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CRITIQUE OF
PURE REASON
IMMANUEL KANT
WITH
AN INTRODUCTION BY THE TRANSLATOR,
J. M. D. MEIKLEJOHN
AND A SPECIAL INTRODUCTION BY
BRANDT V. B. DIXON, LL.D.
PRESIDENT OF NEWCOMB MEMORIAL COLLEGE,
NEW ORLEANS, LA.
REVISED EDITION
COLONIAL
SEP 3
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COPYRIGHT, 1900, BY
THE COLONIAL PRESS
SPECIAL INTRODUCTION
THE philosophy of Immanuel Kant marks an epoch in
the history of modern thought, since it is the rational
outcome of previous speculation, offers a profounder
solution of its problems, and forms the basis of a new de
parture. On the one hand, it sums up the notions formerly held
to be essential and necessary, reveals their inadequacy or im
perfections, and, on the other hand, opens up a fresh and fruitful
field of metaphysical inquiry. To gain a clear idea of its mean
ing and scope, it should be studied in connection with the
philosophic movement of which it is a most important factor.
The transition from the mediaeval to the modern view of the
world involved a profound change in the fundamental convic
tion or assumption which men held in regard to experience and
the sources of knowledge. In the Middle Ages, as in child
hood, opinions were formed subject to external authority; the
evidence of perception or of reason had little relative force ; the
motive for independent inquiry was weak or altogether want
ing; judgment and faith must needs conform to the dictations
of the masters, the decrees of the Church, or the words of super
natural revelation. But, with a growing trust in reason, the
bondage of mere authority was loosened, and a scientific spirit
of investigation arose. Men began to acquire a degree of con
fidence in their ability to discover truth by searching for it,
and an assurance that opinions were valid if well attested by
reason.
This confidence, however, implies the assumption that the
truth, power, or reason of things is, in some way, within them ;
and that the inquiring mind may appropriate it, at least in the
form of knowledge. It, in fact, presupposes some sort of like
ness or identity between the mind and the world ; the posses
sion in common of the nature of reason. The mediaeval view of
the world implied the principle of divine transcendence, but this
iv KANT
new view depends upon the principle of divine immanence,
which dominates all modern thought. To the former the crea
tive power was somehow outside and remote, and the world was
the magical result of an external, unintelligible whim or decree ;
to the latter the world is becoming an intelligible order. Science
proceeds upon the faith that nature contains her own explana
tion ; and free metaphysical inquiry arises in the trust that reason
will make its own revelation.
In the attempt to understand and explain experience, the ob
server is at first greatly impressed with the difference between
objects, or things without, and subject, or the inner mind, which
feels, perceives, and reflects. This seems, at first, so evident and
so extreme as to occasion the belief that they manifest distinct
beings, or substances, essentially unlike. They are contrasted
as outer and inner, extended and non-extended, passive and ac
tive, object and subject, matter and spirit; the former insen
sate, inert, controlled by alien force or influence ; the latter
intelligent, active, and free. But despite this seeming dualism,
some kind of harmony is indicated by the fact that these two
sides are united in a single experience, since one mind conceives
both of them, and that they are connected with each other in
infinitely various ways, especially in and through the body,
which the spirit is supposed to occupy, and by which action and
reaction are maintained with the material world. Moreover, the
need for unity which is fundamental in philosophy requires that
these contradictions shall be resolved.
From the sixteenth century, therefore, the most important
problem of metaphysics has been to establish a monistic theory
of the universe ; for, although dualism may seem sufficient for
practical life, and not objectionable from the point of view of
mere common-sense, which does not reflect deeply, it is essen
tially illogical, and a consistent philosophy cannot tolerate it.
There can be but one essentially true form of being, of which all
particular beings are specific manifestations. Upon this point,
materialism and idealism are agreed, though they differ as to
their conception of what may be this only and true being or
substance.
The study of the natural sciences gave great weight to the evi
dence of facts, and, as philosophy gradually abandoned dual
ism, it sought for a plausible theory based upon the belief that
SPECIAL INTRODUCTION v
bodies possessed objective and absolute existence. During the
eighteenth century materialism reached its most extreme ex
pression in France as shown by the writings of La Mettrie,
Condorcet, Diderot, and others of this school. By this time,
however, matter was no longer conceived as merely inert, but
endowed with force, an intermediate kind of being, a link be
tween matter and spirit. By means of this conception of force,
matter came to be regarded as a potent substance, able to pro
duce from itself all manner of existence, so that every form of
life, feeling, and thought were considered to be results of its ac
tivity. Thus it appears to be both active and passive, cause and
result. All the contradictions formerly held to separate matter
and spirit, now come to be ascribed to matter in itself. This,
however, furnishes no real explanation of them ; for if one ad
mits that the body thinks and that matter produces or possesses
consciousness, no intelligible notion is thereby gained as to how
atomic motion, or mass motion in space and time, becomes a
sensation, emotion, or thought. The subjective and objective
realms are not brought into any comprehensible unity merely byj
.asserting that they are alike resultants of a single substance. |
Even in the study of objective nature, all scientific theories based
upon the ideas of matter and force, themselves contrary notions,
are involved in contradiction, and must be constantly modified
to explain new discoveries, or fit new conditions. On the other
hand, although the inconsistency of this crude form of material
ism is easily shown, and its hypothesis will not satisfy careful
criticism, the great discoveries, and, indeed, the whole develop
ment of science and its practical application to human needs,
confirms and intensifies the original conviction that the objec
tive world is profoundly rational, and a valid manifestation of
infinite and absolute reality, difficulty, and contradictions not
withstanding.
The point of view of idealism, on the other hand, is sub-,
jective or psychological. The objective world is seen as a man-,
ifestation of mental activity, in which the material is sensation, 1
and the method is thought. The outer appearance of things, '
is, therefo/e, nothing more than an exhibit of the inner or sub
jective facts. Mind is the prior condition of all apparent reality.
Every experience is that which the mind has of itself: there
is no other conceivable world. The one which common-sense
vi KANT
and science think that they know, is but the display of that same
thinking and knowing. One deals everywhere with that which
is in essence spiritual. All things consist of the substance of
spirit, which may enter directly into experience; but matter,
considered as " mere stupid substratum " of accidents and qual
ities, is to be utterly repudiated.
Idealism may fairly claim to be more strictly logical and con
sistent than materialism, and escapes its tendency to fatalism.
Without doubt matter is a derived conception, an inference from
mental data ; and all the facts and laws of the known universe
are resolvable into the sensations, perceptions, and reflections
of the cognizing mind. But if this view be narrowly held, if the
independent validity of the outer world be denied, and it is con
sidered merely as an illusion, the mind ignores that profounder
instinct of its own being which intuitively asserts the objective
validity of experience, and which spontaneously credits the
world with independent being. It shuts itself within the confines
of its present consciousness, fails to recognize its own limitations,
and loses that incentive to observation and investigation which
materialism arouses, and is essential to continuous progress.
Moreover, the contradictions of experience are not solved merely
by the assumption that objective matter or subjective mind
alone exists. If either of these substances is to be accepted, the
contradiction falls within it and requires explanation. If dual
ism is to be rejected either matter has subjectivity or mind has
objectivity ; and it remains to be shown that this is possible.
In opposition to the one-sided and somewhat dogmatic claims
of materialism and idealism, the critical philosophy proposes to
ignore these presuppositions of matter and mind, and investigate
directly the nature of experience or knowledge, for in experi-
ence we have an indisputable possession which all must accept.
f From John Locke to Immanuel Kant, therefore, a growing im-
' portance was attached to the inquiry concerning the nature and
capacity of the human understanding, and the criterion of truth.
Experience is the fact to be examined, and it immediately ap
pears to consist of an indefinite number and variety of particular
sensations, ideas, and feelings, harmoniously organized. There
is no appearance of an essence or substance. There are, indeed,
sensations of various sorts, such as hardness, color, etc., but
nowhere matter as such ; feelings, emotions, etc., but not mind.
SPECIAL INTRODUCTION vn
Each of these is a generalized conception, which expresses the
notion that each of the two sides of experience is unified or
organized throughout. The acute scepticism of David Hume
is directed against the immediate knowledge of principles gen
erally. All our ideas, he insists, arise from sensations: these
are known directly, and, although by their order and connec
tion they presuppose certain principles which unite them, such
principles are only suspected or inferred by observation or ex
perience, after it has been constructed : they cannot be directly
observed. Therefore, ideas of the substances matter and mind,
or of the organizing principles of experience which he enumer
ates as resemblance, contiguity in time and space, and causality,
do not exist in thought prior to experience, as idealism claims.
His argument is at best but partially successful, for in the effort
to demonstrate that ideas could not be innate, and must arise
by reflection upon experience, he found it necessary to show
with great clearness that experience in its turn was the result
of definite constructive principles, uniformly valid for all minds.
This, indeed, would seem to be the most important outcome of
his effort. Experience in general, however, varied and dis
cordant, is the expression of principles or processes, which are
themselves fixed and uniform. Not only is this shown in the ar
rangement and connection of the so-called elementary sensa
tions in harmonious relations with one another, but each sense
or perception detail, as may easily be observed, is itself a com
plex product, revealing the truth that processes have been at
work before it made its appearance in perception. A clear dis-
.tinction should be made between the process which is prior to
experience, and the idea which is derived from it, though the
same term be applied to both. Causality for example is an idea
formed by observation of a specific habit of the reason as re
vealed in its conscious results; as a conscious idea, it arises
after the fact. But experience when it arises and is first ob
served reveals that its various elements have already been
causally connected. Causality, as a constructive mode or proc
ess, has already been at work, and the work thus done makes it
possible for the mind to recognize the causal relations which it
has already brought about. Causality is, therefore, a priori
process, an act producing the fact of experience, from which
the idea of causality is derived. This is but an illustration
viii KANT
which applies to all the forms of knowing. As apprehended
consciously they are ideas derived by reflection upon experi
ence. As such, they are subject to revision, and may be vari
ously understood or misunderstood : but as a priori processes
they possess a fixed and immutable character, and a spontane
ous and necessary activity. The material, of whatever sort it
may be, which enters into experience, must first receive the
impress of these activities, and, when it emerges as a perceived
fact, it is revealed as their resultant, possessing the form which
they have given it. Not only is this true of experience as an
organized whole, but it may also be easily seen in regard to
each element thereof. Any objective thing is also a subjective
sense-perception. As such, it is never simple, but may be re
solved into its so-called properties or qualities. Each of these
is specifically known only by comparison and contrast with
others; and the object or thing becomes such for the mind
only after these several and distinct qualities have been com
bined in a single perception. As qualities they are perceived
successively; but, as a thing, they are coincident. In any
given perception, moreover, only a few of the ascribed qualities
are immediately presented : many more are supplied by the
imagination : the object is the unit result of all of them and
is brought into existence for perception by an a priori synthetic
process. Even the simplest sensations which have been sup
posed to be elementary are in fact not so, or at least not when
they make their appearance. Each one discloses that it may
be analyzed and, therefore, is already a synthetic product, pos
sessing the conditions of time, space, quality, etc., relations of
various kinds. All knowledge is synthetic.
The problem which Kant set for himself was to discover
these a priori forms, or synthetic processes of reason ; and his
Critique is an effort to exhibit these in a systematic manner.
He accepts neither sensationalism nor idealism, in the narrow
sense, but aims to be transcendental : i.e., to find a higher stand
point by which their opposing views, anc the dualism of ex
perience generally, may be explained. He admits on the one
hand that sensation furnishes the matter of ideas, and with the
latter that their form is given by the active reason; but this
sensation-matter is not to him the intelligible perceived data
SPECIAL INTRODUCTION ix
as sensationalism taught, nor is the form the conscious idea of
the idealists. Both are prior to experience and are its factors.
The " Critique of Pure Reason " is then an inquiry into the
resources of reason for the construction of experience ; an in
vestigation of its universal and necessary forms, whereby the
;' chaos of mere stimuli is converted into an orderly, organized
world.
The entire argument is his answer to the question which he at
first propounds. How is synthetic knowledge h priori possible ?
After distinguishing between the mere matter and form of
thought, the sense stimuli and the functions of intelligence, he
devotes his attention almost entirely to the latter. There is,
however, a constant implication that his material-be^ 'ore-knowl
edge, this thing-in-itself, outside of and antecedent to the opera
tions of the intellect, lies necessarily beyond the domain of
human thought ; and, on this account, the Critique reaches the
inevitable conclusion that the intellect is shut up within the
domain of its own forms : these prescribe for it the limitations
within which it must forever move. In postulating a thing-in-
itself outside of intelligence, and thus its non-being, Kant fails
to escape dualism ; although, in causing, as he supposed, the
whole of experience to fall under the rational procedure, he
seems at first thought to have achieved a monistic explanation
of it.
But is it necessary to assume that the thing-in-itself has an
unknowable nature? It is clear that as mere matter of sensa
tion, it must have a relation to the processes; since it is re
ceived and used. Also, this relation must be a varied one, since
it is variously used by the different rational functions. Indeed,
it must possess a nature correspondent to the totality of these
functions, an adaptability for experience in general. In what
respect, therefore, can it be said that it lies necessarily outside
the domain of the intellect ? Still further, it seems necessary to
experience, and, as finished product, so to speak, pervades the
latter in every detail. It is apparently as necessary as the func
tions themselves, and is forever in reciprocal relation with them.
Thus Kant seems to be involved in a confusion in which he
maintains the necessary existence of a thing-in-itself, in contrast
to intellect ; but which, nevertheless, must be correlated most
intimately in every cognitive act. If he asserts its existence at
x KANT
all, he subjects it to rational conditions, i.e., gives it a knowable
nature ; which, however, he denies to it. To overcome this con
tradiction in the " Critique of Pure Reason," which occasioned
in it whatever was negative and unsatisfactory, was to be the
task of Kant's successors ; but, for the time being, philosophy
concerned itself with the positive results of his great criticism.
Having satisfied himself that every mental act is a synthesis,
he proceeds to describe the intellectual system, and its functions.
He distinguishes between sensibility which produces sensible
perceptions or ideas, and the understanding which elaborates
them. In the latter, again, he separates the faculty of synthetic
connection of sense intuitions (i.e., the judgment) from the
reason which arranges these judgments under a series of univer
sal ideas. His entire work is a unity of three separate inquiries :
the transcendental (primordial and creative) character of the
sense-intuitions (^Esthetic), of the judgment (Analytic), and
of the reason (Dialectic).
In the first of these he discusses the a priori nature of space
and time. These are shown to be modes of intuiting or perceiv
ing objects; processes of the mind; forms not belonging to
things-in-themseh'es, but imposed upon them by the mental act.
The whole apparent world is thus a transformed world, a
phenomenon.
The results of the sense-intuitions are synthetically arranged
by the forms of the judgment, the categories, twelve in number,
arranged in four groups of three each, denominated quantity,
quality, relation, and modality. One of these, however, relation,
governs and embraces all the others.
Lastly, the reason (in the narrow sense of the term) furnishes
the universal concepts, the absolute, the universe, soul, and God,
under which the infinite mass of judgments are organized, and
the whole of experience reduced to a system.
The above scheme may, perhaps, be criticised, from a modern
point of view, as being mechanical, the result of a somewhat
expirical and selective process, rather than as the necessary de
velopment of a fundamental rational conception. A careful
consideration of his argument will, however, reveal this : that
Kant everywhere assumes the self-activity of reason as the
ground of all experience, and its supreme condition. In this
he presents a view which is far richer and more profound than
SPECIAL INTRODUCTION xi
any which had yet appeared, and from which the thought of the
present century has drawn its chief inspiration. It is true that,
in his philosophy, all objectivity is not explained or assimilated ;
the thin g-in-its elf is, as yet, the unintelligible, but it is not, there
fore, even to Kant essentially and necessarily the unreason.
It remained to be shown that self-consciousness, in appre
hending its own nature in the object, potentially contained the
whole nature of that object without any unknowable residue;
that reason in its essential nature is fully and completely self-
determined, a self-expressed, self-cognizing will.
Kant furnished the necessary conception ; its full realization
he left to others.
KANT'S PREFACE
TO THE FIRST EDITION
(1781)
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 can
not 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 labors 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 con
tradictions, 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 Metaphysic.
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 honor. Now, it is the fashion of the time to heap contempt
and scorn upon her ; and the matron mourns, forlorn and for
saken, like Hecuba.
" Modo maxima rerum,
Tot generis, natisque potens . . .
Nunc trahor exul, inops." *
* Ovid, Metamorphoses.
xiv KANT
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 em
pire 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 under
standing — 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 ex
perience, 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 Meta-
physic necessarily fell back into the antiquated and rotten con
stitution 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 hu
manity. 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 con
tempt. At the same time, this indifference, which has arisen in
the world of science, and which relates to that kind of knowl
edge which we should wish to see destroyed the last, is a phe
nomenon that well deserves our attention and reflection. It is
plainly not the effect of the levity, but of the matured judg-
PREFACE TO THE FIRST EDITION xv
went * 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-ex
amination, 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.
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 re
garding the possibility or impossibility of Metaphysic, 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, dis
covered 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 re
turned 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 prin
ciples, 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 ex
pected ; for it can only be satisfied by the exercise of magical
arts, and of these I have no knowledge. But neither do these
* 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.
XVI
KANT
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 pre
sented by it prove to be insufficient for the solution of even a
single one of those questions to which the very nature of rea
son 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 philo
sophical programme, in which the dogmatist professes to dem
onstrate 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. In
stead 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 com
plete and systematic catalogue of all the simple operations of
reason ; and it is my task to answer the question how far rea
son can go, without the material presented and the aid fur
nished 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 in
quiry. As regards the form, there are two indispensable con
ditions which anyone who undertakes so difficult a task as that
of a critique of pure reason is bound to fulfil. These conditions
are certitude and clearness.
As regards certitude, I have fully convinced myself that, in
this sphere of thought, opinion is perfectly inadmissible, and
PREFACE TO THE FIRST EDITION xvii
that everything which bears the least semblance of a hypo
thesis 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 ab
solutely 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 apodictic
(philosophical) certitude. Whether I have succeeded in what
1 professed to do, it is for the reader to determine; it is the
author's business merely to adduce grounds and reasons, with
out determining what influence these ought to have on the mind
of his judges. But, lest anything he may have said may be
come the innocent cause of doubt in their minds, or tend to
weaken the effect which his arguments might otherwise pro
duce — he may be allowed to point out those passages which
may occasion mistrust or difficulty, although these do not con
cern 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 judgment 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 labor — labor 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 rea
son 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, al
though this exposition is of great importance, it does not be
long essentially to the main purpose of the work, because the
grand question is what and how much can reason and under
standing, 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 sem-
xviii KANT
blance of a 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 announce 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 sub
jective 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 clear
ness, by means of intuitions, that is, by examples or other
modes of illustration in concrete. 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 in
ability 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 de
livered 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 con
sideration also, that the present work is not intended for popu
lar 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. Abbe Ter-
rasson 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 comprehensi-
bility 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
PREFACE TO THE FIRST EDITION xix
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 con
ception of the ti'hole; as he cannot attain soon enough to a
survey of the system, and the coloring and embellishments be
stowed upon it prevent his observing its articulation or organi
zation — 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 sci
ence, according to the plan now laid before him. Metaphysics,
as here represented, is the only science which admits of com
pletion — and with little labor, 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 sci
ence is nothing more than the inventory of all that is given
us by pure reason, systematically arranged. Nothing can es
cape 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 de
terminate experience, renders this completeness not only prac
ticable, but also necessary.
" Tecum habita, et noris quam sit tibi curta supellex."*
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 condi
tions 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-laborer.
For, however complete the list of principles for this system.
* Persius. <
t This work was never published.
xx KANT
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 labor.
CONTENTS
INTRODUCTION
r/iGB
I. Of the Difference between Pure and Empirical Knowledge.. I
II. The Human Intellect, even in an unphilosophical state, is in
possession of certain cognitions a priori 2
III. Philosophy stands in need of a Science which shall determine
the possibility, principles, and extent of Human Knowledge
a priori 4
IV. Of the Difference between Analytical and Synthetical Judg
ments 7
V. In all Theoretical Sciences of Reason, Synthetical Judgments
a priori are contained as Principles 9
VI. The Universal Problem of Pure Reason 12
VII. Idea and Division of a Particular Science, under the Name
of a Critique of Pure Reason 15
TRANSCENDENTAL DOCTRINE OF ELEMENTS
PART I. — TRANSCENDENTAL ESTHETIC
Introductory 21
SECTION I. OF SPACE
Metaphysical Exposition of this Conception 23
Transcendental Exposition of the Conception of Space. ... 25
Conclusions from the foregoing Conceptions 25
SECTION II. OF TIME
Metaphysical Exposition of this Conception 28
Transcendental Exposition of the Conception of Time.... 29
Conclusions from the above Conceptions 30
Elucidation 32
General Remarks on Transcendental Esthetic 35
PART II.— TRANSCENDENTAL LOGIC
I. Of Logic in general 44
II. Of Transcendental Logic 47
III. Of the Division of General Logic into Analytic and Dialectic. . 48
IV. Of the Division of Transcendental Logic into Transcendental
Analytic and Dialectic 51
xxi
jurii KANT
First Division
PAGS
TRANSCENDENTAL ANALYTIC 32
BOOK I. ANALYTIC OF CONCEPTIONS 53
CHAP. I. Of the Transcendental Clue to the Discovery of all Pure
Conceptions of the Understanding 53
SECTION I. Of the Logical use of the Understanding in general. 54
SECTION II. Of the Logical Function of the Understanding in ^*
Judgments 551
SECTION III. Of the Pure Conceptions of the Understanding, or /
Categories 6oS
CHAP. II. Of the Deduction of the Pure Conceptions of the Un
derstanding
SECTION I. Of the Principles of Transcendental Deduction fn
general , 68
Transition to the Transcendental Deduction of the Categories. . 72
SECTION II. Of the Possibility of a Conjunction of the manifold
representations given by Sensje 75
Of the Originally Synthetical Unity of Apperception 76
The Principle of the Synthetical Unity of Apperception is the
highest Principle of all exercise of the Understanding 79
What Objective Unity of Self-consciousness is 80
The Logical Form of all Judgments consists in the Objective
Unity of Apperception of the Conceptions contained therein 81
All Sensuous Intuitions are subject to the Categories, as Con
ditions under which alone the manifold contents of them can
be united in one Consciousness 82
Observation 83
In Cognition, its Application to Objects of Experience is the
only legitimate use of the Category 84
Of the Application of the Categories to Objects of the Senses
in general 86
Transcendental Deduction of the universally possible employ
ment in experience of the Pure Conceptions of the Under
standing 91
Result of this Deduction of the Conceptions of the Under
standing 94
Short view of the above Deduction 96
BOOK II. ANALYTIC OF PRINCIPLES 97
Of the Transcendental Faculty of Judgment in general 98
CHAP. I. Of the Schematism of the Pure Conceptions of the Un
derstanding 100
CHAP. II. System of all Principles of the Pure Understanding. . . . 106
SECTION I^Of the Supreme Principle of all Analytical Judg
ments ioS
CONTENTS xxiu
PACE
SECTION II. Of the Supreme Principle of all Synthetical Judg
ments no
SECTION III. Systematic Representations of all Synthetical Prin
ciples thereof 1 1"2
I. Axioms of Intuition 115
II. Anticipations of Perception 117
III. Analogies of Experience 122
A. First Analogy. — Principle of the Permanence of Sub
stance 124
t-B. Second Analogy. — Principle of the Succession of Time.*>i28
C. Third Analogy. — Principle of Coexistence 138
IV. The Postulates of Empirical Thought 142
Refutation of Idealism 147
General Remark on the System of Principles 153
CHAP. III. Of the Ground of the division of all objects into Phe-'
nomena and Noumena (156
APPENDIX. Of the Equivocal Nature or Amphiboly of the Con
ceptions of Reflection from the Confusion of the Transcen
dental with the Empirical use of the Understanding 168
Remark on the Amphiboly of the Conceptions of Reflection 172
Second Division
TRANSCENDENTAL DIALECTIC
I. Of Transcendental Illusory Appearance 186
II. Of Pure Reason as the Seat of Transcendental Illusory Ap
pearance 189
A. Of Reason in General 189*
B. Of the Logical Use of Reason 192
C. Of the Pure Use of Reason 193
BOOK I. OF THE CONCEPTIONS OF PURE REASON 196
SECTION I. Of Ideas in General 197
SECTION II. Of Transcendental Ideas 202
SECTION III. System of Transcendental Ideas 209
BOOK II. OF THE DIALECTICAL PROCEDURE OF PURE REASON 212
BOOK I. OF THE CONCEPTIONS OF PURE REASON 196
Refutation of the Argument o! Mendelssohn for the Substan
tiality or Permanence of the Soul 221
Conclusion of the Solution of the Psychological Paralogism.. 227
General Remark on the Transition from Rational Psychology
to Cosmology 228
CHAP. II. THE ANTINOMY OF PURE REASON 230
SECTION I. System of Cosmological Ideas 232
SECTION II. Antithetic of Pure Reason 238
First Conflict of the Transcendental Ideas 241
Second Conflict of the Transcendental Ideas 246
P
xxiv KANT
Third Conflict of the Transcendental Ideas
Fourth Conflict of the Transcendental Ideas
SECTION III. Of the Interest of Reason in these Self-contra
dictions 262
SECTION IV. Of the Necessity Imposed upon Pure Reason of
presenting a Solution of its Transcendental Problems 270
SECTION V. Sceptical Exposition of the Cosmological Problems
presented in the four Transcendental Ideas 275
SECTION VI. Transcendental Idealism as the Key to the Solution
of Pure Cosmological Dialectic 278
SECTION VII. Critical Solution of the Cosmological Problems. . 281
SECTION VIII. Regulative Principle of Pure Reason in relation
to the Cosmological Ideas 287
SECTION IX. Of the Empirical Use of the Regulative Principle
of Reason, with regard to the Cosmological Ideas 291
I. Solution of the Cosmological Idea of the Totality of the
Composition of Phenomena in the Universe 292
II. Solution of the Cosmological Idea of the Totality of the
Division of a Whole given in Intuition 295
Concluding Remark on the Solution of the Transcendental
Mathematical Ideas — and Introductory to the Solution of
the Dynamical Ideas 297
III. Solution of the Cosmological Idea of the Totality of the
Deduction of Cosmical Events from their Causes 299
Possibility of Freedom in Harmony with the Universal Law
of Natural Necessity 302
Exposition of the Cosmological Idea of Freedom in Harmony
with the Universal Law of Natural Necessity 304
IV. Solution of the Cosmological Idea of the Totality of the
Dependence of Phenomenal Existences 314
Concluding Remarks on the Antinomy of Pure Reason 317
CHAP. III. THE IDEAL OF PURE REASON.
