however, absolute totality cannot be found. But we need not
detain ourselves with this question, for it has already been
sufficiently answered in our discussion of the antinomies into which
reason falls, when it attempts to reach the unconditioned in the series
of phenomena. If we permit ourselves to be deceived by the illusion of
transcendental idealism, we shall find that neither nature nor freedom
exists. Now the question is: “Whether, admitting the existence of
natural necessity in the world of phenomena, it is possible to consider
an effect as at the same time an effect of nature and an effect of
freedom—or, whether these two modes of causality are contradictory and

No phenomenal cause can absolutely and of itself begin a series. Every
action, in so far as it is productive of an event, is itself an event
or occurrence, and presupposes another preceding state, in which its
cause existed. Thus everything that happens is but a continuation of a
series, and an absolute beginning is impossible in the sensuous world.
The actions of natural causes are, accordingly, themselves effects, and
presuppose causes preceding them in time. A primal action which forms
an absolute beginning, is beyond the causal power of phenomena.

Now, is it absolutely necessary that, granting that all effects are
phenomena, the causality of the cause of these effects must also be a
phenomenon and belong to the empirical world? Is it not rather possible
that, although every effect in the phenomenal world must be connected
with an empirical cause, according to the universal law of nature, this
empirical causality may be itself the effect of a non-empirical and
intelligible causality—its connection with natural causes remaining
nevertheless intact? Such a causality would be considered, in reference
to phenomena, as the primal action of a cause, which is in so far,
therefore, not phenomenal, but, by reason of this faculty or power,
intelligible; although it must, at the same time, as a link in the
chain of nature, be regarded as belonging to the sensuous world.

A belief in the reciprocal causality of phenomena is necessary, if we
are required to look for and to present the natural conditions of
natural events, that is to say, their causes. This being admitted as
unexceptionably valid, the requirements of the understanding, which
recognizes nothing but nature in the region of phenomena, are
satisfied, and our physical explanations of physical phenomena may
proceed in their regular course, without hindrance and without
opposition. But it is no stumbling-block in the way, even assuming the
idea to be a pure fiction, to admit that there are some natural causes
in the possession of a faculty which is not empirical, but
intelligible, inasmuch as it is not determined to action by empirical
conditions, but purely and solely upon grounds brought forward by the
understanding—this action being still, when the cause is phenomenized,
in perfect accordance with the laws of empirical causality. Thus the
acting subject, as a causal phenomenon, would continue to preserve a
complete connection with nature and natural conditions; and the
phenomenon only of the subject (with all its phenomenal causality)
would contain certain conditions, which, if we ascend from the
empirical to the transcendental object, must necessarily be regarded as
intelligible. For, if we attend, in our inquiries with regard to causes
in the world of phenomena, to the directions of nature alone, we need
not trouble ourselves about the relation in which the transcendental
subject, which is completely unknown to us, stands to these phenomena
and their connection in nature. The intelligible ground of phenomena in
this subject does not concern empirical questions. It has to do only
with pure thought; and, although the effects of this thought and action
of the pure understanding are discoverable in phenomena, these
phenomena must nevertheless be capable of a full and complete
explanation, upon purely physical grounds and in accordance with
natural laws. And in this case we attend solely to their empirical and
omit all consideration of their intelligible character (which is the
transcendental cause of the former) as completely unknown, except in so
far as it is exhibited by the latter as its empirical symbol. Now let
us apply this to experience. Man is a phenomenon of the sensuous world
and, at the same time, therefore, a natural cause, the causality of
which must be regulated by empirical laws. As such, he must possess an
empirical character, like all other natural phenomena. We remark this
empirical character in his actions, which reveal the presence of
certain powers and faculties. If we consider inanimate or merely animal
nature, we can discover no reason for ascribing to ourselves any other
than a faculty which is determined in a purely sensuous manner. But
man, to whom nature reveals herself only through sense, cognizes
himself not only by his senses, but also through pure apperception; and
this in actions and internal determinations, which he cannot regard as
sensuous impressions. He is thus to himself, on the one hand, a
phenomenon, but on the other hand, in respect of certain faculties, a
purely intelligible object—intelligible, because its action cannot be
ascribed to sensuous receptivity. These faculties are understanding and
reason. The latter, especially, is in a peculiar manner distinct from
all empirically-conditioned faculties, for it employs ideas alone in
the consideration of its objects, and by means of these determines the
understanding, which then proceeds to make an empirical use of its own
conceptions, which, like the ideas of reason, are pure and

That reason possesses the faculty of causality, or that at least we are
compelled so to represent it, is evident from the imperatives, which in
the sphere of the practical we impose on many of our executive powers.
The words I ought express a species of necessity, and imply a
connection with grounds which nature does not and cannot present to the
mind of man. Understanding knows nothing in nature but that which is,
or has been, or will be. It would be absurd to say that anything in
nature ought to be other than it is in the relations of time in which
it stands; indeed, the ought, when we consider merely the course of
nature, has neither application nor meaning. The question, “What ought
to happen in the sphere of nature?” is just as absurd as the question,
“What ought to be the properties of a circle?” All that we are entitled
to ask is, “What takes place in nature?” or, in the latter case, “What
are the properties of a circle?”

But the idea of an ought or of duty indicates a possible action, the
ground of which is a pure conception; while the ground of a merely
natural action is, on the contrary, always a phenomenon. This action
must certainly be possible under physical conditions, if it is
prescribed by the moral imperative ought; but these physical or natural
conditions do not concern the determination of the will itself, they
relate to its effects alone, and the consequences of the effect in the
world of phenomena. Whatever number of motives nature may present to my
will, whatever sensuous impulses—the moral ought it is beyond their
power to produce. They may produce a volition, which, so far from being
necessary, is always conditioned—a volition to which the ought
enunciated by reason, sets an aim and a standard, gives permission or
prohibition. Be the object what it may, purely sensuous—as pleasure, or
presented by pure reason—as good, reason will not yield to grounds
which have an empirical origin. Reason will not follow the order of
things presented by experience, but, with perfect spontaneity,
rearranges them according to ideas, with which it compels empirical
conditions to agree. It declares, in the name of these ideas, certain
actions to be necessary which nevertheless have not taken place and
which perhaps never will take place; and yet presupposes that it
possesses the faculty of causality in relation to these actions. For,
in the absence of this supposition, it could not expect its ideas to
produce certain effects in the world of experience.

Now, let us stop here and admit it to be at least possible that reason
does stand in a really causal relation to phenomena. In this case it
must—pure reason as it is—exhibit an empirical character. For every
cause supposes a rule, according to which certain phenomena follow as
effects from the cause, and every rule requires uniformity in these
effects; and this is the proper ground of the conception of a cause—as
a faculty or power. Now this conception (of a cause) may be termed the
empirical character of reason; and this character is a permanent one,
while the effects produced appear, in conformity with the various
conditions which accompany and partly limit them, in various forms.

Thus the volition of every man has an empirical character, which is
nothing more than the causality of his reason, in so far as its effects
in the phenomenal world manifest the presence of a rule, according to
which we are enabled to examine, in their several kinds and degrees,
the actions of this causality and the rational grounds for these
actions, and in this way to decide upon the subjective principles of
the volition. Now we learn what this empirical character is only from
phenomenal effects, and from the rule of these which is presented by
experience; and for this reason all the actions of man in the world of
phenomena are determined by his empirical character, and the
co-operative causes of nature. If, then, we could investigate all the
phenomena of human volition to their lowest foundation in the mind,
there would be no action which we could not anticipate with certainty,
and recognize to be absolutely necessary from its preceding conditions.
So far as relates to this empirical character, therefore, there can be
no freedom; and it is only in the light of this character that we can
consider the human will, when we confine ourselves to simple
observation and, as is the case in anthropology, institute a
physiological investigation of the motive causes of human actions.

But when we consider the same actions in relation to reason—not for the
purpose of explaining their origin, that is, in relation to speculative
reason, but to practical reason, as the producing cause of these
actions—we shall discover a rule and an order very different from those
of nature and experience. For the declaration of this mental faculty
may be that what has and could not but take place in the course of
nature, ought not to have taken place. Sometimes, too, we discover, or
believe that we discover, that the ideas of reason did actually stand
in a causal relation to certain actions of man; and that these actions
have taken place because they were determined, not by empirical causes,
but by the act of the will upon grounds of reason.

Now, granting that reason stands in a causal relation to phenomena; can
an action of reason be called free, when we know that, sensuously, in
its empirical character, it is completely determined and absolutely
necessary? But this empirical character is itself determined by the
intelligible character. The latter we cannot cognize; we can only
indicate it by means of phenomena, which enable us to have an immediate
cognition only of the empirical character.* An action, then, in so far
as it is to be ascribed to an intelligible cause, does not result from
it in accordance with empirical laws. That is to say, not the
conditions of pure reason, but only their effects in the internal
sense, precede the act. Pure reason, as a purely intelligible faculty,
is not subject to the conditions of time. The causality of reason in
its intelligible character does not begin to be; it does not make its
appearance at a certain time, for the purpose of producing an effect.
If this were not the case, the causality of reason would be subservient
to the natural law of phenomena, which determines them according to
time, and as a series of causes and effects in time; it would
consequently cease to be freedom and become a part of nature. We are
therefore justified in saying: “If reason stands in a causal relation
to phenomena, it is a faculty which originates the sensuous condition
of an empirical series of effects.” For the condition, which resides in
the reason, is non-sensuous, and therefore cannot be originated, or
begin to be. And thus we find—what we could not discover in any
empirical series—a condition of a successive series of events itself
empirically unconditioned. For, in the present case, the condition
stands out of and beyond the series of phenomena—it is intelligible,
and it consequently cannot be subjected to any sensuous condition, or
to any time-determination by a preceding cause.

[*Footnote: The real morality of actions—their merit or demerit, and
even that of our own conduct, is completely unknown to us. Our
estimates can relate only to their empirical character. How much is the
result of the action of free will, how much is to be ascribed to nature
and to blameless error, or to a happy constitution of temperament
(merito fortunae), no one can discover, nor, for this reason, determine
with perfect justice.]

But, in another respect, the same cause belongs also to the series of
phenomena. Man is himself a phenomenon. His will has an empirical
character, which is the empirical cause of all his actions. There is no
condition—determining man and his volition in conformity with this
character—which does not itself form part of the series of effects in
nature, and is subject to their law—the law according to which an
empirically undetermined cause of an event in time cannot exist. For
this reason no given action can have an absolute and spontaneous
origination, all actions being phenomena, and belonging to the world of
experience. But it cannot be said of reason, that the state in which it
determines the will is always preceded by some other state determining
it. For reason is not a phenomenon, and therefore not subject to
sensuous conditions; and, consequently, even in relation to its
causality, the sequence or conditions of time do not influence reason,
nor can the dynamical law of nature, which determines the sequence of
time according to certain rules, be applied to it.

Reason is consequently the permanent condition of all actions of the
human will. Each of these is determined in the empirical character of
the man, even before it has taken place. The intelligible character, of
which the former is but the sensuous schema, knows no before or after;
and every action, irrespective of the time-relation in which it stands
with other phenomena, is the immediate effect of the intelligible
character of pure reason, which, consequently, enjoys freedom of
action, and is not dynamically determined either by internal or
external preceding conditions. This freedom must not be described, in a
merely negative manner, as independence of empirical conditions, for in
this case the faculty of reason would cease to be a cause of phenomena;
but it must be regarded, positively, as a faculty which can
spontaneously originate a series of events. At the same time, it must
not be supposed that any beginning can take place in reason; on the
contrary, reason, as the unconditioned condition of all action of the
will, admits of no time-conditions, although its effect does really
begin in a series of phenomena—a beginning which is not, however,
absolutely primal.

I shall illustrate this regulative principle of reason by an example,
from its employment in the world of experience; proved it cannot be by
any amount of experience, or by any number of facts, for such arguments
cannot establish the truth of transcendental propositions. Let us take
a voluntary action—for example, a falsehood—by means of which a man has
introduced a certain degree of confusion into the social life of
humanity, which is judged according to the motives from which it
originated, and the blame of which and of the evil consequences arising
from it, is imputed to the offender. We at first proceed to examine the
empirical character of the offence, and for this purpose we endeavour
to penetrate to the sources of that character, such as a defective
education, bad company, a shameless and wicked disposition, frivolity,
and want of reflection—not forgetting also the occasioning causes which
prevailed at the moment of the transgression. In this the procedure is
exactly the same as that pursued in the investigation of the series of
causes which determine a given physical effect. Now, although we
believe the action to have been determined by all these circumstances,
we do not the less blame the offender. We do not blame him for his
unhappy disposition, nor for the circumstances which influenced him,
nay, not even for his former course of life; for we presuppose that all
these considerations may be set aside, that the series of preceding
conditions may be regarded as having never existed, and that the action
may be considered as completely unconditioned in relation to any state
preceding, just as if the agent commenced with it an entirely new
series of effects. Our blame of the offender is grounded upon a law of
reason, which requires us to regard this faculty as a cause, which
could have and ought to have otherwise determined the behaviour of the
culprit, independently of all empirical conditions. This causality of
reason we do not regard as a co-operating agency, but as complete in
itself. It matters not whether the sensuous impulses favoured or
opposed the action of this causality, the offence is estimated
according to its intelligible character—the offender is decidedly
worthy of blame, the moment he utters a falsehood. It follows that we
regard reason, in spite of the empirical conditions of the act, as
completely free, and therefore, therefore, as in the present case,

The above judgement is complete evidence that we are accustomed to
think that reason is not affected by sensuous conditions, that in it no
change takes place—although its phenomena, in other words, the mode in
which it appears in its effects, are subject to change—that in it no
preceding state determines the following, and, consequently, that it
does not form a member of the series of sensuous conditions which
necessitate phenomena according to natural laws. Reason is present and
the same in all human actions and at all times; but it does not itself
exist in time, and therefore does not enter upon any state in which it
did not formerly exist. It is, relatively to new states or conditions,
determining, but not determinable. Hence we cannot ask: “Why did not
reason determine itself in a different manner?” The question ought to
be thus stated: “Why did not reason employ its power of causality to
determine certain phenomena in a different manner?” But this is a
question which admits of no answer. For a different intelligible
character would have exhibited a different empirical character; and,
when we say that, in spite of the course which his whole former life
has taken, the offender could have refrained from uttering the
falsehood, this means merely that the act was subject to the power and
authority—permissive or prohibitive—of reason. Now, reason is not
subject in its causality to any conditions of phenomena or of time; and
a difference in time may produce a difference in the relation of
phenomena to each other—for these are not things and therefore not
causes in themselves—but it cannot produce any difference in the
relation in which the action stands to the faculty of reason.

Thus, then, in our investigation into free actions and the causal power
which produced them, we arrive at an intelligible cause, beyond which,
however, we cannot go; although we can recognize that it is free, that
is, independent of all sensuous conditions, and that, in this way, it
may be the sensuously unconditioned condition of phenomena. But for
what reason the intelligible character generates such and such
phenomena and exhibits such and such an empirical character under
certain circumstances, it is beyond the power of our reason to decide.
The question is as much above the power and the sphere of reason as the
following would be: “Why does the transcendental object of our external
sensuous intuition allow of no other form than that of intuition in
space?” But the problem, which we were called upon to solve, does not
require us to entertain any such questions. The problem was merely
this—whether freedom and natural necessity can exist without opposition
in the same action. To this question we have given a sufficient answer;
for we have shown that, as the former stands in a relation to a
different kind of condition from those of the latter, the law of the
one does not affect the law of the other and that, consequently, both
can exist together in independence of and without interference with
each other.

The reader must be careful to remark that my intention in the above
remarks has not been to prove the actual existence of freedom, as a
faculty in which resides the cause of certain sensuous phenomena. For,
not to mention that such an argument would not have a transcendental
character, nor have been limited to the discussion of pure
conceptions—all attempts at inferring from experience what cannot be
cogitated in accordance with its laws, must ever be unsuccessful. Nay,
more, I have not even aimed at demonstrating the possibility of
freedom; for this too would have been a vain endeavour, inasmuch as it
is beyond the power of the mind to cognize the possibility of a reality
or of a causal power by the aid of mere a priori conceptions. Freedom
has been considered in the foregoing remarks only as a transcendental
idea, by means of which reason aims at originating a series of
conditions in the world of phenomena with the help of that which is
sensuously unconditioned, involving itself, however, in an antinomy
with the laws which itself prescribes for the conduct of the
understanding. That this antinomy is based upon a mere illusion, and
that nature and freedom are at least not opposed—this was the only
thing in our power to prove, and the question which it was our task to

 IV. Solution of the Cosmological Idea of the Totality of the
 Dependence of Phenomenal Existences

In the preceding remarks, we considered the changes in the world of
sense as constituting a dynamical series, in which each member is
subordinated to another—as its cause. Our present purpose is to avail
ourselves of this series of states or conditions as a guide to an
existence which may be the highest condition of all changeable
phenomena, that is, to a necessary being. Our endeavour to reach, not
the unconditioned causality, but the unconditioned existence, of
substance. The series before us is therefore a series of conceptions,
and not of intuitions (in which the one intuition is the condition of
the other).