SECTION I. Of the Ideal ^n General 318
SECTION II. Of the Transcendental Ideal 320
SECTION III. Of the Arguments Employed by Speculative Rea
son in Proof of the Existence of a Supreme Being 327
L SECTION IV. Of the Impossibility of an Ontological Proof of the
Existence of God 331
SECTION V. Of the impossibility of a Cosmological Proof of
the Existence of God 337
Detection and Explanation of the Dialectical Illusion in all
Transcendental Arguments for the Existence of a Neces
sary Being 344
SECTION VI. Of the Impossibility of a Physico-Theological
Proof 347
SECTION VII. Critique of all Theology based upon Speculative
Principles of Reason 353
APPENDIX. Of the Regulative Employment of the Ideas of Pure
Reason 350,
CONTENTS xxv
TAGK
Of the Ultimate End of the Natural Dialectic of Human
Reason 375
TRANSCENDENTAL DOCTRINE OF METHOD
INTRODUCTION 307
CHAP. I. The Discipline of Pure Reason 398
SECTION I. The Discipline of Pure Reason in the Sphere of
Dogmatism 400
SECTION II. The Discipline of Pure Reason in Polemics .415
Scepticism Not a Permanent State for Human Reason 425
SECTION III. The Discipline of Pure Reason in Hypothesis 432
SECTION IV. The Discipline of Pure Reason in Relation to Proofs.
CHAP. II. The Canon of Pure Reason 446
SECTION I. Of the Ultimate End of the Pure Use of Reason 447
SECTION II. Of the Ideal of the Summum Bonum as a Determin
ing Ground of ths ultimate End of Pure Reason 451
SECTION III. Of Opinion, Knowledge, and Belief 460,
CHAP. III. The Architectonic of Pure Reason 466
CHAP. IV. The History of Pure Reason 477
ILLUSTRATIONS
FACING PAGE
IMMANUEL KANT (Portrait) .... Frontispiece
Photogravure from a steel engraving
ALEXANDER 66
Photo-engraving from the original marble bust
A PAGE FROM LUTHER'S NEW TESTAMENT . . . .158
Fac-simile example of printing in the Sixteenth Century
THE PUGILIST 396
Photo-engraving from the original marble statue
CRITIQUE OF PURE REASON
INTRODUCTION
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 other
wise 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 purs is antecedent to experience4 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 addi
tion 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 re
quires close investigation, and is not to be answered at first
sight — whether there exists a knowledge altogether indepen
dent 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 h 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
2 CRITIQUE OF PURE REASON
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 imme
diately from experience, but from a general rule, which, how
ever, 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 sup
ports 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 experi
ence. 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 concep
tion which can only be derived from experience.
II. — THE HUMAN INTELLECT, EVEN IN AN UNPHILOSOPHICAL
STATE, is IN POSSESSION OF CERTAIN COGNITIONS A PRIORI
~"""N
The question now is as to a criterion, by which we may
securely distinguish a pure from an empirical cognition. Ex
perience no doubt teaches us that this or that object is con
stituted 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 a judgment a priori; if, moreover, it is not
derived from any other proposition, unless from one equally
involving the idea of necessity, it is absolutely a priori. Sec
ondly, an empirical judgment 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 judgment carries with it strict and absolute uni-
INTRODUCTION 3
versality, 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 exten
sion of validity, from that which may be predicated of a propo
sition valid in most cases, to that which is asserted of a proposi
tion which holds good in all ; as, for example, in the affirma
tion, "all bodies are heavy." When, on the contrary, strict
universality characterizes a judgment, 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
judgment, or the unlimited universality which we attach to a
judgment 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 judg
ments which are necessary, and in the strictest sense universal,
consequently puxe_a priori, it will be an easy matter.-ter'sriow.
If we desire an example from the sciences,,. .we "need only take '
any proposition in mathematics. J^'We'cast our eyes upon the
commonest _operatioris--»f--the^"understanding, the proposition,
" every change' must have a cause," will amply serve our pur
pose, m-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 judg
ment being therefore merely subjective. Besides, without seek
ing for such examples of principles existing a priori in cogni
tion, we might easily show that such principles are the indis
pensable basis of the possibility of experience itself, and con
sequently prove their existence a priori. For whence could
our experience itself acquire certainty, if all the rules on which
jt depends were themselves empirical, and consequently for
tuitous? No one, therefore, can admit the validity of the use
of such rules as first principles. But, for the present, we may
4 CRITIQUE OF PURE REASON
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 cog
nition, namely, universality and necessity.
Not only in judgments, 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 re
ferred to mere sensuous experience — color, hardness or soft
ness, 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 ex
perience has taught us to connect with it, still we cannot think
away those through which we cogitate it as substance, or ad
hering to substance, although our conception of substance is
more determined than that of an object. Compelled, therefore,
\-v 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 EX
TENT 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 com
pletely-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 judgments beyond its bounds. And just in this trans
cendental or supersensible sphere, where experience affords us
neither instruction nor guidance, lie the investigations of Rea
son, 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 sensu
ous phenomena. So high a value do we set upon these investi
gations, that even at the risk of error, we persist in following
them out, and permit neither doubt nor disregard nor indiffer
ence to restrain us from the pursuit. These unavoidable prob-
INTRODUCTION
5
lems of mere pure reason are God, Freedom (of will) and Im
mortality. 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 understanding.
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 with
out 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, valid
ity, 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 under
stand 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 stand
still by some evident contradiction, we hurry on undoubtingly
in our course. This, however, may be avoided, if we are suffi
ciently 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 repre
sented 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 knowl-
6 CRITIQUE OF PURE REASON
edge. 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 appre
hension or suspicion, and flatters us into the belief of its solid-
Iity, is this. 'A great part, gerhaps the greatest part, of the busi
ness of our reason consists in the analyzation 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 ;
while, 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 real a 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 know
ing 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 knowledge.
INTRODUCTION 7
IV. — OF THE DIFFERENCE BETWEEN ANALYTICAL AND
SYNTHETICAL JUDGMENTS
In all judgments wherein the relation of a subject to the
predicate is cogitated (I mention affirmative judgments only
here; the application to negative will be very easy), this rela
tion 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 judgment
analytical, in the second, synthetical. Analytical judgments
(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 judgments. The former may be called ex
plicative, the latter augmentative* judgments; because the
former add in the predicate nothing to the conception of the
subject, but only analyze it into its constituent conceptions,
which were thought already in the subject, although in a con
fused manner; the latter add to_our conceptions, of the subject
a predicate which was not contained~Tn~!t7and which no analysis
could" ever have discovered therein. For example, when I say,
" all bodies are extended," this is an analytical judgment. For
I need not go beyond the conception of body in order to find
extension connected with it, but merely analyze 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 judgment. 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. But the addition of such a predicate therefore, it be
comes a synthetical judgment.
Judgments of experience, as such, are always synthetical, i
For it would be absurd to think of grounding an analytical
judgment on experience, because in forming such a judgment,
I need not go out of the sphere of my conceptions, and there
fore recourse to the testimony of experience is quite unneces
sary. That " bodies are extended " is not an empirical judg-
* That is, judgments which really add the conceptions which make up the sum
to, and do not merely analyze or explain of our knowledge.
8 CRITIQUE OF PURE REASON
ment, but a proposition which stands firm a priori. For before
addressing myself to experience, I already have in my concep
tion all the requisite conditions for the judgment, 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 judgment, 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 indi
cates an object of experience, a part of the totality of experi
ence, 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 con
nected with the above characteristics, and therefore" I syntheti
cally 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 bodyj 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 intuitions.
But to synthetical judgments 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 ex
istence which a certain time antecedes, and from this I can
derive analytical judgments. But the conception of a cause
lies quite out of the above conception, and indicates something
entirely different from "that which happens," and is conse
quently not contained in that conception. How then am I able
to assert concerning the general conception — " that which hap
pens " — something entirely different from that conception, and
to recognize the conception of cause although not contained in
INTRODUCTION 9
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 predi
cate 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 com
pletely a priori and from pure conceptions. Upon such syn
thetical, that is augmentative propositions, depends the whole
aim of our speculative knowledge a priori; for although ana
lytical judgments 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
JUDGMENTS A PRIORI ARE CONTAINED AS PRINCIPLES
I. Mathematical judgments are always synthetical. Hith
erto 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 con
jectures. For as it was found that mathematical conclusions
all proceed according to the principle of contradiction (which
the nature of every apodictic certainty requires), people be
came 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 contradic
tion, 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 propo
sitions are always judgments a priori, and not empirical, be
cause 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 mathe
matics, 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
10
— 12, is a merely analytical proposition, following (according
to the principle of contradiction), from the conception of the
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
Jembraces both. The conception of twelve is by no means ob
tained by merely cogitating the union of seven and five; and
we may analyze 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 re
course to an intuition which corresponds to one of the two —
our five fingers, for example, or like Segner in his " Arith
metic," 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 intui
tion, 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 concep
tion of straight, contains no notion of quantity, but is merely
qualitative. The conception of the shortest is therefore 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
INTRODUCTION n
whole is equal to itself, or (a + b) > a, the wV>le 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 apodictic judgments is already contained in our con
ception, and that the judgment 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 con
ception 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 judgments a priori, as principles. I shall
adduce two propositions. For instance, the proposition, " in
all changes of the material world, the quantity of matter re
mains unchanged " ; or, that, " in all communication of mo
tion, 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 perma
nency, but merely its presence in space, which it fills. I there
fore 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 synthet
ical, and nevertheless conceived d 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 con-
12 CRITIQUE OF PURE REASON
tained in it, and by means of synthetical judgments d 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 d 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 labor, 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 con
tained in the question, " How are synthetical judgments d priori
possible? "
That metaphysical science has hitherto remained in so vacil
lating 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 judgments,
did not sooner suggest itself to philosophers. Upon the solu
tion of this problem, or upon sufficient proof of the impossibility
of synthetical knowledge d 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 re
gard 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 cansalitatis) , insisting
that such proposition d 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 as
sertion, destructive to all pure philosophy, he would have been
guarded, had he had our problem before his eyes in its univer
sality. For he would then have perceived that, according to
his own argument, there likewise could not be any pure mathe
matical science, which assuredly cannot exist without synthet
ical propositions d priori — an absurdity from which his good
understanding must have saved him.
INTRODUCTION 13
In the solution of the above problem is at the same time com
prehended the possibility of the use of pure reason in the
foundation and construction of all sciences which contain
theoretical knowledge d priori of objects, that is to say, the
answer to the following questions:
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,
as far as regard its true aim, can it be said that this science
really exists, leaves anyone at liberty to doubt with reason the
very possibility of its existence.
Yet, in a certain sense, this kind of knowledge must unques
tionably be looked upon as given; in other words, metaphysics .
must be considered as really existing, if not as a science, never
theless as a natural disposition of the human mind (metaphysica
naturalis). For human reason, without any instigations im-
putable 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 ques
tions 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
* As to the existence of pure natural quantity of matter, the vis inertia, the
science, or physics, perhaps many may equality of action and reaction, etc. —
still express doubts. But we have only to be soon convinced that they form a
to look at the different propositions science of pure physics (physica pura, or
which are commonly treated of at the rationales), which well deserves to be
commencement of proper (empirical) separately exposed as a special science,
physical science — those, for example, in its whole extent, whether that be
relating to the permanence of the same great or confined.
I4 CRITIQUE OF PURE REASON
contradictions, we must not rest satisfied with the mere natural
disposition of the mind to metaphysics, that is, with the ex
istence 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 ques
tions, or on the ability or inability of reason to form any judg
ment 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 : tHow is metaphysics possible as a science ?
Thus, the critique of reason leads at last, naturally and neces
sarily, 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 scepticism.
Besides, this science, cannot be of great and formidable pro
lixity, 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 con
ceptions, 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 con
ceptions, but not how we arrive, a priori, at them ; and this
it is her duty to show, in order to be able afterwards to deter
mine 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
INTRODUCTION 15
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 en
deavoring, by a method quite opposed to all those hitherto fol
lowed, to further the growth and fruitfulness of a science in
dispensable 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 par
ticular science, which may be called the Critique of Pure Rea
son. For reason is the faculty which furnishes us with the
principles of knowledge a priori. ,HpnC£i_rilrp reason is the
faculty which contains the principles of cognizing anything
absolutely...^ 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 ex
tended application of such an organon would afford us a sys
tem of pure reason. As this, however, is demanding a great
deal, and it is yet doubtful whether any extension of our knowl
edge 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 propcedeutic 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 con
tain a complete exposition not only of our synthetical a priori,
but of our analytical a priori knowledge, it is of too wide a
!6 CRITIQUE OF PURE REASON
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 can
not 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 conse
quently, 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 with
out, but altogether within ourselves, cannot remain concealed,
and in all probability is limited enough to be completely sur
veyed and fairly estimated, according to its worth or worth
lessness. Still less let the reader here expect a critique of
books and systems of pure reason ; our present object is ex
clusively 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 an
cient 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 foundation.
Transcendental philosophy is the idea of a science, for which
the Critique of Pure Reason must sketch the whole plan archi
tectonically, 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.
INTRODUCTION I7
Our critique must, indeed, lay before us a complete enumera
tion of all the radical conceptions which constitute the said
pure knowledge. But from the complete analysis of these con
ceptions themselves, as also from a complete investigation of
those derived from them, it abstains with reason; partly be
cause 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 anal
ysis and deduction, with which, after all, we have at present
nothing to do. This completeness of the analysis of these rad
ical conceptions, as well as of the deduction from the concep
tions 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 noth
ing 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 knowl
edge 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. Trans
cendental philosophy is consequently a philosophy of the pure
and merely speculative reason. For all that is practical, so far
i8 CRITIQUE OF PURE REASON
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 in
troduction or 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 for
mer, 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 doc
trine of sense must form the first part of our science of ele
ments, because the conditions under which alone the objects of
human knowledge are given, must precede those under which
they are thought.
TRANSCENDENTAL DOCTRINE
OF
ELEMENTS
PART FIRST
TRANSCENDENTAL /ESTHETIC
INTRODUCTORY
IN whatsoever mode, or by whatsoever means, our knowl
edge 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 ground
work, all thought points. But an intuition can take place only
in so far as the object is given to us. This, again, is only pos
sible, to man at least, on condition that the object affect the
mind in a certain manner. The capacity for receiving represen
tations (receptivity) through the mode in which we are affected
by objects, is called sensibility. By means of sensibility, there
fore, objects are given to us, and it alone furnishes us with
intuitions; by the understanding they are thought, and from
it arise conceptions. But all thought must directly, or indi-\
rectly, 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 meanVof sensa
tion, is called an empirical intuition. The undetermined ob
ject of an empirical intuition, is ca\\*-phenomenon. That which
in the phenomenon corresponds to the sensation, I term its
matter; but that which effects that the content of the phenome
non 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
ai
22 KANT
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 sen
sation. 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 rep
resentation oTirEody, all that the understanding thinks as be
longing to it, as substance, force, divisibility, etc., and also
whatever belongs to sensation, as impenetrability, hardness,
color, etc.; yet there is still something left us from this em
pirical intuition, namely, extension and shape. These belong
to pure Jntuition, which exists d 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 .-Esthetic.* There must, then, be such a sci
ence, 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.
In the science of transcendental aesthetic accordingly, we
shall first isolate sensibility or the sensuous faculty, by sepa
rating from it all that is annexed to its perceptions by the
conceptions of understanding, so that nothing be left but em
pirical 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 phe
nomena, which is all that the sensibility can afford a priori.
From this investigation it will be found that there are two pure
* The Germans are the only people rather our judgment which forms the
who at present use this word to indi- proper test as to the correctness of the
cate what others call the critique of principles. On this account it is ad-
taste. At the foundation of this term visable to give up the use of the term
lies the disappointed hope, which the as designating the critique of taste, and
eminent analyst, Baumgarten, conceived, to apply it solely to that doctrine, which
of subjecting the criticise? of the beauti- is true science — the science of the laws
ful to principles of reason, and so of ele- of sensibility — and thus come nearer to
vating its rules into a science. But his the language and the sense of the an-
endeavors were vain. For the said rules cients in their well-known division of the
or criteria are, in respect to their chief objects of cognition into aioflr/Ta itai voijra,
sources, merely empirical, consequently or to share it with speculative philoso-
neyer can serve as determinate laws ft phy, and employ it partly in a transcen-
Pnori, by which our judgment in mat- dental, partly in a psychological signi-
ters of taste is to be directed. It is fication.
CRITIQUE OF PURE REASON 23
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
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. Therein 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 rep
resented 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 determina
tions 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 in
formed 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 concep
tion ; and an exposition is metaphysical, when it contains that
which represents the conception as given a priori.
i. 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 foun
dation. Consequently, the representation of space cannot be
borrowed from the relations of external phenomena through
24 KANT
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 phe
nomena.
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, conse
quently the general notion of spaces, of this or that space, de
pends 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 geom
etry — for example, that " in a triangle, two sides together are
greater than the third," are never deduced from general con
ceptions of line and triangle, but from intuition, and this a priori
with apodictic certainty.
4. Space is represented as an infinite given quantity. Now
every conception must indeed be considered as a representa
tion which is contained in an infinite multitude of different pos
sible 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.
CRITIQUE OF PURE REASON 25
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 possi
bility of other synthetical a priori cognitions. For this pur
pose, it is requisite, firstly, that such cognitions do really flow
from the given conception; and, secondly, that the said cog
nitions 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 prin
ciples are always apodictic, that is, united with the conscious
ness of their necessity, as, " Space has only three dimensions."
But propositions of this kind cannot be empirical judgments,
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 possi
bility 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 simi
lar to ours, can with the utmost certainty be distinguished from
it by these marks.
Conclusions from the foregoing conceptions
i. Space does not represent any property of ob jects asjhings
in themselves, noTdoes jt repres.ent therrun fHeirjEeTatipns to
* That is, the analysis of a conception the object of which you have a con-
only gives you what is contained in it, ception, but merely evolves it. — J. M.
and does not add to your knowledge of D. M.
26 KANT
each other ; in other words, space does not represent to us any
determination of objects such as attaches to the objects them
selves, and would remain, even though all subjective conditions
of the intuition were abstracted. For neither absolute nor rela
tive determinations of objects can be intuited prior to the ex
istence of the things to which they belong, and therefore not
a priori.
2. Space is nothing else than the form of all phenomena of
the external sense, that is, the subjective condition of the sensi
bility, 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. li w^^ep_art_frprn
the subjective condition, under which alone we can obtain ex-
te_rnal intuition, or, in other words, by means of which we are
affected by objects, the representation of space has no meaning
whatsoever. TriTs" predicate "[of space] is~l>nTy~lipplicable 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 ab
straction 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, beffi^injujted
or not, or by whatsoever subject one will. AsToThe 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 judgment to the conception of the subject,
then the judgment will possess unconditioned validity. For
example, the proposition, " All objects are beside each other in
CRITIQUE OF PURE REASON 27
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 objects, and at the same time also the ideality of space in re
gard to objects when they are considered by means of reason
as things in themselves, that is, without reference to the consti
tution 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 sub
jective representations from which we can deduce synthetical
propositions a priori, as we can from the intuition of space.
Therefore, to speak accurately, no ideality whatever belongs
to these, although they agree in this respect with the represen
tation of space, that they belong merely to the subjective nat
ure of the mode of sensuous perception ; such a mode, for ex
ample, as that of sight, of hearing, and of feeling, by means
of the sensations of color, sound, and heat, but which, because
they are only sensations, and not intuitions, do not of them
selves 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 anyone against illustrating the asserted ideality
of space by examples quite insufficient, for example, by color,
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 color, it may
appear different. On the contrary, the transcendental concep-
— tion of phenomena in space is a critical amBoiimeif that, in
general, nothing which is intuited in space is a thing in itself,
28 KANT
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.
Section II — Of Time
Metaphysical exposition of this conception
1. Time is not an empirical conception. . For neither, xoex-
istence~nor succession would be perceived by us, if the represen
tation 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 succession.
2. Time is a necessary representation, lying at the founda
tion of all our intuitions. With regard to phenomena in gen
eral, 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 phenom
ena 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 apodictic principles of the relations of time, or axioms of
time in general, such as, " Time has only one dimension," " Dif
ferent 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 apodictic 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 experi
ence, and not by means of it.
4. jrimejis not a discursive, or as it is called, general con
ception, but_a pure formLpf tVip ynsuous intuition. Different
times are merely parts of one and the same time. But the
CRITIQUE OF PURE REASON 29
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.
Transcendental exposition of the conception of time
I may here refer to what is said above, where, for the sake
of brevity, I have placed under the head of metaphysical ex
position, 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 predi
cates 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.
* Kant's meaning is: You cannot af- conception, or whatever other form of
firm and deny the same thing of a sub- thought there be, can mediate the con-
ject, except by means of the representa- nection of such predicates. — J. M. D. M.
tion, time. No other idea, intuition, or
3o KANT
Conclusions from the above conceptions
1. 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 percep
tion any real object. In the latter case, as an order or deter
mination inherent in things themselves, it could not be ante
cedent 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.
2. 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 endeavor to supply this want by analogies,
and represent the course of time by a line progressing to in
finity, 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, while 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 internal intuition.
3. 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 them
selves, 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 d 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
CRITIQUE OF PURE REASON $i
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 neces
sarily in relations of time."
If we abstract our internal intuition of ourselves, and all
external intuitions, possible only by virtue of this internal intui
tion, 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 phenom
ena, because these are things which we regard as objects of
our senses. It is no longer objective, if we make abstraction
of the sensuousness of our intuition, in other words, of that
mode of representation which is peculiar to us, and speaks of
things in general Time is therefore merely a subjective con
dition 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. Neverthe
less, 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 representa
tion 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 ob
jective 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 pre
sented 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 pre
sented to us through the medium of the senses. Herein con
sists, therefore, the transcendental ideality of time, according
to which, if we abstract the subjective conditions of sensuous
32 KANT
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 illus
trations, 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 phe
nomenon. In reference to this subject, see the remark, else
where in this work, on Space.
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 answer
ing this. I grant the whole argument. Time, no doubt, is
something real, that is, it is the real form of our internal intui
tion. 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 represen
tation of myself as an object. But if I could intuite myself,
or be intuited by another being, without this condition of sen
sibility, 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 intui
tion.* If we take away from it the special condition of our
*I can indeed say "my representa- internal sense. Time, therefore, is not
tions follow one another, or are sue- a thing in itself, nor is it any objective
cessive"; but this means only that we determination pertaining to or inherent
are conscious of them as in a succession, in things.
that is, according to the form of the
CRITIQUE OF PURE REASON 33
sensibility, the conception of time also vanishes ; and it in
heres not in the objects themselves, but solely in the subject
(or mind) which intuites them.
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 demon
strating apodictically 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 imme
diately 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 sub
ject 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 intuition,
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
3
34
KANT
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 experi
ence 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 contain
ing in themselves everything that is real. If they adopt the
second view of inherence, which is preferred by some meta
physical 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 refer
ence to real things (for example, in space) — at all events their
apodictic 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 imaginations,* having their source really in experience,
inasmuch as, out of relations abstracted from experience, im
agination has made up something which contains, indeed, gen
eral 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 endeavors to
pass the limits of that sphere. The latter has, indeed, this ad
vantage, that the representations of space and time do not come
in their way when they wish to judge of objects, not as phe
nomena, but merely in their relation to the understanding. De
void, however, of a true and objectively valid a priori intuition,
they can neither furnish any basis for the possibility of mathe
matical cognitions a priori, nor bring the propositions of ex
perience 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.
* This word is here used, and will be notes a poetical inventive power is a
hereafter always used, in its primitive secondary one. — J. M. D. M,
sense. That meaning of it which de-
CRITIQUE OF PURE REASON 35
In conclusion, that transcendental ^Esthetic cannot contain
any more than these two elements — space and time, is suffi
ciently obvious from the fact that all other conceptions apper
taining 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, con
sequently motion must be something which is found in space
only through experience — in other words, is an empirical
datum. In like manner, transcendental ^Esthetic cannot num
ber 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 determi
nations, in one word, experience, is necessary.
General Remarks on Transcendental ^Esthetic
I. In order to prevent any misunderstanding, it will be req
uisite, 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 ap
pear 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 own
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 mat
ter. The former alone can we recognize d priori, that is,
antecedent to all actual perception ; and for this reason such
cognition is called pure intuition. The latter is that in our cog
nition which is called cognition d posteriori, that is, empirical
36 KANT
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 sensibil
ity, 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 them
selves ? " remains unanswerable even after the most thorough
examination of the phenomenal world.
To say, then, that all our sensibility is nothing but the con
fused representation of things containing exclusively that which
belongs to them as things in themselves, and this under an
accumulation of characteristic marks and partial representa
tions which we cannot distinguish in consciousness, is a falsifi
cation 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 understand
ing, 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 com
prised 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 repre
sents a property (the moral property) of actions, which be
longs to them in themselves. On the other hand, the represen
tation 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 coelo 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
CRITIQUE OF PURE REASON 37
has assigned an entirely erroneous point of view to all investi
gations into the nature and origin of our cognitions, inasmuch
as it regards the distinction between the sensuous and the in
tellectual as merely logical, whereas it is plainly transcenden
tal, 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 in
tuition, 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 organ
ization of this or that sense. Accordingly, we are accustomed
to say that the former is a cognition which represents the ob
ject itself, while 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 or 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 intui
tion 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 rain drops of course are not such, for they
are, as phenomena, empirical objects), the question of the rela-
38 KANT
tion of the representation to the object is transcendental ; and
not only are the rain drops 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 funda
mental dispositions of our sensuous intuition, while the trans
cendental object remains for us utterly unknown.
The second important concern of our Esthetic is, that it
do not obtain favor merely as a plausible hypothesis, but pos
sess 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.
Suppose, then, that Space and Time are in themselves ob
jective, 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 apodictic 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 apodictic 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 empir
ical, that is, a proposition of experience. But an empirical
proposition cannot possess the qualities of necessity and abso
lute 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 concep
tions no synthetical cognitions, but only analytical ones, can
be obtained. Take, for example, the proposition, " Two straight
lines cannot inclose 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 pos
sible to construct a figure with three straight lines," and en
deavor, in like manner, to deduce it from the mere conception
of a straight line and the number three. All your endeavors
CRITIQUE OF PURE REASON 39
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
apodictic 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 sub
jective conditions in order to construct a triangle, must also
necessarily belong to the triangle in itself? For to your con
ceptions 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 syn
thetical 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 con
ditions of all our intuitions, in relation to which all objects are
therefore mere phenomena, and not things in themselves, pre
sented to us in this particular manner. And for this reason,
in respect to the form of phenomena, much may be said a priori,
while 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 ex
ternal 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,
40 KANT
to-wit, of place in an intuition (extension), change of place
(motion), and laws according- to which this change is deter
mined (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 itself.
The same is the case with the internal intuition, not only
because, in the internal intuition, the representation of the ex
ternal 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 ex
perience, and which, as the formal condition of the mode ac
cording 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 representa
tion, 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 repre
sentation, 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 representa
tions, 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 me
dium of sense is so far phenomenal ; consequently, we must
either refuse altogether to admit an internal sense, or the sub
ject, which is the object of that sense, could only be repre
sented 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 the subject can 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
CRITIQUE OF PURE REASON 41
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 affect that, and can in this way alone pro
duce 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 repre
sentations are to combine themselves in the mind; since the
subject intuites itself, not as it would represent itself immedi
ately 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-conscious
ness, 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 appear
ance.* But this will not happen, because of our principle of
42
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, inas
much 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 more
over, 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 ab
surdity which no one has as yet been guilty of.
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,
from our representation of the object, his handles, or extension to all exter-
we denominate phenomenon. Thus the nal objects, considered as things in
predicates of space and time are rightly themselves, without regarding the de-
attributed to objects of the senses as terminate relation of these objects to
such and in this there is no illusion. the subject, and without limiting my
Un the contrary, if I ascribe redness to judgment to that relation— then, and
the rose as a thing 'in itself, or to Saturn then only, arises illusion.
CRITIQUE OF PURE REASON 43
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 derivations), and not an original (intuit us origina-
rius), consequently not an intellectual intuition; and this in
tuition, 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.
Conclusion of the Transcendental Esthetic
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 pos
session of pure a priori intuitions, namely, space and time,
in which we find, when in a judgment a priori we pass out
beyond the given conception, something which is not discov
erable 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 judgments 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 ex
perience.
PART SECOND
TRANSCENDENTAL LOGIC
I. — OF LOGIC IN GENERAL
OUR knowledge springs from two main sources in the
mind, the first of which is the faculty or power of re
ceiving representations (receptivity for impressions) ;
the second is the power of cognizing by means of these repre
sentations (spontaneity in the production of conceptions).
Through the first an object is given to us; through the sec
ond, it is, in relation to the representation (which is a mere
determination of the mind), thought. Intuition and concep
tions 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 con
sequently 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 posteriori.
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 un-
44
CRITIQUE OF PURE REASON 45
derstanding. 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 knowl
edge 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, Esthetic, from the science of the laws of the under
standing, that is, Logic.
Now, logic in its turn may be considered as twofold — namely,
as logic of the general [universal], or of the particular use
of the understanding. ^The first contains the absolutely neces
sary laws of thought, without which no use whatever 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 par
ticular 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 com
pletion; 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 for-
me'r, 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
46 KANT
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 re
quired. 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 con
ditions 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 consti
tutes 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
twp-Tules : —
•" i. )As general logic, it makes abstraction of all content of
tn> cognition of the understanding, and of the difference of
objects, and has to do with nothing but the mere form of
thought.
U^jAs pure logic, it has no empirical principles, and conse
quently 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 d priori.
What I call applied logic (contrary to the common accep
tation of this term, according to which it should contain cer
tain 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 concrete, 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,
CRITIQUE OF PURE REASON 47
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 prin
ciples.
II. — OF TRANSCENDENTAL LOGIC
General logic, as we have seen, makes abstraction of all con
tent and 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 gen
eral. 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 ob
jects). In this case, there would exist a kind of logic, in which
we should not make abstraction of all content of cognition ;
for that logic which should comprise merely the laws of pure
thought (of an object), would of course exclude all those cog
nitions 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 them
selves ; while, on the contrary, general logic has nothing to do
with the origin of our cognitions, but contemplates our repre
sentations, 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 (intui
tions or conceptions) are applied or are possible only d priori;
that is to say, the d priori possibility of cognition and the
48 KANT
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 pos
sibility 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 sen
suous intuitions, but merely as acts of pure thought (which
are therefore conceptions, but neither of empirical nor sestheti-
cal 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 deter
mine the origin, the extent, and the objective validity of such
cognitions, must be called Transcendental -Logic, because it has
not, like general logic, to djo__\vith. 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 van
ity of their whole art, is this—" What is truth ? " The defini
tion 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 an-
CRITIQUE OF PURE REASON 49
swer, 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
to 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 accu
rate, yet not sufficient. For although a cognition may be per
fectly 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 con
dition 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 discover.
4
5o KANT
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 all 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 cogni
tion, accurately as it may accord with logical laws, is insuffi
cient 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 after
wards 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 judgment, has been employed as an or
ganon 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 igno
rance, nay, even intentional sophistries, the coloring of truth,
in which the thoroughness of procedure which logic requires
was imitated, and their topic employed to cloak the empty pre
tensions. 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 un
derstanding, 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
CRITIQUE OF PURE REASON 51
knowledge must end in mere prating; anyone being able to
maintain or oppose, with some appearance of truth, any single
assertion whatever.
Such instruction is quite unbecoming the dignity of philos
ophy. 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 cog
nition merely that part of thought which has its origin in the
understanding alone. The exercise of this pure cognition, how
ever, depends upon this as its condition, that objects to which
it may be applied be given to us in intuition, for without intui
tion, the whole of our cognition is without objects, and is there
fore quite void. That part of transcendental logic, then, which
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 un
derstanding by themselves, and that even beyond the boun
daries 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 pass
ing judgments 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 syntheti
cally, affirm, and determine respecting objects in general. In
5i KANT
this case the exercise of the pure understanding becomes dia
lectical. 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 metaphys
ical 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 judgments made by the pure understanding, and to
guard it from sophistical delusion.
FIRST DIVISION
TRANSCENDENTAL ANALYTIC
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 neces
sary, ist, That the conceptions be pure and not empirical; 2d,
That they belong not to intuition and sensibility, but to thought
and understanding; 3d, That they be elementary conceptions,
and as such, quite different from deduced or compound con
ceptions ; 4th, That our table of these elementary conceptions
be complete, and fill up the whole sphere of the pure under
standing. Now this completeness of a science cannot be ac
cepted with confidence on the guarantee of a mere estimate
of its existence in an aggregate formed only by means of re
peated 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 sensi
bility. It is a unity self-subsistent, self-sufficient, and not to
CRITIQUE OF PURE REASON 53
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 articula
tion 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 concep
tions, and the other the principles of pure understanding.
BOOK 1
By the term " Analytic of Conceptions," I do not under
stand the analysis of these, or the usual process in philosophical
investigations of dissecting the conceptions which present them
selves, 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 analyzing the pure use of this
faculty. For this is the proper duty of a transcendental philos
ophy ; 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 devel
oped 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 Con
ceptions of the Understanding
When we call into play a faculty of cognition, different con
ceptions manifest themselves according to the different circum
stances, 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
54
them. Where this process, conducted as it is, mechanically,
so to speak, will end, cannot be determined with certainty. Be
sides, the conceptions which we discover in this haphazard man
ner present themselves by no means in order and systematic
unity, but are at last coupled together only according to resem
blances 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 alto
gether 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 prin
ciple ; 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 com
pleteness of the system of all be determined a priori — both
which would otherwise have been dependent on mere choice or
chance.
Transcendental Clue to the Discovery of All Pure Conceptions
of the Understanding
Section I. — Of the Logical use of the Understanding in general
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 intui
tion there is no other mode of cognition, except through con
ceptions ; consequently, the cognition of every, at least of
every human, understanding is a cognition through conceptions
— not intuitive, but discursive. All intuitions, as sensuous, de
pend on affections ; conceptions, therefore, upon functions. By
the word function, I understand the unity of the act of arrang
ing 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 concep
tions than to judge by means of them. As no representation,
except an intuition, relates immediately to its object, a concep-
CRITIQUE OF PURE REASON 55
tion never relates immediately to an object, but only to some
other representation thereof, be that an intuition or itself a con
ception. A judgment, therefore, is the mediate cognition of
an object, consequently the representation of a representation
of it. In every judgment 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 imme
diately connected with an object. For example, in the judg
ment — " 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 judgments, accordingly,
are functions of unity in our representations, inasmuch as, in
stead of an immediate, a higher representation, which com
prises 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 judg
ments, 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 judg
ments, 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 judgment; for example, "Every metal is a body."
All the functions of the understanding therefore can be dis
covered, when we can completely exhibit the functions of unity
in judgments. And that this may be effected very easily, the
following section will show.
Section II. — Of the Logical Function of the Understanding in
Judgments
If we abstract all the content of a judgment, and consider
only the intellectual form thereof, we find that the function
of thought in a judgment can be brought under four heads, of
KANT
which each contains three momenta. These may be conven
iently represented in the following table : —
Quantity of judgments
Universal.
Particular.
Singular.
ii in
Quality Relation
Affirmative. Categorical.
Negative. Hypothetical
Infinite. Disjunctive,
IV
Modality
Problematical.
Assertorical.
Apodictical.
As this division appears to differ in some, though not essen
tial points, from the usual technic of logicians, the following
observations, for the prevention of otherwise possible misun
derstanding, will not be without their use.
i. Logicians say, with justice, that in the use of judgments
in syllogisms, singular judgments may be treated like universal
ones. For, precisely because a singular judgment has no extent
at all, its predicate cannot refer to a part of that which is con
tained 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 judgment, merely as a cognition, in
regard to quantity. The singular judgment relates to the gen
eral one, as unity to infinity, and is therefore in itself essentially
different. Thus, if we estimate a singular judgment judicium
singular e~) not merely according to its intrinsic validity as a
judgment, 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 judgment (judicium com-
CRITIQUE OF PURE REASON 57
mune), and in a complete table of the momenta of thought de
serves a separate place — though, indeed, this would not be nec
essary in a logic limited to the consideration of the use of judg
ments in reference to each other.
2. In like manner, in transcendental logic, infinite must be
distinguished from affirmative judgments, although in general
logic they are rightly enough classed under affirmative. Gen
eral 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 mor
tal " — by this negative judgment 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 exist
ences, 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 remain
ing part of the extent of this sphere. But this part remains,
notwithstanding this exception, infinite, and more and more
parts may be taken1 away from the whole sphere, without in
the slightest degree thereby augmenting or affirmatively deter
mining our conception of the soul. These judgments, there
fore, 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 judgments, because the func
tion 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 judgments are those (a) of the
predicate to the subject; (&) of the principle to its conse
quence; (c) of the divided cognition and all the members of
the division to each other. In the first of these three classes,
5 8 KANT
we consider only two conceptions; in the second, two judg
ments; in the third, several judgments 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 ex
ists," 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 judgment ex
cept a certain consequence. Finally, the disjunctive judgment
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 commu
nity, in so far as all the propositions taken together fill up the
sphere of the cognition. The disjunctive judgment 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 propo
sition, " 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 judgment 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 par
ticular given cognition. And this is all that I find necessary,
for the sake of what follows, to remark in this place.
4. The modality of judgments is a quite peculiar function,
with this distinguishing characteristic, that it contributes noth
ing to the content of a judgment ( for besides quantity, quality,
and relation, there is nothing more that constitutes the content
of a judgment), but concerns itself only with the value of the
copula in relation to thought in general. Problematical judg
ments are those in which the affirmation or negation is accepted
as merely possible (ad libitum). In the assertorical, we regard
CRITIQUE OF PURE REASON 59
the proposition as real (true) ; in the apodictical, we look on
it as necessary.* Thus the two judgments (antecedens et con-
sequens), the relation of which constitutes a hypothetical judg
ment, 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 per
fect justice," is not stated assertorically, but as an ad libitum
judgment, which someone may choose to adopt, and the conse
quence alone is assertorical. Hence such judgments 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 judg
ment 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 under
standing. The apodictical proposition cogitates the assertori
cal as determined by these very laws of the understanding, con
sequently as affirming a priori, and in this manner it expresses
logical necessity. Now because all is here gradually incorpo
rated with the understanding — inasmuch as in the first place
we judge problematically ; then accept assertorically our judg
ment as true ; lastly, affirm it as inseparably united with the
understanding, that is, as necessary and apodictical — we may
safely reckon these three functions of modality as so many
momenta of thought.
* Just as if thought were in the first of reason. A remark which will be ex-
instance a function of the understanding; plained in the sequel,
in the second, of judgment; in the third
6o KANT
Section III— Of the pure Conceptions of the Understanding,
or Categories
General logic, as has been repeatedly said, makes abstraction
of all content of cognition, and expects to receive representa
tions from some other quarter, in order, by means of analysis,
to convert them into conceptions. On the contrary, transcen
dental 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 in
finite 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, apd
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 cog
nition. This synthesis is pure when the diversity is not given
empirically but a priori (as that in space and time). Our rep
resentations 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 em
pirically) 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
an 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 indispens
able 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,
CRITIQUE OF PURE REASON 61
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 con
ception 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 necessary.
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 in order to the a priori cognition of all objects, is
the diversity of the pure intuition ; the synthesis of this di
versity 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 repre
sentation of this necessary synthetical unity, furnish the third
requisite for the cognition of an object, and these conceptions
are given by the understanding.
The same function which gives unity to the different repre
sentations in a judgment, gives also unity to the mere syn
thesis 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 judgment, introduces, by means of the syn
thetical unity of the manifold in intuition, a transcendental con
tent 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 judg
ments. 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
62 KANT
purpose being originally identical with his, notwithstanding
the great difference in the execution.
TABLE OF THE CATEGORIES.
Of Quantity Of Quality
Unity. Reality.
Plurality. Negation.
Totality. Limitation.
Ill
Of Relation
Of Inherence and Subsistence (substantia et accidens).
Of Causality and Dependence (cause and effect).
Of Community (reciprocity between the agent and patient).
IV
Of Modality
Possibility. — Impossibility.
Existence. — Non-existence.
Necessity. — Contingence.
This, then, is a catalogue of all the originally pure concep
tions of the synthesis which the understanding contains a priori,
and these conceptions alone entitle it to be called a pure under
standing; 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 com
mon principle, namely, the faculty of judgment (which is just
the same as the power of thought), and has not arisen rhap-
sodically 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 where
fore 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 con
ceptions. 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}. After
wards he believed that he had discovered five others, which
CRITIQUE OF PURE REASON 63
were added under the name of post predicaments. But his cat
alogue 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 concep
tion (motus) — which can by no means belong to this genealog
ical 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 cate
gories, as the true primitive conceptions of the pure under
standing, 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 fact.
Let it be allowed me to call these pure, but deduced concep
tions of the understanding, the predicables of the pure under
standing, in contradistinction to predicaments. If we are in
possession of the original and primitive, the deduced and sub
sidiary conceptions can easily be added, and the genealogical
tree of the understanding completely delineated. As my pres
ent 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 anyone 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 analyze 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 hide from our view the main aim of our investiga
tion, at the same time raising doubts and objections, the con
sideration of which, without injustice to our main purpose,
64
may be very well postponed till another opportunity. Mean
while, 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 requi
site explanations, is not only a possible, but an easy undertak
ing. 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.
Our table of the categories suggests considerations of some
importance, which may perhaps have significant results in re
gard 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 sci
ence, 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 element
ary 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.*
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 under
standing.
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 understanding.
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.
* In the " Metaphysical Principles of Natural Science."
CRITIQUE OF PURE REASON 65
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 deter
mining, and determined by other substances ; and finally, Ne
cessity 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 concep
tion of the pure understanding. For the conjunction of the
first and second, in order to produce the third conception, re
quires 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 un
derstanding is here necessary ; and so in the other instances.
III. With respect to one category, namely, that of com
munity, 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 judgment 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 judgment, the sphere of
the judgment (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 con
versely).
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 contempo
raneously and reciprocally, as a cause in relation to the deter
mination of the others (for example, in a body — the parts of
which mutually attract and repel each other). And this is an
5
66 KANT
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
riot with the world make up a whole. The process of under
standing by which it represents to itself the sphere of a divided
conception, is employed also when we think of a thing as di
visible ; 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 sub
stances), independently of the others, and yet as united in one
whole.
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
d 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 school
men — " Quodlibet ens est unum, verum, bo num." Now,
though the inferences from this principle were mere tautolog
ical 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 pred
icates 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 significa
tion, 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 under-
CRITIQUE OF PURE REASON 67
stand 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 cogi
tated 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 com
pleteness. 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 of 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 deduc
tions from it (consistency with each other and with experience)
— and lastly, the completeness of the principle of the explana
tion 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, set
ting aside their application to objects of experience, as general
logical laws of the consistency of cognition with itself.
68 KANT
CHAPTER II
Of the Deduction of the Pure Conceptions of the Understanding
SECTION I
Of the Principles of a Transcendental Deduction in general
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, with
out opposition from anyone ; and consider ourselves, even with
out any attempt at deduction, justified in attaching to them a
sense, and a supposititious signification, because we have al
ways experience at hand to demonstrate their objective reality.
There exist also, however, usurped conceptions, such as for
tune, 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 de
duction for these terms, inasmuch as we cannot produce any
manifest ground of right, either from experience or from rea
son, on which the claim to employ them can be founded.
Among the many conceptions, which make up the very varie
gated 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 suffi
cient; but it is necessary to know how these conceptions can
apply to objects without being derived from experience. I
term, therefore, an explanation of the manner in which con
ceptions can apply a priori to objects, the transcendental deduc
tion of conceptions, and I distinguish it from the empirical
deduction, which indicates the mode in which a conception is
obtained through experience and reflection thereon ; conse
quently, does not concern itself with the right, but only with
the fact of our obtaining conceptions in such and such a man
ner. We have already seen that we are in possession of two
perfectly different kinds of conceptions, which nevertheless
CRITIQUE OF PURE REASON 69
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 con
ceptions of the understanding. To attempt an empirical de
duction of either of these classes would be labor in vain, because^
the distinguishing characteristic of their nature consists in this,/
that they apply to their objects, without having borrowed any-f
thing 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-
their production. It will be found that the impres
sions of sense give the first occasion for bringing into action
the whole faculty of cognition, and for the production of ex
perience, 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 ef
forts of our faculty of cognition to mount from particular per
ceptions 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 quccstio facti, I shall entitle an explanation of the posses
sion 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 cognitions.
But although it is admitted that the only possible deduction
of pure a priori cognition is a transcendental deduction, it is
?0 KANT
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 ob
jective validity a priori. Geometry, nevertheless, advances
steadily and securely in the province of pure a priori cogni
tions, without needing to ask from Philosophy any certificate
as to the pure and legitimate origin of its fundamental concep
tion 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 concep
tions of Understanding, on the contrary, commences the ab
solute necessity of seeking a transcendental deduction, not only
of these conceptions themselves, but likewise of space, be
cause, 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 the7
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 intui
tion ; — and for this reason, we have already found a transcen
dental deduction of it needful. The reader, then, must be quite
convinced of the absolute necessity of a transcendental deduc
tion, before taking a single step in the field of pure reason ;
because otherwise he goes to work blindly, and after he has
wandered 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 un
dertaking, so that he may not afterwards complain 6f the
obscurity in which the subject itself is deeply involved, or
become too soon impatient of the obstacles in his path ; — be
cause we have a choice of only two things — either at once to
CRITIQUE OF PURE REASON 71
give up all pretensions to knowledge beyond the limits of pos
sible experience, or to bring this critical investigation to com
pletion.
We have been able, with very little trouble, to make it com
prehensible 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, indepen
dently 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 arid time are pure
intuitions, which contain a priori the condition of the possibil
ity of objects as phenomena, and an a priori synthesis in these
intuitions possesses : objectiv£}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 our
selves 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 valid
ity 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 cor
respond 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 cor
respond to the conditions which understanding requires for
the synthetical unity or thought, is an assertion, the grounds
for which are not so easily to be discovered. For phenomena
72 KANT
might be so constituted, as not to correspond to the conditions
of the unity of thought ; and all things might lie in such con
fusion, that, for example, nothing could be met with in the
sphere of phenomena to suggest a law of synthesis, and so cor
respond 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 labor of these inves
tigations by saying, " Experience is constantly offering us ex
amples of the relation of cause and effect in phenomena, and
presents us with abundant opportunity of abstracting the con
ception 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 uni
versal law. We may certainly collect from phenomena a law,
according to which this or that usually happens, but the ele
ment 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 char
acter, if we treated them merely as the productions of ex
perience.
Transition to the Transcendental Deduction of the Categories
There are only two possible ways in which synthetical repre
sentation and its objects can coincide with and relate necessarily
to each other, and, as it were, meet together. Either the object
CRITIQUE OF PURE REASON 73
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 de
terminative 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 cog
nition of objects; firstly, Intuition, by means of which the ob
ject, though only as phenomenon, is given; secondly, Concep
tion, 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 under
standing also, [as conditions under which alone something, if
not intuited, is yet thought as object. If this question be an
swered 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, be
sides the intuition of the senses through which an object is
given,\jij:onception 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 meansri ! .
Tor in that case they apply necessarily and a priori to objects I
of experience, because only through them can an object ofS
experience be thought. \
The whole aim of the transcendental deduction of all a priori
conceptions is to show that these conceptions are a priori con
ditions of the possibility of all experience. Conceptions which
74 KANT
afford us the objective foundation of the possibility of experi
ence, 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 in
comprehensible.
The celebrated Locke, for want of due reflection on these
points, and because he met with pure conceptions of the un
derstanding in experience, sought also to deduce them from
experience, and yet proceeded so inconsequently as to attempt,
with their aid, to arrive at 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 wras^ forced to derive 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
,f_rom them, -to overstep, the, limits ;of ..experience, The empirical
derivation, however, which both of these philosophers attrib-
futed to these conceptions, cannot possibly be reconciled with
j 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 him
self up entirely to scepticism — a natural consequence, after hav
ing 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
CRITIQUE OF PURE REASON 75
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 rela
tion to one of the logical functions of judgment. The fol
lowing will make this plain. The function of the categorical
judgment 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 experi
ence must be contemplated always as subject, and never as mere
predicate. And so with all the other categories.
SECTION II
Of the Possibility of a Conjunction of the Manifold Repre
sentations given by Sense
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 i&ji
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 un
conscious, be it of the manifold in intuition, sensuous or non-
sensuous, or of several conceptions — is an act of the under
standing. 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
Deviously conjoined it ourselves.; Of all mental notions, that
of conjunction is the only one which cannot be given through
76 KANT
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 ap
pears to be its contrary, must, nevertheless, always presuppose
it; for where the understanding has not previously conjoined,
it cannot dissect or analyze, because only as conjoined by it,
must that which is to be analyzed have been given to our faculty
of representation.
But the conception of conjunction includes, besides the con
ception of the manifold and of the synthesis of it, that of the
unity of it also. Conjunction is the representation of the syn
thetical 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 mani
fold, render the conception of conjunction possible. This unity,
which a priori precedes all conceptions of conjunction, is not
the category of unity ; for all the categories are based upon
logical functions of judgment, 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,
in that, namely, which contains the ground of the unity of
diverse conceptions in judgments, the ground, consequently,
of the possibility of the existence of the understanding, even in
regard to its logical use.
Of the Originally Synthetical Unity of Apperception
The / 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 / think, in
the subject in which this diversity is found. But this repre-
* Whether the representations are in when we speak of the manifold, is a!-
themselves identical, and consequently ways distinguishable from our con-
whether one can be thought analytically sciousness of the other; and it is only
by means of and through the other, is respecting the synthesis of this (pos-
a question which we need not at present sible) consciousness that we here treat,
consider. Our consciousness of the one,
CRITIQUE OF PURE REASON 77
sentation, 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 a self-consciousness
which, while it gives birth to the representation / think, must
necessarily be capable of accompanying all our representations.
It is in all acts of consciousness one and the same, and unac
companied by it, no representation can exist for me. The unity
of this apperception I call the transcendental unity of self-con
sciousness, in order to indicate the possibility of a priori cogni
tion arising from it. For the manifold representations which
are given in an intuition would not all of them be my repre
sentations, if they did not all belong to one self-consciousness,
that is, as my representations (even although I am not con
scious of them as such), they must conform to the condition
under which alone they can exist altogether in a common self-
consciousness, because otherwise they would not all without
exception belong to me. From this primitive conjunction fol
low many important results.