But it is evident that, as all phenomena are subject to change and
conditioned in their existence, the series of dependent existences
cannot embrace an unconditioned member, the existence of which would be
absolutely necessary. It follows that, if phenomena were things in
themselves, and—as an immediate consequence from this
supposition—condition and conditioned belonged to the same series of
phenomena, the existence of a necessary being, as the condition of the
existence of sensuous phenomena, would be perfectly impossible.

An important distinction, however, exists between the dynamical and the
mathematical regress. The latter is engaged solely with the combination
of parts into a whole, or with the division of a whole into its parts;
and therefore are the conditions of its series parts of the series, and
to be consequently regarded as homogeneous, and for this reason, as
consisting, without exception, of phenomena. If the former regress, on
the contrary, the aim of which is not to establish the possibility of
an unconditioned whole consisting of given parts, or of an
unconditioned part of a given whole, but to demonstrate the possibility
of the deduction of a certain state from its cause, or of the
contingent existence of substance from that which exists necessarily,
it is not requisite that the condition should form part of an empirical
series along with the conditioned.

In the case of the apparent antinomy with which we are at present
dealing, there exists a way of escape from the difficulty; for it is
not impossible that both of the contradictory statements may be true in
different relations. All sensuous phenomena may be contingent, and
consequently possess only an empirically conditioned existence, and yet
there may also exist a non-empirical condition of the whole series, or,
in other words, a necessary being. For this necessary being, as an
intelligible condition, would not form a member—not even the highest
member—of the series; the whole world of sense would be left in its
empirically determined existence uninterfered with and uninfluenced.
This would also form a ground of distinction between the modes of
solution employed for the third and fourth antinomies. For, while in
the consideration of freedom in the former antinomy, the thing
itself—the cause (substantia phaenomenon)—was regarded as belonging to
the series of conditions, and only its causality to the intelligible
world—we are obliged in the present case to cogitate this necessary
being as purely intelligible and as existing entirely apart from the
world of sense (as an ens extramundanum); for otherwise it would be
subject to the phenomenal law of contingency and dependence.

In relation to the present problem, therefore, the regulative principle
of reason is that everything in the sensuous world possesses an
empirically conditioned existence—that no property of the sensuous
world possesses unconditioned necessity—that we are bound to expect,
and, so far as is possible, to seek for the empirical condition of
every member in the series of conditions—and that there is no
sufficient reason to justify us in deducing any existence from a
condition which lies out of and beyond the empirical series, or in
regarding any existence as independent and self-subsistent; although
this should not prevent us from recognizing the possibility of the
whole series being based upon a being which is intelligible, and for
this reason free from all empirical conditions.

But it has been far from my intention, in these remarks, to prove the
existence of this unconditioned and necessary being, or even to
evidence the possibility of a purely intelligible condition of the
existence or all sensuous phenomena. As bounds were set to reason, to
prevent it from leaving the guiding thread of empirical conditions and
losing itself in transcendent theories which are incapable of concrete
presentation; so it was my purpose, on the other band, to set bounds to
the law of the purely empirical understanding, and to protest against
any attempts on its part at deciding on the possibility of things, or
declaring the existence of the intelligible to be impossible, merely on
the ground that it is not available for the explanation and exposition
of phenomena. It has been shown, at the same time, that the contingency
of all the phenomena of nature and their empirical conditions is quite
consistent with the arbitrary hypothesis of a necessary, although
purely intelligible condition, that no real contradiction exists
between them and that, consequently, both may be true. The existence of
such an absolutely necessary being may be impossible; but this can
never be demonstrated from the universal contingency and dependence of
sensuous phenomena, nor from the principle which forbids us to
discontinue the series at some member of it, or to seek for its cause
in some sphere of existence beyond the world of nature. Reason goes its
way in the empirical world, and follows, too, its peculiar path in the
sphere of the transcendental.

The sensuous world contains nothing but phenomena, which are mere
representations, and always sensuously conditioned; things in
themselves are not, and cannot be, objects to us. It is not to be
wondered at, therefore, that we are not justified in leaping from some
member of an empirical series beyond the world of sense, as if
empirical representations were things in themselves, existing apart
from their transcendental ground in the human mind, and the cause of
whose existence may be sought out of the empirical series. This would
certainly be the case with contingent things; but it cannot be with
mere representations of things, the contingency of which is itself
merely a phenomenon and can relate to no other regress than that which
determines phenomena, that is, the empirical. But to cogitate an
intelligible ground of phenomena, as free, moreover, from the
contingency of the latter, conflicts neither with the unlimited nature
of the empirical regress, nor with the complete contingency of
phenomena. And the demonstration of this was the only thing necessary
for the solution of this apparent antinomy. For if the condition of
every conditioned—as regards its existence—is sensuous, and for this
reason a part of the same series, it must be itself conditioned, as was
shown in the antithesis of the fourth antinomy. The embarrassments into
which a reason, which postulates the unconditioned, necessarily falls,
must, therefore, continue to exist; or the unconditioned must be placed
in the sphere of the intelligible. In this way, its necessity does not
require, nor does it even permit, the presence of an empirical
condition: and it is, consequently, unconditionally necessary.

The empirical employment of reason is not affected by the assumption of
a purely intelligible being; it continues its operations on the
principle of the contingency of all phenomena, proceeding from
empirical conditions to still higher and higher conditions, themselves
empirical. Just as little does this regulative principle exclude the
assumption of an intelligible cause, when the question regards merely
the pure employment of reason—in relation to ends or aims. For, in this
case, an intelligible cause signifies merely the transcendental and to
us unknown ground of the possibility of sensuous phenomena, and its
existence, necessary and independent of all sensuous conditions, is not
inconsistent with the contingency of phenomena, or with the unlimited
possibility of regress which exists in the series of empirical

Concluding Remarks on the Antinomy of Pure Reason.

So long as the object of our rational conceptions is the totality of
conditions in the world of phenomena, and the satisfaction, from this
source, of the requirements of reason, so long are our ideas
transcendental and cosmological. But when we set the
unconditioned—which is the aim of all our inquiries—in a sphere which
lies out of the world of sense and possible experience, our ideas
become transcendent. They are then not merely serviceable towards the
completion of the exercise of reason (which remains an idea, never
executed, but always to be pursued); they detach themselves completely
from experience and construct for themselves objects, the material of
which has not been presented by experience, and the objective reality
of which is not based upon the completion of the empirical series, but
upon pure a priori conceptions. The intelligible object of these
transcendent ideas may be conceded, as a transcendental object. But we
cannot cogitate it as a thing determinable by certain distinct
predicates relating to its internal nature, for it has no connection
with empirical conceptions; nor are we justified in affirming the
existence of any such object. It is, consequently, a mere product of
the mind alone. Of all the cosmological ideas, however, it is that
occasioning the fourth antinomy which compels us to venture upon this
step. For the existence of phenomena, always conditioned and never
self-subsistent, requires us to look for an object different from
phenomena—an intelligible object, with which all contingency must
cease. But, as we have allowed ourselves to assume the existence of a
self-subsistent reality out of the field of experience, and are
therefore obliged to regard phenomena as merely a contingent mode of
representing intelligible objects employed by beings which are
themselves intelligences—no other course remains for us than to follow
analogy and employ the same mode in forming some conception of
intelligible things, of which we have not the least knowledge, which
nature taught us to use in the formation of empirical conceptions.
Experience made us acquainted with the contingent. But we are at
present engaged in the discussion of things which are not objects of
experience; and must, therefore, deduce our knowledge of them from that
which is necessary absolutely and in itself, that is, from pure
conceptions. Hence the first step which we take out of the world of
sense obliges us to begin our system of new cognition with the
investigation of a necessary being, and to deduce from our conceptions
of it all our conceptions of intelligible things. This we propose to
attempt in the following chapter.

 Chapter III. The Ideal of Pure Reason

 Section I. Of the Ideal in General

We have seen that pure conceptions do not present objects to the mind,
except under sensuous conditions; because the conditions of objective
reality do not exist in these conceptions, which contain, in fact,
nothing but the mere form of thought. They may, however, when applied
to phenomena, be presented in concreto; for it is phenomena that
present to them the materials for the formation of empirical
conceptions, which are nothing more than concrete forms of the
conceptions of the understanding. But ideas are still further removed
from objective reality than categories; for no phenomenon can ever
present them to the human mind in concreto. They contain a certain
perfection, attainable by no possible empirical cognition; and they
give to reason a systematic unity, to which the unity of experience
attempts to approximate, but can never completely attain.

But still further removed than the idea from objective reality is the
Ideal, by which term I understand the idea, not in concreto, but in
individuo—as an individual thing, determinable or determined by the
idea alone. The idea of humanity in its complete perfection supposes
not only the advancement of all the powers and faculties, which
constitute our conception of human nature, to a complete attainment of
their final aims, but also everything which is requisite for the
complete determination of the idea; for of all contradictory
predicates, only one can conform with the idea of the perfect man. What
I have termed an ideal was in Plato’s philosophy an idea of the divine
mind—an individual object present to its pure intuition, the most
perfect of every kind of possible beings, and the archetype of all
phenomenal existences.

Without rising to these speculative heights, we are bound to confess
that human reason contains not only ideas, but ideals, which possess,
not, like those of Plato, creative, but certainly practical power—as
regulative principles, and form the basis of the perfectibility of
certain actions. Moral conceptions are not perfectly pure conceptions
of reason, because an empirical element—of pleasure or pain—lies at the
foundation of them. In relation, however, to the principle, whereby
reason sets bounds to a freedom which is in itself without law, and
consequently when we attend merely to their form, they may be
considered as pure conceptions of reason. Virtue and wisdom in their
perfect purity are ideas. But the wise man of the Stoics is an ideal,
that is to say, a human being existing only in thought and in complete
conformity with the idea of wisdom. As the idea provides a rule, so the
ideal serves as an archetype for the perfect and complete determination
of the copy. Thus the conduct of this wise and divine man serves us as
a standard of action, with which we may compare and judge ourselves,
which may help us to reform ourselves, although the perfection it
demands can never be attained by us. Although we cannot concede
objective reality to these ideals, they are not to be considered as
chimeras; on the contrary, they provide reason with a standard, which
enables it to estimate, by comparison, the degree of incompleteness in
the objects presented to it. But to aim at realizing the ideal in an
example in the world of experience—to describe, for instance, the
character of the perfectly wise man in a romance—is impracticable. Nay
more, there is something absurd in the attempt; and the result must be
little edifying, as the natural limitations, which are continually
breaking in upon the perfection and completeness of the idea, destroy
the illusion in the story and throw an air of suspicion even on what is
good in the idea, which hence appears fictitious and unreal.

Such is the constitution of the ideal of reason, which is always based
upon determinate conceptions, and serves as a rule and a model for
limitation or of criticism. Very different is the nature of the ideals
of the imagination. Of these it is impossible to present an
intelligible conception; they are a kind of monogram, drawn according
to no determinate rule, and forming rather a vague picture—the
production of many diverse experiences—than a determinate image. Such
are the ideals which painters and physiognomists profess to have in
their minds, and which can serve neither as a model for production nor
as a standard for appreciation. They may be termed, though improperly,
sensuous ideals, as they are declared to be models of certain possible
empirical intuitions. They cannot, however, furnish rules or standards
for explanation or examination.

In its ideals, reason aims at complete and perfect determination
according to a priori rules; and hence it cogitates an object, which
must be completely determinable in conformity with principles, although
all empirical conditions are absent, and the conception of the object
is on this account transcendent.

 Section II. Of the Transcendental Ideal (Prototypon Trancendentale)

Every conception is, in relation to that which is not contained in it,
undetermined and subject to the principle of determinability. This
principle is that, of every two contradictorily opposed predicates,
only one can belong to a conception. It is a purely logical principle,
itself based upon the principle of contradiction; inasmuch as it makes
complete abstraction of the content and attends merely to the logical
form of the cognition.

But again, everything, as regards its possibility, is also subject to
the principle of complete determination, according to which one of all
the possible contradictory predicates of things must belong to it. This
principle is not based merely upon that of contradiction; for, in
addition to the relation between two contradictory predicates, it
regards everything as standing in a relation to the sum of
possibilities, as the sum total of all predicates of things, and, while
presupposing this sum as an a priori condition, presents to the mind
everything as receiving the possibility of its individual existence
from the relation it bears to, and the share it possesses in, the
aforesaid sum of possibilities.* The principle of complete
determination relates the content and not to the logical form. It is
the principle of the synthesis of all the predicates which are required
to constitute the complete conception of a thing, and not a mere
principle analytical representation, which enounces that one of two
contradictory predicates must belong to a conception. It contains,
moreover, a transcendental presupposition—that, namely, of the material
for all possibility, which must contain a priori the data for this or
that particular possibility.

[*Footnote: Thus this principle declares everything to possess a
relation to a common correlate—the sum-total of possibility, which, if
discovered to exist in the idea of one individual thing, would
establish the affinity of all possible things, from the identity of the
ground of their complete determination. The determinability of every
conception is subordinate to the universality (Allgemeinheit,
universalitas) of the principle of excluded middle; the determination
of a thing to the totality (Allheit, universitas) of all possible

The proposition, everything which exists is completely determined,
means not only that one of every pair of given contradictory
attributes, but that one of all possible attributes, is always
predicable of the thing; in it the predicates are not merely compared
logically with each other, but the thing itself is transcendentally
compared with the sum-total of all possible predicates. The proposition
is equivalent to saying: “To attain to a complete knowledge of a thing,
it is necessary to possess a knowledge of everything that is possible,
and to determine it thereby in a positive or negative manner.” The
conception of complete determination is consequently a conception which
cannot be presented in its totality in concreto, and is therefore based
upon an idea, which has its seat in the reason—the faculty which
prescribes to the understanding the laws of its harmonious and perfect

Now, although this idea of the sum-total of all possibility, in so far
as it forms the condition of the complete determination of everything,
is itself undetermined in relation to the predicates which may
constitute this sum-total, and we cogitate in it merely the sum-total
of all possible predicates—we nevertheless find, upon closer
examination, that this idea, as a primitive conception of the mind,
excludes a large number of predicates—those deduced and those
irreconcilable with others, and that it is evolved as a conception
completely determined a priori. Thus it becomes the conception of an
individual object, which is completely determined by and through the
mere idea, and must consequently be termed an ideal of pure reason.

When we consider all possible predicates, not merely logically, but
transcendentally, that is to say, with reference to the content which
may be cogitated as existing in them a priori, we shall find that some
indicate a being, others merely a non-being. The logical negation
expressed in the word not does not properly belong to a conception, but
only to the relation of one conception to another in a judgement, and
is consequently quite insufficient to present to the mind the content
of a conception. The expression not mortal does not indicate that a
non-being is cogitated in the object; it does not concern the content
at all. A transcendental negation, on the contrary, indicates non-being
in itself, and is opposed to transcendental affirmation, the conception
of which of itself expresses a being. Hence this affirmation indicates
a reality, because in and through it objects are considered to be
something—to be things; while the opposite negation, on the other band,
indicates a mere want, or privation, or absence, and, where such
negations alone are attached to a representation, the non-existence of
anything corresponding to the representation.

Now a negation cannot be cogitated as determined, without cogitating at
the same time the opposite affirmation. The man born blind has not the
least notion of darkness, because he has none of light; the vagabond
knows nothing of poverty, because he has never known what it is to be
in comfort;* the ignorant man has no conception of his ignorance,
because he has no conception of knowledge. All conceptions of negatives
are accordingly derived or deduced conceptions; and realities contain
the data, and, so to speak, the material or transcendental content of
the possibility and complete determination of all things.

[*Footnote: The investigations and calculations of astronomers have
taught us much that is wonderful; but the most important lesson we have
received from them is the discovery of the abyss of our ignorance in
relation to the universe—an ignorance the magnitude of which reason,
without the information thus derived, could never have conceived. This
discovery of our deficiencies must produce a great change in the
determination of the aims of human reason.]