For example, this universal identity of the apperception of
the manifold given in intuition, contains a synthesis of repre
sentations, and is possible only by means of the consciousness
of this synthesis. For the empirical consciousness which ac
companies different representations is in itself fragmentary
and disunited, and without relation to the identity of the sub
ject. 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 apper
ception is possible only under the presupposition of a synthetical
unity, f The thought, " These representations given in intui-
* Apperception simply means conscious' I thereby think to myself a property
ness. But it has been considered better which (as a characteristic mark) can be
to employ this term, not only because discovered somewhere, or can be united
Kant saw fit to have another word be- with other representations; consequent-
sides Bewusstseyn, but because the term ly, it is only by means of a forethought
consciousness denotes a state, apperception possible synthetical unity that I can
an act of the ego; and from this alone think to myself the analytical. A rep-
the superiority of the latter is apparent. resentation which is cogitated as com-
J. M. D. M. mon to different representations is re-
t All general conceptions — as such — garded as belonging to such as, besides
depend, for their existence, on the ana- this common representation, contain
lytical unity of consciousness. For ex- something different; consequently it
ample, when I think of red in general, must be previously thought in syntheti-
78 KANT
tion, 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 con
sciousness 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 con
sciousness, do I call them my representations, for otherwise
I must have as many-colored and various a self as are the rep
resentations of which I am conscious. Synthetical unity of the
manifold in intuitions, as given a priori, is therefore the foun
dation of the identity of apperception itself, which antecedes a
priori all determinate thought. But the conjunction of repre
sentations into a conception is not to be found in objects them
selves, nor can it be, as it were, borrowed from them and taken
up into the understanding by perception, but it is on the con
trary 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 apper
ception. This principle is the highest in all human cognition.
This fundamental principle of the necessary unity of apper
ception is indeed an identical, and therefore analytical propo
sition; but it nevertheless explains the necessity for a syn
thesis 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 mani
fold 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 un
derstanding, in which all the manifold should be given by
means of consciousness itself, would be intuitive; our under
standing 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.
cal unity with other although only point with which we must connect every
possible representations, before I can operation of the understanding, even
think in it the analytical unity of con- the whole of logic, and after it our
sciousness which makes it a concepias transcendental philosophy; indeed, this
comsnums And thus the synthetical faculty is the understanding itself,
unity of apperception is the highest
CRITIQUE OF PURE REASON 79
The principle of the Synthetical Unity of Apperception is the
highest principle of all exercise of the Understanding
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 of 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 conscious
ness ; for without this nothing can be thought or cognized, be
cause the given representations would not have in common the
act of the apperception / think; and therefore could not be
connected in one self-consciousness.
Understanding is to speak generally, the faculty of Cogni
tions. These consist in the determined relation of given repre
sentations 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 conscious
ness alone that constitutes the possibility of representations re
lating to an object, and therefore of their objective validity,
and of their becoming cognitions, and consequently, the possi
bility 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 intui
tion, is the principle of the original synthetical unity of apper
ception. Thus the mere form of external sensuous intuition,
namely, space, affords us, per se, no cognition ; it merely con
tributes the manifold 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 deter-
* Space and Time, and all portions on the contrary, they are many repre-
thereof, are Intuitions; consequently are, sentations contained in one, the con-
with a manifold for their content, single sciousness of which is, so to speak,
representations. (See the Transcendental compounded. The unity of conscious-
Asthctic.) Consequently, they are not ness is nevertheless synthetical, and
pure conceptions, by means of which therefore primitive. From this peculiar
the same consciousness is found in a character of consciousness follow many
great number of representations ; but, important consequences.
8o KANT
mined 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 con
sciousness 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, / think.
But this principle is not to be regarded as a principle for
every possible understanding, but only for that understanding
by means of whose pure apperception in the thought / 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 ob
jects of the representation should at the same time exist, would
not require a special act of synthesis of the manifold as the con
dition 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
It is by means of the transcendental unity of apperception
that all the manifold given in an intuition is united into a con
ception of the object. On this account it is called objective,
and must be distinguished from the subjective unity of con
sciousness, which is a determination of the internal sense, by
CRITIQUE OF PURE REASON 81
means of which the said manifold in intuition is given empiri
cally to be so united. Whether I can be empirically conscious
of the manifold as co-existent or as successive, depends upon
circumstances, or empirical conditions. Hence the empirical
unity of consciousness by means of association of representa
tions, itself relates to a phenomenal world, and is wholly con
tingent. On the contrary, the pure form of intuition in time,
merely as an intuition, which contains a given manifold, is sub
ject to the original unity of consciousness, and that solely by
means of the necessary relation of the manifold in intuition to
the / think, consequently by means of the pure synthesis of the
understanding, which lies a priori at the foundation of all em
pirical synthesis. The transcendental unity of apperception is
alone objectively valid; the empirical which we do not con-i
sider 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 uni
versally valid.
The Logical Form of all Judgments consists in the Objective
Unity of Apperception of the Conceptions contained therein
I could never satisfy myself with the definition! which lo
gicians give of a judgment. 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 disjunc
tive judgments, these latter containing a relation not of con
ceptions but of judgments 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.
But if I investigate more closely the relation of given cogni
tions in every judgment, and distinuguish it, as belonging to
* The tedious doctrine of the four drawing a conclusion than that in the
syllogistic figures concerns only cate- first figure, the artifice would not have
gorical syllogisms; and although it is had much success had not its authors
nothing more than an artifice by surrep- succeeded in bringing categorical judg-
titiously introducing immediate conclu- ments into exclusive respect, as those
sions (consequentite immediate?) among to which all others must be referred—
the premises of a pure syllogism, to give a doctrine, however, which is utterly
rise to an appearance of more modes of false.
6
S2 KANT
the understanding, from the relation which is produced accord
ing to laws of the reproductive imagination (which has only
subjective validity), I find that a judgment is nothing but the
mode of bringing given cognitions under the objective unity
of apperception. This is plain from our use of the term of
relation is in judgments, 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 al
though the judgment is empirical, therefore contingent, as in
the judgment, " 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 apperception 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 repre
sentations, 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 judgment, 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 ac
cording 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, with
out 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 Condi
tions under which alone the manifold Content of them can be
united in one Consciousness
The manifold content given in a sensuous intuition comes
necessarily under the original synthetical unity of appercep
tion, because thereby alone is the unity of intuition possible.
But that act of the understanding, by which the manifold con
tent of given representations (whether intuitions or concep
tions), is brought under one apperception, is the logical func-
CRITIQUE OF PURE REASON 83
tion of judgments. 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 judgment, by means of which
it is brought into union in one consciousness. Now the cate
gories are nothing else than these functions of judgment, so
far as the manifold in a given intuition is determined in relation
to them. Consequently, the manifold in a given intuition is
necessarily subject to the categories of the understanding.
Observation
The manifold in an intuition, which I call mine, is repre
sented 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-con
sciousness a priori, in the same manner as an empirical intui
tion 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 em
pirical intuition is given, in order to fix my attention exclu
sively on the unity which is brought by the understanding into
the intuition by means of the category. In what follows, 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 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.
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 un
derstanding, and independently of it. How this takes place
remains here undetermined. For if I cogitate an understand
ing which was itself intuitive (as, for example, a divine un-
* The proof of this rests on the repre- the manifold to be intuited, and also
sented unity of intuition, by means of the relation of this latter to unity of
which an object is given, and which apperception,
always includes in itself a synthesis of
84
KANT
derstanding which should not represent given objects, but by
whose representation the objects themselves should be given
or produced) — the categories would possess no signification 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 quar
ter, 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 pro
duces 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 judgment 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
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 ; con
sequently, our thought of an object by means of a pure con
ception 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 mathemat
ical conceptions, therefore, are not per se cognition, except in
CRITIQUE OF PURE REASON 85
so far as we presuppose that there exist things, which can
only be represented conformably to the form of our pure sensu
ous 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.
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 transcen
dental aesthetic determined the limits of the exercise of the
pure form of our sensuous intuition. Space and time, as con
ditions 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 noth
ing, 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 gen
eral, be the intuition like or unlike to ours, provided only it be
sensuous, and not intellectual. But this extension of concep
tions beyond the range of our intuition is of no advantage ; for
they are then mere empty conceptions of objects, as to the possi
bility 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 deter
mining 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 predi
cates, which are implied in the presupposition that nothing
86
KANT
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 determination in
time) is to be met with, and so on. But it is no proper knowl
edge 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
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 con
ception of substance, that is something that can exist as sub
ject, 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 in
tuition 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
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 possibil
ity 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 cer
tain form of sensuous intuition exists in the mind a priori
which rests on the receptivity of the representative faculty (sen
sibility), the understanding, as a spontaneity, is able to deter
mine the internal sense by means of the diversity of given
representations, conformably to the synthetical unity of apper
ception, and thus to cogitate the synthetical unity of the apper
ception 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
CRITIQUE OF PURE REASON 87
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 (syn
thesis 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 un
derstanding (synthesis intellcctualis}. Both are transcenden
tal, not merely because they themselves precede d priori all
experience, but also because they form the basis for the possi
bility 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 trans
cendental unity cogitated in the categories, must, to be distin
guished 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, imagina
tion, 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 syn
thesis 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 d priori, according
to its form, conformably to the unity of apperception, in so far
is the imagination a faculty of determining sensibility d priori,
and its synthesis of intuitions according to the categories, must
be the transcendental synthesis of the imagination. It is an op
eration of the understanding on sensibility, and the first appli
cation 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 under
standing 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 reproduc
tive, 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 d priori cogni-
KANT
tion, and for this reason belongs not to transcendental philos
ophy, but to psychology.
We have now arrived at the proper place for explaining the
paradox, which must have struck everyone in our exposition
of the internal sense, 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 contra
dictory, 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 understand
ing, and its original power of conjoining the manifold of intui
tion, 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 intui
tion, 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 in
ternal 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 un
derstanding 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 syn
thetical unity are by no means one and the same with the in
ternal 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 conscious
ness of the determination of the manifold by the transcendental
act of the imagination (synthetical influence of the understand-
CRITIQUE OF PURE REASON 89
ing on the internal sense), which I have named figurative syn
thesis.
This we can indeed always perceive in ourselves. We can
not cogitate a geometrical line without drawing it in thought,
nor a circle without describing it, nor represent the three di
mensions 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 at
tention 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),* conse
quently the synthesis of the manifold in space, if we make ab
straction 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 [the] / who think is distinct
from the / 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 my
self 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 my
self ? " or this — " How I can be an object of my own intuition
and internal perception ? " 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
* Motion of an object in space does a space, is a pure act of the successive
not belong to a pure science, conse- synthesis of the manifold in external
quently not to geometry; because, that intuition by means of productive imag-
a thing is movable cannot be known ination, and belongs not only to geom-
& priori, but only from experience. But etry, but even to transcendental philos-
motion, considered as the description of ophy.
9c KANT
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 fol
lows 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 conse
quently, if we grant respecting this latter, that by means of
them we know objects only in so far as we are affected exter
nally, we must also confess, with regard to the internal sense,
that by means of it we intuite ourselves only as we are inter
nally 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.*
On the other hand, in the transcendental synthesis of the
manifold content of representations, consequently in the syn
thetical 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 f 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 knowl
edge 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,
* I do not see why so much difficulty intuition of self is required, and this
should be found in admitting that our intuition possesses a form given a priori,
internal sense is affected by ourselves. namely, time, which is sensuous, and
Every act of attention exemplifies it. belongs to our receptivity of the de-
In such an act the understanding de- terminable. Now, as I do not possess
termines the internal sense by the syn- another intuition of self which gives the
thetical conjunction which it cogitates, determining in me (of the spontaneity of
conformably to the internal intuition which I am conscious), prior to the act
which corresponds to the manifold in of determination, in the same manner as
the synthesis of the understanding. time gives the determinable, it is clear
How much the mind is usually affected that I am unable to determine my own
thereby every one will be able to per- existence as that of a spontaneous be-
ceive in himself. ing, but I am only able to represent to
t The / think expresses the act of de- myself the spontaneity of my thought,
termining my own existence. My ex- that is, of my determination, and my
istence is tlms already given by the act existence remains ever determinable in
of consciousness; but the mode in which a purely sensuous manner, that is to
I must determine my existence, that is, say, like the existence of a phenomenon,
the mnc!e in w'nich I must place the But it is because of this spontaneity that
manifold belonging to my existence, is I call myself an intelligence.
not thereby given. For this purpose
CRITIQUE OF PURE REASON 91
in which I do not use the categories, whereby I cogitate an
object, by means of the conjunction of the manifold in one ap
perception. In the same way as I require, in order to the cog
nition 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 syn
thesis, but subjected in relation to the manifold which this in
telligence 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 re
lations 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 intel
lectual, nor given by the understanding), only as it appears to
itself, and not as it would cognize itself, if its intuition were
intellectual.
Transcendental Deduction of the universally possible employ
ment in experience of the Pure Conceptions of the Under
standing
In the metaphysical deduction, the a priori origin of the
categories was proved by their complete accordance with the
general logical functions of thought ; in the transcendental de
duction was exhibited the possibility of the categories as a
priori cognitions of objects of an intuition in general. At
present we are about to explain the possibility of cognizing,
a priori, by means of the categories, all objects which can pos
sibly be presented to our senses, not, indeed, according to the
form of their intuition, but according to the laws of their con
junction or synthesis, and thus, as it were, of prescribing laws
to nature, and even of rendering nature possible. For if the
categories were adequate 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 un
derstanding itself.
I premise, that by the term synthesis of apprehension, I un-
92 KANT
derstand the combination of the manifold in an empirical intui
tion, 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 phe
nomenon be always conformable, 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 Trans. ^Esthetic.} Therefore is unity of the synthesis of
the manifold without or within us, consequently also a con
junction 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 intui
tion. Consequently all synthesis, whereby alone is even per
ception possible, is subject to the categories. And, as experi
ence 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.
*******
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 syn
thetical unity of the manifold in space. But this very syn
thetical unity remains, even when I abstract the form of space,
and has its seat in the understanding, and is in fact the category
* Space represented as an object (as eating that it antecedes all conceptions,
geometry really requires it to be) con- although it presupposes a synthesis
tains more than the mere form of the which does not belong to sense, through
intuition; namely, a combination of the which alone, however, all our concep-
mamfold given according to the form of tions of space and time are possible,
sensibility into a representation that For as by means of this unity alone
can be intuited; so that the form of the (the understanding determining the sen-
intuihon gives us merely the manifold, sibility) space and time are given as
but the formal intuition gives unity of intuitions, it follows that the unity of
representation. _ In the Esthetic I re- this intuition A priori belongs to space
garcled this unity as belonging entirely and time, and not to the conception of
to oensibihty, for the purpose of indi- the understanding.
CRITIQUE OF PURE REASON 93
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.*
To take another example, when I perceive the freezing of
water, I apprehend two states (fluidity and solidity), which
as such, stand towards 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 syn
thetical unity of the manifold, without which the aforesaid rela
tion 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,
/ 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 cases.
Categories are conceptions which prescribe laws a priori to
phenomena, consequently to nature as the complex of all phe
nomena (natura materialiter spectata). And now the question
arises — inasmuch as these categories are not derived from nat
ure, 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 under
standing and with its a priori form — that is, its faculty of con
joining the manifold — than it is to understand how the phe
nomena themselves must correspond with the a priori form of
* In this manner it is proved that the the category. It is one and the same
synthesis of apprehension, which is em- spontaneity which at one time, under
pirical, must necessarily be conformable the name of imagination, at another un
to the synthesis of apperception, which der that of understanding, produces con-
is intellectual, and contained d priori in junction in the manifold of intuition.
94 KANT
our sensuous intuition. For laws do not exist in the phenom
ena 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 imagina
tion, a mental act to which understanding contributes unity of
intellectual synthesis, and sensibility, manifoldness of appre
hension. Now as all possible perception depends on the syn
thesis 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 gen
eral) is dependent on them as the original ground of her neces
sary 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 com
petent 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 partic
ular laws; but in regard to experience in general, and every
thing 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 Under
standing
We cannot think any object except by means of the cate
gories ; we cannot cognize any thought except by means of in
tuitions corresponding to these conceptions. Now all our in-
CRITIQUE OF PURE REASON 95
tuitions are sensuous, and our cognition, in so far as the object
of it is given, is empirical. But empirical cognition is expe
rience ; consequently no a priori cognition is possible for us,
except of objects of possible experience*
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 concep
tions of the understanding — there are, unquestionably, ele
ments of cognition, which exist in the mind a priori. Now
there are only two ways in which a necessary harmony of ex
perience with the conceptions of its objects can be cogitated.
Either experience makes these conceptions possible, or the con
ceptions make experience possible. The former of these state
ments will not hold good with respect to the categories (nor in
regard to pure sensuous intuition), for they are a priori con
ceptions, and therefore independent of experience. The asser
tion of an empirical origin would attribute to them a sort of
generatio cequivoca. 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 pre
sent us in their application to phenomena, the following sec
tion on the transcendental exercise of the faculty of judgment
will inform the reader.
It is quite possible that someone may propose a species of
prce formation-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 or
dered and disposed by our Creator, that their exercise perfectly
harmonizes with the laws of nature which regulate experience.
* Lest my readers should stumble at In the absence of intuition, our thought
this assertion, and the conclusions that of an object may still have true and
may be too rashly drawn from it, I must useful consequences in regard to the
remind them that the categories in the exercise of reason by the subject. But
act of thought are by no means limited as this exercise of reason is not always
by the conditions of our sensuous in- directed on the determination of the
tuition, but have an unbounded sphere object, in other words, on cognition
of action. It is only the cognition of thereof, but also on the determination
the object of thought, the determining of the subject and its volition, I do not
of the object, which requires intuition. intend to treat of it in this place.
96 KANT
Now, not to mention that with such an hypothesis it is impos
sible 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 con
clusive 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 arbi
trary subjective necessity of uniting certain empirical repre
sentations 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 judgment, is nothing but mere illusion ; nor would there
be wanting people who would deny any such subjective neces
sity in respect to themselves, though they must feel it. At all
events, we could not dispute with anyone 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 con
ceptions of the understanding (and with them of all theoretical
a priori cognition), as principles of the possibility of experi
ence, 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 con
ceptions. As we now proceed to the exposition of the em
ployment of these, I shall not designate the chapters in this
manner any further.
CRITIQUE OF PURE REASON 97
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, Judgment, and Reason. This sci- V
ence, accordingly, treats in its analytic of Conceptions, Judg
ments, and Conclusions in exact correspondence with the func
tions and order of those mental powers which we include
generally under the generic denomination of understanding.
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 rea- v
son 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 con
tent, that of pure a priori cognitions, to-wit, cannot imitate
general logic in this division. For it is evident that the trans
cendental employment of reason is not objectively valid, and
therefore does not belong to the logic of truth (that is, to ana
lytic), but as a logic of illusion, occupies a particular depart
ment in the scholastic system under the name of transcendental
Dialectic.
Understanding and judgment accordingly possess in trans
cendental logic a canon of objectively valid, and therefore true
exercise, and are comprehended in the analytical department
of that logic. But reason, in her endeavors to arrive by a priori
means at some true statement concerning objects, and to extend
cognition beyond the bounds of possible experience, is alto
gether dialectic, and her illusory assertions cannot be con
structed into a canon such as an analytic ought to contain.
Accordingly, the analytic of principles will be merely a canon
for the faculty of judgment, for the instruction of this faculty
in its application to phenomena of the pure conceptions of the
understanding1, which contain the necessary condition for the
establishment of a priori laws. On this account, although the
7
98 KANT
subject of the following chapters is the especial principles o£
understanding, I shall make use of the term " Doctrine of the
faculty of judgment," in order to define more particularly my
present purpose.
Of the Transcendental Faculty of Judgment in General
If understanding in general be defined as the faculty of laws
or rules, the faculty of judgment 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 dates legis}. General logic contains no directions or
precepts for the faculty of judgment, 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, judgments and conclu
sions, 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 judg
ment. Thus, it is evident, that the understanding is capable
of being instructed by rules, but that the judgment is a pe
culiar 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 dis
cipline can compensate. For although education may furnish,
and, as it were, ingraft 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 mis
use.* 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 pro-
* Deficiency in judgment is properly the epithet of learned. But as such per-
that which is called stupidity; and for sons frequently labor under a deficiency
such a thing we know no remedy. A in the faculty of judgment, it is not un-
dull or narrow-minded person, to whom common to find men extremely learned,
nothing is wanting but a proper de- who in the application of their science
gree of understanding, may be improved betray to a lamentable degree this ir-
by tuition, even so far as to deserve remediable want.
CRITIQUE OF PURE REASON 99
found teacher in his particular science, and yet in the appli
cation of these rules, he may very possibly blunder — either
because he is wanting in natural judgment (though not in
understanding), and while he can comprehend the general in
abstracto, cannot distinguish whether a particular case in con-
creto ought to rank under the former; or because his faculty
of judgment has not been sufficiently exercised by examples
and real practice. Indeed, the grand and only use of examples,
is to sharpen the judgment. 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 understand
ing to apprehend rules or laws in their universality, independ
ently of particular circumstances of experience ; and hence,
accustom us to employ them more as formulae than as princi
ples. Examples are thus the go-cart of the judgment, which
he who is naturally deficient in that faculty, cannot afford to
dispense with.
But although general logic cannot give directions to the fac
ulty of judgment, the case is very different as regards transcen
dental 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 judgment in the employment of the pure
understanding. For, as a doctrine, that is, as an endeavor to
enlarge the sphere of the understanding in regard to pure d
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 mis
takes of the faculty of judgment (lapsus fudicii) in the em
ployment of the few pure conceptions of the understanding
which we possess, although its use is in this case purely nega
tive, philosophy is called upon to apply all its acuteness and
penetration.
But transcendental philosophy has this peculiarity, that be
sides indicating the rule, or rather the general condition for
rules, which is given in the pure conception of the understand
ing, 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
ioo KANT
conceptions which must relate a priori to their objects, whose
objective validity consequently cannot be demonstrated a pos
teriori, and is, at the same time, under the obligation of pre
senting 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 judgment will
contain two chapters. The first will treat of the sensuous con
dition under which alone pure conceptions of the understanding
can be employed — that is, of the schematism of the pure under
standing. The second will treat of those synthetical judgments
which are derived a priori from pure conceptions of the under
standing 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 of the Pure Conceptions of the Under
standing
( In all subsumptions of an object under a conception, the
I 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 con
tained 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 cate
gories 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 transcen
dental doctrine of the faculty of judgment, with the purpose,
CRITIQUE OF PURE REASON joi
to-wit, of showing how pure conceptions of the understanding \
can be applied to phenomena. In all other sciences, where the I
conceptions by which the object is thought in the general are
not so different and heterogeneous from those which represent
the object in concrete — 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 applica
tion of the former to the latter possible. This mediating repre
sentation 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 syntheti
cal unity of the manifold in general. Time, as the formal con
dition of the manifold of the internal sense, consequently of
the conjunction of all representations, contains d priori a mani
fold of the pure intuition. Now a transcendental determina
tion 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 homo
geneous with the phenomenon, inasmuch as time ', 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, medi
ates the subsumption of the latter under the former.
After what has been proved in our deduction of the cate
gories, 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 concep
tions 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 re-
102 KANT
gard 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 concep
tion 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 imag
ination. But as the synthesis of imagination has for its aim no
single intuition, but merely unity in the determination of sen
sibility, 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 hun
dred, this thought is rather the representation of a method of
representing in an image a sum (e.g. a thousand) in con
formity 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 conception. No image
could ever be adequate to our conception of a triangle in gen
eral. For the generalness of the conception it never could
attain to, as this includes under itself all triangles, whether
right-angled, acute-angled, etc., while 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 adequate 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 concep-
CRITIQUE OF PURE REASON 103
tion. 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 indi
vidual form which experience presents to me, or indeed to any
possible image that I can represent to myself in concrete. 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 imagi
nation — 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 con
ception of the understanding is something that cannot be re
duced into any image — it is nothing else than the pure syn
thesis 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 representa
tions 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 con
ceptions 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 therewith.
For the external sense the pure image of all quantities (quan-
torum) is space; the pure image of all objects of sense in gen
eral, is time. But the pure schema of quantity (quantitatis)
as a conception of the understanding, is number, a representa
tion 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 appre
hension of the intuition.
Reality, in the pure conception of the understanding, is that
104 KANT
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 them
selves (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 (= o = 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 gradu
ally ascend from negation to the quantity thereof.
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, while 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 is in the phenomenon is unchangeable in existence, that
is, substance, and it is only by it that the succession and coex
istence 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 reac
tion), 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 gen
eral (as, for example, opposites cannot exist together at the
same time in the same thing, but only after each other), and
CRITIQUE OF PURE REASON 105
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 repre
sentation 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, there
fore, 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 com
plex or totality in time.
Hence it is apparent that the schematism of the understand
ing, by means of the transcendental synthesis of the imagina
tion, 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 in
ternal sense (a receptivity). Thus, the schemata of the pure
conceptions of the understanding are the true and only condi
tions 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 ap
perception) ; and so to render them susceptible of a complete
connection in one experience. But within this whole of pos
sible experience lie all our cognitions, and in the universal re
lation 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 sche
mata of sensibility are the sole agents in realizing the categories,
they do, nevertheless, also restrict them, that is, they limit the
jo6 KANT
categories by conditions which lie beyond the sphere of under
standing — namely, in sensibility. Hence the schema is prop
erly only the phenomenon, or the sensuous conception of an
object in harmony with the category. (Numerus est quantitas
phenomenon — sensatio realitas phenomenon ; constans et per-
durabile rerum substantia phenomenon — ccternitas, necessitas,
phenomena, etc.) Now, if we remove a restrictive condition,
we thereby amplify, it appears, the formerly limited concep
tion. 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 concep
tion 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 any
thing else. Of this representation I can make nothing, inas
much 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 concep
tions, 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 gen
eral conditions under which alone the transcendental faculty
of judgment is justified in using the pure conceptions of the
understanding for synthetical judgments. Our duty at present
is to exhibit in systematic connection those judgments which
the understanding really produces a priori. For this purpose,
CRITIQUE OF PURE REASON 107
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 com
plete and systematic catalogue of all the transcendental prin
ciples of the use of the understanding.
Principles a priori are so called, not merely because they
contain in themselves the grounds of other judgments, 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 of 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 prin
ciples of transcendental aesthetic, according to which space and
time are the conditions of the possibility of things as phenom
ena, 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 intui
tion, 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 judgments
a priori, not indeed for the purpose of proving their accuracy
and apodictic certainty, which is unnecessary, but merely to
render conceivable and deduce the possibility of such evident
a priori cognitions.
But we shall have also to speak of the principle of analytical
judgments, in opposition to synthetical judgments, which is
the proper subject of our inquiries, because this very opposi
tion will free the theory of the latter from all ambiguity, and
place it clearly before our eyes in its true nature.
io8 KANT
Section I. — Of the Supreme Principle ol all Analytical
Judgments
Whatever may be the content of our cognition, and in what
ever manner our cognition may be related to its object, the
universal, although only negative condition of all our judgments
is that they do not contradict themselves ; otherwise these judg
ments are in themselves (even without respect to the object)
nothing. But although there may exist no contradiction in our
judgment, 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
judgment, and thus, without being self-contradictory, a judg
ment 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 an
universal but purely negative criterion of all truth. But it be
longs to logic alone, because it is valid of cognitions, merely as
cognitions, and without respect to their content, and de
clares that the contradiction entirely nullifies them. We
can also, however, make a positive use of this princi
ple, 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 judgment 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 al
ways 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 cog
nition. 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
CRITIQUE OF PURE REASON 109
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 un
necessarily 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 apodictic 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 ex
ample, 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 an
other not young, that is, old. Now the principle of contradic
tion 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 sep
arate 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 sub
ject 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 ana
lytical, 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 proposi
tion of contradiction, without the necessity of adding the con
dition " at the same time." — This is the reason why I have al
tered the formula of this principle — an alteration which shows
very clearly the nature of an analytical proposition.
no
KANT
Section II. — Of the Supreme Principle of all Synthetical
Judgments
The explanation of the possibility of synthetical judgments
is a task with which general Logic has nothing to do ; indeed she
needs not even be acquainted with its name. But in transcen
dental Logic it is the most important matter to be dealt with, —
indeed the only one, if the question is of the possibility of syn
thetical judgments 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 ex
tent and limits of the pure understanding.
In an analytical judgment I do not go beyond the given con
ception, in order to arrive at some decision respecting it. If the
judgment 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 judgments,
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 judgment cannot be discerned merely from the
judgment 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 judgments? 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 imagina
tion ; their synthetical unity (which is requisite to a judgment),
upon the unity of apperception. In this, therefore, is to be
sought the possibility of synthetical judgments, and as all three
contain the sources of a priori representations, the possibility of
pure synthetical judgments also ; nay, they are necessary upon
these grounds, if we are to possess a knowledge of objects,
which rests solely upon the synthesis of representations.
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.
CRITIQUE OF PURE REASON m
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 under
stood in the sense of to present the object, not mediately but im
mediately in intuition, means nothing else than to apply the rep
resentation 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 with
out 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 ex
perience, without which they have no meaning. And so is it
with all conceptions without distinction.
The possibility of experience is, then, that which gives ob
jective reality to all our a priori cognitions. Now experience de
pends 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 percep
tions, 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 founda
tion, 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 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 conceptions.
Although, then, respecting space, or the forms which pro
ductive imagination describes therein, we do cognize much ft,
priori in synthetical judgments, and are really in no need of ex
perience 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
112
KANT
those pure synthetical judgments do relate, though but medi
ately, to possible experience, or rather to the possibility of ex
perience, and upon that alone is founded the objective validity
of their synthesis.
While then, on the one hand, experience, as empirical syn
thesis, 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 judg
ments 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 judgments 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 experi
ence, 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 va
lidity in an a priori synthetical judgment.
Section III. — Systematic Representation of all Synthetical
Principles thereof
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 ac
cording 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 neces
sity, and we may therefore at least expect them to be deter
mined 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,
CRITIQUE OF PURE REASON 113 ''?
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 prin
ciples for principles of the pure understanding, or conversely;
for the character of necessity, according to conceptions which
distinguishes the latter, and the absence of this in every em
pirical proposition, how extensively valid soever it may be, is a
perfect safeguard against confounding them. There are, how
ever, 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 experi
ence, consequently their objective validity, nay the possibility
of such a priori synthetical cognitions (the deduction thereof)
rests entirely upon the pure understanding.
On this account, I shall not reckon among my principles
those of mathematics; though I shall include those upon the
possibility and objective validity d priori, of principles of the
mathematical science, which, consequently, are to be looked
upon as the principle of these, and which proceed from concep
tions to intuition, and not from intuition to conceptions.
In the application of the pure conceptions of the understand
ing 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
apodictic ; 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, al
though 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
8
J14 KANT
of principles, because these are nothing else than rules for the
objective employment of the former. Accordingly, all princi
ples of the pure understanding are —
I
Axioms of
Intuition.
II HI
Anticipations Analogies
of of
Perception. Experience.
IV
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 — ac
cording 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, inasmuch 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 V
dynamical principles.* It must be observed, however, that by \y
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 un-
* All combination (conjunctio) is either in so far as its parts do belong neces-
composition (comfositio) or connection sarily to each other; for example, the
(nexus). The former is the synthesis of accident to a substance, or the effect to
a manifold, the parts of which do not the cause. Consequently it is a syn-
necessarily belong to each other. For thesis of that which, though heterogenc-
example, the two triangles into which on.?, is represented as connected, a priori.
a square is divided by a diagonal do not This combination — not an arbitrary one
necessarily belong to each other, and of — I entitle dynamical, because it concerns
this kind is the synthesis of the homo- the connection of the existence of the
geneous in everything that can be mathe- manifold. This, again, may be divided
tnatically considered. This synthesis can into the physical synthesis of the phe-
be divided into those of aggregation and nomena among each other, and the
coalition, the former of which is applied metaphysical synthesis, or the connec-
tp extensive, the latter to intensive qimn- tion of phenomena a priori in the faculty
tities. The second sort of combination of cognition.
(nc.rus) is the synthesis of a manifold,
CRITIQUE OF PURE REASON 115
derstanding, 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 pos
sible. 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.
I. — Axioms of Intuition
The Principle of these is, " All Intuitions are Extensive Quantities "
PROOF
All phenomena contain, as regards their form, an Intuition in space
and time, which lies a priori at the foundation of all without excep
tion. 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 ob
ject is rendered possible, is the conception of a quantity (quanti).
Consequently, even the perception of an object as phenomenon is pos
sible 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 cogi
tated ; that is to say, all phenomena are quantities, and extensive quan
tities, because as intuitions in space or time, they must be represented
by means of the same synthesis, through which space and time them
selves are determined.
An .extensive quantity I call that wherein the representation of the
parts renders possible (and therefore necessarily antecedes) the repre
sentation 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 por
tions 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, accord
ingly, to be considered as aggregates, that is, as a collection of
previously given parts; which is not the case with every sort of quan
tities, but only with those which are represented and apprehended by
us as extensive.
n6 KANT
On this successive synthesis of the productive imagination, in the
generation of figures, is founded the mathematics of extension, or ge
ometry, with its axioms, which express the conditions of sensuous in
tuition d priori, under which alone the schema of a pure conception of
external intuition can exist; for example, "between two points only
one straight line is possible," " two straight lines cannot inclose a
space," etc. These are the axioms which properly relate only to quan
tities (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 d
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 propo
sitions, then, cannot be termed axioms (for in that case we should
have an affinity 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 ob
jects 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 es
sential form of all intuition, is that which renders possible the appre
hension 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 understandings. But in this case, no a priori synthetical cogni
tion of them could be possible, consequently not through pure concep
tions of space, and the science which determines these conceptions, that
is to say. geometry, would itself be impossible.
II. — Anticipations of Perception
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
PROOF
Perception is empirical consciousness, that is to say, a consciousness,
which contains an element of sensation. Phenomena as objects of per
ception are not pure, that is, merely formal intuitions, like space and
time, for they cannot be perceived in themselves. 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 transi
tion from empirical consciousness to pure consciousness is possible,
inasmuch as the real in this consciousness entirely evanishes, 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 = o onwards, up to a certain quantity of the
sensation. Now as sensation in itself is not an objective representa
tion, 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 = o 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 sensation.
All cognition, by means of which I am enabled to cognize and de
termine 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 W/>OATJX«. But as there is in phenomena some
n8 KANT
thing 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, anticipa
tions of phenomena, because they represent a priori that which may
always be given d posteriori in experience. But suppose that in every
sensation, as sensation in general, without any particular sensation be
ing thought of, there existed something which could be cognized d
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 sen
sations. 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 — o.
That which in the empirical intuition corresponds to sensation is reality
(realitas phenomenon); that which corresponds to the absence of it,
negation = o. 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 con
catenation 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 takes 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.
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 in
tensive quantity, that is, a degree. If we consider this reality as cause
(be it of sensation or of another reality in the phenomenon, for ex
ample, 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 do.
Accordingly, every sensation, consequently every reality in phenom
ena, however small it may be, has a degree, that is, an intensive quan
tity, which may always be lessened, and between reality and negation
there exists a continuous connection of possible realities, and possible
smaller perceptions. Every color — 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.
CRITIQUE OF PURE REASON 119
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), conse
quently, 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 con
stituent parts which are given before space or time. Such quantities
may also be called flowing, because the 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 prop
erly 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 expres
sion 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 in
tensive, are continuous quantities, the proposition, " All change (tran
sition 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 of 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 see
ing 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 injur-
120 KANT
ing 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 draw.
If all reality in perception has a degree, between which and negation
there is an endless sequence of ever smaller degrees, and if neverthe
less every sense must have a determinate degree of receptivity for sen
sations ; 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; sec
ondly, 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 phe
nomena 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 unaltered.
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 mo
mentum 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 hypothe
sis — 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 concep
tions) 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 conse
quently is merely metaphysical, I oppose a transcendental demonstra
tion, 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 understand
ing 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
CRITIQUE OF PURE REASON 121
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 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 prin
ciple of the understanding.
Nevertheless, this principle of the anticipation of perception must
somewhat startle an inquirer whom initiation into transcendental philos
ophy has rendered cautious. We may 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 pro
nounce synthetically and a priori respecting phenomena, and thus antici
pate 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, colors, taste, etc.). But the real
— that which corresponds to sensation — in opposition to negation — o,
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 in
ternal sense can be raised from o 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 homo
geneous ascension from o 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 cog
nize a priori only a single quality, namely, continuity ; but in respect
to all quality (the real in phenomena), we cannot cognize a priori any
thing more than the intensive quantity thereof, namely, that they have
a degree. All else is left to experience.
122
KANT
III. — Analogies of Experience
The principle of these is : Experience is possible only through the repre
sentation of a necessary connection of perceptions
PROOF
Experience is an empirical cognition ; that is to say, a cognition which
determines an object by means of perceptions. It is therefore a syn
thesis of perceptions, a synthesis which is not itself contained in per
ception, 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 con
nected 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 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, conse
quently 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 co-existence.
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 syn
thetical unity of all phenomena according to their relation in time.
For the original apperception relates to our internal sense (the com
plex 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 be
come 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 deter-
CRITIQUE OF PURE REASON 123
mination 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 phe
nomena, 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 :ntui-
tion in every empirical example. But the existence of phenomena can
not 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 antici
pating in what respect the empirical intuition of it would be distinguish
able from that of others.
The two principles above mentioned, which I called mathematical,
in consideration of the fact of their authorizing the application of
mathematics to 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 accord
ing 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 com
pose, and give a priori, that is construct, the degree of our sensations
of the sunlight. We may therefore entitle these two principles
constitutive.
The case is very different with those principles whose province it is
to subject the existence of phenomena to rules a priori. For as ex
istence does not admit of being constructed, it is clear that they must
only concern the relations of existence, and be merely regulative prin
ciples. 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 philos
ophy mean something very different from that which they represent in
mathematics. In the latter they are formulae, which enounce the equal
ity 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 prio/i 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 prin
ciple. The same holds good also of the postulates of empirical thought
I24 KANT
in general, which relate to the synthesis of mere intuition (which con
cerns 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 demonstration.
But what has been observed of all synthetical propositions, and must
be particularly remarked in this place, is this, that these analogies pos
sess 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 impos
sible to cognize aught concerning them synthetically a priori. But they
are nothing but phenomena ; a complete knowledge of which — a knowl
edge 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 unity of empirical cogni
tion in the 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 func
tion 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 appli
cation 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.
FIRST ANALOGY
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
PROOF
All phenomena exist in time, wherein alone as substratum, that is,
as the permanent form of the internal intuition, co-existence and suc
cession 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 co-existence can be represented only as
determinations thereof. Now, time in itself cannot be an object of
CRITIQUE OF PURE REASON 125
perception. It follows that in objects of perception, that is, in phe
nomena, there must be found a substratum which represents time in -
general, and in which all change or co-existence 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 sub
stance ; all that pertains to existence can be cogitated only as a deter- *" \
mination 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 suc^
cessive, is consequently always changing. By it alone we could, there-,
fore, never determine whether this manifold, as an object of experience,
is co-existent or successive, unless it had for a foundation something
that exists always, that is, something fixed and permanent, of the ex
istence of which all succession and co-existence 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 em
pirical representation of time itself, in which alone all determination
of time is possible. Permanence is, in fact, just another expression for V
time, as the abiding correlate of all existence of phenomena, and of
all change, and of all co-existence. For change does not affect time
itself, but only the phenomena in time (just as co-existence cannot be
regarded as a modus of time itself, seeing that in time no parts are co
existent, but all successive). If we were to attribute succession to time
itself, we should be obliged to cogitate another time, in which this suc
cession 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 sub
stratum of all determination of time, and consequently also as the
condition as 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 sub
stances, 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 ex
presses himself in a more precise and definite manner, when he says:
" In all changes in the world, the substance remains, and the accidents
i26 KANT
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 sub
stance 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 can
not 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 pos
sible 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 (sub
stance) 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 of 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 sub
stratum 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 phe
nomenon, 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 per
petually 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 mis
takenly 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 experi
ence, 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 repre
sent the unity of time, to wit, the identity of the substratum, as that
through which alone all change possesses complete and thorough unity. . U
Thi :> permanence is, however, nothing but the manner in which we
represent to ourselves the existence of things in the phenomenal world.
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 determina-
CRITIQUE OF PURE REASON 127
tions, 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 acci
dent only as the mode in which the existence of a substance is posi
tively 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, -
while 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 con
dition thereof, than because it contains in itself any relation.
Now, upon this notion of permanence rests the proper notion of the
conception of 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 sub
ject to change; the mutable suffers no change, but rather alternation,
that is, when certain determinations cease others begin."
Change, then, 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 in 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 be
ginning with objects which existed previously, and which continue to
exist till the object 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 repre
sentation of a time, in which a phenomenon no longer exists.
Substances (in the world of phenomena) are tlie 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 co-existent, but as successive.
Accordingly, permanence is a necessary condition under which alone
phenomena, as things or objects, are determinable in a possible experi
ence. But as regards the empirical criterion of this necessary perma-
128 KANT
nence, and with it of the substantiality of phenomena, we shall find
sufficient opportunity to speak in the sequel.
B
SECOND ANALOGY
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
PROOF
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 extinc
tion 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 ex
tinction, because the conception of change presupposes the same sub
ject as existing with two opposite determinations, and consequently a:»
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 de
termines the internal sense in respect of a relation of time. But im
agination 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 unde
termined 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
CRITIQUE OF PURE REASON 129
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 suc
ceed 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 re
quiring 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 phe
nomena were things in themselves, no man would be able to conjecture
from the succession of our representations how this manifold is con
nected 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 cogni
tion. 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 also 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 transcen
dental 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, while 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 con
ception, drawn from the representations of apprehension, must har
monize. 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,
m opposition to the representations of apprehension, can only be dis
tinguished therefrom as the object of them, if it is subject to a rule,
which distinguishes it from every other apprehension, and which ren
ders necessary a mode of connection of the manifold. That in the
9
1 3o KANT
phenomenon which contains the condition of this necessary rule of ap
prehension 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, can
not 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 pre
cedes, 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 appre
hension, as I have shown above in the example of a house, my appre
hension of an event is not yet sufficiently distinguished from other
apprehensions. But I remark also, that if in a phenomenon which con
tains an occurrence, I call the antecedent state of my perception, A, and
the following state, B, the perception B can only follow A in appre
hension, 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 per
ception 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 appre
hension 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 per
ceptions in the apprehension of a house, might begin at the roof and
end at the foundation, or vice versa; or I might apprehend the mani
fold 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 rny 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 other
wise 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 phe
nomenon 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 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 suc
ceeding point of time to the preceding point, although it does certainly
CRITIQUE OF PURE REASON 131
relate to a preceding point of time ; from a given time, on the other
hand, there is always a necessary progression to the determined suc
ceeding time. Therefore, because there certainly is something that
follows, I must of necessity connect it with something else, which ante-
cedes, 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 event.
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 an
other, 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 would 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 phenome
nal world.
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 pre
supposition that even the experience of an event is possible.
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 al
ways 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 fur
nishes us with — " Everything that happens must have a cause " — would
be just as contingent as experience itself. The universality and neces
sity of the rule or law would be perfectly spurious attributes of it. In
deed, 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 complete-
I32 KANT
ness 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, determin
ing 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 ex
perience 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 be
fore), 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 suc
cession in the object.
We have representations within us, of which also we can be conscious.
But, however widely extended, however accurate and thorough-going
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 representa
tions 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 exist 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 sig
nificancy over and above the subjective, which is proper to it, as a de
termination of a state of mind ? " If we try to discover what sort of
new property the relation to an object gives to our subjective repre
sentations, and what new importance they thereby receive, we shall
find that this relation has no other effect than that of rendering neces
sary the connection of our representations in a certain manner, and of
subjecting them to a rule; and that conversely, it is only because a cer
tain order is necessary in the relations of time of our representations,
that objective significancy is ascribed to them.
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 as
sume, 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 some
thing 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 phenomena 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
CRITIQUE OF PURE REASON 133
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 suc
cession, and make that which happens precede that upon which it fol
lows; 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 con
sequence, 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 conse
quently a formal condition of all perception, that the preceding neces
sarily 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 suc
ceeding 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 phe
nomena that we can empirically cognize this continuity in the connec
tion of times.
For all experience and for the possibility of experience, understand
ing 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 repre
sentation 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 de
termine 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 an universal rule upon that which was con
tained 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 d priori in the form of internal intui
tion (time), in which all our perceptions must have place.
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 con
nected series of my perceptions. But this rule of the determination of
a thing according to succession in time is as follows : " In what pre
cedes may be found the condition, under which an event always (that
is, necessarily) follows." From all this it is obvious that the principle
i34 KANT
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 fol
lowing momenta of argument. To all empirical cognition belongs the
synthesis of the manifold by the imagination, a synthesis which is al
ways 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 syn
thesis 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 judgment, 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 repre
sented to myself anything as objective, I must look upon it as a mere
dream. Thus the relation of phenomena (as possible perceptions), ac
cording 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 condi
tion of the objective validity of our empirical judgments 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 ex
perience, because it is itself the ground of the possibility of experience.
Here, however, a difficulty arises, which must be resolved. The prin
ciple 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 mo
ment 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
CRITIQUE OF PURE REASON 135
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 the 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 hori
zontal 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 con
ception of substance. As I do not wish this critical essay, the sole pur
pose of which is to treat of the sources of our synthetical cognition d
priori, to be crowded with analyses which merely explain, but do not
enlarge the sphere of our conceptions, I reserve the detailed explana
tion 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 (phe
nomenon) ? But after what has been said above, the solution of this
question becomes easy enough, although by the common mode of pro
cedure — merely analyzing our conceptions — it would be quite impossible.
The conception of an 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 cri-
136
KANT
terion, is a sufficient proof of the presence of substantiality, without any
necessity on my part of endeavoring 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 extinc
tion, cannot itself (in the sphere of phenomena) arise and pass away,
is a sound and safe conclusion, a conclusion which leads us to the con
ception of empirical necessity and permanence in existence, and conse
quently to the conception of a substance as phenomenon.
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, sup
posing 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 ad
mitted 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 an
other 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 com
ing into existence of another state (be the content of the change, that
is, the state which is changed, what it may), and consequently the suc
cession of the states themselves, can very well be considered d priori,
in relation to the law of causality and the conditions of time.*
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
* It must be remarked, that I do not form manner, it does not change its
speak of the change of certain rela- state (of motion) ; but only when its
tions, but of the change of the state. motion increases or decreases.
Thus, when a body moves in an uni-
CRITIQUE OF PURE REASON 137
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 the thing
leaves, and the second determines the state into which the thing
passes. 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 change
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 in
creases 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 the 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 be
tween 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 ap
pears so greatly to extend our knowledge of nature, is possible com
pletely a priori, is indeed a question which deserves investigation, al
though the first view seems to demonstrate the truth and reality of the
principle, and the question, how it is possible, may be considered super
fluous. 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 thorough-going 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 intui
tions. This progression in time determines everything, and is itself
determined by nothing else. That is to say, the parts of the progres
sion exist only in time, and by means of the synthesis thereof, and are
not given antecedently to it. For this reason, every transition in per
ception to anything which follows upon another in time, is a determina-
x38
KANT
tion of time by means of the production of this perception. And as this
determination of time is, always and in all parts, a quantity, the per
ception 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 d priori.
Thus, as time contains the sensuous condition a priori of the possi
bility 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 d priori of the possibility of a continuous de
termination 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.
THIRD ANALOGY
Principle of Co-existence, According to the Law of Reciprocity
or Community
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.
PROOF
Things are co-existent, 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 perception of these objects can
reciprocally follow each other, I say, they exist contemporaneously.
Now co-existence is the existence of the manifold in the same time.
But time itself is not an object of perception; and therefore we can
not conclude from the fact that things are placed in the same time, the
other fact, that the perceptions 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 co-existent, 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
CRITIQUE OF PURE REASON 139
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 per
ceptions has its foundation in the object, and to enable us to represent
co-existence 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 re
ciprocal, it is the relation of community or reciprocity. Consequently
the co-existence of substances in space cannot be cognized in experi
ence otherwise than under the precondition of their reciprocal action.
This is therefore the condition of the possibility of things themselves
as objects of experience.
Things are co-existent, 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 phe
nomena each is completely isolated, that is, that no one acts upon an
other. Then I say that the co-existence 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 follow
ing perception, but would be quite unable to distinguish whether the
one phenomenon follows objectively upon the first, or is co-existent
with it.
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 co
existence 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. Conse
quently it is absolutely necessary that all substances in the world of
phenomena, in so far as they are co-existent, stand in a relation of com
plete community of reciprocal action to each other.
I4o KANT
The word community has in our language* two meanings, and con
tains the two notions conveyed in the Latin communio, and commercium.
We employ it in this place in the latter sense — that of a dynamical com
munity, 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 co-existence with us; that we cannot empirically change our po
sition (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 ex
istence of these places only through their reciprocal influence, and
thereby also the co-existence 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
co-existence takes place. But in this place it is not an object of pos
sible 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 co-existent 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 sub
stances as phenomena, the perception of one substance must render
possible the perception of another, and conversely. For otherwise suc
cession, which is always found in perceptions as apprehensions, would
be predicated of external objects, and their representation of their co
existence 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 co-existence would be a notion be
yond the reach of our minds. By virtue of this commercium, phe
nomena, in so far as they are apart from, and nevertheless in connec
tion 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 noth
ing more than principles of the determination of the existence of phe-
* German.
CRITIQUE OF PURE REASON 141
nomena in time, according to the three modi of this determination;
to wit, the relation to time itself as a quantity (the quantity of ex
istence, that is, duration), the relation in time as a series or succession,
finally, the relation in time as the complex of all existence (simul
taneity). This unity of determination in regard to time is thoroughly
dynamical ; that is to say, time is not considered as that in which ex
perience determines immediately to every existence its position ; for
this is impossible, inasmuch as absolute time is not an object of per
ception, 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 re
gards relations of time, determines for every phenomenon its position
in time, and consequently a priori, and with validity for all and every
time.
By nature, in the empirical sense of the word, we understand the
totality of phenomena connected, in respect of their existence, accord
ing 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 expres
sion of all this is : 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
it, 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 intel
lectual and likewise synthetical propositions a priori. Had we en
deavored to prove these analogies dogmatically, that is, from concep
tions ; that is to say, had we employed this method in attempting to
show that everything which exists, exists only in that which is perma
nent — 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 co-existent, the states co-exist in
connection with each other according to a rule — all our labor would
have been utterly in vain. For mere conceptions of things, analyze
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 experi
ence 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 phe
nomena, we found a priori conditions of the universal and necessary
determination a= to time of all existences in the world of phenomena,
I42 KANT
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.
IV. The Postulates of Empirical Thought
1. That which agrees with the formal conditions (intuition and con
ception) 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.
EXPLANATION
The categories of modality possess this peculiarity, that they
do not in the least determine the object, or enlarge the concep
tion 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 ob
ject itself is not more definitely determined in thought, but
the question is only in what relation it, including all its deter
minations, stands to the understanding and its employment in
experience, to the empirical faculty of judgment, and to the
reason in its application to experience.
For this very reason, too, the categories of modality are
nothing more than explanations of the conceptions of possi
bility, reality, and necessity, as employed in experience, and at
* The unity of the universe, in which existence, we could not conclude from
all phenomena must be connected, is the fact of the latter as a merely ideal
evidently a mere consequence of the relation to the former as a real one.
tacitly admitted principle of the com- We have, however, shown in its place,
munity of all substances which are co- that community is the proper ground of
existent. For were substances isolated, the possibility of an empirical cognition
tbey could not as parts constitute a of co-existence, and that we may there-
whole, and were their connection (re- fore properly reason from the latter to
ciprocal action of the manifold) not the former as its condition,
necessary from the very fact of co-
CRITIQUE OF PURE REASON 143
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 con
cern 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 con
tains a synthesis must be regarded as empty and without ref
erence to an object, if its synthesis does not belong to experi
ence — either as borrowed from it, and in this case it is called
an empirical conception, or such as is the ground and d priori
condition of experience (its form), and in this case it is a pure
conception, a conception which nevertheless belongs to experi
ence, 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 d priori synthet
ical conception, if not in the synthesis which constitutes the
form of empirical cognition of objects? That in such a con
ception no contradiction exists is indeed a necessary logical con
dition, but very far from being sufficient to establish the ob
jective reality of the conception, that is, the possibility of such
an object as is thought in the conception. Thus, in the concep
tion 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 d 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 repre
sent to myself a thing that is permanent, so that everything in it
which changes belongs merely to its state or condition, from
I44 KANT
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 al
ways 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 per
ceived 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 experi
ence, do we know that they possess objective reality, that is,
transcendental truth; and that independent of experience,
though not independent of all relation to the form of an experi
ence in general and its synthetical unity, in which alone objects
can be empirically cognized.