If, therefore, a transcendental substratum lies at the foundation of
the complete determination of things—a substratum which is to form the
fund from which all possible predicates of things are to be supplied,
this substratum cannot be anything else than the idea of a sum-total of
reality (omnitudo realitatis). In this view, negations are nothing but
limitations—a term which could not, with propriety, be applied to them,
if the unlimited (the all) did not form the true basis of our

This conception of a sum-total of reality is the conception of a thing
in itself, regarded as completely determined; and the conception of an
ens realissimum is the conception of an individual being, inasmuch as
it is determined by that predicate of all possible contradictory
predicates, which indicates and belongs to being. It is, therefore, a
transcendental ideal which forms the basis of the complete
determination of everything that exists, and is the highest material
condition of its possibility—a condition on which must rest the
cogitation of all objects with respect to their content. Nay, more,
this ideal is the only proper ideal of which the human mind is capable;
because in this case alone a general conception of a thing is
completely determined by and through itself, and cognized as the
representation of an individuum.

The logical determination of a conception is based upon a disjunctive
syllogism, the major of which contains the logical division of the
extent of a general conception, the minor limits this extent to a
certain part, while the conclusion determines the conception by this
part. The general conception of a reality cannot be divided a priori,
because, without the aid of experience, we cannot know any determinate
kinds of reality, standing under the former as the genus. The
transcendental principle of the complete determination of all things is
therefore merely the representation of the sum-total of all reality; it
is not a conception which is the genus of all predicates under itself,
but one which comprehends them all within itself. The complete
determination of a thing is consequently based upon the limitation of
this total of reality, so much being predicated of the thing, while all
that remains over is excluded—a procedure which is in exact agreement
with that of the disjunctive syllogism and the determination of the
objects in the conclusion by one of the members of the division. It
follows that reason, in laying the transcendental ideal at the
foundation of its determination of all possible things, takes a course
in exact analogy with that which it pursues in disjunctive syllogisms—a
proposition which formed the basis of the systematic division of all
transcendental ideas, according to which they are produced in complete
parallelism with the three modes of syllogistic reasoning employed by
the human mind.

It is self-evident that reason, in cogitating the necessary complete
determination of things, does not presuppose the existence of a being
corresponding to its ideal, but merely the idea of the ideal—for the
purpose of deducing from the unconditional totality of complete
determination, The ideal is therefore the prototype of all things,
which, as defective copies (ectypa), receive from it the material of
their possibility, and approximate to it more or less, though it is
impossible that they can ever attain to its perfection.

The possibility of things must therefore be regarded as derived—except
that of the thing which contains in itself all reality, which must be
considered to be primitive and original. For all negations—and they are
the only predicates by means of which all other things can be
distinguished from the ens realissimum—are mere limitations of a
greater and a higher—nay, the highest reality; and they consequently
presuppose this reality, and are, as regards their content, derived
from it. The manifold nature of things is only an infinitely various
mode of limiting the conception of the highest reality, which is their
common substratum; just as all figures are possible only as different
modes of limiting infinite space. The object of the ideal of reason—an
object existing only in reason itself—is also termed the primal being
(ens originarium); as having no existence superior to him, the supreme
being (ens summum); and as being the condition of all other beings,
which rank under it, the being of all beings (ens entium). But none of
these terms indicate the objective relation of an actually existing
object to other things, but merely that of an idea to conceptions; and
all our investigations into this subject still leave us in perfect
uncertainty with regard to the existence of this being.

A primal being cannot be said to consist of many other beings with an
existence which is derivative, for the latter presuppose the former,
and therefore cannot be constitutive parts of it. It follows that the
ideal of the primal being must be cogitated as simple.

The deduction of the possibility of all other things from this primal
being cannot, strictly speaking, be considered as a limitation, or as a
kind of division of its reality; for this would be regarding the primal
being as a mere aggregate—which has been shown to be impossible,
although it was so represented in our first rough sketch. The highest
reality must be regarded rather as the ground than as the sum-total of
the possibility of all things, and the manifold nature of things be
based, not upon the limitation of the primal being itself, but upon the
complete series of effects which flow from it. And thus all our powers
of sense, as well as all phenomenal reality, phenomenal reality, may be
with propriety regarded as belonging to this series of effects, while
they could not have formed parts of the idea, considered as an
aggregate. Pursuing this track, and hypostatizing this idea, we shall
find ourselves authorized to determine our notion of the Supreme Being
by means of the mere conception of a highest reality, as one, simple,
all-sufficient, eternal, and so on—in one word, to determine it in its
unconditioned completeness by the aid of every possible predicate. The
conception of such a being is the conception of God in its
transcendental sense, and thus the ideal of pure reason is the
object-matter of a transcendental theology.

But, by such an employment of the transcendental idea, we should be
over stepping the limits of its validity and purpose. For reason placed
it, as the conception of all reality, at the basis of the complete
determination of things, without requiring that this conception be
regarded as the conception of an objective existence. Such an existence
would be purely fictitious, and the hypostatizing of the content of the
idea into an ideal, as an individual being, is a step perfectly
unauthorized. Nay, more, we are not even called upon to assume the
possibility of such an hypothesis, as none of the deductions drawn from
such an ideal would affect the complete determination of things in
general—for the sake of which alone is the idea necessary.

It is not sufficient to circumscribe the procedure and the dialectic of
reason; we must also endeavour to discover the sources of this
dialectic, that we may have it in our power to give a rational
explanation of this illusion, as a phenomenon of the human mind. For
the ideal, of which we are at present speaking, is based, not upon an
arbitrary, but upon a natural, idea. The question hence arises: How
happens it that reason regards the possibility of all things as deduced
from a single possibility, that, to wit, of the highest reality, and
presupposes this as existing in an individual and primal being?

The answer is ready; it is at once presented by the procedure of
transcendental analytic. The possibility of sensuous objects is a
relation of these objects to thought, in which something (the empirical
form) may be cogitated a priori; while that which constitutes the
matter—the reality of the phenomenon (that element which corresponds to
sensation)—must be given from without, as otherwise it could not even
be cogitated by, nor could its possibility be presentable to the mind.
Now, a sensuous object is completely determined, when it has been
compared with all phenomenal predicates, and represented by means of
these either positively or negatively. But, as that which constitutes
the thing itself—the real in a phenomenon, must be given, and that, in
which the real of all phenomena is given, is experience, one, sole, and
all-embracing—the material of the possibility of all sensuous objects
must be presupposed as given in a whole, and it is upon the limitation
of this whole that the possibility of all empirical objects, their
distinction from each other and their complete determination, are
based. Now, no other objects are presented to us besides sensuous
objects, and these can be given only in connection with a possible
experience; it follows that a thing is not an object to us, unless it
presupposes the whole or sum-total of empirical reality as the
condition of its possibility. Now, a natural illusion leads us to
consider this principle, which is valid only of sensuous objects, as
valid with regard to things in general. And thus we are induced to hold
the empirical principle of our conceptions of the possibility of
things, as phenomena, by leaving out this limitative condition, to be a
transcendental principle of the possibility of things in general.

We proceed afterwards to hypostatize this idea of the sum-total of all
reality, by changing the distributive unity of the empirical exercise
of the understanding into the collective unity of an empirical whole—a
dialectical illusion, and by cogitating this whole or sum of experience
as an individual thing, containing in itself all empirical reality.
This individual thing or being is then, by means of the above-mentioned
transcendental subreption, substituted for our notion of a thing which
stands at the head of the possibility of all things, the real
conditions of whose complete determination it presents.*

[*Footnote: This ideal of the ens realissimum—although merely a mental
representation—is first objectivized, that is, has an objective
existence attributed to it, then hypostatized, and finally, by the
natural progress of reason to the completion of unity, personified, as
we shall show presently. For the regulative unity of experience is not
based upon phenomena themselves, but upon the connection of the variety
of phenomena by the understanding in a consciousness, and thus the
unity of the supreme reality and the complete determinability of all
things, seem to reside in a supreme understanding, and, consequently,
in a conscious intelligence.]

 Section III. Of the Arguments employed by Speculative Reason in Proof
 of the Existence of a Supreme Being

Notwithstanding the pressing necessity which reason feels, to form some
presupposition that shall serve the understanding as a proper basis for
the complete determination of its conceptions, the idealistic and
factitious nature of such a presupposition is too evident to allow
reason for a moment to persuade itself into a belief of the objective
existence of a mere creation of its own thought. But there are other
considerations which compel reason to seek out some resting place in
the regress from the conditioned to the unconditioned, which is not
given as an actual existence from the mere conception of it, although
it alone can give completeness to the series of conditions. And this is
the natural course of every human reason, even of the most uneducated,
although the path at first entered it does not always continue to
follow. It does not begin from conceptions, but from common experience,
and requires a basis in actual existence. But this basis is insecure,
unless it rests upon the immovable rock of the absolutely necessary.
And this foundation is itself unworthy of trust, if it leave under and
above it empty space, if it do not fill all, and leave no room for a
why or a wherefore, if it be not, in one word, infinite in its reality.

If we admit the existence of some one thing, whatever it may be, we
must also admit that there is something which exists necessarily. For
what is contingent exists only under the condition of some other thing,
which is its cause; and from this we must go on to conclude the
existence of a cause which is not contingent, and which consequently
exists necessarily and unconditionally. Such is the argument by which
reason justifies its advances towards a primal being.

Now reason looks round for the conception of a being that may be
admitted, without inconsistency, to be worthy of the attribute of
absolute necessity, not for the purpose of inferring a priori, from the
conception of such a being, its objective existence (for if reason
allowed itself to take this course, it would not require a basis in
given and actual existence, but merely the support of pure
conceptions), but for the purpose of discovering, among all our
conceptions of possible things, that conception which possesses no
element inconsistent with the idea of absolute necessity. For that
there must be some absolutely necessary existence, it regards as a
truth already established. Now, if it can remove every existence
incapable of supporting the attribute of absolute necessity, excepting
one—this must be the absolutely necessary being, whether its necessity
is comprehensible by us, that is, deducible from the conception of it
alone, or not.

Now that, the conception of which contains a therefore to every
wherefore, which is not defective in any respect whatever, which is
all-sufficient as a condition, seems to be the being of which we can
justly predicate absolute necessity—for this reason, that, possessing
the conditions of all that is possible, it does not and cannot itself
require any condition. And thus it satisfies, in one respect at least,
the requirements of the conception of absolute necessity. In this view,
it is superior to all other conceptions, which, as deficient and
incomplete, do not possess the characteristic of independence of all
higher conditions. It is true that we cannot infer from this that what
does not contain in itself the supreme and complete condition—the
condition of all other things—must possess only a conditioned
existence; but as little can we assert the contrary, for this supposed
being does not possess the only characteristic which can enable reason
to cognize by means of an a priori conception the unconditioned and
necessary nature of its existence.

The conception of an ens realissimum is that which best agrees with the
conception of an unconditioned and necessary being. The former
conception does not satisfy all the requirements of the latter; but we
have no choice, we are obliged to adhere to it, for we find that we
cannot do without the existence of a necessary being; and even although
we admit it, we find it out of our power to discover in the whole
sphere of possibility any being that can advance well-grounded claims
to such a distinction.

The following is, therefore, the natural course of human reason. It
begins by persuading itself of the existence of some necessary being.
In this being it recognizes the characteristics of unconditioned
existence. It then seeks the conception of that which is independent of
all conditions, and finds it in that which is itself the sufficient
condition of all other things—in other words, in that which contains
all reality. But the unlimited all is an absolute unity, and is
conceived by the mind as a being one and supreme; and thus reason
concludes that the Supreme Being, as the primal basis of all things,
possesses an existence which is absolutely necessary.

This conception must be regarded as in some degree satisfactory, if we
admit the existence of a necessary being, and consider that there
exists a necessity for a definite and final answer to these questions.
In such a case, we cannot make a better choice, or rather we have no
choice at all, but feel ourselves obliged to declare in favour of the
absolute unity of complete reality, as the highest source of the
possibility of things. But if there exists no motive for coming to a
definite conclusion, and we may leave the question unanswered till we
have fully weighed both sides—in other words, when we are merely called
upon to decide how much we happen to know about the question, and how
much we merely flatter ourselves that we know—the above conclusion does
not appear to be so great advantage, but, on the contrary, seems
defective in the grounds upon which it is supported.

For, admitting the truth of all that has been said, that, namely, the
inference from a given existence (my own, for example) to the existence
of an unconditioned and necessary being is valid and unassailable;
that, in the second place, we must consider a being which contains all
reality, and consequently all the conditions of other things, to be
absolutely unconditioned; and admitting too, that we have thus
discovered the conception of a thing to which may be attributed,
without inconsistency, absolute necessity—it does not follow from all
this that the conception of a limited being, in which the supreme
reality does not reside, is therefore incompatible with the idea of
absolute necessity. For, although I do not discover the element of the
unconditioned in the conception of such a being—an element which is
manifestly existent in the sum-total of all conditions—I am not
entitled to conclude that its existence is therefore conditioned; just
as I am not entitled to affirm, in a hypothetical syllogism, that where
a certain condition does not exist (in the present, completeness, as
far as pure conceptions are concerned), the conditioned does not exist
either. On the contrary, we are free to consider all limited beings as
likewise unconditionally necessary, although we are unable to infer
this from the general conception which we have of them. Thus conducted,
this argument is incapable of giving us the least notion of the
properties of a necessary being, and must be in every respect without

This argument continues, however, to possess a weight and an authority,
which, in spite of its objective insufficiency, it has never been
divested of. For, granting that certain responsibilities lie upon us,
which, as based on the ideas of reason, deserve to be respected and
submitted to, although they are incapable of a real or practical
application to our nature, or, in other words, would be
responsibilities without motives, except upon the supposition of a
Supreme Being to give effect and influence to the practical laws: in
such a case we should be bound to obey our conceptions, which, although
objectively insufficient, do, according to the standard of reason,
preponderate over and are superior to any claims that may be advanced
from any other quarter. The equilibrium of doubt would in this case be
destroyed by a practical addition; indeed, Reason would be compelled to
condemn herself, if she refused to comply with the demands of the
judgement, no superior to which we know—however defective her
understanding of the grounds of these demands might be.

This argument, although in fact transcendental, inasmuch as it rests
upon the intrinsic insufficiency of the contingent, is so simple and
natural, that the commonest understanding can appreciate its value. We
see things around us change, arise, and pass away; they, or their
condition, must therefore have a cause. The same demand must again be
made of the cause itself—as a datum of experience. Now it is natural
that we should place the highest causality just where we place supreme
causality, in that being, which contains the conditions of all possible
effects, and the conception of which is so simple as that of an
all-embracing reality. This highest cause, then, we regard as
absolutely necessary, because we find it absolutely necessary to rise
to it, and do not discover any reason for proceeding beyond it. Thus,
among all nations, through the darkest polytheism glimmer some faint
sparks of monotheism, to which these idolaters have been led, not from
reflection and profound thought, but by the study and natural progress
of the common understanding.

There are only three modes of proving the existence of a Deity, on the
grounds of speculative reason.

All the paths conducting to this end begin either from determinate
experience and the peculiar constitution of the world of sense, and
rise, according to the laws of causality, from it to the highest cause
existing apart from the world—or from a purely indeterminate
experience, that is, some empirical existence—or abstraction is made of
all experience, and the existence of a supreme cause is concluded from
a priori conceptions alone. The first is the physico-theological
argument, the second the cosmological, the third the ontological. More
there are not, and more there cannot be.

I shall show it is as unsuccessful on the one path—the empirical—as on
the other—the transcendental, and that it stretches its wings in vain,
to soar beyond the world of sense by the mere might of speculative
thought. As regards the order in which we must discuss those arguments,
it will be exactly the reverse of that in which reason, in the progress
of its development, attains to them—the order in which they are placed
above. For it will be made manifest to the reader that, although
experience presents the occasion and the starting-point, it is the
transcendental idea of reason which guides it in its pilgrimage and is
the goal of all its struggles. I shall therefore begin with an
examination of the transcendental argument, and afterwards inquire what
additional strength has accrued to this mode of proof from the addition
of the empirical element.

 Section IV. Of the Impossibility of an Ontological Proof of the
 Existence of God

It is evident from what has been said that the conception of an
absolutely necessary being is a mere idea, the objective reality of
which is far from being established by the mere fact that it is a need
of reason. On the contrary, this idea serves merely to indicate a
certain unattainable perfection, and rather limits the operations than,
by the presentation of new objects, extends the sphere of the
understanding. But a strange anomaly meets us at the very threshold;
for the inference from a given existence in general to an absolutely
necessary existence seems to be correct and unavoidable, while the
conditions of the understanding refuse to aid us in forming any
conception of such a being.