But when we fashion to ourselves new conceptions of sub
stances, forces, action and reaction, from the material presented
to us by perception, without following the example of experi
ence in their connection, we create mere chimeras, of the pos
sibility 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 concep
tions 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 sub
ject 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 pres
ent 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
CRITIQUE OF PURE REASON 145
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 con-
creto 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 main
tain, 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 d 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 mak
ing 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 quan
tities, 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 con
sidered 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 something is determined in experience as an object, con-
10
,46 KANT
sequently completely & 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 ex
istence is to be cognized, but still that the object have some con
nection 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 con
clude its existence. For, let the conception be ever so com
plete, 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 the 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 ex
istence, 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 perceptions in a possible experience, and we are able, with
the guidance of these analogies, to reason in the series of pos
sible 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 pre-
CRITIQUE OF PURE REASON 147
tensions to discover the existence of a thing which we do not
immediately perceive are vain. Idealism, however, brings for
ward powerful objections to these rules for proving existence
mediately. This is, therefore, the proper place for its refutation.
Refutation of Idealism
Idealism — I mean material idealism — is the theory which de
clares the existence of objects in space without us to be either
(i) 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 (as-
sertio), to wit, I am. The second is the dogmatical idealism of
Berkeley, who maintains that space, together with all the ob
jects 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 prop
erty 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 judgment 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.
Theorem
The simple but empirically determined consciousness of my own existence
proves the existence of external objects in space
PROOF
I am conscious of my own existence as determined in time. All
determination in regard to time presupposes the existence of some
thing permanent in perception. But this permanent something cannot
I48 KANT
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 with
out 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 1. The reader will observe, that in the foregoing proof the
game which idealism plays, is retorted upon itself, and with more jus
tice. 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 our
selves, 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 sub
ject. 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 ex
isting, 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.
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 determina
tion 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
* The immediate consciousness of the as external, that is, to present it to the
existence of external things is, in the sense in intuition, we must already pos-
preceding theorem, not presupposed, sess an external sense, and must thereby
but proved, be the possibility of this distinguish immediately the mere recep-
consciousness understood by us or not. tivity of an external intuition from the
The question as to the possibility of it spontaneity which characterizes every
would stand thus: Have we an internal act of imagination. For merely to imag-
sense, but no external sense, and is ine also an external sense, would anni-
r-nr belief in external perception a mere hilate the faculty of intuition itself
Hehision? But it is evidpnt that, in order which is to be determined by the imag-
merely to fancy to ourselves anything ination.
CRITIQUE OF PURE REASON 149
that can correspond and be submitted to the conception of a substance
as intuition, except matter. This idea of permanence is not itself de
rived 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 /, 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
/ has not any predicate of intuition, which, in its character of perma
nence, could serve as correlate to the determination of time in the in
ternal 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 repre
sentations 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 ob
jects. The sole aim of our remarks has, however, been to prove that
internal experience in general is possible only through external ex
perience 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 con
nection 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 ex
istence 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 a 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. More
over, 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
,50 KANT
considered as empirical effects, or as something that happens and has
a beginning. Necessity, therefore, regards only the relations of phe
nomena according to the dynamical law of causality, and the possibility
grounded thereon, of reasoning from some given existence (of a cause)
d priori to another existence (of an effect). Everything that happens
is hypothctically 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 d 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 sub
ject 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 syn
thetical 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 noth
ing 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 of and beyond the field of possible ex
perience (the world), such a question cannot come before the tribunal
of mere understanding, which decides only upon questions that con
cern the employment of given phenomena for the construction of em
pirical cognition. It is rather a problem for ideal reason, which passes
beyond the sphere of a possible experience, and aims at forming a
judgment 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 him
self, 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 as
signed 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 synthetical solu-
CRITIQUE OF PURE REASON 151
tion, questions, however, which come under the jurisdiction of reason
alone. For they are tantamount to asking, whether all things as phe
nomena do without exception belong to the complex and connected
whole of a single experience, of which every given perception is a part,
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 appercep
tion, the rules which alone make this experience possible. Other forms
of intuition, besides those of space and time, other forms of under
standing 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 experi
ence, which is the only mode of cognition by which objects are pre
sented 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 de
cide, 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 remark
able. " All real is possible ;" from this follows naturally, according to
the logical laws of conversion, the particular proposition, " Some pos
sible 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 though 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 con
ception of understanding, there might be no omission of anything that,
in the common opinion, belongs to them. In reality, however, the no
tion 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 ex
plained in the sequel.
J52 KANT
Before concluding this fourth section, and at the same time the sys
tem of all principles of the pure understanding, it seems proper to
mention the reasons which induced me to term the principles of modal
ity postulates. This expression I do not here use in the sense which
some more recent philosophers, contrary to its meaning with mathe
maticians, 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 evi
dent 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
assertion.
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, inas
much 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 con
nection 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 modal
ity 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 cognition.
* When I think the reality of a thinp, ity. But while the notion of possibility
1 do really tliink more than the pos- is merely the notion of a position of a
sibility, but not in the thing: for that thing in relation to the understanding
can never contain more in reality than (its empirical use), reality is the con-
was contained in its complete possibil- Junction of the thing with perception.
CRITIQUE OF PURE REASON 153
General Remark of the System of Principles
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 (i) 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 (3) how, 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 ob
tained 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 sub
stance," that is, something that can exist only as a subject and
not as mere predicate ; or, " everything is a quantity " — to con
struct propositions such as these, we require something to
enable us to go out beyond the given conception and connect an
other with it. For the same reason the attempt to prove a syn
thetical 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, with
out this relation to conceptions, we could not conceive the ex
istence 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 pos
sibility of the thing itself that is said to be contingent. If, ac
cordingly, we look back to our proof of the principle of causal
ity, we shall find that we were able to prove it as valid only of
objects of possible experience, and, indeed, only as itself the
•54
KANT
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, " Every
thing 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 con
sequence, 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 pos
sible, 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.
But it is still more remarkable that, to understand the pos
sibility of things according to the categories, and thus to demon
strate 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 ( I ) 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 de
termines 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 concep
tion 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
* We can easily conceive the non- that the former is the opposite of the
existence of matter; but the ancients latter. For this opposite is merely a
did not thence infer its contingency. logical and not a real opposite to the
But even the alternation of the ex- other. If we wish to demonstrate the
istence and non-existence of a given contingency of the motion, what we
state in a thing, in which all change con- ought to prove is, that, instead of the
sists, by no means proves the con- motion which took place in the preced-
tingency of that state— the ground of ing point of time, it was possible for
proof being the reality of its opposite. the body to have been then in rest, not
For example, a body is in a state of rest that it is afterwards in rest; for, in this
after motion, but we cannot infer the case, both opposites are perfectly con-
contingency of the motion from the fact sistent with each other.
CRITIQUE OF PURE REASON 155
capable of being intuited. Change is the connection of deter
minations 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 fol
low, reason without an example cannot only not conceive, but
cannot even make intelligible without intuition ; and this in
tuition is the motion of a point in space ; the existence of which
in different spaces (as a consequence of opposite determina
tions) alone makes the intuition of change possible. For, in
order to make even internal change cogitable, 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 in
tuition to be able to represent the successive existence of our
selves in different states. The proper ground of this fact is,
that all change to be perceived as change pre-supposes some
thing permanent in intuition, while in the internal sense no
permanent intuition is to be found. Lastly, the objective pos
sibility 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 recipro
cally, 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 attrib
uting to the substances of the world — as cogitated by the un
derstanding 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 con
ceive the possibility of community (of substances as phe
nomena) if we represent them to ourselves as in space, conse
quently 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 quan
tities, and consequently the objective reality of the category of
1 56 KANT
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 in
ternal consciousness and the determination of our own nature
without the aid of external empirical intuitions is under dis
cussion, 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 Prin
ciples 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 relation.
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 un
derstanding, 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 inclosed 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 coun
try, and while constantly deluding him with vain hopes, en
gages 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 per
fectly contented with what it contains, or whether we must not
of necessity be contented with it, if we can find nowhere else
CRITIQUE OF PURE REASON 157
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 mo
menta of the arguments.
We have seen that everything which the understanding
draws from itself, without borrowing from experience, it never- i
theless possesses only for the behoof and use of experience, j
The principles of the pure understanding, whether constitu-~\
tive a priori (as the mathematical principles), or merely regu
lative (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 imag
ination 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 under
standing are not only a priori true, but the very source of all V
truth, that is, of the accordance of our cognition with objects, ,
and on this ground, that they contain the basis of the possi
bility 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 labor 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
'58
KANT
to do one thing, and that of very great importance, to deter
mine, namely, the bounds that limit its employment, and to
know what lies within or without its own sphere. This pur
pose can be obtained only by such profound investigations as
we have instituted. But if it cannot distinguish whether cer
tain 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
iLis-jeferred merely to phenomena, that is to objects of a pos-
_sibJej?£/>m'gMcg._ That the Tatter use"uf u Ltincepliuii Isthe only
admissible one, is evident from the reasons following. For
every conception are requisite, firstly, the logical form of a con
ception (of thought) in general; and, secondly, the possibility
of presenting to this an object to which it may apply. Failing
this latter, it has no sense, and is utterly void of content, al
though 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 de
gree of their d priori possibility, relate to empirical intuitions,
that is, to data towards a possible experience. Without this
they possess no objective validity, but are a mere play of im
agination 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 " — " Be
tween two points there can be only one straight line," etc. Al
though all these principles, and the representation of the object
with which this science occupies itself are generated in the mind
entirely & priori, they would nevertheless have no significance,
if we were not always able to exhibit their significance in and
CRITIQUE OF PURE REASON 159
by means of phenomena (empirical objects). Hence it is requi
site that an abstract conception be made sensuous, that is, that
an object corresponding to it in intuition be forthcoming, other
wise 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 pro
duced a priori, together with the synthetical principles or for
mulas 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 corre
sponding 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 con
fined, 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, con
sequently upon time and the synthesis of the homogeneous
therein. Reality, in contradistinction to negation, can be ex
plained only by cogitating a time which is either filled there
with 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 endeavor to realize by representing to myself some
thing that can exist only as a subject. But not only am T per
fectly ignorant of any conditions under which this logical pre
rogative 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 conse
quently do not know whether it has any meaning at all. In
160 KANT
like manner, if I leave out the notion of time, in which some
thing 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 con
ception, 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 substitu
tion of the logical possibility of the conception — the condition
of which is that it be not self-contradictory, for the transcen
dental 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 inexperienced.*
* In one word, to none of these con- ject, and consequently their real possi-
ceptions belongs a corresponding ob- bility cannot be demonstrated, if we
CRITIQUE OF PURE REASON 161
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 re
sult, to-wit, that the understanding is competent to effect noth
ing a priori, except the anticipation of the form of a possible
experience in general, and that, as that which is not phenome
non cannot be an object of experience, it can never overstep
the limits of sensibility, within which alone objects are pre
sented to us. Its principles are merely principles of the ex
position 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 intui
tion we possess — are abstracted, does not determine an object,
but merely expresses the thought of an object in general, ac
cording to different modes. Now, to employ a conception, the
function of judgment is required, by which an object is sub
sumed under the conception, consequently the at least formal
condition, under which something can be given in intuition.
Failing this condition of judgment (schema), subsumption is
impossible ; for there is in such a case nothing given, which
may be subsumed under the conception. The merely trans
cendental use of the categories is therefore, in fact, no use at
all, and has no determined, or even, as regards its form, de-
terminable 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 em
pirical and never of transcendental use, and that beyond the
take away sensuous intuition— the only which, however, is not the question;
intuition which we possess, and there what we want to know being, whether
then remain-, nothing but the logical it relates to an object and thus pos-
possibility, that is, the fact that the sesses any meaning,
conception or thought is possible—
162 KANT
sphere of possible experience no synthetical d, priori principles
are possible.
It may be advisable, therefore, to express ourselves thus.
The pure categories, apart from the formal conditions of sen
sibility, have a merely transcendental meaning, but are never
theless not of transcendental use, because this is in itself im
possible, inasmuch as all the conditions of any employment or
use of them (in judgments) are absent, to wit, the formal con
ditions 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 trans-
cendentally, they are of no use at all, when separated from sen
sibility, 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 subjelct 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 existence, 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, con
sidered 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
I 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.
CRITIQUE OF PURE REASON 163
But we are met at the very commencement with an ambiguity,
which may easily occasion great misapprehension. The under
standing, when it terms an object in a certain relation phenome
non, at the same time forms out of this relation a representa
tion or notion of an object in itself, and hence believes that it
can form also conceptions of such objects. Now as the under
standing 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 some
thing 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 ab
straction 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 com
prehends that it cannot employ its categories for the considera
tion 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
1 64 KANT
the conception of it is not self-contradictory, but only by means
of an intuition corresponding to the conception. If, there
fore, 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 fac
ulty 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 ex
tend 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, be
cause we cannot assume that such can be given, without pre
supposing the possibility of another than the sensuous mode of
intuition, a supposition we are not justified in making.
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 noume
non, 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 under
standing) 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
CRITIQUE OF "PURE REASON 165
the objective validity of sensuous cognition ; for things in them
selves, which lie beyond its province, are called noumena, for
the very purpose of indicating that this cognition does not ex
tend its application to all that the understanding thinks. But,
after all, the possibility of such noumena is quite incompre
hensible, 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 asscrtorically. The con
ception of a nournenon is therefore merely a limitative concep
tion, and therefore only of negative use. But it is not an arbi
trary 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 there
fore 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, ab
solutely necessary. But, in this case, a noumenon is not a par
ticular intelligible object for our understanding; on the con
trary, the kind of understanding to which it could belong is it
self 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 it-
166 KANT
self, 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 intel-
ligibilis* which quite departs from the meaning of the ancients
— an acceptation in which, indeed, there is to be found no dif
ficulty, but which at the same time depends on mere verbal quib
bling. According to this meaning, some have chosen to call the
complex of phenomena, in so far as it is intuited, mundus sensi
bilis, but in so far as the connection thereof is cogitated accord
ing to general laws of thought, mundus intelligibilis. Astrono
my, in so far as we can 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 phenome
non — and in this sense we regard it if it is cogitated as giving 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. The 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 com
plete connection of phenomena, and not according to what they
may be, apart from their relation to possible experience, conse
quently 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 pos
sible by means of our categories. Understanding and sensibility,
with us, can determine objects only in conjunction. If we sepa-
* We must not translate this ex- suous. Objects of the one or the other
pression by intellectual, as is commonly mode of intuition ought to be called,
done in German works; for it is cognt- however harshly it may sound, intelli-
tions alone that are intellectual or sen- gible or sensible.
CRITIQUE OF PURE REASON 167
rate them, we have intuitions without conceptions, or concep
tions 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 cate
gories, let him attempt to construct with them a synthetical
proposition. It would, of course, be unnecessary for this pur
pose to construct an analytical proposition, for that does not ex
tend 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 in
different. The attempt must therefore be made with a syntheti
cal and so-called transcendental principle, for example, Every
thing 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 there
in do not relate to possible experience but to things in themselves
(noumena) ? Where is to be found the third term, which is al
ways requisite 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, com
pletely renouncing pure and non-sensuous judgment. Thus the
conception of pure and merely intelligible objects is completely
void of all principles of its application, because we cannot im
agine any mode in which they might be given, and the prob
lematical thought which leaves a place open for them serves only,
like a void space, to limit the use of empirical principles, with
out containing at the same time any other object of cognition be
yond their sphere.
,68 KANT
APPENDIX
Of the Equivocal Nature or Amphiboly of the Conceptions of
Reflection from the Confusion of the Transcendental with
the Empirical Use of the Understanding
Reflection (reftexio) is not occupied about objects them
selves, for the purpose of directly obtaining conceptions of them,
but is that state of the mind in which we set ourselves to dis
cover the subjective conditions under which we obtain concep
tions. It is the consciousness of the relation of given repre
sentations to the different sources or faculties of cognition, by
which alone their relation to each other can be rightly de
termined. The first question which occurs in considering our
representations is, to what faculty or cognition do they belong ?
To the understanding or to the senses? Many judgments are
admitted to be true from mere habit or inclination; but, be
cause reflection neither precedes nor follows, it is held to be a
judgment that has its origin in the understanding. All judg
ments do not require examination, that is, investigation into the
grounds of their truth. For, when they are immediately cer
tain (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 judgment, 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 repre
sentations 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 sen
suous intuition, I term transcendental reflection. Now, the re
lations 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 de
termining (matter and form). The proper determination of
these relations rests on the question, to what faculty of cogni
tion they subjectively belong, whether to sensibility or under
standing? For, on the manner in which we solve this question
depends the manner in which we must cogitate these relations.
Before constructing any objective judgment, we compare the
conceptions that are to be placed in the judgment, and observe
CRITIQUE OF PURE REASON 169
whether there exists identity (of many representations in one
conception), if a general judgment is to be constructed, or dif
ference, of a particular; whether there is agreement when
affirmative, and opposition when negative judgments are to be
constructed, and so on. For this reason we ought to call these
conceptions, conceptions of comparison (conceptus compara-
tionis). 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 op
position, 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 dis
tinguishing the mode of cognition to which they belong, in other
words, by means of transcendental reflection. We may, there
fore 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 them
selves) contains the ground of possibility of objective com
parison 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 re
flection is a duty which no one can neglect who wishes to es
tablish an d priori judgment upon things. We shall now pro
ceed 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.
i. Identity and Difference. — When an object is presented to
us several times, but always with the same internal determi
nations (qualitas et quantitas), it, if an object of pure under
standing, 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
170
KANT
in this respect perfectly the same, the difference of place at the
same time is a sufficient ground for asserting the numerical dif
ference 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
intelligibility, 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 prin
ciple of the indiscernible (principium identatis indiscernibi-
liuni) 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, al
though 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 be
tween 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 the phenomenon
(realitas phenomenon} 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 re
gards its existence) to anything different from itself. On the
other hand, the internal determinations of a substantia phe
nomenon in space are nothing but relations, and it is itself noth
ing more than a complex of mere relations. Substance in space
CRITIQUE OF PURE REASON 171
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 sub
stance phenomenal in space, and which we term matter. On the
other hand, as an object of the pure understanding, every sub
stance must have internal determinations 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
is 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 com
position 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 con
nected 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 judgment one may call the given con
ceptions logical matter (for the judgment) the relation of these
to each other (by means of the copula), the form of the judg
ment. In an object, the composite parts thereof (essentialia)
are the matter ; the mode in which they are connected in the ob
ject, the form. In respect to things in general, unlimited reality
was regarded as the matter of all possibility, the limitation there
of (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 as
sumed 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 of their state (that
is, of their representations). Hence, with him, space and time
were possible — the former through the relation of substances,
172
KANT
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 in
tuition (as a subjective property of sensibility) must antecede
all matter (sensations), consequently space and time must ante-
cede 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 pos
sibility of itself presupposes, on the contrary, a given formal in
tuition (space and time).
Remark on the Amphiboly of the Conceptions of Reflection
Let me be allowed to term the position which we assign to a
conception either in the sensibility or in the pure understand
ing, the transcendental place. In this manner, the appoint
ment 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 thor
oughly shield us from the surreptitious devices of the pure un
derstanding and the delusions which thence arise, as it would
always distinguish to what faculty of cognition each concep
tion 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.
CRITIQUE OF PURE REASON 173
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 con
stitutes its conception (quantity, reality), but set forth merely
the comparison of representations, which precedes our concep
tions of things. But this comparison requires a previous re
flection, that is, a determination of the place to which the rep
resentations of the things which are compared belong, whether,
to wit, they are cogitated by the pure understanding or given by
sensibility.
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. With
out 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 substi
tution of an object of pure understanding for a phenomenon.
For want of this doctrine of transcendental topic, and con
sequently deceived by the amphiboly of the conceptions of re
flection, the celebrated Leibnitz constructed an intellectual sys
tem of the world, or rather, believed himself conpetent to
cognize the internal nature of things, by comparing all objects
merely with the understanding and the abstract formal concep
tions 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 nought but a misconcep
tion. 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 con
ceptions one from another. The conditions of sensuous in
tuition, which contain in themselves their own means of distinc
tion, he did not look upon as primitive, because sensibility was
to him but a confused mode of representation, and not any par
ticular source of representations. A phenomenon was for him
the representation of the thing in itself, although distinguished
174
KANT
from cognition by the understanding only in respect of the
logical form — the former with its usual want of analysis con
taining, according to him, a certain mixture of collateral repre
sentations 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 sys
tem of noogony (if I may be allowed to make use of such ex
pressions) sensualized the conceptions of the understanding,
that it 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 repre
sentations, which, however, can present us with objective judg
ments of things only in conjunction, each of these great men
recognized but one of these faculties, which, in their opinion, ap
plied 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.
ist. He compares them in regard to their identity or dif
ference — 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 concep
tions — whether, that is, their object ought to be classed among
phenomena, or among things in themselves, it was to be ex
pected 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 phenomenon) , and that he
should believe that he had thereby contributed in no small de
gree to extend our knowledge of nature. In truth, if I cognize
in all its inner determinations a drop of water as a thing in it
self, 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 in
ternal determination of things, and one place, B, may contain a
thinr^ which is perfectly similar and equal to another in a place,
A, just as well as if the two things were in every respect dif-
CRITIQUE OF PURE REASON 175
ferent 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. Con
sequently, 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.
2d. 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 = o, 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 an
tagonistic actions and operations in nature, which nevertheless,
as depending on real forces, must be called realitates phe
nomena. General mechanics can even present us with the
empirical condition of this opposition in an a priori rule, as it di
rects 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 Leibnitz-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 contradic
tion (by which the conception itself of a thing is annihilated),
and find themselves unable to conceive an opposition of recipro
cal 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.
3d. The Leibnitzian Monadology has really no better founda
tion than on this philosopher's mode of falsely representing the
difference of the internal and external solely in relation to the
176 KANT
understanding. Substances, in general, must have something
inward, which is therefore free from external relations, con
sequently from that of composition also. The simple — that
which can be represented by a unit — is therefore the founda
tion of that which is internal in things in themselves. The in
ternal 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 where
by 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 har
mony, 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 an
other, 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 ap
plied in each particular case (systema assis tent ice} , 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, con
sequently 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
CRITIQUE OF PURE REASON 177
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 them
selves. But things were intelligible substances (substantial nou-
mena). 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 representa
tion of objects, in the understanding, and left to sense nought
but the despicable task of confusing and disarranging the repre
sentations of the former.
But even if we could frame any synthetical proposition con
cerning things in themselves by means of the pure understand
ing (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 them
selves, 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 con
ceptions of reflection. Matter is substantia phenomenon. 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 per
forms, and which are indeed never anything but phenomena of
the external sense. I cannot therefore find anything that is ab
solutely, but only what is comparatively internal, and which it
self 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 under
standing. But the transcendental object, which is the founda
tion of the phenomenon which we call matter, is a mere nescio
quid, the nature of which we could not understand, even though
some one were found able to tell us. For we can understand
nothing that does not bring with it something in intuition cor
responding 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
12
178 KANT
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 in
terior of nature, and no one can say what progress this knowl
edge 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 in
tuition 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 exist
ence 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 demonstra
tion 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 dis
cover 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 in
tellectual intuition, certain limitations present themselves, which
forbid us to pass beyond the conceptions, and render all empiri
cal use of them impossible. And thus these limitations prove,
CRITIQUE OF PURE REASON 179
that the representation of an object as a thing in general is not
only insufficient, but, without sensuous determination and in
dependently 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 alto
gether 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 differ
ent 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 employ
ment 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 interven
tion 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,
i8o KANT
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 indis-
tinguishables 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, conse
quently, all things are completely identical (numero eadeni)
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 con
ception, 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 con
ceptions cannot, in conjunction, produce any negation. But
in sensuous intuition, wherein reality (take for example, mo
tion) 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 = o. We are therefore not justified in saying,
that all reality is in perfect agreement and harmony, because
no contradiction is discoverable among its conceptions.* Ac
cording to mere conceptions, that which is internal is the sub
stratum of all relations or external determinations. When,
therefore, I abstract all conditions of intuition, and confine my
self solely to the conception of a thing in general, I can make
abstraction of all external relations, and there must neverthe-
* If anyone wishes here to have re- thing or nothing. But an example can-
course to the usual subterfuge, and to not be found except in experience,
say, that at least realitates noumena can- which never presents to us anything
not be in opposition to each other, it more than phenomena, and thus the
will be requisite for him to adduce an proposition means nothing more than
example of this pure and non-sensuous the conception which contains only af-
reality, that it may be understood firmatives, does not contain nnv nepa-
whether the notion represents some- tive — a proposition nobody ever doubted.
CRITIQUE OF PURE REASON 181
less 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 determina
tions, inasmuch as it renders them possible ; and that therefore
this substratum is something which does not contain any ex
ternal 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 con
ceptions of relations presuppose given things, and without these
are impossible. But, as in 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 con
ception of a thing in general, and this presents to us the sub
stratum 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 noth
ing but the internal in general, through which alone the external
is possible. But this necessity, which is grounded upon ab
straction 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 in themselves, but only
i82 KANT
phenomena. What we cognize in matter is nothing but rela
tions (what we call its internal determinations are but com
paratively 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 rela
tions ; 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 abstract o,
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 in
tuition, 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.
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 knowl
edge (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 prob-
CRITIQUE OF PURE REASON 183
lematical, that is to say, it is the notion of a thing of which we
can neither say that it is possible, nor that it is impossible, in
asmuch 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 be
yond the conditions of our sensibility, and to assume the ex
istence of objects of pure thought, that is, of noumena, inas
much 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 ref
erence 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 con
ception of a noumenon is therefore not the conception of an
object, but merely a problematical conception inseparably con
nected 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 in
tuition? — a question to which only an indeterminate answer
can be given. That answer is : Inasmuch as sensuous intui
tion does not apply to all things without distinction, there re
mains 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 ad
mitted 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 phenome-
184
KANT
non), and which cannot be thought either as a quantity or as
reality, or as substance (because these conceptions always re
quire 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 be
yond those which are presented to us as phenomena, and to stray
into intelligible worlds ; nay, it does not even allo " us to en
deavor 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 trans
cendental, 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 representa
tions. Accordingly we think something in general, and de
termine it on the one hand sensuously, but, on the other, distin
guish 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 (noume
non), 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 im
portance, seems to be necessary to the completeness of the
CRITIQUE OF PURE REASON 185
system. The highest conception, with which a trascendental
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 concep
tion 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 ob
jects 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 pos
sible 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 con
ception 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 cer
tainly something, as forms of intuition, but are not themselves
objects which are intuited (ens imaginarium) .