Philosophers have always talked of an absolutely necessary being, and
have nevertheless declined to take the trouble of conceiving
whether—and how—a being of this nature is even cogitable, not to
mention that its existence is actually demonstrable. A verbal
definition of the conception is certainly easy enough: it is something
the non-existence of which is impossible. But does this definition
throw any light upon the conditions which render it impossible to
cogitate the non-existence of a thing—conditions which we wish to
ascertain, that we may discover whether we think anything in the
conception of such a being or not? For the mere fact that I throw away,
by means of the word unconditioned, all the conditions which the
understanding habitually requires in order to regard anything as
necessary, is very far from making clear whether by means of the
conception of the unconditionally necessary I think of something, or
really of nothing at all.

Nay, more, this chance-conception, now become so current, many have
endeavoured to explain by examples which seemed to render any inquiries
regarding its intelligibility quite needless. Every geometrical
proposition—a triangle has three angles—it was said, is absolutely
necessary; and thus people talked of an object which lay out of the
sphere of our understanding as if it were perfectly plain what the
conception of such a being meant.

All the examples adduced have been drawn, without exception, from
judgements, and not from things. But the unconditioned necessity of a
judgement does not form the absolute necessity of a thing. On the
contrary, the absolute necessity of a judgement is only a conditioned
necessity of a thing, or of the predicate in a judgement. The
proposition above-mentioned does not enounce that three angles
necessarily exist, but, upon condition that a triangle exists, three
angles must necessarily exist—in it. And thus this logical necessity
has been the source of the greatest delusions. Having formed an a
priori conception of a thing, the content of which was made to embrace
existence, we believed ourselves safe in concluding that, because
existence belongs necessarily to the object of the conception (that is,
under the condition of my positing this thing as given), the existence
of the thing is also posited necessarily, and that it is therefore
absolutely necessary—merely because its existence has been cogitated in
the conception.

If, in an identical judgement, I annihilate the predicate in thought,
and retain the subject, a contradiction is the result; and hence I say,
the former belongs necessarily to the latter. But if I suppress both
subject and predicate in thought, no contradiction arises; for there is
nothing at all, and therefore no means of forming a contradiction. To
suppose the existence of a triangle and not that of its three angles,
is self-contradictory; but to suppose the non-existence of both
triangle and angles is perfectly admissible. And so is it with the
conception of an absolutely necessary being. Annihilate its existence
in thought, and you annihilate the thing itself with all its
predicates; how then can there be any room for contradiction?
Externally, there is nothing to give rise to a contradiction, for a
thing cannot be necessary externally; nor internally, for, by the
annihilation or suppression of the thing itself, its internal
properties are also annihilated. God is omnipotent—that is a necessary
judgement. His omnipotence cannot be denied, if the existence of a
Deity is posited—the existence, that is, of an infinite being, the two
conceptions being identical. But when you say, God does not exist,
neither omnipotence nor any other predicate is affirmed; they must all
disappear with the subject, and in this judgement there cannot exist
the least self-contradiction.

You have thus seen that when the predicate of a judgement is
annihilated in thought along with the subject, no internal
contradiction can arise, be the predicate what it may. There is no
possibility of evading the conclusion—you find yourselves compelled to
declare: There are certain subjects which cannot be annihilated in
thought. But this is nothing more than saying: There exist subjects
which are absolutely necessary—the very hypothesis which you are called
upon to establish. For I find myself unable to form the slightest
conception of a thing which when annihilated in thought with all its
predicates, leaves behind a contradiction; and contradiction is the
only criterion of impossibility in the sphere of pure a priori

Against these general considerations, the justice of which no one can
dispute, one argument is adduced, which is regarded as furnishing a
satisfactory demonstration from the fact. It is affirmed that there is
one and only one conception, in which the non-being or annihilation of
the object is self-contradictory, and this is the conception of an ens
realissimum. It possesses, you say, all reality, and you feel
yourselves justified in admitting the possibility of such a being.
(This I am willing to grant for the present, although the existence of
a conception which is not self-contradictory is far from being
sufficient to prove the possibility of an object.)* Now the notion of
all reality embraces in it that of existence; the notion of existence
lies, therefore, in the conception of this possible thing. If this
thing is annihilated in thought, the internal possibility of the thing
is also annihilated, which is self-contradictory.

[*Footnote: A conception is always possible, if it is not
self-contradictory. This is the logical criterion of possibility,
distinguishing the object of such a conception from the nihil
negativum. But it may be, notwithstanding, an empty conception, unless
the objective reality of this synthesis, but which it is generated, is
demonstrated; and a proof of this kind must be based upon principles of
possible experience, and not upon the principle of analysis or
contradiction. This remark may be serviceable as a warning against
concluding, from the possibility of a conception—which is logical—the
possibility of a thing—which is real.]

I answer: It is absurd to introduce—under whatever term disguised—into
the conception of a thing, which is to be cogitated solely in reference
to its possibility, the conception of its existence. If this is
admitted, you will have apparently gained the day, but in reality have
enounced nothing but a mere tautology. I ask, is the proposition, this
or that thing (which I am admitting to be possible) exists, an
analytical or a synthetical proposition? If the former, there is no
addition made to the subject of your thought by the affirmation of its
existence; but then the conception in your minds is identical with the
thing itself, or you have supposed the existence of a thing to be
possible, and then inferred its existence from its internal
possibility—which is but a miserable tautology. The word reality in the
conception of the thing, and the word existence in the conception of
the predicate, will not help you out of the difficulty. For, supposing
you were to term all positing of a thing reality, you have thereby
posited the thing with all its predicates in the conception of the
subject and assumed its actual existence, and this you merely repeat in
the predicate. But if you confess, as every reasonable person must,
that every existential proposition is synthetical, how can it be
maintained that the predicate of existence cannot be denied without
contradiction?—a property which is the characteristic of analytical
propositions, alone.

I should have a reasonable hope of putting an end for ever to this
sophistical mode of argumentation, by a strict definition of the
conception of existence, did not my own experience teach me that the
illusion arising from our confounding a logical with a real predicate
(a predicate which aids in the determination of a thing) resists almost
all the endeavours of explanation and illustration. A logical predicate
may be what you please, even the subject may be predicated of itself;
for logic pays no regard to the content of a judgement. But the
determination of a conception is a predicate, which adds to and
enlarges the conception. It must not, therefore, be contained in the

Being is evidently not a real predicate, that is, a conception of
something which is added to the conception of some other thing. It is
merely the positing of a thing, or of certain determinations in it.
Logically, it is merely the copula of a judgement. The proposition, God
is omnipotent, contains two conceptions, which have a certain object or
content; the word is, is no additional predicate—it merely indicates
the relation of the predicate to the subject. Now, if I take the
subject (God) with all its predicates (omnipotence being one), and say:
God is, or, There is a God, I add no new predicate to the conception of
God, I merely posit or affirm the existence of the subject with all its
predicates—I posit the object in relation to my conception. The content
of both is the same; and there is no addition made to the conception,
which expresses merely the possibility of the object, by my cogitating
the object—in the expression, it is—as absolutely given or existing.
Thus the real contains no more than the possible. A hundred real
dollars contain no more than a hundred possible dollars. For, as the
latter indicate the conception, and the former the object, on the
supposition that the content of the former was greater than that of the
latter, my conception would not be an expression of the whole object,
and would consequently be an inadequate conception of it. But in
reckoning my wealth there may be said to be more in a hundred real
dollars than in a hundred possible dollars—that is, in the mere
conception of them. For the real object—the dollars—is not analytically
contained in my conception, but forms a synthetical addition to my
conception (which is merely a determination of my mental state),
although this objective reality—this existence—apart from my
conceptions, does not in the least degree increase the aforesaid
hundred dollars.

By whatever and by whatever number of predicates—even to the complete
determination of it—I may cogitate a thing, I do not in the least
augment the object of my conception by the addition of the statement:
This thing exists. Otherwise, not exactly the same, but something more
than what was cogitated in my conception, would exist, and I could not
affirm that the exact object of my conception had real existence. If I
cogitate a thing as containing all modes of reality except one, the
mode of reality which is absent is not added to the conception of the
thing by the affirmation that the thing exists; on the contrary, the
thing exists—if it exist at all—with the same defect as that cogitated
in its conception; otherwise not that which was cogitated, but
something different, exists. Now, if I cogitate a being as the highest
reality, without defect or imperfection, the question still
remains—whether this being exists or not? For, although no element is
wanting in the possible real content of my conception, there is a
defect in its relation to my mental state, that is, I am ignorant
whether the cognition of the object indicated by the conception is
possible a posteriori. And here the cause of the present difficulty
becomes apparent. If the question regarded an object of sense merely,
it would be impossible for me to confound the conception with the
existence of a thing. For the conception merely enables me to cogitate
an object as according with the general conditions of experience; while
the existence of the object permits me to cogitate it as contained in
the sphere of actual experience. At the same time, this connection with
the world of experience does not in the least augment the conception,
although a possible perception has been added to the experience of the
mind. But if we cogitate existence by the pure category alone, it is
not to be wondered at, that we should find ourselves unable to present
any criterion sufficient to distinguish it from mere possibility.

Whatever be the content of our conception of an object, it is necessary
to go beyond it, if we wish to predicate existence of the object. In
the case of sensuous objects, this is attained by their connection
according to empirical laws with some one of my perceptions; but there
is no means of cognizing the existence of objects of pure thought,
because it must be cognized completely a priori. But all our knowledge
of existence (be it immediately by perception, or by inferences
connecting some object with a perception) belongs entirely to the
sphere of experience—which is in perfect unity with itself; and
although an existence out of this sphere cannot be absolutely declared
to be impossible, it is a hypothesis the truth of which we have no
means of ascertaining.

The notion of a Supreme Being is in many respects a highly useful idea;
but for the very reason that it is an idea, it is incapable of
enlarging our cognition with regard to the existence of things. It is
not even sufficient to instruct us as to the possibility of a being
which we do not know to exist. The analytical criterion of possibility,
which consists in the absence of contradiction in propositions, cannot
be denied it. But the connection of real properties in a thing is a
synthesis of the possibility of which an a priori judgement cannot be
formed, because these realities are not presented to us specifically;
and even if this were to happen, a judgement would still be impossible,
because the criterion of the possibility of synthetical cognitions must
be sought for in the world of experience, to which the object of an
idea cannot belong. And thus the celebrated Leibnitz has utterly failed
in his attempt to establish upon a priori grounds the possibility of
this sublime ideal being.

The celebrated ontological or Cartesian argument for the existence of a
Supreme Being is therefore insufficient; and we may as well hope to
increase our stock of knowledge by the aid of mere ideas, as the
merchant to augment his wealth by the addition of noughts to his cash

 Section V. Of the Impossibility of a Cosmological Proof of the
 Existence of God

It was by no means a natural course of proceeding, but, on the
contrary, an invention entirely due to the subtlety of the schools, to
attempt to draw from a mere idea a proof of the existence of an object
corresponding to it. Such a course would never have been pursued, were
it not for that need of reason which requires it to suppose the
existence of a necessary being as a basis for the empirical regress,
and that, as this necessity must be unconditioned and a priori, reason
is bound to discover a conception which shall satisfy, if possible,
this requirement, and enable us to attain to the a priori cognition of
such a being. This conception was thought to be found in the idea of an
ens realissimum, and thus this idea was employed for the attainment of
a better defined knowledge of a necessary being, of the existence of
which we were convinced, or persuaded, on other grounds. Thus reason
was seduced from her natural courage; and, instead of concluding with
the conception of an ens realissimum, an attempt was made to begin with
it, for the purpose of inferring from it that idea of a necessary
existence which it was in fact called in to complete. Thus arose that
unfortunate ontological argument, which neither satisfies the healthy
common sense of humanity, nor sustains the scientific examination of
the philosopher.

The cosmological proof, which we are about to examine, retains the
connection between absolute necessity and the highest reality; but,
instead of reasoning from this highest reality to a necessary
existence, like the preceding argument, it concludes from the given
unconditioned necessity of some being its unlimited reality. The track
it pursues, whether rational or sophistical, is at least natural, and
not only goes far to persuade the common understanding, but shows
itself deserving of respect from the speculative intellect; while it
contains, at the same time, the outlines of all the arguments employed
in natural theology—arguments which always have been, and still will
be, in use and authority. These, however adorned, and hid under
whatever embellishments of rhetoric and sentiment, are at bottom
identical with the arguments we are at present to discuss. This proof,
termed by Leibnitz the argumentum a contingentia mundi, I shall now lay
before the reader, and subject to a strict examination.

It is framed in the following manner: If something exists, an
absolutely necessary being must likewise exist. Now I, at least, exist.
Consequently, there exists an absolutely necessary being. The minor
contains an experience, the major reasons from a general experience to
the existence of a necessary being.* Thus this argument really begins
at experience, and is not completely a priori, or ontological. The
object of all possible experience being the world, it is called the
cosmological proof. It contains no reference to any peculiar property
of sensuous objects, by which this world of sense might be
distinguished from other possible worlds; and in this respect it
differs from the physico-theological proof, which is based upon the
consideration of the peculiar constitution of our sensuous world.

[*Footnote: This inference is too well known to require more detailed
discussion. It is based upon the spurious transcendental law of
causality, that everything which is contingent has a cause, which, if
itself contingent, must also have a cause; and so on, till the series
of subordinated causes must end with an absolutely necessary cause,
without which it would not possess completeness.]

The proof proceeds thus: A necessary being can be determined only in
one way, that is, it can be determined by only one of all possible
opposed predicates; consequently, it must be completely determined in
and by its conception. But there is only a single conception of a thing
possible, which completely determines the thing a priori: that is, the
conception of the ens realissimum. It follows that the conception of
the ens realissimum is the only conception by and in which we can
cogitate a necessary being. Consequently, a Supreme Being necessarily

In this cosmological argument are assembled so many sophistical
propositions that speculative reason seems to have exerted in it all
her dialectical skill to produce a transcendental illusion of the most
extreme character. We shall postpone an investigation of this argument
for the present, and confine ourselves to exposing the stratagem by
which it imposes upon us an old argument in a new dress, and appeals to
the agreement of two witnesses, the one with the credentials of pure
reason, and the other with those of empiricism; while, in fact, it is
only the former who has changed his dress and voice, for the purpose of
passing himself off for an additional witness. That it may possess a
secure foundation, it bases its conclusions upon experience, and thus
appears to be completely distinct from the ontological argument, which
places its confidence entirely in pure a priori conceptions. But this
experience merely aids reason in making one step—to the existence of a
necessary being. What the properties of this being are cannot be
learned from experience; and therefore reason abandons it altogether,
and pursues its inquiries in the sphere of pure conception, for the
purpose of discovering what the properties of an absolutely necessary
being ought to be, that is, what among all possible things contain the
conditions (requisita) of absolute necessity. Reason believes that it
has discovered these requisites in the conception of an ens
realissimum—and in it alone, and hence concludes: The ens realissimum
is an absolutely necessary being. But it is evident that reason has
here presupposed that the conception of an ens realissimum is perfectly
adequate to the conception of a being of absolute necessity, that is,
that we may infer the existence of the latter from that of the former—a
proposition which formed the basis of the ontological argument, and
which is now employed in the support of the cosmological argument,
contrary to the wish and professions of its inventors. For the
existence of an absolutely necessary being is given in conceptions
alone. But if I say: “The conception of the ens realissimum is a
conception of this kind, and in fact the only conception which is
adequate to our idea of a necessary being,” I am obliged to admit, that
the latter may be inferred from the former. Thus it is properly the
ontological argument which figures in the cosmological, and constitutes
the whole strength of the latter; while the spurious basis of
experience has been of no further use than to conduct us to the
conception of absolute necessity, being utterly insufficient to
demonstrate the presence of this attribute in any determinate existence
or thing. For when we propose to ourselves an aim of this character, we
must abandon the sphere of experience, and rise to that of pure
conceptions, which we examine with the purpose of discovering whether
any one contains the conditions of the possibility of an absolutely
necessary being. But if the possibility of such a being is thus
demonstrated, its existence is also proved; for we may then assert
that, of all possible beings there is one which possesses the attribute
of necessity—in other words, this being possesses an absolutely
necessary existence.

All illusions in an argument are more easily detected when they are
presented in the formal manner employed by the schools, which we now
proceed to do.

If the proposition: “Every absolutely necessary being is likewise an
ens realissimum,” is correct (and it is this which constitutes the
nervus probandi of the cosmological argument), it must, like all
affirmative judgements, be capable of conversion—the conversio per
accidens, at least. It follows, then, that some entia realissima are
absolutely necessary beings. But no ens realissimum is in any respect
different from another, and what is valid of some is valid of all. In
this present case, therefore, I may employ simple conversion, and say:
“Every ens realissimum is a necessary being.” But as this proposition
is determined a priori by the conceptions contained in it, the mere
conception of an ens realissimum must possess the additional attribute
of absolute necessity. But this is exactly what was maintained in the
ontological argument, and not recognized by the cosmological, although
it formed the real ground of its disguised and illusory reasoning.

Thus the second mode employed by speculative reason of demonstrating
the existence of a Supreme Being, is not only, like the first, illusory
and inadequate, but possesses the additional blemish of an ignoratio
elenchi—professing to conduct us by a new road to the desired goal, but
bringing us back, after a short circuit, to the old path which we had
deserted at its call.

I mentioned above that this cosmological argument contains a perfect
nest of dialectical assumptions, which transcendental criticism does
not find it difficult to expose and to dissipate. I shall merely
enumerate these, leaving it to the reader, who must by this time be
well practised in such matters, to investigate the fallacies residing

The following fallacies, for example, are discoverable in this mode of
proof: 1. The transcendental principle: “Everything that is contingent
must have a cause”—a principle without significance, except in the
sensuous world. For the purely intellectual conception of the
contingent cannot produce any synthetical proposition, like that of
causality, which is itself without significance or distinguishing
characteristic except in the phenomenal world. But in the present case
it is employed to help us beyond the limits of its sphere. 2. “From the
impossibility of an infinite ascending series of causes in the world of
sense a first cause is inferred”; a conclusion which the principles of
the employment of reason do not justify even in the sphere of
experience, and still less when an attempt is made to pass the limits
of this sphere. 3. Reason allows itself to be satisfied upon
insufficient grounds, with regard to the completion of this series. It
removes all conditions (without which, however, no conception of
Necessity can take place); and, as after this it is beyond our power to
form any other conceptions, it accepts this as a completion of the
conception it wishes to form of the series. 4. The logical possibility
of a conception of the total of reality (the criterion of this
possibility being the absence of contradiction) is confounded with the
transcendental, which requires a principle of the practicability of
such a synthesis—a principle which again refers us to the world of
experience. And so on.

The aim of the cosmological argument is to avoid the necessity of
proving the existence of a necessary being priori from mere
conceptions—a proof which must be ontological, and of which we feel
ourselves quite incapable. With this purpose, we reason from an actual
existence—an experience in general, to an absolutely necessary
condition of that existence. It is in this case unnecessary to
demonstrate its possibility. For after having proved that it exists,
the question regarding its possibility is superfluous. Now, when we
wish to define more strictly the nature of this necessary being, we do
not look out for some being the conception of which would enable us to
comprehend the necessity of its being—for if we could do this, an
empirical presupposition would be unnecessary; no, we try to discover
merely the negative condition (conditio sine qua non), without which a
being would not be absolutely necessary. Now this would be perfectly
admissible in every sort of reasoning, from a consequence to its
principle; but in the present case it unfortunately happens that the
condition of absolute necessity can be discovered in but a single
being, the conception of which must consequently contain all that is
requisite for demonstrating the presence of absolute necessity, and
thus entitle me to infer this absolute necessity a priori. That is, it
must be possible to reason conversely, and say: The thing, to which the
conception of the highest reality belongs, is absolutely necessary. But
if I cannot reason thus—and I cannot, unless I believe in the
sufficiency of the ontological argument—I find insurmountable obstacles
in my new path, and am really no farther than the point from which I
set out. The conception of a Supreme Being satisfies all questions a
priori regarding the internal determinations of a thing, and is for
this reason an ideal without equal or parallel, the general conception
of it indicating it as at the same time an ens individuum among all
possible things. But the conception does not satisfy the question
regarding its existence—which was the purpose of all our inquiries;
and, although the existence of a necessary being were admitted, we
should find it impossible to answer the question: What of all things in
the world must be regarded as such?

It is certainly allowable to admit the existence of an all-sufficient
being—a cause of all possible effects—for the purpose of enabling
reason to introduce unity into its mode and grounds of explanation with
regard to phenomena. But to assert that such a being necessarily
exists, is no longer the modest enunciation of an admissible
hypothesis, but the boldest declaration of an apodeictic certainty; for
the cognition of that which is absolutely necessary must itself possess
that character.

The aim of the transcendental ideal formed by the mind is either to
discover a conception which shall harmonize with the idea of absolute
necessity, or a conception which shall contain that idea. If the one is
possible, so is the other; for reason recognizes that alone as
absolutely necessary which is necessary from its conception. But both
attempts are equally beyond our power—we find it impossible to satisfy
the understanding upon this point, and as impossible to induce it to
remain at rest in relation to this incapacity.

Unconditioned necessity, which, as the ultimate support and stay of all
existing things, is an indispensable requirement of the mind, is an
abyss on the verge of which human reason trembles in dismay. Even the
idea of eternity, terrible and sublime as it is, as depicted by Haller,
does not produce upon the mental vision such a feeling of awe and
terror; for, although it measures the duration of things, it does not
support them. We cannot bear, nor can we rid ourselves of the thought
that a being, which we regard as the greatest of all possible
existences, should say to himself: I am from eternity to eternity;
beside me there is nothing, except that which exists by my will; whence
then am I? Here all sinks away from under us; and the greatest, as the
smallest, perfection, hovers without stay or footing in presence of the
speculative reason, which finds it as easy to part with the one as with
the other.

Many physical powers, which evidence their existence by their effects,
are perfectly inscrutable in their nature; they elude all our powers of
observation. The transcendental object which forms the basis of
phenomena, and, in connection with it, the reason why our sensibility
possesses this rather than that particular kind of conditions, are and
must ever remain hidden from our mental vision; the fact is there, the
reason of the fact we cannot see. But an ideal of pure reason cannot be
termed mysterious or inscrutable, because the only credential of its
reality is the need of it felt by reason, for the purpose of giving
completeness to the world of synthetical unity. An ideal is not even
given as a cogitable object, and therefore cannot be inscrutable; on
the contrary, it must, as a mere idea, be based on the constitution of
reason itself, and on this account must be capable of explanation and
solution. For the very essence of reason consists in its ability to
give an account, of all our conceptions, opinions, and assertions—upon
objective, or, when they happen to be illusory and fallacious, upon
subjective grounds.

Detection and Explanation of the Dialectical Illusion in all
Transcendental Arguments for the Existence of a Necessary Being.

Both of the above arguments are transcendental; in other words, they do
not proceed upon empirical principles. For, although the cosmological
argument professed to lay a basis of experience for its edifice of
reasoning, it did not ground its procedure upon the peculiar
constitution of experience, but upon pure principles of reason—in
relation to an existence given by empirical consciousness; utterly
abandoning its guidance, however, for the purpose of supporting its
assertions entirely upon pure conceptions. Now what is the cause, in
these transcendental arguments, of the dialectical, but natural,
illusion, which connects the conceptions of necessity and supreme
reality, and hypostatizes that which cannot be anything but an idea?
What is the cause of this unavoidable step on the part of reason, of
admitting that some one among all existing things must be necessary,
while it falls back from the assertion of the existence of such a being
as from an abyss? And how does reason proceed to explain this anomaly
to itself, and from the wavering condition of a timid and reluctant
approbation—always again withdrawn—arrive at a calm and settled insight
into its cause?

It is something very remarkable that, on the supposition that something
exists, I cannot avoid the inference that something exists necessarily.
Upon this perfectly natural—but not on that account reliable—inference
does the cosmological argument rest. But, let me form any conception
whatever of a thing, I find that I cannot cogitate the existence of the
thing as absolutely necessary, and that nothing prevents me—be the
thing or being what it may—from cogitating its non-existence. I may
thus be obliged to admit that all existing things have a necessary
basis, while I cannot cogitate any single or individual thing as
necessary. In other words, I can never complete the regress through the
conditions of existence, without admitting the existence of a necessary
being; but, on the other hand, I cannot make a commencement from this

If I must cogitate something as existing necessarily as the basis of
existing things, and yet am not permitted to cogitate any individual
thing as in itself necessary, the inevitable inference is that
necessity and contingency are not properties of things
themselves—otherwise an internal contradiction would result; that
consequently neither of these principles are objective, but merely
subjective principles of reason—the one requiring us to seek for a
necessary ground for everything that exists, that is, to be satisfied
with no other explanation than that which is complete a priori, the
other forbidding us ever to hope for the attainment of this
completeness, that is, to regard no member of the empirical world as
unconditioned. In this mode of viewing them, both principles, in their
purely heuristic and regulative character, and as concerning merely the
formal interest of reason, are quite consistent with each other. The
one says: “You must philosophize upon nature,” as if there existed a
necessary primal basis of all existing things, solely for the purpose
of introducing systematic unity into your knowledge, by pursuing an
idea of this character—a foundation which is arbitrarily admitted to be
ultimate; while the other warns you to consider no individual
determination, concerning the existence of things, as such an ultimate
foundation, that is, as absolutely necessary, but to keep the way
always open for further progress in the deduction, and to treat every
determination as determined by some other. But if all that we perceive
must be regarded as conditionally necessary, it is impossible that
anything which is empirically given should be absolutely necessary.

It follows from this that you must accept the absolutely necessary as
out of and beyond the world, inasmuch as it is useful only as a
principle of the highest possible unity in experience, and you cannot
discover any such necessary existence in the would, the second rule
requiring you to regard all empirical causes of unity as themselves

The philosophers of antiquity regarded all the forms of nature as
contingent; while matter was considered by them, in accordance with the
judgement of the common reason of mankind, as primal and necessary. But
if they had regarded matter, not relatively—as the substratum of
phenomena, but absolutely and in itself—as an independent existence,
this idea of absolute necessity would have immediately disappeared. For
there is nothing absolutely connecting reason with such an existence;
on the contrary, it can annihilate it in thought, always and without
self-contradiction. But in thought alone lay the idea of absolute
necessity. A regulative principle must, therefore, have been at the
foundation of this opinion. In fact, extension and
impenetrability—which together constitute our conception of matter—form
the supreme empirical principle of the unity of phenomena, and this
principle, in so far as it is empirically unconditioned, possesses the
property of a regulative principle. But, as every determination of
matter which constitutes what is real in it—and consequently
impenetrability—is an effect, which must have a cause, and is for this
reason always derived, the notion of matter cannot harmonize with the
idea of a necessary being, in its character of the principle of all
derived unity. For every one of its real properties, being derived,
must be only conditionally necessary, and can therefore be annihilated
in thought; and thus the whole existence of matter can be so
annihilated or suppressed. If this were not the case, we should have
found in the world of phenomena the highest ground or condition of
unity—which is impossible, according to the second regulative
principle. It follows that matter, and, in general, all that forms part
of the world of sense, cannot be a necessary primal being, nor even a
principle of empirical unity, but that this being or principle must
have its place assigned without the world. And, in this way, we can
proceed in perfect confidence to deduce the phenomena of the world and
their existence from other phenomena, just as if there existed no
necessary being; and we can at the same time, strive without ceasing
towards the attainment of completeness for our deduction, just as if
such a being—the supreme condition of all existences—were presupposed
by the mind.

These remarks will have made it evident to the reader that the ideal of
the Supreme Being, far from being an enouncement of the existence of a
being in itself necessary, is nothing more than a regulative principle
of reason, requiring us to regard all connection existing between
phenomena as if it had its origin from an all-sufficient necessary
cause, and basing upon this the rule of a systematic and necessary
unity in the explanation of phenomena. We cannot, at the same time,
avoid regarding, by a transcendental subreptio, this formal principle
as constitutive, and hypostatizing this unity. Precisely similar is the
case with our notion of space. Space is the primal condition of all
forms, which are properly just so many different limitations of it; and
thus, although it is merely a principle of sensibility, we cannot help
regarding it as an absolutely necessary and self-subsistent thing—as an
object given a priori in itself. In the same way, it is quite natural
that, as the systematic unity of nature cannot be established as a
principle for the empirical employment of reason, unless it is based
upon the idea of an ens realissimum, as the supreme cause, we should
regard this idea as a real object, and this object, in its character of
supreme condition, as absolutely necessary, and that in this way a
regulative should be transformed into a constitutive principle. This
interchange becomes evident when I regard this supreme being, which,
relatively to the world, was absolutely (unconditionally) necessary, as
a thing per se. In this case, I find it impossible to represent this
necessity in or by any conception, and it exists merely in my own mind,
as the formal condition of thought, but not as a material and
hypostatic condition of existence.

 Section VI. Of the Impossibility of a Physico-Theological Proof

If, then, neither a pure conception nor the general experience of an
existing being can provide a sufficient basis for the proof of the
existence of the Deity, we can make the attempt by the only other
mode—that of grounding our argument upon a determinate experience of
the phenomena of the present world, their constitution and disposition,
and discover whether we can thus attain to a sound conviction of the
existence of a Supreme Being. This argument we shall term the
physico-theological argument. If it is shown to be insufficient,
speculative reason cannot present us with any satisfactory proof of the
existence of a being corresponding to our transcendental idea.

It is evident from the remarks that have been made in the preceding
sections, that an answer to this question will be far from being
difficult or unconvincing. For how can any experience be adequate with
an idea? The very essence of an idea consists in the fact that no
experience can ever be discovered congruent or adequate with it. The
transcendental idea of a necessary and all-sufficient being is so
immeasurably great, so high above all that is empirical, which is
always conditioned, that we hope in vain to find materials in the
sphere of experience sufficiently ample for our conception, and in vain
seek the unconditioned among things that are conditioned, while
examples, nay, even guidance is denied us by the laws of empirical

If the Supreme Being forms a link in the chain of empirical conditions,
it must be a member of the empirical series, and, like the lower
members which it precedes, have its origin in some higher member of the
series. If, on the other hand, we disengage it from the chain, and
cogitate it as an intelligible being, apart from the series of natural
causes—how shall reason bridge the abyss that separates the latter from
the former? All laws respecting the regress from effects to causes, all
synthetical additions to our knowledge relate solely to possible
experience and the objects of the sensuous world, and, apart from them,
are without significance.

The world around us opens before our view so magnificent a spectacle of
order, variety, beauty, and conformity to ends, that whether we pursue
our observations into the infinity of space in the one direction, or
into its illimitable divisions in the other, whether we regard the
world in its greatest or its least manifestations—even after we have
attained to the highest summit of knowledge which our weak minds can
reach, we find that language in the presence of wonders so
inconceivable has lost its force, and number its power to reckon, nay,
even thought fails to conceive adequately, and our conception of the
whole dissolves into an astonishment without power of expression—all
the more eloquent that it is dumb. Everywhere around us we observe a
chain of causes and effects, of means and ends, of death and birth;
and, as nothing has entered of itself into the condition in which we
find it, we are constantly referred to some other thing, which itself
suggests the same inquiry regarding its cause, and thus the universe
must sink into the abyss of nothingness, unless we admit that, besides
this infinite chain of contingencies, there exists something that is
primal and self-subsistent—something which, as the cause of this
phenomenal world, secures its continuance and preservation.

This highest cause—what magnitude shall we attribute to it? Of the
content of the world we are ignorant; still less can we estimate its
magnitude by comparison with the sphere of the possible. But this
supreme cause being a necessity of the human mind, what is there to
prevent us from attributing to it such a degree of perfection as to
place it above the sphere of all that is possible? This we can easily
do, although only by the aid of the faint outline of an abstract
conception, by representing this being to ourselves as containing in
itself, as an individual substance, all possible perfection—a
conception which satisfies that requirement of reason which demands
parsimony in principles, which is free from self-contradiction, which
even contributes to the extension of the employment of reason in
experience, by means of the guidance afforded by this idea to order and
system, and which in no respect conflicts with any law of experience.

This argument always deserves to be mentioned with respect. It is the
oldest, the clearest, and that most in conformity with the common
reason of humanity. It animates the study of nature, as it itself
derives its existence and draws ever new strength from that source. It
introduces aims and ends into a sphere in which our observation could
not of itself have discovered them, and extends our knowledge of
nature, by directing our attention to a unity, the principle of which
lies beyond nature. This knowledge of nature again reacts upon this
idea—its cause; and thus our belief in a divine author of the universe
rises to the power of an irresistible conviction.

For these reasons it would be utterly hopeless to attempt to rob this
argument of the authority it has always enjoyed. The mind, unceasingly
elevated by these considerations, which, although empirical, are so
remarkably powerful, and continually adding to their force, will not
suffer itself to be depressed by the doubts suggested by subtle
speculation; it tears itself out of this state of uncertainty, the
moment it casts a look upon the wondrous forms of nature and the
majesty of the universe, and rises from height to height, from
condition to condition, till it has elevated itself to the supreme and
unconditioned author of all.