4. The object of 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 a.<=
follows :
NOTHING.
As
I.
Empty conception without object,
ens rationis.
186 KANT
II. HI.
Empty object of a conception, Empty intuition without object,
nihil privativum. ens imaginarium.
IV.
Empty object without conception,
nihil negativum.
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 com
pletely 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 some
thing real, be an object.
SECOND DIVISION
TRANSCENDENTAL DIALECTIC
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 de
ceitful. Hence it must not be separated from the analytical part
of logic. Still less must phenomenon J and appearance be held
to be identical. For truth or illusory appearance does not re
side in the object, in so far as it is intuited, but in the judgment
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
* Sdicin. t Wahrscheinlichkeit. J Erscheinung.
CRITIQUE OF PURE REASON 187
cause of error, are only to be found in a judgment, that is, in the
relation of an object to our understanding. In a cognition,
which completely harmonizes with the laws of the understand
ing, no error can exist. In a representation of the senses — as
not containing any judgment — 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 an
other 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 judgment) must necessarily accord with
these laws. But in accordance with the laws of the understand
ing consists the formal element in all truth. In the senses there
is no judgment — 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 subjec
tive grounds of a judgment blend and are confounded with the
objective, and cause them to deviate from their proper deter
mination,* just as a body in motion would always of itself pro
ceed in a straight line, but if another impetus gives to it a dif
ferent direction, it will then start off into a curvilinear line of
motion. To distinguish the peculiar action of the understand
ing from the power which mingles with it, it is necessary to con
sider an erroneous judgment as the diagonal between two
forces, that determine the judgment 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 judgments this must be done by
means of transcendental reflection, whereby, as has been already
shown, each representation has its place appointed in the cor
responding faculty of cognition, and consequently the influence
of the one faculty upon the other is made apparent.
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 under
standing, and in which the judgment is misled by the influence
of imagination. Our purpose is to speak of transcendental illu
sory appearance, which influences principles — that are not even
* Sensibility, subjected to the under- so far as it exercises an influence upon
standing", as the object upon which the the action of the_ understanding, and
understanding employs its functions, is determines it to judgment, sensibility
the source of real cognitions. But, in is itself the cause of error.
,88 KANT
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 under
stand principles of the transcendental use or misuse of the cate
gories, which is in reality a mere fault of the judgment 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 recogni-
nizes no line of demarcation. Thus transcendental and trans
cendent are not identical terms. The principles of the pure un
derstanding, 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 understanding.
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 criti
cism. — 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
CRITIQUE OF PURE REASON 189
as an objective necessity of the determination of things in them
selves. This illusion it is impossible to avoid, just as we can
not avoid perceiving that the sea appears to be higher at a dis
tance 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 after
wards, although he is not deceived by this illusion.
Transcendental dialectic will therefore content itself with
exposing the illusory appearance in transcendental judgments,
and guarding us against it; but to make it, as in the case of
logical illusion, entirely disappear and cease to be illusion, is ut
terly 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 artifici
ally 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 requi
site 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
illusion have been exposed, does not cease to deceive, and con
tinually to lead reason into momentary errors, which it becomes
necessary continually to remove.
II. Of Pure Reason as the Seat of the Transcendental
Illusory Appearance
A. — Of Reason in General
All our knowledge begins with sense, proceeds thence to un
derstanding, 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 con
fess 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
I9o KANT
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 con
clusions {consequently immediate) ; but the nature of the
latter, which itself generates conceptions, is not to be under
stood from this definition. Now as a division of reason into a
logical and a transcendental faculty presents itself here, it be
comes 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 dis
tinguished 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; al
though it is not in itself, and as regards its proper origin, en
titled 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 prin
ciple. Mathematical axioms (for example, there can be only
one straight line between two points) are general a priori cog
nitions, and are therefore rightly denominated principles, rela
tively 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 condi
tion 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 proposi
tions, they may be termed principles, in respect of their possible
use.
CRITIQUE OF PURE REASON 19!
But if we consider these principles of the pure understand
ing in relation to their origin, we shall find them to be anything
rather than cognitions from conceptions. For they would not
even be possible d 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 in
structs 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 prin
ciples. At the same time, all general propositions may be
termed comparative principles.
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 sim
plifying 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 concep
tions. 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 some
thing very different from cognition by means of the understand
ing, 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 con
trary, the understanding, to the manifold cognition of which it
gives a unity d priori by means of conceptions — a unity which
1 92 KANT
may be called rational unity, and which is of a nature very dif
ferent from that of the unity produced by the understanding.
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.
B. — Of the Logical use of Reason
A distinction is commonly made between that which is im
mediately 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 judgment concluded is so contained in the first proposition,
that it can be deduced from it without the mediation of a third
notion, the conclusion is called immediate (consequentia imme-
diata*) : I prefer the term conclusion of the understanding.
But if, in addition to the fundamental cognition, a second judg
ment 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 mor
tal, 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 judgment.
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 judgment. And finally I determine my cogni
tion 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
CRITIQUE OF PURE REASON 193
rule, represents between a cognition and its condition, consti
tute the different kinds of syllogisms. These are just threefold
— analogously with all judgments, in so far as they differ in the
mode of expressing the relation of a cognition in the under
standing — namely, categorical, hypothetical and disjunctive.
When, as often happens, the conclusion is a judgment which
may follow from other given judgments, through which a per
fectly different object is cogitated, I endeavor 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 endeavors
to subject the great variety of the cognitions of the understand
ing to the smallest possible number of principles (general condi
tions), and thus to produce in it the highest unity.
C. — Of the pure use of Reason
Can we isolate reason, and, if so, is it in this case a peculiar
source of conceptions and judgments 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 subor
dinated 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 rea
son, for the purpose of bringing the understanding into com
plete accordance with itself, just as understanding subjects the
manifold content of intuition to conceptions, and thereby intro
duces 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 sub
jective 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 an uni-
13
i94 KANT
formity as might contribute to the convenience and the enlarge
ment 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 rea
son 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 ap
plicable to intuitions, for the purpose of subjecting them to rules
— for this is the province of the understanding with its cate
gories — but to conceptions and judgments. If pure reason does
apply to objects and the intuition of them, it does so not imme
diately, but mediately — through the understanding and its
judgments, 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 experi
ence, 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 prin
ciple makes the unity of experience possible and borrows noth
ing from reason, which, without a reference to possible experi
ence, could never have produced by means of mere conceptions
any such synthetical unity.
2. Reason, in its logical use, endeavors to discover the gen
eral condition of its judgment (the conclusion), and a syllo
gism is itself nothing but a judgment by means of the subsump-
tion 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 understand
ing the unconditioned whereby the unity of the former is com
pleted.
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
CRITIQUE OF PURE REASON 195
is consequently itself unconditioned — is also given, that is, con
tained in the object and its connection.
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 syn
thesis 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 condi
tioned, and will thus afford us material for many a priori syn
thetical 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 empir
ical 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 ex
ists 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 intro
duce 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 transcen
dental 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 pro
ceed 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
196
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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 syllogisms.
BOOK I
OF THE CONCEPTIONS OF PURE REASON
The conceptions of pure reason — we do not here speak of the
possibility of them — are not obtained by reflection, but by infer
ence or conclusion. The conceptions of understanding are also
cogitated a priori antecedently to experience, and render it pos
sible ; but they contain nothing but the unity of reflection upon
phenomena, in so far as these must necessarily belong to a pos
sible empirical consciousness. Through them alone are cogni
tion 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 ob
jects 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 ex
perience, 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 pos
sible 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 uncondi
tioned, 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 em
pirical use, but which is never itself an element in an empirical
synthesis. If, notwithstanding, such conceptions possess objec
tive validity, they may be called conceptus ratiocinati (concep
tions legitimately concluded) ; in cases where they do not, they
CRITIQUE OF PURE REASON 197
have been admitted on account of having the appearance of
being correctly concluded, and may be called conceptus ratio-
cinantes (sophistical conceptions). But as this can only be
sufficiently demonstrated in that part of our treatise which re
lates to the dialectical conclusions of reason, we shall omit any
consideration of it in this place. As we called the pure con
ceptions of the understanding categories, we shall also distin
guish those of pure reason by a new name, and call them trans
cendental ideas. These terms, however, we must in the first
place explain and justify.
Sec. I. — Of Ideas in General.
Spite of the great wealth of words which European languages
possess, the thinker finds himself often at a loss for an expres
sion exactly suited to his conception, for want of which he is
unable to make himself intelligible either to others or to him
self. To coin new words is a pretension to legislation in lan
guage 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 al
though it may be doubtful whether it was formerly used in ex
actly this sense — than to make our labor vain by want of suffi
cient care to render ourselves intelligible.
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 im-
providently, 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 other
wise 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.
,98 KANT
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,) inas
much 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 rea
son, by which they have been imparted to human reason, which,
however, exists no longer in its original state, but is obliged
with great labor 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 spell
ing out phenomena according to synthetical unity, for the pur
pose 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 corre
sponding 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 prac
tical,* 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 the formation of a perfectly adequate idea on the sub-
. * He certainly extended the applies- can I follow him in his mystical deduc
tion of his conception to the speculative tion of these ideas, or in his hypostatiza-
cognitions also, provided they were tion of them; although, in truth, the ele-
given pure and completely & priori, nay, vated and exaggerated language which
even to mathematics, although this sci- he employed in describing them is quite
ence cannot possess an object other- capable of an interpretation more sub-
where than in possible experience. I dued and more in accordance with fact
cannot follow him in this, and as little and the nature of things.
CRITIQUE OF PURE REASON 199
ject, would in fact transform virtue into a nonentity change
able according to time and circumstance, and utterly incapable
of being employed as a rule. On the contrary, everyone 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 rela
tion to which all possible objects of experience are indeed ser
viceable 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 judgments 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.
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 happi
ness, for this follows necessarily from the former), is to say
the least, a necessary idea, which must be placed at the founda
tion not only of the first plan of the constitution of a state, but
of all its laws. And in this, it is 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 hav« existed,
if those institutions had been established at the proper time and
2oo KANT
in accordance with ideas; while instead of this, conceptions,
crude for the very reason that they have been drawn from ex
perience, have marred and frustrated all our better views and
intentions. The more legislation and government are in har
mony 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 legis
lative 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 realiza
tion, are problems which no one can or ought to determine —
and for this reason, that it is the destination of freedom to over
step 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, an animal, the regular order of nature — prob
ably 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 exaggera
tions of expression in the writings of this philosopher, the men
tal power exhibited in this ascent from the ectypal mode of re
garding the physical world to the architectonic connection
thereof according to ends, that is, ideas, is an effort which de
serves imitation and claims respect. But as regards the prin
ciples 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
CRITIQUE OF PURE REASON 201
a position of peculiar merit, which is not appreciated only be
cause 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 sub
terranean 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 con
vinced by the considerations following as well as by those above,
to exert themselves to preserve to the expression idea its orig
inal 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 there
by suffer. We are in no want of words to denominate ade
quately every mode of representation, without the necessity of
encroaching upon terms which are proper to others. The fol
lowing is a graduated list of them. The genus is representation
in general (representation . Under it stands representation with
consciousness (perceptio). A perception which relates solely
to the subject as a modification of its state, is a sensation (sen-
satio), an objective perception is a cognition (cognitio}. A
cognition is either an intuition or a conception (intuitus vel con-
ceptus}. 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 com
mon to several things. A conception is either empirical or pure.
A pure conception, in so far as it has its origin in the under-
202 KANT
standing alone, and is not the conception of a pure sensuous im
age, is called notio. A conception formed from notions, which
transcends the possibility of experience, is an idea, or a concep
tion of reason. To one who has accustomed himself to these
distinctions, it must be quite intolerable to hear the representa
tion of the color red called an idea. It ought not even to be
called a notion or conception of understanding.
Sec. 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 judgments — converted into a conception of the synthesis of
intuitions — produced the categories, which direct the employ
ment 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 cate
gories, 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 uni
versality of a cognition according to conceptions, and the syl
logism itself is a judgment which is determined a priori in the
whole extent of its condition. The proposition, " Caius is mor
tal," is one which may be obtained from experience by the aid
of the understanding alone ; but my wish is to find a concep
tion, which contains the condition under which the predicate of
this judgment 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 cog
nition 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 quan
tity of the extent in relation to such a condition is called uni
versality (universalitas) . To this corresponds totality (uni-
versitas) of conditions in the synthesis of intuitions. The
CRITIQUE OF PURE REASON 203
transcendental conception of reason is therefore nothing else
than the conception of the totality of the conditions of a given
condition. 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 prosyilogisms to the uncondi
tioned — one to the subject which cannot be employed as a predi
cate, 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, cor
responding to their transcendental employment, in concrete,
and be thus of no greater utility than to direct the understand
ing how, while extending them as widely as possible, to main
tain 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 rea
son, we again light upon an expression, which we find it impos
sible 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 con
ception 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
204 KANT
of reason, its loss would be greatly to the detriment of all trans
cendental philosophy. The word absolute is at present fre
quently used to denote that something can be predicated of a
thing considered in itself and intrinsically. In this sense abso
lutely 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 in
dicate that a thing is valid in all respects — for example, abso
lute sovereignty. Absolutely possible would in this sense sig
nify 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 coin
cide. 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 ccelo, and I
can by no means conclude that, because a thing is in itself pos
sible, 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 con
ception 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 indif
ference to the philosopher, I trust that the proper determina
tion 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 par
ticular 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 ob
ject nothing else than absolute totality in the synthesis of condi
tions, and does not rest satisfied till it has attained to the abso-
CRITIQUE OF PURE REASON 205
lutely, that is, in all respects and relations, unconditioned. For
pure reason leaves to the understanding everything that im
mediately 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 phe
nomena, 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 condi
tions is not a conception that can be employed in experience,
because no experience is unconditioned), but solely for the pur
pose of directing it to a certain unity, of which the understand
ing has no conception, and the aim of which is to collect into
an absolute whole all acts of the understanding. Hence the ob
jective employment of the pure conceptions of reason is always
transcendent, while that of the pure conceptions of the under
standing 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 pres
ent under consideration are transcendental ideas. They are
conceptions of pure reason, for they regard all empirical cogni
tion as determined by means of an absolute totality of condi
tions. 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 ex
perience, in which, consequently, no object can ever be pre
sented that would be perfectly adequate to a transcendental
idea. When we use the word idea, we say, as regards its ob
ject (an object of the pure understanding), a great deal, but as
regards its subject (that is, in respect of its reality under con
ditions of experience), exceedingly little, because the idea, as
the conception of a maximum, can never be completely and
adequately presented in concrete. Now, as in the merely specu-
* Vernunftemheit, Verstandeseinheit.
206 KANT
lative 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 concep
tion were non-existent — it is commonly said of a 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 concrete, although only partially,
nay, it is the indispensable condition of all practical employ
ment 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 con
ception 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 pos
sesses even causality and the power of producing that which its
conception contains. Hence we cannot say of wisdom, in a dis
paraging 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 endeavors the primitive con
dition 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 men
tion that they perhaps render possible a transition from our
conceptions of nature and the non-ego to the practical concep
tions, 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 contem-
CRITIQUE OF PURE REASON 207
plate reason in its speculative use alone, nay, in a still more re
stricted 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 enable 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
judgment — by means of the subsumption of the condition of a
possible judgment under the condition of a given judgment.
The given judgment is the general rule (major). The sub-
sumption of the condition of another possible judgment under
the condition of the rule is the minor. The actual judgment,
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 [that is] com
pound 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 condi
tions (premisses). Now every series, whose exponent (of the
categorical or hypothetical judgment) is given, can be con
tinued ; consequently the same procedure of reason conducts us
to the ratiocinatio polysyllogistica, which is a series of syl
logisms, that can be continued either on the side of the condi
tions (per prosyllogismos) or of the conditioned (per episyl-
logismos) to an indefinite extent.
But we very soon perceive that the chain or series of pro-
2o8 KANT
syllogisms, 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 rela
tion 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 pre-supposi-
tion that all the members of the series on the side of the con
ditions are given (totality in the series of premises), because
only under this supposition is the judgment we may be consid
ering possible a priori; while on the side of the conditioned
or the inferences, only an incomplete and becoming, and not a
pre-supposed or given series, consequently only a potential pro
gression, is cogitated. Hence, when a cognition is contem
plated 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 cognition 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 suffi
ciently guaranteed and determined on grounds a parte priori.
It may be the case, that upon the side of the conditions the
series of premises 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 admit
ting 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 neces
sary, 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.
CRITIQUE OF PURE REASON 209
Sec. 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 con
ceptions, the object of which cannot be given empirically, and
which therefore lie beyond the sphere of the faculty of under
standing. We have observed, from the natural relation which
the transcendental use of our cognition, in syllogisms as well
as in judgments, 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 un
derstanding never proceeds, to the unconditioned which the
understanding never can reach.
Now the most general relations which can exist in our rep
resentations are, ist, the relation to the subject; 2d, the rela
tion to objects, either as phenomena, or as objects of thought
in general. If we connect this subdivision with the main divi
sion, all the relations of our representations, of which we can
form either a conception or an idea, are threefold: i. 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 rea
son (transcendental ideas) on the other hand, with the uncon
ditional 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 condi
tion of the possibility of all that is cogitable (the being of all
14
zio KANT
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 transcen
dental doctrine of God (theologia transcendentalis) . Under
standing cannot originate even the outline of any of these sci
ences, 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 transcen
dental 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 concep
tions 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, nec
essarily 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 uncondi
tioned 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 paradoxical.
An objective deduction, such as we were able to present in
the case of the categories, is impossible as regards these trans
cendental 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 complete
ness 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)
CRITIQUE OF PURE REASON 211
given condition, there is no further necessity, in proceeding
with the series, for a conception of reason ; for the understand
ing takes of itself every step downward, from the condition
to the conditioned. Thus the transcendental ideas are avail
able 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 ra~
tionis, an arbitrary fiction of thought, and not a necessary pre
supposition of reason. For the possibility of the conditioned
presupposes the totality of its conditions, but not of its conse
quences. 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 transcen
dental ideas of 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 premises to the conclusion.* Now whether
there lies unobserved at the foundation of these ideas an anal
ogy of the same kind as exists between the logical and trans
cendental 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 prelimi
nary 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
* The science of Metaphysics has for would render Theology, Ethics, and
the proper object of its inquiries only through the conjunction of both, Re-
three grand ideas: God, Freedom, and ligion, solely dependent on the specu-
Immortality, and it aims at showing lative faculty of reason. In a systematic
that the second conception, conjoined representation of these ideas the above-
with the first, must lead to the third, as mentioned arrangement — the synthetical
a necessary conclusion. All the other one — would be the most suitable ; but
subjects with which it occupies itself in the investigation which must neces-
are merely means for the attainment and sarily precede it, the analytical, which
realization of these ideas. It does not reverses this arrangement, would be bet-
require these ideas for the construction ter adapted to our purpose, as in it we
of a science of nature, but, on the con- should proceed from that which experi-
trary, for the purpose of passing beyond ence immediately presents to us — psy-
the sphere of nature. A complete in- chology, to cosmology, and thence to
sight into and comprehension of them theology.
2I2 . KANT
with other conceptions in the systems of philosophers, and not
properly distinguished from the conceptions of the understand
ing; we have exposed their origin, and thereby at the same
time their determinate number, and presented them in a syste
matic connection, and have thus marked out and inclosed a
definite sphere of pure reason.
BOOK II
OF THE DIALECTICAL PROCEDURE OF PURE REASON
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. Sut 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 problemati
cal 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 premises,
and by means of which we conclude from something that we
do know, to something of which we do not even possess a con
ception, 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 labor he may
be able to guard against the error, but he can never be thor
oughly rid of the illusion which continually mocks and misleads
him.
Of these dialectical arguments there are three kinds, corre-
CRITIQUE OF PURE REASON 213
spending to the number of the ideas, which their conclusions
present. In the argument or syllogism of the first class, I con
clude, from the transcendental conception of the subject which
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 argu
ments, 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 gen
eral, 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 trans
cendental 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 unexcep
tionable. In this manner the paralogism has its foundation in
the nature of human reason, and is the parent of an unavoid
able, 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 judgment, /
think. But it is readily perceived that this thought is as it were
the vehicle of all conceptions in general, and consequently of
214 KANT
transcendental conceptions also, and that it is therefore re
garded 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 all empirical
content (impressions of the senses), it enables us to distinguish
two different kinds of objects. /, 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 expres-,
sion, 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 deter
mines me in concrete), may be concluded from this conception
/, in so far as it appears in all thought.
Now, the rational doctrine of the soul is really an under
taking 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, / think, whose foundation or want of foun
dation 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 per
ception 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 prin
ciple. For this internal perception is nothing more than the
mere apperception, / think, which in fact renders all transcen
dental conceptions possible, in which we say, I think substance,
cause, etc. For internal experience in general and its possi
bility, or perception in general, and its relation to other per
ceptions, 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 im
mediately change the rational into an empirical psychology.
CRITIQUE OF PURE REASON 215
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 con
tain 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 cate
gories — 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 a thing in itself is represented,
and proceed 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 follows:
i
The soul is SUBSTANCE.
ii in
As regards the different
times in which it ex-
As regards its quality, ists, it is numerically
it is SIMPLE. identical, that is UN
ITY, not Plurality.
IV
It is in relation to possible objects in space.*
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 sub
stance, that of Incorruptibility; its identity, as intellectual sub
stance, gives the conception of Personality; all these three to
gether, 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
* The reader, who may not so easily have, moreover, to apologize for the
perceive the psychological sense of these Latin terms which have been employed,
expressions — taken here in their trans- instead of their German synonyms,
cendental abstraction, and cannot guess contrary to the rules of correct writing,
why the latter attribute of the soul be- But I judged it better to sacrifice ele-
longs to the category of existence, will gance of language to perspicuity of ex-
find the expressions sufficiently ex- position,
plained and justified in the sequel. I
ai6 KANT
this, limited and determined by the conception of spirituality,
gives us that of Immortality.
Now to these conceptions relate four paralogisms of a trans
cendental 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 con
sciousness 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 cog
nized only by means of the thoughts that are its predicates, and
of which, apart from these, we cannot form the least conception.
Hence we are obliged to go round this representation in a per
petual circle, inasmuch as we must always employ it, in order
to frame any judgment 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 par
ticular 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 anything.
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 judgment which is
apodictic 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 ob
jects 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), but in regard to its mere
possibility — for the purpose of discovering, what properties
CRITIQUE OF PURE REASON 217
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 like
wise 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 be
long to possible experience (such as the quality of simplicity),
nor could it make any apodictic enunciation on the nature of
thinking beings: — it would therefore not be a rational psy
chology.
Now, as the proposition I think (in the problematical sense)
contains the form of every judgment 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 understand
ing excludes all empirical elements; and we cannot, as has
been shown above, have any favorable conception beforehand
of its procedure. We shall therefore follow with a critical eye
this proposition through all the predicaments of pure psychol
ogy; 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 argu
ment. 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 con
sists. 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 func
tion of thought. All the modi of self-consciousness in thought
are hence not conceptions of objects (conceptions of the under
standing — 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
2i8 KANT
in it can be connected conformably with the general condition
of the unity of apperception in thought), is the object.
1. In all judgments I am the determining subject of that re
lation which constitutes a judgment. 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 apodic-
tic 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 discov
ered in thought; and are perhaps (in so far as I consider the
thinking self merely as such) not to be discovered in the think
ing self at all.
2. That the / 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 labor 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 amid all the
manifold representations of which I am conscious, is likewise
a proposition lying in the conceptions themselves, and is conse
quently 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 re-
CRITIQUE OF PURE REASON 219
quire not a mere analysis of the proposition, but synthetical
judgments 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 proposition.
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 con
scious of their existence apart from and unconnected with mat
ter. 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 favoring 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 predi
cate (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 pos
sible and legitimate, not only, as we have maintained, in rela
tion to objects of possible experience, and as principles of the
possibility of this experience itself, but are applicable to things
as 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 paral
ogism, which is represented in the following syllogism:
22o KANT
That zvhich cannot be cogitated otherwise than as subject,
does not exist otherwise than as subject, and is therefore sub
stance.
A thinking being, considered merely as such, cannot be cogi
tated 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 gener
ally 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 figure dictionis.*
That this famous argument is a mere paralogism, will be
plain to anyone who will consider the general remark which
precedes our exposition of the principles of the pure under
standing, 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 real
ity; 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 per
manent, 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 sub
stance — 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
_* Thought is taken in the two premisses tated otherwise than as subjects. In
in two totally different senses. In the the second, we do not speak of things
major it is considered as relating and but of thought (all objects being ab-
applying to objects in general, conse- tracted), in which the Ego is always
quently to objects of intuition also. In the subject of consciousness. Hence the
merely the relation to the self-conscious- ploy my Ego only as the subject of the
ness of the subject, as the form of judgment." But this is an identical
thought In the former premise we proposition, and throws no light on the
speak ot things which cannot be cogi- mode of my existence.
CRITIQUE OF PURE REASON 221
this conception, is shown to be also invalid, and to be, in fact,
nothing more than the logical qualitative unity of self-con
sciousness in thought; while we remain perfectly ignorant,
whether the subject is composite or not.