But although we have nothing to object to the reasonableness and
utility of this procedure, but have rather to commend and encourage it,
we cannot approve of the claims which this argument advances to
demonstrative certainty and to a reception upon its own merits, apart
from favour or support by other arguments. Nor can it injure the cause
of morality to endeavour to lower the tone of the arrogant sophist, and
to teach him that modesty and moderation which are the properties of a
belief that brings calm and content into the mind, without prescribing
to it an unworthy subjection. I maintain, then, that the
physico-theological argument is insufficient of itself to prove the
existence of a Supreme Being, that it must entrust this to the
ontological argument—to which it serves merely as an introduction, and
that, consequently, this argument contains the only possible ground of
proof (possessed by speculative reason) for the existence of this

The chief momenta in the physico-theological argument are as follow: 1.
We observe in the world manifest signs of an arrangement full of
purpose, executed with great wisdom, and argument in whole of a content
indescribably various, and of an extent without limits. 2. This
arrangement of means and ends is entirely foreign to the things
existing in the world—it belongs to them merely as a contingent
attribute; in other words, the nature of different things could not of
itself, whatever means were employed, harmoniously tend towards certain
purposes, were they not chosen and directed for these purposes by a
rational and disposing principle, in accordance with certain
fundamental ideas. 3. There exists, therefore, a sublime and wise cause
(or several), which is not merely a blind, all-powerful nature,
producing the beings and events which fill the world in unconscious
fecundity, but a free and intelligent cause of the world. 4. The unity
of this cause may be inferred from the unity of the reciprocal relation
existing between the parts of the world, as portions of an artistic
edifice—an inference which all our observation favours, and all
principles of analogy support.

In the above argument, it is inferred from the analogy of certain
products of nature with those of human art, when it compels Nature to
bend herself to its purposes, as in the case of a house, a ship, or a
watch, that the same kind of causality—namely, understanding and
will—resides in nature. It is also declared that the internal
possibility of this freely-acting nature (which is the source of all
art, and perhaps also of human reason) is derivable from another and
superhuman art—a conclusion which would perhaps be found incapable of
standing the test of subtle transcendental criticism. But to neither of
these opinions shall we at present object. We shall only remark that it
must be confessed that, if we are to discuss the subject of cause at
all, we cannot proceed more securely than with the guidance of the
analogy subsisting between nature and such products of design—these
being the only products whose causes and modes of organization are
completely known to us. Reason would be unable to satisfy her own
requirements, if she passed from a causality which she does know, to
obscure and indemonstrable principles of explanation which she does not

According to the physico-theological argument, the connection and
harmony existing in the world evidence the contingency of the form
merely, but not of the matter, that is, of the substance of the world.
To establish the truth of the latter opinion, it would be necessary to
prove that all things would be in themselves incapable of this harmony
and order, unless they were, even as regards their substance, the
product of a supreme wisdom. But this would require very different
grounds of proof from those presented by the analogy with human art.
This proof can at most, therefore, demonstrate the existence of an
architect of the world, whose efforts are limited by the capabilities
of the material with which he works, but not of a creator of the world,
to whom all things are subject. Thus this argument is utterly
insufficient for the task before us—a demonstration of the existence of
an all-sufficient being. If we wish to prove the contingency of matter,
we must have recourse to a transcendental argument, which the
physico-theological was constructed expressly to avoid.

We infer, from the order and design visible in the universe, as a
disposition of a thoroughly contingent character, the existence of a
cause proportionate thereto. The conception of this cause must contain
certain determinate qualities, and it must therefore be regarded as the
conception of a being which possesses all power, wisdom, and so on, in
one word, all perfection—the conception, that is, of an all-sufficient
being. For the predicates of very great, astonishing, or immeasurable
power and excellence, give us no determinate conception of the thing,
nor do they inform us what the thing may be in itself. They merely
indicate the relation existing between the magnitude of the object and
the observer, who compares it with himself and with his own power of
comprehension, and are mere expressions of praise and reverence, by
which the object is either magnified, or the observing subject
depreciated in relation to the object. Where we have to do with the
magnitude (of the perfection) of a thing, we can discover no
determinate conception, except that which comprehends all possible
perfection or completeness, and it is only the total (omnitudo) of
reality which is completely determined in and through its conception

Now it cannot be expected that any one will be bold enough to declare
that he has a perfect insight into the relation which the magnitude of
the world he contemplates bears (in its extent as well as in its
content) to omnipotence, into that of the order and design in the world
to the highest wisdom, and that of the unity of the world to the
absolute unity of a Supreme Being. Physico-theology is therefore
incapable of presenting a determinate conception of a supreme cause of
the world, and is therefore insufficient as a principle of theology—a
theology which is itself to be the basis of religion.

The attainment of absolute totality is completely impossible on the
path of empiricism. And yet this is the path pursued in the
physico-theological argument. What means shall we employ to bridge the

After elevating ourselves to admiration of the magnitude of the power,
wisdom, and other attributes of the author of the world, and finding we
can advance no further, we leave the argument on empirical grounds, and
proceed to infer the contingency of the world from the order and
conformity to aims that are observable in it. From this contingency we
infer, by the help of transcendental conceptions alone, the existence
of something absolutely necessary; and, still advancing, proceed from
the conception of the absolute necessity of the first cause to the
completely determined or determining conception thereof—the conception
of an all-embracing reality. Thus the physico-theological, failing in
its undertaking, recurs in its embarrassment to the cosmological
argument; and, as this is merely the ontological argument in disguise,
it executes its design solely by the aid of pure reason, although it at
first professed to have no connection with this faculty and to base its
entire procedure upon experience alone.

The physico-theologians have therefore no reason to regard with such
contempt the transcendental mode of argument, and to look down upon it,
with the conceit of clear-sighted observers of nature, as the
brain-cobweb of obscure speculatists. For, if they reflect upon and
examine their own arguments, they will find that, after following for
some time the path of nature and experience, and discovering themselves
no nearer their object, they suddenly leave this path and pass into the
region of pure possibility, where they hope to reach upon the wings of
ideas what had eluded all their empirical investigations. Gaining, as
they think, a firm footing after this immense leap, they extend their
determinate conception—into the possession of which they have come,
they know not how—over the whole sphere of creation, and explain their
ideal, which is entirely a product of pure reason, by illustrations
drawn from experience—though in a degree miserably unworthy of the
grandeur of the object, while they refuse to acknowledge that they have
arrived at this cognition or hypothesis by a very different road from
that of experience.

Thus the physico-theological is based upon the cosmological, and this
upon the ontological proof of the existence of a Supreme Being; and as
besides these three there is no other path open to speculative reason,
the ontological proof, on the ground of pure conceptions of reason, is
the only possible one, if any proof of a proposition so far
transcending the empirical exercise of the understanding is possible at

 Section VII. Critique of all Theology based upon Speculative
 Principles of Reason

If by the term theology I understand the cognition of a primal being,
that cognition is based either upon reason alone (theologia rationalis)
or upon revelation (theologia revelata). The former cogitates its
object either by means of pure transcendental conceptions, as an ens
originarium, realissimum, ens entium, and is termed transcendental
theology; or, by means of a conception derived from the nature of our
own mind, as a supreme intelligence, and must then be entitled natural
theology. The person who believes in a transcendental theology alone,
is termed a deist; he who acknowledges the possibility of a natural
theology also, a theist. The former admits that we can cognize by pure
reason alone the existence of a Supreme Being, but at the same time
maintains that our conception of this being is purely transcendental,
and that all we can say of it is that it possesses all reality, without
being able to define it more closely. The second asserts that reason is
capable of presenting us, from the analogy with nature, with a more
definite conception of this being, and that its operations, as the
cause of all things, are the results of intelligence and free will. The
former regards the Supreme Being as the cause of the world—whether by
the necessity of his nature, or as a free agent, is left undetermined;
the latter considers this being as the author of the world.

Transcendental theology aims either at inferring the existence of a
Supreme Being from a general experience, without any closer reference
to the world to which this experience belongs, and in this case it is
called cosmotheology; or it endeavours to cognize the existence of such
a being, through mere conceptions, without the aid of experience, and
is then termed ontotheology.

Natural theology infers the attributes and the existence of an author
of the world, from the constitution of, the order and unity observable
in, the world, in which two modes of causality must be admitted to
exist—those of nature and freedom. Thus it rises from this world to a
supreme intelligence, either as the principle of all natural, or of all
moral order and perfection. In the former case it is termed
physico-theology, in the latter, ethical or moral-theology.*

[*Footnote: Not theological ethics; for this science contains ethical
laws, which presuppose the existence of a Supreme Governor of the
world; while moral-theology, on the contrary, is the expression of a
conviction of the existence of a Supreme Being, founded upon ethical

As we are wont to understand by the term God not merely an eternal
nature, the operations of which are insensate and blind, but a Supreme
Being, who is the free and intelligent author of all things, and as it
is this latter view alone that can be of interest to humanity, we
might, in strict rigour, deny to the deist any belief in God at all,
and regard him merely as a maintainer of the existence of a primal
being or thing—the supreme cause of all other things. But, as no one
ought to be blamed, merely because he does not feel himself justified
in maintaining a certain opinion, as if he altogether denied its truth
and asserted the opposite, it is more correct—as it is less harsh—to
say, the deist believes in a God, the theist in a living God (summa
intelligentia). We shall now proceed to investigate the sources of all
these attempts of reason to establish the existence of a Supreme Being.

It may be sufficient in this place to define theoretical knowledge or
cognition as knowledge of that which is, and practical knowledge as
knowledge of that which ought to be. In this view, the theoretical
employment of reason is that by which I cognize a priori (as necessary)
that something is, while the practical is that by which I cognize a
priori what ought to happen. Now, if it is an indubitably certain,
though at the same time an entirely conditioned truth, that something
is, or ought to happen, either a certain determinate condition of this
truth is absolutely necessary, or such a condition may be arbitrarily
presupposed. In the former case the condition is postulated (per
thesin), in the latter supposed (per hypothesin). There are certain
practical laws—those of morality—which are absolutely necessary. Now,
if these laws necessarily presuppose the existence of some being, as
the condition of the possibility of their obligatory power, this being
must be postulated, because the conditioned, from which we reason to
this determinate condition, is itself cognized a priori as absolutely
necessary. We shall at some future time show that the moral laws not
merely presuppose the existence of a Supreme Being, but also, as
themselves absolutely necessary in a different relation, demand or
postulate it—although only from a practical point of view. The
discussion of this argument we postpone for the present.

When the question relates merely to that which is, not to that which
ought to be, the conditioned which is presented in experience is always
cogitated as contingent. For this reason its condition cannot be
regarded as absolutely necessary, but merely as relatively necessary,
or rather as needful; the condition is in itself and a priori a mere
arbitrary presupposition in aid of the cognition, by reason, of the
conditioned. If, then, we are to possess a theoretical cognition of the
absolute necessity of a thing, we cannot attain to this cognition
otherwise than a priori by means of conceptions; while it is impossible
in this way to cognize the existence of a cause which bears any
relation to an existence given in experience.

Theoretical cognition is speculative when it relates to an object or
certain conceptions of an object which is not given and cannot be
discovered by means of experience. It is opposed to the cognition of
nature, which concerns only those objects or predicates which can be
presented in a possible experience.

The principle that everything which happens (the empirically
contingent) must have a cause, is a principle of the cognition of
nature, but not of speculative cognition. For, if we change it into an
abstract principle, and deprive it of its reference to experience and
the empirical, we shall find that it cannot with justice be regarded
any longer as a synthetical proposition, and that it is impossible to
discover any mode of transition from that which exists to something
entirely different—termed cause. Nay, more, the conception of a cause
likewise that of the contingent—loses, in this speculative mode of
employing it, all significance, for its objective reality and meaning
are comprehensible from experience alone.

When from the existence of the universe and the things in it the
existence of a cause of the universe is inferred, reason is proceeding
not in the natural, but in the speculative method. For the principle of
the former enounces, not that things themselves or substances, but only
that which happens or their states—as empirically contingent, have a
cause: the assertion that the existence of substance itself is
contingent is not justified by experience, it is the assertion of a
reason employing its principles in a speculative manner. If, again, I
infer from the form of the universe, from the way in which all things
are connected and act and react upon each other, the existence of a
cause entirely distinct from the universe—this would again be a
judgement of purely speculative reason; because the object in this
case—the cause—can never be an object of possible experience. In both
these cases the principle of causality, which is valid only in the
field of experience—useless and even meaningless beyond this region,
would be diverted from its proper destination.

Now I maintain that all attempts of reason to establish a theology by
the aid of speculation alone are fruitless, that the principles of
reason as applied to nature do not conduct us to any theological
truths, and, consequently, that a rational theology can have no
existence, unless it is founded upon the laws of morality. For all
synthetical principles of the understanding are valid only as immanent
in experience; while the cognition of a Supreme Being necessitates
their being employed transcendentally, and of this the understanding is
quite incapable. If the empirical law of causality is to conduct us to
a Supreme Being, this being must belong to the chain of empirical
objects—in which case it would be, like all phenomena, itself
conditioned. If the possibility of passing the limits of experience be
admitted, by means of the dynamical law of the relation of an effect to
its cause, what kind of conception shall we obtain by this procedure?
Certainly not the conception of a Supreme Being, because experience
never presents us with the greatest of all possible effects, and it is
only an effect of this character that could witness to the existence of
a corresponding cause. If, for the purpose of fully satisfying the
requirements of Reason, we recognize her right to assert the existence
of a perfect and absolutely necessary being, this can be admitted only
from favour, and cannot be regarded as the result or irresistible
demonstration. The physico-theological proof may add weight to
others—if other proofs there are—by connecting speculation with
experience; but in itself it rather prepares the mind for theological
cognition, and gives it a right and natural direction, than establishes
a sure foundation for theology.

It is now perfectly evident that transcendental questions admit only of
transcendental answers—those presented a priori by pure conceptions
without the least empirical admixture. But the question in the present
case is evidently synthetical—it aims at the extension of our cognition
beyond the bounds of experience—it requires an assurance respecting the
existence of a being corresponding with the idea in our minds, to which
no experience can ever be adequate. Now it has been abundantly proved
that all a priori synthetical cognition is possible only as the
expression of the formal conditions of a possible experience; and that
the validity of all principles depends upon their immanence in the
field of experience, that is, their relation to objects of empirical
cognition or phenomena. Thus all transcendental procedure in reference
to speculative theology is without result.

If any one prefers doubting the conclusiveness of the proofs of our
analytic to losing the persuasion of the validity of these old and time
honoured arguments, he at least cannot decline answering the
question—how he can pass the limits of all possible experience by the
help of mere ideas. If he talks of new arguments, or of improvements
upon old arguments, I request him to spare me. There is certainly no
great choice in this sphere of discussion, as all speculative arguments
must at last look for support to the ontological, and I have,
therefore, very little to fear from the argumentative fecundity of the
dogmatical defenders of a non-sensuous reason. Without looking upon
myself as a remarkably combative person, I shall not decline the
challenge to detect the fallacy and destroy the pretensions of every
attempt of speculative theology. And yet the hope of better fortune
never deserts those who are accustomed to the dogmatical mode of
procedure. I shall, therefore, restrict myself to the simple and
equitable demand that such reasoners will demonstrate, from the nature
of the human mind as well as from that of the other sources of
knowledge, how we are to proceed to extend our cognition completely a
priori, and to carry it to that point where experience abandons us, and
no means exist of guaranteeing the objective reality of our
conceptions. In whatever way the understanding may have attained to a
conception, the existence of the object of the conception cannot be
discovered in it by analysis, because the cognition of the existence of
the object depends upon the object’s being posited and given in itself
apart from the conception. But it is utterly impossible to go beyond
our conception, without the aid of experience—which presents to the
mind nothing but phenomena, or to attain by the help of mere
conceptions to a conviction of the existence of new kinds of objects or
supernatural beings.

But although pure speculative reason is far from sufficient to
demonstrate the existence of a Supreme Being, it is of the highest
utility in correcting our conception of this being—on the supposition
that we can attain to the cognition of it by some other means—in making
it consistent with itself and with all other conceptions of
intelligible objects, clearing it from all that is incompatible with
the conception of an ens summun, and eliminating from it all
limitations or admixtures of empirical elements.

Transcendental theology is still therefore, notwithstanding its
objective insufficiency, of importance in a negative respect; it is
useful as a test of the procedure of reason when engaged with pure
ideas, no other than a transcendental standard being in this case
admissible. For if, from a practical point of view, the hypothesis of a
Supreme and All-sufficient Being is to maintain its validity without
opposition, it must be of the highest importance to define this
conception in a correct and rigorous manner—as the transcendental
conception of a necessary being, to eliminate all phenomenal elements
(anthropomorphism in its most extended signification), and at the same
time to overflow all contradictory assertions—be they atheistic,
deistic, or anthropomorphic. This is of course very easy; as the same
arguments which demonstrated the inability of human reason to affirm
the existence of a Supreme Being must be alike sufficient to prove the
invalidity of its denial. For it is impossible to gain from the pure
speculation of reason demonstration that there exists no Supreme Being,
as the ground of all that exists, or that this being possesses none of
those properties which we regard as analogical with the dynamical
qualities of a thinking being, or that, as the anthropomorphists would
have us believe, it is subject to all the limitations which sensibility
imposes upon those intelligences which exist in the world of

A Supreme Being is, therefore, for the speculative reason, a mere
ideal, though a faultless one—a conception which perfects and crowns
the system of human cognition, but the objective reality of which can
neither be proved nor disproved by pure reason. If this defect is ever
supplied by a moral theology, the problematic transcendental theology
which has preceded, will have been at least serviceable as
demonstrating the mental necessity existing for the conception, by the
complete determination of it which it has furnished, and the ceaseless
testing of the conclusions of a reason often deceived by sense, and not
always in harmony with its own ideas. The attributes of necessity,
infinitude, unity, existence apart from the world (and not as a world
soul), eternity (free from conditions of time), omnipresence (free from
conditions of space), omnipotence, and others, are pure transcendental
predicates; and thus the accurate conception of a Supreme Being, which
every theology requires, is furnished by transcendental theology alone.

 APPENDIX. Of the Regulative Employment of the Ideas of Pure Reason

The result of all the dialectical attempts of pure reason not only
confirms the truth of what we have already proved in our Transcendental
Analytic, namely, that all inferences which would lead us beyond the
limits of experience are fallacious and groundless, but it at the same
time teaches us this important lesson, that human reason has a natural
inclination to overstep these limits, and that transcendental ideas are
as much the natural property of the reason as categories are of the
understanding. There exists this difference, however, that while the
categories never mislead us, outward objects being always in perfect
harmony therewith, ideas are the parents of irresistible illusions, the
severest and most subtle criticism being required to save us from the
fallacies which they induce.

Whatever is grounded in the nature of our powers will be found to be in
harmony with the final purpose and proper employment of these powers,
when once we have discovered their true direction and aim. We are
entitled to suppose, therefore, that there exists a mode of employing
transcendental ideas which is proper and immanent; although, when we
mistake their meaning, and regard them as conceptions of actual things,
their mode of application is transcendent and delusive. For it is not
the idea itself, but only the employment of the idea in relation to
possible experience, that is transcendent or immanent. An idea is
employed transcendently, when it is applied to an object falsely
believed to be adequate with and to correspond to it; imminently, when
it is applied solely to the employment of the understanding in the
sphere of experience. Thus all errors of subreptio—of misapplication,
are to be ascribed to defects of judgement, and not to understanding or

Reason never has an immediate relation to an object; it relates
immediately to the understanding alone. It is only through the
understanding that it can be employed in the field of experience. It
does not form conceptions of objects, it merely arranges them and gives
to them that unity which they are capable of possessing when the sphere
of their application has been extended as widely as possible. Reason
avails itself of the conception of the understanding for the sole
purpose of producing totality in the different series. This totality
the understanding does not concern itself with; its only occupation is
the connection of experiences, by which series of conditions in
accordance with conceptions are established. The object of reason is,
therefore, the understanding and its proper destination. As the latter
brings unity into the diversity of objects by means of its conceptions,
so the former brings unity into the diversity of conceptions by means
of ideas; as it sets the final aim of a collective unity to the
operations of the understanding, which without this occupies itself
with a distributive unity alone.

I accordingly maintain that transcendental ideas can never be employed
as constitutive ideas, that they cannot be conceptions of objects, and
that, when thus considered, they assume a fallacious and dialectical
character. But, on the other hand, they are capable of an admirable and
indispensably necessary application to objects—as regulative ideas,
directing the understanding to a certain aim, the guiding lines towards
which all its laws follow, and in which they all meet in one point.
This point—though a mere idea (focus imaginarius), that is, not a point
from which the conceptions of the understanding do really proceed, for
it lies beyond the sphere of possible experience—serves,
notwithstanding, to give to these conceptions the greatest possible
unity combined with the greatest possible extension. Hence arises the
natural illusion which induces us to believe that these lines proceed
from an object which lies out of the sphere of empirical cognition,
just as objects reflected in a mirror appear to be behind it. But this
illusion—which we may hinder from imposing upon us—is necessary and
unavoidable, if we desire to see, not only those objects which lie
before us, but those which are at a great distance behind us; that is
to say, when, in the present case, we direct the aims of the
understanding, beyond every given experience, towards an extension as
great as can possibly be attained.

If we review our cognitions in their entire extent, we shall find that
the peculiar business of reason is to arrange them into a system, that
is to say, to give them connection according to a principle. This unity
presupposes an idea—the idea of the form of a whole (of cognition),
preceding the determinate cognition of the parts, and containing the
conditions which determine a priori to every part its place and
relation to the other parts of the whole system. This idea,
accordingly, demands complete unity in the cognition of the
understanding—not the unity of a contingent aggregate, but that of a
system connected according to necessary laws. It cannot be affirmed
with propriety that this idea is a conception of an object; it is
merely a conception of the complete unity of the conceptions of
objects, in so far as this unity is available to the understanding as a
rule. Such conceptions of reason are not derived from nature; on the
contrary, we employ them for the interrogation and investigation of
nature, and regard our cognition as defective so long as it is not
adequate to them. We admit that such a thing as pure earth, pure water,
or pure air, is not to be discovered. And yet we require these
conceptions (which have their origin in the reason, so far as regards
their absolute purity and completeness) for the purpose of determining
the share which each of these natural causes has in every phenomenon.
Thus the different kinds of matter are all referred to earths, as mere
weight; to salts and inflammable bodies, as pure force; and finally, to
water and air, as the vehicula of the former, or the machines employed
by them in their operations—for the purpose of explaining the chemical
action and reaction of bodies in accordance with the idea of a
mechanism. For, although not actually so expressed, the influence of
such ideas of reason is very observable in the procedure of natural

If reason is the faculty of deducing the particular from the general,
and if the general be certain in se and given, it is only necessary
that the judgement should subsume the particular under the general, the
particular being thus necessarily determined. I shall term this the
demonstrative or apodeictic employment of reason. If, however, the
general is admitted as problematical only, and is a mere idea, the
particular case is certain, but the universality of the rule which
applies to this particular case remains a problem. Several particular
cases, the certainty of which is beyond doubt, are then taken and
examined, for the purpose of discovering whether the rule is applicable
to them; and if it appears that all the particular cases which can be
collected follow from the rule, its universality is inferred, and at
the same time, all the causes which have not, or cannot be presented to
our observation, are concluded to be of the same character with those
which we have observed. This I shall term the hypothetical employment
of the reason.

The hypothetical exercise of reason by the aid of ideas employed as
problematical conceptions is properly not constitutive. That is to say,
if we consider the subject strictly, the truth of the rule, which has
been employed as an hypothesis, does not follow from the use that is
made of it by reason. For how can we know all the possible cases that
may arise? some of which may, however, prove exceptions to the
universality of the rule. This employment of reason is merely
regulative, and its sole aim is the introduction of unity into the
aggregate of our particular cognitions, and thereby the approximating
of the rule to universality.

The object of the hypothetical employment of reason is therefore the
systematic unity of cognitions; and this unity is the criterion of the
truth of a rule. On the other hand, this systematic unity—as a mere
idea—is in fact merely a unity projected, not to be regarded as given,
but only in the light of a problem—a problem which serves, however, as
a principle for the various and particular exercise of the
understanding in experience, directs it with regard to those cases
which are not presented to our observation, and introduces harmony and
consistency into all its operations.

All that we can be certain of from the above considerations is that
this systematic unity is a logical principle, whose aim is to assist
the understanding, where it cannot of itself attain to rules, by means
of ideas, to bring all these various rules under one principle, and
thus to ensure the most complete consistency and connection that can be
attained. But the assertion that objects and the understanding by which
they are cognized are so constituted as to be determined to systematic
unity, that this may be postulated a priori, without any reference to
the interest of reason, and that we are justified in declaring all
possible cognitions—empirical and others—to possess systematic unity,
and to be subject to general principles from which, notwithstanding
their various character, they are all derivable such an assertion can
be founded only upon a transcendental principle of reason, which would
render this systematic unity not subjectively and logically—in its
character of a method, but objectively necessary.

We shall illustrate this by an example. The conceptions of the
understanding make us acquainted, among many other kinds of unity, with
that of the causality of a substance, which is termed power. The
different phenomenal manifestations of the same substance appear at
first view to be so very dissimilar that we are inclined to assume the
existence of just as many different powers as there are different
effects—as, in the case of the human mind, we have feeling,
consciousness, imagination, memory, wit, analysis, pleasure, desire and
so on. Now we are required by a logical maxim to reduce these
differences to as small a number as possible, by comparing them and
discovering the hidden identity which exists. We must inquire, for
example, whether or not imagination (connected with consciousness),
memory, wit, and analysis are not merely different forms of
understanding and reason. The idea of a fundamental power, the
existence of which no effort of logic can assure us of, is the problem
to be solved, for the systematic representation of the existing variety
of powers. The logical principle of reason requires us to produce as
great a unity as is possible in the system of our cognitions; and the
more the phenomena of this and the other power are found to be
identical, the more probable does it become, that they are nothing but
different manifestations of one and the same power, which may be
called, relatively speaking, a fundamental power. And so with other

These relatively fundamental powers must again be compared with each
other, to discover, if possible, the one radical and absolutely
fundamental power of which they are but the manifestations. But this
unity is purely hypothetical. It is not maintained, that this unity
does really exist, but that we must, in the interest of reason, that
is, for the establishment of principles for the various rules presented
by experience, try to discover and introduce it, so far as is
practicable, into the sphere of our cognitions.

But the transcendental employment of the understanding would lead us to
believe that this idea of a fundamental power is not problematical, but
that it possesses objective reality, and thus the systematic unity of
the various powers or forces in a substance is demanded by the
understanding and erected into an apodeictic or necessary principle.
For, without having attempted to discover the unity of the various
powers existing in nature, nay, even after all our attempts have
failed, we notwithstanding presuppose that it does exist, and may be,
sooner or later, discovered. And this reason does, not only, as in the
case above adduced, with regard to the unity of substance, but where
many substances, although all to a certain extent homogeneous, are
discoverable, as in the case of matter in general. Here also does
reason presuppose the existence of the systematic unity of various
powers—inasmuch as particular laws of nature are subordinate to general
laws; and parsimony in principles is not merely an economical principle
of reason, but an essential law of nature.

We cannot understand, in fact, how a logical principle of unity can of
right exist, unless we presuppose a transcendental principle, by which
such a systematic unit—as a property of objects themselves—is regarded
as necessary a priori. For with what right can reason, in its logical
exercise, require us to regard the variety of forces which nature
displays, as in effect a disguised unity, and to deduce them from one
fundamental force or power, when she is free to admit that it is just
as possible that all forces should be different in kind, and that a
systematic unity is not conformable to the design of nature? In this
view of the case, reason would be proceeding in direct opposition to
her own destination, by setting as an aim an idea which entirely
conflicts with the procedure and arrangement of nature. Neither can we
assert that reason has previously inferred this unity from the
contingent nature of phenomena. For the law of reason which requires us
to seek for this unity is a necessary law, inasmuch as without it we
should not possess a faculty of reason, nor without reason a consistent
and self-accordant mode of employing the understanding, nor, in the
absence of this, any proper and sufficient criterion of empirical
truth. In relation to this criterion, therefore, we must suppose the
idea of the systematic unity of nature to possess objective validity
and necessity.

We find this transcendental presupposition lurking in different forms
in the principles of philosophers, although they have neither
recognized it nor confessed to themselves its presence. That the
diversities of individual things do not exclude identity of species,
that the various species must be considered as merely different
determinations of a few genera, and these again as divisions of still
higher races, and so on—that, accordingly, a certain systematic unity
of all possible empirical conceptions, in so far as they can be deduced
from higher and more general conceptions, must be sought for, is a
scholastic maxim or logical principle, without which reason could not
be employed by us. For we can infer the particular from the general,
only in so far as general properties of things constitute the
foundation upon which the particular rest.

That the same unity exists in nature is presupposed by philosophers in
the well-known scholastic maxim, which forbids us unnecessarily to
augment the number of entities or principles (entia praeter
necessitatem non esse multiplicanda). This maxim asserts that nature
herself assists in the establishment of this unity of reason, and that
the seemingly infinite diversity of phenomena should not deter us from
the expectation of discovering beneath this diversity a unity of
fundamental properties, of which the aforesaid variety is but a more or
less determined form. This unity, although a mere idea, thinkers have
found it necessary rather to moderate the desire than to encourage it.
It was considered a great step when chemists were able to reduce all
salts to two main genera—acids and alkalis; and they regard this
difference as itself a mere variety, or different manifestation of one
and the same fundamental material. The different kinds of earths
(stones and even metals) chemists have endeavoured to reduce to three,
and afterwards to two; but still, not content with this advance, they
cannot but think that behind these diversities there lurks but one
genus—nay, that even salts and earths have a common principle. It might
be conjectured that this is merely an economical plan of reason, for
the purpose of sparing itself trouble, and an attempt of a purely
hypothetical character, which, when successful, gives an appearance of
probability to the principle of explanation employed by the reason. But
a selfish purpose of this kind is easily to be distinguished from the
idea, according to which every one presupposes that this unity is in
accordance with the laws of nature, and that reason does not in this
case request, but requires, although we are quite unable to determine
the proper limits of this unity.

If the diversity existing in phenomena—a diversity not of form (for in
this they may be similar) but of content—were so great that the
subtlest human reason could never by comparison discover in them the
least similarity (which is not impossible), in this case the logical
law of genera would be without foundation, the conception of a genus,
nay, all general conceptions would be impossible, and the faculty of
the understanding, the exercise of which is restricted to the world of
conceptions, could not exist. The logical principle of genera,
accordingly, if it is to be applied to nature (by which I mean objects
presented to our senses), presupposes a transcendental principle. In
accordance with this principle, homogeneity is necessarily presupposed
in the variety of phenomena (although we are unable to determine a
priori the degree of this homogeneity), because without it no empirical
conceptions, and consequently no experience, would be possible.

The logical principle of genera, which demands identity in phenomena,
is balanced by another principle—that of species, which requires
variety and diversity in things, notwithstanding their accordance in
the same genus, and directs the understanding to attend to the one no
less than to the other. This principle (of the faculty of distinction)
acts as a check upon the reason and reason exhibits in this respect a
double and conflicting interest—on the one hand, the interest in the
extent (the interest of generality) in relation to genera; on the
other, that of the content (the interest of individuality) in relation
to the variety of species. In the former case, the understanding
cogitates more under its conceptions, in the latter it cogitates more
in them. This distinction manifests itself likewise in the habits of
thought peculiar to natural philosophers, some of whom—the remarkably
speculative heads—may be said to be hostile to heterogeneity in
phenomena, and have their eyes always fixed on the unity of genera,
while others—with a strong empirical tendency—aim unceasingly at the
analysis of phenomena, and almost destroy in us the hope of ever being
able to estimate the character of these according to general

The latter mode of thought is evidently based upon a logical principle,
the aim of which is the systematic completeness of all cognitions. This
principle authorizes me, beginning at the genus, to descend to the
various and diverse contained under it; and in this way extension, as
in the former case unity, is assured to the system. For if we merely
examine the sphere of the conception which indicates a genus, we cannot
discover how far it is possible to proceed in the division of that
sphere; just as it is impossible, from the consideration of the space
occupied by matter, to determine how far we can proceed in the division
of it. Hence every genus must contain different species, and these
again different subspecies; and as each of the latter must itself
contain a sphere (must be of a certain extent, as a conceptus
communis), reason demands that no species or sub-species is to be
considered as the lowest possible. For a species or sub-species, being
always a conception, which contains only what is common to a number of
different things, does not completely determine any individual thing,
or relate immediately to it, and must consequently contain other
conceptions, that is, other sub-species under it. This law of
specification may be thus expressed: entium varietates non temere sunt

But it is easy to see that this logical law would likewise be without
sense or application, were it not based upon a transcendental law of
specification, which certainly does not require that the differences
existing phenomena should be infinite in number, for the logical
principle, which merely maintains the indeterminateness of the logical
sphere of a conception, in relation to its possible division, does not
authorize this statement; while it does impose upon the understanding
the duty of searching for subspecies to every species, and minor
differences in every difference. For, were there no lower conceptions,
neither could there be any higher. Now the understanding cognizes only
by means of conceptions; consequently, how far soever it may proceed in
division, never by mere intuition, but always by lower and lower
conceptions. The cognition of phenomena in their complete determination
(which is possible only by means of the understanding) requires an
unceasingly continued specification of conceptions, and a progression
to ever smaller differences, of which abstraction bad been made in the
conception of the species, and still more in that of the genus.

This law of specification cannot be deduced from experience; it can
never present us with a principle of so universal an application.
Empirical specification very soon stops in its distinction of
diversities, and requires the guidance of the transcendental law, as a
principle of the reason—a law which imposes on us the necessity of
never ceasing in our search for differences, even although these may
not present themselves to the senses. That absorbent earths are of
different kinds could only be discovered by obeying the anticipatory
law of reason, which imposes upon the understanding the task of
discovering the differences existing between these earths, and supposes
that nature is richer in substances than our senses would indicate. The
faculty of the understanding belongs to us just as much under the
presupposition of differences in the objects of nature, as under the
condition that these objects are homogeneous, because we could not
possess conceptions, nor make any use of our understanding, were not
the phenomena included under these conceptions in some respects
dissimilar, as well as similar, in their character.

Reason thus prepares the sphere of the understanding for the operations
of this faculty: 1. By the principle of the homogeneity of the diverse
in higher genera; 2. By the principle of the variety of the homogeneous
in lower species; and, to complete the systematic unity, it adds, 3. A
law of the affinity of all conceptions which prescribes a continuous
transition from one species to every other by the gradual increase of
diversity. We may term these the principles of the homogeneity, the
specification, and the continuity of forms. The latter results from the
union of the two former, inasmuch as we regard the systematic
connection as complete in thought, in the ascent to higher genera, as
well as in the descent to lower species. For all diversities must be
related to each other, as they all spring from one highest genus,
descending through the different gradations of a more and more extended

We may illustrate the systematic unity produced by the three logical
principles in the following manner. Every conception may be regarded as
a point, which, as the standpoint of a spectator, has a certain
horizon, which may be said to enclose a number of things that may be
viewed, so to speak, from that centre. Within this horizon there must
be an infinite number of other points, each of which has its own
horizon, smaller and more circumscribed; in other words, every species
contains sub-species, according to the principle of specification, and
the logical horizon consists of smaller horizons (subspecies), but not
of points (individuals), which possess no extent. But different
horizons or genera, which include under them so many conceptions, may
have one common horizon, from which, as from a mid-point, they may be
surveyed; and we may proceed thus, till we arrive at the highest genus,
or universal and true horizon, which is determined by the highest
conception, and which contains under itself all differences and
varieties, as genera, species, and subspecies.

To this highest standpoint I am conducted by the law of homogeneity, as
to all lower and more variously-determined conceptions by the law of
specification. Now as in this way there exists no void in the whole
extent of all possible conceptions, and as out of the sphere of these
the mind can discover nothing, there arises from the presupposition of
the universal horizon above mentioned, and its complete division, the
principle: Non datur vacuum formarum. This principle asserts that there
are not different primitive and highest genera, which stand isolated,
so to speak, from each other, but all the various genera are mere
divisions and limitations of one highest and universal genus; and hence
follows immediately the principle: Datur continuum formarum. This
principle indicates that all differences of species limit each other,
and do not admit of transition from one to another by a saltus, but
only through smaller degrees of the difference between the one species
and the other. In one word, there are no species or sub-species which
(in the view of reason) are the nearest possible to each other;
intermediate species or sub-species being always possible, the
difference of which from each of the former is always smaller than the
difference existing between these.

The first law, therefore, directs us to avoid the notion that there
exist different primal genera, and enounces the fact of perfect
homogeneity; the second imposes a check upon this tendency to unity and
prescribes the distinction of sub-species, before proceeding to apply
our general conceptions to individuals. The third unites both the
former, by enouncing the fact of homogeneity as existing even in the
most various diversity, by means of the gradual transition from one
species to another. Thus it indicates a relationship between the
different branches or species, in so far as they all spring from the
same stem.

But this logical law of the continuum specierum (formarum logicarum)
presupposes a transcendental principle (lex continui in natura),
without which the understanding might be led into error, by following
the guidance of the former, and thus perhaps pursuing a path contrary
to that prescribed by nature. This law must, consequently, be based
upon pure transcendental, and not upon empirical, considerations. For,
in the latter case, it would come later than the system; whereas it is
really itself the parent of all that is systematic in our cognition of
nature. These principles are not mere hypotheses employed for the
purpose of experimenting upon nature; although when any such connection
is discovered, it forms a solid ground for regarding the hypothetical
unity as valid in the sphere of nature—and thus they are in this
respect not without their use. But we go farther, and maintain that it
is manifest that these principles of parsimony in fundamental causes,
variety in effects, and affinity in phenomena, are in accordance both
with reason and nature, and that they are not mere methods or plans
devised for the purpose of assisting us in our observation of the
external world.

But it is plain that this continuity of forms is a mere idea, to which
no adequate object can be discovered in experience. And this for two
reasons. First, because the species in nature are really divided, and
hence form quanta discreta; and, if the gradual progression through
their affinity were continuous, the intermediate members lying between
two given species must be infinite in number, which is impossible.
Secondly, because we cannot make any determinate empirical use of this
law, inasmuch as it does not present us with any criterion of affinity
which could aid us in determining how far we ought to pursue the
graduation of differences: it merely contains a general indication that
it is our duty to seek for and, if possible, to discover them.

When we arrange these principles of systematic unity in the order
conformable to their employment in experience, they will stand thus:
Variety, Affinity, Unity, each of them, as ideas, being taken in the
highest degree of their completeness. Reason presupposes the existence
of cognitions of the understanding, which have a direct relation to
experience, and aims at the ideal unity of these cognitions—a unity
which far transcends all experience or empirical notions. The affinity
of the diverse, notwithstanding the differences existing between its
parts, has a relation to things, but a still closer one to the mere
properties and powers of things. For example, imperfect experience may
represent the orbits of the planets as circular. But we discover
variations from this course, and we proceed to suppose that the planets
revolve in a path which, if not a circle, is of a character very
similar to it. That is to say, the movements of those planets which do
not form a circle will approximate more or less to the properties of a
circle, and probably form an ellipse. The paths of comets exhibit still
greater variations, for, so far as our observation extends, they do not
return upon their own course in a circle or ellipse. But we proceed to
the conjecture that comets describe a parabola, a figure which is
closely allied to the ellipse. In fact, a parabola is merely an
ellipse, with its longer axis produced to an indefinite extent. Thus
these principles conduct us to a unity in the genera of the forms of
these orbits, and, proceeding farther, to a unity as regards the cause
of the motions of the heavenly bodies—that is, gravitation. But we go
on extending our conquests over nature, and endeavour to explain all
seeming deviations from these rules, and even make additions to our
system which no experience can ever substantiate—for example, the
theory, in affinity with that of ellipses, of hyperbolic paths of
comets, pursuing which, these bodies leave our solar system and,
passing from sun to sun, unite the most distant parts of the infinite
universe, which is held together by the same moving power.

The most remarkable circumstance connected with these principles is
that they seem to be transcendental, and, although only containing
ideas for the guidance of the empirical exercise of reason, and
although this empirical employment stands to these ideas in an
asymptotic relation alone (to use a mathematical term), that is,
continually approximate, without ever being able to attain to them,
they possess, notwithstanding, as a priori synthetical propositions,
objective though undetermined validity, and are available as rules for
possible experience. In the elaboration of our experience, they may
also be employed with great advantage, as heuristic [Footnote: From the
Greek, eurhioko.] principles. A transcendental deduction of them cannot
be made; such a deduction being always impossible in the case of ideas,
as has been already shown.

We distinguished, in the Transcendental Analytic, the dynamical
principles of the understanding, which are regulative principles of
intuition, from the mathematical, which are constitutive principles of
intuition. These dynamical laws are, however, constitutive in relation
to experience, inasmuch as they render the conceptions without which
experience could not exist possible a priori. But the principles of
pure reason cannot be constitutive even in regard to empirical
conceptions, because no sensuous schema corresponding to them can be
discovered, and they cannot therefore have an object in concreto. Now,
if I grant that they cannot be employed in the sphere of experience, as
constitutive principles, how shall I secure for them employment and
objective validity as regulative principles, and in what way can they
be so employed?

The understanding is the object of reason, as sensibility is the object
of the understanding. The production of systematic unity in all the
empirical operations of the understanding is the proper occupation of
reason; just as it is the business of the understanding to connect the
various content of phenomena by means of conceptions, and subject them
to empirical laws. But the operations of the understanding are, without
the schemata of sensibility, undetermined; and, in the same manner, the
unity of reason is perfectly undetermined as regards the conditions
under which, and the extent to which, the understanding ought to carry
the systematic connection of its conceptions. But, although it is
impossible to discover in intuition a schema for the complete
systematic unity of all the conceptions of the understanding, there
must be some analogon of this schema. This analogon is the idea of the
maximum of the division and the connection of our cognition in one
principle. For we may have a determinate notion of a maximum and an
absolutely perfect, all the restrictive conditions which are connected
with an indeterminate and various content having been abstracted. Thus
the idea of reason is analogous with a sensuous schema, with this
difference, that the application of the categories to the schema of
reason does not present a cognition of any object (as is the case with
the application of the categories to sensuous schemata), but merely
provides us with a rule or principle for the systematic unity of the
exercise of the understanding. Now, as every principle which imposes
upon the exercise of the understanding a priori compliance with the
rule of systematic unity also relates, although only in an indirect
manner, to an object of experience, the principles of pure reason will
also possess objective reality and validity in relation to experience.
But they will not aim at determining our knowledge in regard to any
empirical object; they will merely indicate the procedure, following
which the empirical and determinate exercise of the understanding may
be in complete harmony and connection with itself—a result which is
produced by its being brought into harmony with the principle of
systematic unity, so far as that is possible, and deduced from it.

I term all subjective principles, which are not derived from
observation of the constitution of an object, but from the interest
which Reason has in producing a certain completeness in her cognition
of that object, maxims of reason. Thus there are maxims of speculative
reason, which are based solely upon its speculative interest, although
they appear to be objective principles.

When principles which are really regulative are regarded as
constitutive, and employed as objective principles, contradictions must
arise; but if they are considered as mere maxims, there is no room for
contradictions of any kind, as they then merely indicate the different
interests of reason, which occasion differences in the mode of thought.
In effect, Reason has only one single interest, and the seeming
contradiction existing between her maxims merely indicates a difference
in, and a reciprocal limitation of, the methods by which this interest
is satisfied.

This reasoner has at heart the interest of diversity—in accordance with
the principle of specification; another, the interest of unity—in
accordance with the principle of aggregation. Each believes that his
judgement rests upon a thorough insight into the subject he is
examining, and yet it has been influenced solely by a greater or less
degree of adherence to some one of the two principles, neither of which
are objective, but originate solely from the interest of reason, and on
this account to be termed maxims rather than principles. When I observe
intelligent men disputing about the distinctive characteristics of men,
animals, or plants, and even of minerals, those on the one side
assuming the existence of certain national characteristics, certain
well-defined and hereditary distinctions of family, race, and so on,
while the other side maintain that nature has endowed all races of men
with the same faculties and dispositions, and that all differences are
but the result of external and accidental circumstances—I have only to
consider for a moment the real nature of the subject of discussion, to
arrive at the conclusion that it is a subject far too deep for us to
judge of, and that there is little probability of either party being
able to speak from a perfect insight into and understanding of the
nature of the subject itself. Both have, in reality, been struggling
for the twofold interest of reason; the one maintaining the one
interest, the other the other. But this difference between the maxims
of diversity and unity may easily be reconciled and adjusted; although,
so long as they are regarded as objective principles, they must
occasion not only contradictions and polemic, but place hinderances in
the way of the advancement of truth, until some means is discovered of
reconciling these conflicting interests, and bringing reason into union
and harmony with itself.

The same is the case with the so-called law discovered by Leibnitz, and
supported with remarkable ability by Bonnet—the law of the continuous
gradation of created beings, which is nothing more than an inference
from the principle of affinity; for observation and study of the order
of nature could never present it to the mind as an objective truth. The
steps of this ladder, as they appear in experience, are too far apart
from each other, and the so-called petty differences between different
kinds of animals are in nature commonly so wide separations that no
confidence can be placed in such views (particularly when we reflect on
the great variety of things, and the ease with which we can discover
resemblances), and no faith in the laws which are said to express the
aims and purposes of nature. On the other hand, the method of
investigating the order of nature in the light of this principle, and
the maxim which requires us to regard this order—it being still
undetermined how far it extends—as really existing in nature, is beyond
doubt a legitimate and excellent principle of reason—a principle which
extends farther than any experience or observation of ours and which,
without giving us any positive knowledge of anything in the region of
experience, guides us to the goal of systematic unity.

Of the Ultimate End of the Natural Dialectic of Human Reason.

The ideas of pure reason cannot be, of themselves and in their own
nature, dialectical; it is from their misemployment alone that
fallacies and illusions arise. For they originate in the nature of
reason itself, and it is impossible that this supreme tribunal for all
the rights and claims of speculation should be itself undeserving of
confidence and promotive of error. It is to be expected, therefore,
that these ideas have a genuine and legitimate aim. It is true, the mob
of sophists raise against reason the cry of inconsistency and
contradiction, and affect to despise the government of that faculty,
because they cannot understand its constitution, while it is to its
beneficial influences alone that they owe the position and the
intelligence which enable them to criticize and to blame its procedure.

We cannot employ an a priori conception with certainty, until we have
made a transcendental deduction therefore. The ideas of pure reason do
not admit of the same kind of deduction as the categories. But if they
are to possess the least objective validity, and to represent anything
but mere creations of thought (entia rationis ratiocinantis), a
deduction of them must be possible. This deduction will complete the
critical task imposed upon pure reason; and it is to this part Of our
labours that we now proceed.

There is a great difference between a thing’s being presented to the
mind as an object in an absolute sense, or merely as an ideal object.
In the former case I employ my conceptions to determine the object; in
the latter case nothing is present to the mind but a mere schema, which
does not relate directly to an object, not even in a hypothetical
sense, but which is useful only for the purpose of representing other
objects to the mind, in a mediate and indirect manner, by means of
their relation to the idea in the intellect. Thus I say the conception
of a supreme intelligence is a mere idea; that is to say, its objective
reality does not consist in the fact that it has an immediate relation
to an object (for in this sense we have no means of establishing its
objective validity), it is merely a schema constructed according to the
necessary conditions of the unity of reason—the schema of a thing in
general, which is useful towards the production of the highest degree
of systematic unity in the empirical exercise of reason, in which we
deduce this or that object of experience from the imaginary object of
this idea, as the ground or cause of the said object of experience. In
this way, the idea is properly a heuristic, and not an ostensive,
conception; it does not give us any information respecting the
constitution of an object, it merely indicates how, under the guidance
of the idea, we ought to investigate the constitution and the relations
of objects in the world of experience. Now, if it can be shown that the
three kinds of transcendental ideas (psychological, cosmological, and
theological), although not relating directly to any object nor
determining it, do nevertheless, on the supposition of the existence of
an ideal object, produce systematic unity in the laws of the empirical
employment of the reason, and extend our empirical cognition, without
ever being inconsistent or in opposition with it—it must be a necessary
maxim of reason to regulate its procedure according to these ideas. And
this forms the transcendental deduction of all speculative ideas, not
as constitutive principles of the extension of our cognition beyond the
limits of our experience, but as regulative principles of the
systematic unity of empirical cognition, which is by the aid of these
ideas arranged and emended within its own proper limits, to an extent
unattainable by the operation of the principles of the understanding

I shall make this plainer. Guided by the principles involved in these
ideas, we must, in the first place, so connect all the phenomena,
actions, and feelings of the mind, as if it were a simple substance,
which, endowed with personal identity, possesses a permanent existence
(in this life at least), while its states, among which those of the
body are to be included as external conditions, are in continual
change. Secondly, in cosmology, we must investigate the conditions of
all natural phenomena, internal as well as external, as if they
belonged to a chain infinite and without any prime or supreme member,
while we do not, on this account, deny the existence of intelligible
grounds of these phenomena, although we never employ them to explain
phenomena, for the simple reason that they are not objects of our
cognition. Thirdly, in the sphere of theology, we must regard the whole
system of possible experience as forming an absolute, but dependent and
sensuously-conditioned unity, and at the same time as based upon a
sole, supreme, and all-sufficient ground existing apart from the world
itself—a ground which is a self-subsistent, primeval and creative
reason, in relation to which we so employ our reason in the field of
experience, as if all objects drew their origin from that archetype of
all reason. In other words, we ought not to deduce the internal
phenomena of the mind from a simple thinking substance, but deduce them
from each other under the guidance of the regulative idea of a simple
being; we ought not to deduce the phenomena, order, and unity of the
universe from a supreme intelligence, but merely draw from this idea of
a supremely wise cause the rules which must guide reason in its
connection of causes and effects.

Now there is nothing to hinder us from admitti