Refutation of the Argument of Mendelssohn for the Substan
tiality 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 endeav
ored to prove in his Phado, that the soul cannot be annihilated,
by showing that a simple being cannot cease to exist. Inas
much 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 mo
ment in which it is not, no time can be discovered — which is
impossible. But this philosopher did not consider, that, grant
ing 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 in
finite 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 elan-
guescence, if I may employ this expression), be changed into
nothing. For consciousness itself has always a degree, which
may be lessened. f Consequently the faculty of being conscious
* Verschwinden. musician, who strikes at once several
t Clearness is not, as logicians main- notes in improvising a piece of music.
tain, the consciousness of a representa- But a representation is clear, in which
tion. For a certain degree of conscious- our consciousness is sufficient for the
ness, which may not, however, be consciousness of the difference of this
sufficient for recollection, is to be met representation from others. If we are
with in many dim representations. For only conscious that there is a difference,
without any consciousness at all, we but are not conscious of the difference-
should not be able to recognize any that is, what the difference is — the rep-
difference in the obscure representations resentation must be termed obscure.
we connect; as we really can do with There is, consequently, an infinite series
many conceptions, such as those of of degrees of consciousness down to its
right and justice, and those of the entire disappearance.
222
KANT
may be diminished ; and so with all other faculties. The per
manence 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 psy
chologist to affirm, from mere conceptions, its permanence be
yond life.*
If, now, we take the above propositions — as they must be
accepted as valid for all thinking beings in the system of ra
tional 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
* There are some who think they have
done enough to establish a new possi
bility 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 m
connecting empirical intuitions pre
sented 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 sub
stances; and conversely, of the coalition
of several into one simple substance.
For, although divisibility presupposes
composition, it does not necessarily re
quire 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 con
sciousness — 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 everything 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 ex
istence in it; and the unity of substance
was merely a mode of existence, which
by this division alone has been trans
formed into a plurality of subsistence.
In the same manner several simple sub
stances 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 (n9t 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 dynam
ical 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 exam
ple—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 ob
ject is given — a self-subsistent being,
merely because the unity of appercep
tion in thought cannot allow him to
believe in 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 in
dependence of experience, to employ the
principle of the rationalist in a directly
opposite manner — still preserving the
formal unity required by his opponent?
CRITIQUE OF PURE REASON 223
problematical Idealism, is perfectly unavoidable in this ration
alistic 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 possi
bility of a proof.
But if we proceed analytically — the " I think " as a proposi
tion 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 psy
chology 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 real
ity is cogitated, after everything empirical had been abstracted :
as is shown in the following table:
/ think,
II Hi
as Subject, as simple Subject,
IV
as identical Subject,
in every state of my thought.
Now, inasmuch as it is not determined in this second propo
sition, 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 sim
plicity of its nature is given in the very fact of its possibilty.
Now in space there is nothing real that is at the same time
simple ; for points, which are the only simple things in space,
224 KANT
are merely limits, but not constituent parts of space. From this
follows the impossibility of a definition on the basis of mate
rialism of the constitution of my Ego as a merely thinking sub
ject. But, because my existence is considered in the first prop
osition as given, for it does not mean, " Every thinking being
exists " (for this would be predicating of them absolute neces
sity), but only, "/ 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 intui
tion, perfectly undetermined — proposition, "I think?"
There does not then exist any rational psychology as a doc
trine 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
CRITIQUE OF PURE REASON 225
origin in a mere misunderstanding. The unity of conscious
ness, 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 noth
ing 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. Consequent
ly, the subject cannot be cognized. The subject of the cate
gories cannot, therefore, for the very reason that it cogitates
these, frame any conception of itself as an object of the cate
gories ; 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.*
Thus, then, appears the vanity of the hope of establishing a
cognition which is to extend its rule beyond the limits of ex
perience — 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.
* The " I think " is, as has been al- one of which we have a conception, and
ready stated, an empirical proposition, about which we wish to know whether
and contains the expression, " I exist.' it does or does not exist, out of, and
But I cannot say Everything, which apart from this conception. An unde-
thinks, exists;" for in this case the termined perception signifies here mere-
property of thought would constitute ly something real that has been given,
all beings possessing it, necessary be- only, however, to thought in general —
ings. Hence my existence cannot be but not as a phenomenon, nor as a thing
considered as an inference from the in itself (noumenon), but only as some-
proposition, " I think," as Descartes thing that really exists, and is desig-
maintained — because in this case the nated as such in the proposition, " I
major premise, " Everything, which think." For it must be remarked that,
thinks, exists," must precede — but the when I call the proposition, " I think,"
two propositions are identical. The an empirical proposition, I do not
proposition " I think " expresses an tin- thereby mean that the Ego in the propo-
determined empirical tuition, that is, sition is an empirical representation; on
perception (proving consequently that the contrary, it is purely intellectual,
sensation, which must belong to sensi- because it belongs to thought in general,
bility. lies at the foundation of this But without some empirical representa-
proposition) ; but it precedes experience, tion, which presents to the mind ma-
wliose province it is to determine an terial for thought, the mental act, " I
object of perception by means of the think," would not take place; and the
categories in relation to time; and ex- empirical is only the condition of the
istence in this proposition is not a application or employment of the pure
category, as it does not apply to an intellectual faculty,
undetermined given object, but only to
15
226
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 apodictically ; 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 neces
sary 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 fall
ing 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 experi
ence 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 superflu
ous, nothing disproportionate to its use, nothing unsuited to its
end; but that, on the contrary, everything is perfectly con
formed 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 accepted 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 con-
CRITIQUE OF PURE REASON 227
duct in this world — without regard to mere sublinary interests
— the citizen of a better. This mighty, irresistible proof — ac
companied by an ever-increasing knowledge of the conforma-
bility to a purpose in everything we see around us, by the
conviction of the boundless immensity of creation, by the con
sciousness 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 empiri
cally determined existence with the supposed consciousness of
a possible separate existence of my thinking self; and I be
lieve that I cognize what is substantial in myself as a transcen
dental subject, when I have nothing more in thought than the
unity of consciousness, which lies at the basis of all determina
tion of cognition.
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, al
though occupying itself with an object of experience — only in
so far, however, as it ceases to be an object of experience. But
a sufficient answej 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 — con-
228
KANT
sequently, 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 primi
tive forces and faculties, will easily judge to be also beyond
the region of human cognition.
General Remark. — On the Transition from Rational Psychol
ogy 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 phenom
enon; 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 conscious
ness 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 in
tuiting 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 ap
plicable 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, " 7
exist thinking," is not the mere representation of a logical func
tion. It determines the subject (which is in this case an object
CRITIQUE OF PURE REASON 229
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 /, but also for the pur
pose of determining the mode of its existence, that is, of cog
nizing itself as noumenon. But this is impossible, for the in
ternal 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 experi
ence, 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 world.
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
23o KANT
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 intui
tion of self as a phenomenon is exposed. We shall have occa
sion 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 for
mal species of syllogisms — just as the categories find their logi
cal schema in the four functions of all judgments. The first
kind of these sophistical arguments related to the unconditioned
unity of the subjective conditions of all representations in gen
eral (of the subject or soul), in correspondence with the cate
gorical 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 ob
jective conditions of the possibility of objects in general.
But it is worthy of remark, that the transcendental paralo
gism produced in the mind only a one-sided 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; al-
CRITIQUE OF PURE REASON 231
though this theory itself passes into naught, in the crucible of
pure reason.
Very different is the case, when we apply reason to the ob
jective synthesis of phenomena. Here, certainly, reason estab
lishes, 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 obsti
nate 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 explana
tion 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 founda
tion for a dialectical psychology, the antinomy of pure reason
will present us with the transcendental principles of a pre
tended 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 experience.
232 KANT
Sec. 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 rea
son does not properly give birth to any conception, but only
frees the conception of the understanding from the unavoid
able limitation of a possible experience, and thus endeavors
to raise it above the empirical, though it must still be in con
nection 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 phe
nomena), 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, // the condi
tioned 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 consti
tutes 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 con
sequences (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 deter-
CRITIQUE OF PURE REASON 233
minable 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 exam
ple, the series m, n, o, in which n is given as conditioned in rela
tion to in, but at the same time as the condition of o, and let the
series proceed upwards from the conditioned n to m (I, k, i,
etc.), and also downwards from the condition n to the condi
tioned 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
°> P> <1> 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 antecedcntia, 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 phenome
non, not the consequences which succeed, but the grounds or
principles which precede.
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 intuition, 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 con
ditioned, 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
234 KANT
of time in relation to past time only as conditioned, because
this given moment comes into existence only through the past
time — or 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 condi
tioned. 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 limita
tion, 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 divi
sion of parts, whereby the real in matter becomes either noth
ing or that which is not matter, that is to say, the simple.* Con
sequently we find here also a series of conditions and a progress
to be 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
* Das Einfaghe.
CRITIQUE OF PURE REASON 235
say, reason has no ground, in regard to it, to proceed regres-
sively 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 possi
bility 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 cate
gory of causality, that we can find a series of causes to a given
effect, and in which we ascend from the latter, as the condi
tioned, 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, corre
sponding 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.
The absolute Completeness
of the
COMPOSITION
of the given totality of all phenomena.
236 KANT
II HI
The absolute Completeness The absolute Completeness
of the of the
DIVISION ORIGINATION
of a given totality of a phenomenon,
in a phenomenon.
IV
The absolute Completeness
of the DEPENDENCE of the EXISTENCE
of what is changeable in a phenomenon.
We must here remark, in the first place, that the idea of
absolute totality relates to nothing but the exposition of phe
nomena, 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 premises, so as to render it un
necessary to presuppose others. This unconditioned is always
contained in the absolute totality of the series, when we en
deavor to form a representation of it in thought. But this
absolutely complete synthesis is itself but an idea; for it is
impossible, at least beforehand, to know whether any such syn
thesis is possible in the case of phenomena. When we repre
sent all existence in thought by means of pure conceptions of
the understanding, without any conditions of sensuous intui
tion, 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 suc
cessive 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
CRITIQUE OF PURE REASON 237
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 phe
nomenon (following the guidance of the categories, which rep
resent it as a series of conditions to a given conditioned) the
unconditioned is necessarily contained — it being still left unas
certained 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 abso
lutely 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 poten
tially 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 rela
tion to the existence of changeable things, absolute physical ne
cessity.
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,
* The absolute totality of the series maliter), signifies the complex of the
of conditions to a given conditioned is determinations of a thing, connected ac-
always unconditioned; because beyond cording to an internal principle of
it there exist no other conditions, on causality. On the other hand, we un-
which it might depend. But the abso- derstand by nature, substantive (material-
lute totality of such a series is only an tier), the sum-total of phenomena, in
idea, or rather a problematical concep- so far as they, by virtue of an internal
tion, the possibility of which must be principle of causality, are connected
investigated — particularly in relation to with each other throughout. In the for-
the mode in which the unconditioned, mer sense we speak of the nature of
as the transcendental idea which is the liquid matter, of fire, etc., and employ
real subject of inquiry, may be con- the word only adjective; while, if speak-
tained therein. ing of the objects of nature, we have in
t Nature, understood adjectivf (for- our minds the idea of a subsisting whole.
238 KANT
but to the unity in the existence of phenomena. In this case
the condition of that which happens is called a cause ; the un
conditioned 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 con
tingent, and the unconditioned necessary. The unconditioned
necessity of phenomena may be called natural necessity.
The ideas which we are at present engaged in discussing I
have called cosmological ideas; partly because by the term
ivorld is understood the entire content of all phenomena, and
our ideas are directed solely to the unconditioned among phe
nomena ; partly also, because ivorld, 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 re
gard to the fact that these ideas are all transcendent, and, al
though 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 trans
cendent physical conceptions. This distinction does not at pres
ent seem to be of particular importance, but we shall afterwards
find it to be of some value.
Sec. 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 seem
ingly dogmatical cognitions (thesis cum antithesi), in none of
which we can discover any decided superiority. Antithetic
is not therefore occupied with one-sided statements, but is en
gaged 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 appli
cation of the principles of the understanding to objects of ex-
CRITIQUE OF PURE REASON 239
perience, but venture with it beyond these boundaries, there
arise certain sophistical propositions or theorems. These asser
tions 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 con
trary proposition.
The questions which naturally arise in the consideration of
this dialectic of pure reason, are, therefore : ist. In what propo
sitions is pure reason unavoidably subject to an antinomy?
2d. What are the causes of this antinomy? 3d. 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
removed.
This dialectical doctrine will not relate to the unity of under
standing 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 accord
ing 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
the wrong side, are certain to carry away the crown of victory,
24o KANT
if they only take care to have the right to make the last attack,
and are not obliged to sustain another onset from their op
ponent. 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 favor
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 scien
tific ignorance, which undermines the foundations of all knowl
edge, in order, if possible, to destroy our belief and confidence
therein. For the sceptical method aims at certainty, by endeav
oring 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 transcen
dental 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 hid
den, inasmuch as its demonstrations must always proceed under
the guidance of pure intuition, and by means of an always evi
dent synthesis. In experimental philosophy doubt and delay
CRITIQUE OF PURE REASON
241
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 soon or later. Moral philosophy can always
exhibit its principles, with their practical consequences, in con-
creto — at least in possible experiences, and thus escape the mis
takes and ambiguities of abstraction. But transcendental propo
sitions, 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 rea
son, 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.*
FIRST CONFLICT OF THE TRANSCENDENTAL IDEAS
Thesis
The world has a beginning in
time, and is also limited in regard
to space.
PROOF
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 in
finity of a series consists in the
fact, that it never can be com
pleted by means of a successive
synthesis. It follows that an in
finite series already elapsed is im
possible, and that consequently a
beginning of the world is a neces
sary condition of its existence.
And this was the first thing to be
proved.
As regards the second, let us
Antithesis
The world has no beginning, and
no limits in space, but is, in rela
tion both to time and space, infinite.
PROOF
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 orig
inate of itself, or by means of some
other cause). Consequently, many
series of things may have a begin
ning in the world, but the world
* The antinomies stand in the order of the four transcendental ideas above
detailed.
16
242
KANT
take the opposite for granted. In
this case, the world must be an in
finite given total of co-existent
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 con
sidered as a given whole, con
sequently, not as a contempo
raneously given whole. The world
is consequently, as regards ex
tension in space, not infinite, but
enclosed in limits. And this was
the second thing to be proved.
* We may consider an undetermined
quantity as a whole, when it is enclosed
within limits, although we cannot con
struct or ascertain its totality by meas
urement, that is, by the successive syn
thesis of its parts. For its limits of
themselves determine its completeness
as a whole.
itself cannot have a beginning,
and is, therefore, in relation to
past time, infinite.
As regards the second state
ment, let us first take the opposite
for granted — that the world is
finite and limited in space; it fol
lows 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 re
lation of the world to a void space
is merely a relation to no object.
But such a relation, and con
sequently the limitation of the
world by void space, is nothing.
Consequently, the world, as re
gards space, is not limited, that is,
it is infinite in regard to exten
sion.*
* Space is merely the form of external
intuition (formal .intuition), and not a
real object which can be externally per
ceived. Space, prior to all things which
determine it (fill or limit it), or, rather,
which present an empirical intuition con
formable to it, is, under the title of
absolute space, nothing but the mere
Eossibility of external phenomena, in so
jr as they 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 con
nected 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 ex
ternal intuition, which are very far from
being possible perceptions. For exam
ple, 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 en
tity.
CRITIQUE OF PURE REASON
243
Observations on the First Antinomy
ON THE THESIS ON THE ANTITHESIS
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 advan
tage 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 dogma
tists of both parties has been
completely set aside.
The thesis might also have
been unfairly demonstrated,
by the introduction of an er
roneous conception of the in
finity of a given quantity. A
quantity is infinite, if a greater
than itself cannot possibly ex
ist. The quantity is measured
by the number of given units
— which are taken as a stand
ard — 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 ex
tension) is impossible. It is,
therefore, limited in both re
spects. In this manner I might
The proof in favor of the
infinity of the cosmical succes
sion and the cosmical content
is based upon the considera
tion, that, in the opposite case,
a void time and a void space
must constitute the limits of
the world. Now I am not un
aware, that there are some
ways of escaping this conclu
sion. 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 hold
ing the existence of an abso
lute time before the beginning
of the world, or an absolute
space extending beyond the
actual world — which is impos
sible. I am quite well satis
fied 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, be
cause it is not itself an object,
but only the form of possible
objects. Consequently, things,
244
KANT
have conducted my proof ; but
the conception given in it does
not agree with the true con
ception of an infinite whole.
In this there is no representa
tion of its quantity, it is not
said how large it is; conse
quently its conception is not
the conception of a maximum.
We cogitate in it merely its
relation to an arbitrarily as
sumed 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 in
finity, 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 suc
cessive states up to a given
(the present) moment cannot
have elapsed, and that the
world must therefore have a
beginning.
In regard to the second part
of the thesis, the difficulty as
* 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 in
finite.
as phenomena, determine
space ; that is to say, they ren
der 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 lim
ited by phenomena, but phe
nomena cannot be limited by
an empty space without them.
This is true of time also. All
this being granted, it is never
theless indisputable, that we
must assume these two nonen
tities, void space without and
void time before the world, if
we assume the existence of
cosmical limits, relatively to
space or time.
For, as regards the subter
fuge adopted by those who en
deavor to evade the conse
quence — that, if the world is
limited as to space and time,
the infinite void must deter
mine the existence of actual
things in regard to their di
mensions — it arises solely
from the fact that, instead of
a sensuous world, an intelligi-
* 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 ad
mitted, although its possibility cannot
on that account be affirmed.
CRITIQUE OF PURE REASON
245
to an infinite and yet elapsed
series disappears ; for the
manifold of a world infinite in
extension is contemporane
ously given. But, in order to
cogitate the total of this mani
fold, as we cannot have the
aid of limits constituting by
themselves this total in intui
tion, we are obliged to give
some account of our concep
tion, which in this case can
not proceed from the whole to
the determined quantity of the
parts, but must demonstrate
the possibility of a whole by
means of a successive synthe
sis of the parts. But as this
synthesis must constitute a se
ries that cannot be completed,
it is impossible for us to cogi
tate prior to it, and conse
quently not by means of it, a
totality. For the conception
of totality itself is in the pres
ent case the representation of
a completed synthesis of the
parts ; and this completion,
and consequently its concep
tion, is impossible.
ble world — of which nothing
is known — is cogitated ; in
stead of a real beginning (an
existence, which is preceded
by a period in which nothing
exists) an existence which
presupposes no other condi
tion than that of time ; and,
instead of limits of extension,
boundaries of the universe.
But the question relates to the
mundus phenomenon, 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 d
priori condition of the possi
bility of phenomena, is left out
of view, the whole world of
sense disappears. In our
problem is this alone consid
ered as given. The mundus
intelligibilis is nothing but the
general conception of a world,
in which abstraction has been
made of all conditions of in
tuition, and in relation to
which no synthetical proposi
tion — either affirmative or
negative — is possible.
346
KANT
SECOND CONFLICT OF THE TRANSCENDENTAL IDEAS
Thesis
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.
PROOF
For, grant that composite sub
stances do not consist of simple
parts; in this case, if all com
bination or composition were an
nihilated in thought, no composite
part, and (as, by the supposition,
there do not exist simple parts)
no simple part would exist. Con
sequently, no substance; con
sequently, nothing would exist.
Either, then, it is impossible
to annihilate composition in
thought; or, after such anni
hilation, there must remain
something that subsists without
composition, that is, something
that is simple. But in the former
case the composite could not it
self 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 sup
position, the second must contain
the truth — that the substantial
composite in the world consists of
simple parts.
It follows as an immediate in
ference, that the things in the
world are all, without exception,
simple beings — that composition
is merely an external condition
pertaining to them — and that, al
though we never can separate and
isolate the elementary substances
from the state of composition,
Antithesis
No composite thing in the world
consists of simple parts ; and there
does not exist in the world any
simple substance.
PROOF
Let it be supposed that a com
posite thing (as substance) con
sists of simple parts. Inasmuch
as all external relation, con
sequently all composition of sub
stances, is possible only in space;
the space, occupied by that which
is composite, must consist of the
same number of parts as is con
tained 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 abso
lutely 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 con
sequently 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 com
posite, 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
CRITIQUE OF PURE REASON
247
reason must cogitate these as the
primary subjects of all composi
tion, and consequently, as prior
thereto — and as simple substances.
idea, the objective reality of which
cannot be demonstrated in any
possible experience; it is con
sequently, 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 trans
cendental idea; the empirical in
tuition 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 can
not be inferred from any per
ception whatever. As, therefore,
an absolutely simple object can
not 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 com
posite), but we were obliged to
prove it from the relation of a
given object to a possible ex
perience in general.
248
KANT
Observations on the Second Antinomy
ON THE THESIS
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 consti
tuted 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 ideate,
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 — noth
ing, not even a point, remains ;
for a point is possible only as
the limit of a space — conse
quently of a composite. Space
and time, therefore, do not
consist of simple parts. That
which belongs only to the con
dition 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 de-
ON THE ANTITHESIS
Against the assertion of the
infinite subdivisibility of mat
ter, whose ground of proof is
purely mathematical, objec
tions 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 ab
stract but arbitrary concep
tions, which cannot have any
application to real things.
Just as if it were possible to
imagine another mode of in
tuition than that given in the
primitive intuition of space;
and just as if its a priori de
terminations 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 mathemati
cal point, which is simple —
not, however, a part, but a
mere limit of space — physical
points, which are indeed like
wise simple, but possess the
peculiar property, as parts of
CRITIQUE OF PURE REASON
249
gree of change does not orig
inate 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 fail
ure, 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 dis
tinction — as indeed has really
now and then happened. Be
sides, I am here speaking only
of the simple, in so far as it is
necessarily given in the com
posite — the latter being capa
ble 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 ex
ample, in consciousness), and
not as an element of the com
posite. As an element, the
term atomus * would be more
appropriate. And as I wish
* A masculine formed by Kant, in
stead of the common neuter atomon,
which is generally translated in the
scholastic philosophy by the terms in-
separabile, indiscernibile, simplex. Kant
wished to have a term opposed to
monas, and so hit upon this oirof \tyop.tvov
With Democritus dro^o?, and with Ci
cero atomus is feminine. — Note by Rosen-
kranz.
space, of filling it merely by
their aggregation. I shall not
repeat here the common and
clear refutations of this ab
surdity, which are to be found
everywhere in numbers : every
one knows that it is impossi
ble to undermine the evidence
of mathematics by mere dis
cursive conceptions; I shall
only remark, that, if in this
case philosophy endeavors to
gain an advantage over mathe
matics by sophistical artifices,
it is because it forgets that the
discussion relates solely to
phenomena and their condi
tions. It is not sufficient to
find the conception of the sim
ple 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 understand
ing, it may be necessary to be
in possession of the simple be
fore composition is possible.
But this does not hold good of
the Totum substantiate phe
nomenon, which, as an empir
ical intuition in space, pos
sesses the necessary property
of containing no simple part,
for the very reason that no
25°
KANT
to prove the existence of sim
ple substances, only in relation
to, and as the elements of, the
composite, I might term the
antithesis of the second An
tinomy, transcendental Atom
istic. But as this word has
long been employed to desig
nate a particular theory of
corporeal phenomena (mo-
leculcc}, and thus presupposes
a basis of empirical concep
tions, I prefer calling it the di
alectical principle of Monad-
ology.
part of space is simple. Mean
while, the Monadists have
been subtle enough to escape
from this difficulty, by presup
posing intuition and the dy
namical relation of substances
as the condition of the possi
bility of space, instead of re
garding space as the condition
of the possibility of the objects
of external intuition, that is, of
bodies. Now we have a con
ception of bodies only as phe
nomena, 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 .^Esthetic. If bodies were
things in themselves, the proof
of the Monadists would be un
exceptionable.
The second dialectical as
sertion possesses the peculi
arity 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 trans
cendental idea — the absolute
simplicity of substance. The
proposition is, that the object
of the internal sense, the think
ing 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
CRITIQUE OF PURE REASON 251
shall merely remark, that, if
something is cogitated merely
as an object, without the addi
tion of any synthetical deter
mination of its intuition — as
happens in the case of the bare
representation, / — it is certain
that no manifold and no com
position can be perceived in
such a representation. As,
moreover, the predicates
whereby I cogitate this object
are merely intuitions of the in
ternal sense, there cannot be
discovered in them anything
to prove the existence of a
manifold whose parts are ex
ternal to each other, and con
sequently, 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 deter
minations. 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 phe
nomenon, 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 con
tained in it a manifold whose
parts are external to each
other.
252
KANT
THIRD CONFLICT OF TRANSCENDENTAL IDEAS
Thesis
Causality according to the laws of
nature is not the only causality op
erating to originate the phenomena
of the world. A causality of free
dom is also necessary to account
fully for these phenomena.
PROOF
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 pre
vious condition, which it follows
with absolute certainty, in con
formity with a rule. But this pre
vious condition must itself be
something that has happened
(that has arisen in time, as it did
not exist before), for, if it has al
ways been in existence, its con
sequence or effect would not thus
originate for the first time, but
would likewise have always ex
isted. The causality, therefore,
of a cause, whereby something
happens, is itself a thing that has
happened. Now this again presup
poses, 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, there
fore, 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 no
thing can happen without a suffi
cient a priori determined cause.
The proposition, therefore — if all
Antithesis
There is no such thing as free-
dom, but everything in the world
happens solely according to the
laws of nature.
PROOF
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 con
sequences from that state. In this
case, not only the series originated
by this spontaneity, but the deter
mination of this spontaneity itself
to the production of the series,
that is to say, the causality itself
must have an absolute commence
ment, such, that nothing can pre
cede to determine this action ac
cording to unvarying laws. But
every beginning of action presup
poses in the acting cause a state
of inaction; and a dynamically
primal beginning of action pre
supposes 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. Trans
cendental freedom is therefore
opposed to the natural law of
cause and effect, and such a con
junction of successive states in
effective causes is destructive of
the possibility of unity in experi
ence, and for that reason not to be
found in experience — is con
sequently a mere fiction of
thought.
We have, therefore, nothing but
CRITIQUE OF PURE REASON
253
causality is possible only in ac
cordance with the laws of nature
—is, when stated in this unlimited
and general manner, self-contra
dictory. It follows that this can
not 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 the 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 trans
cendental freedom, without which
even in the course of nature the
succession of phenomena on the
side of causes is never complete.
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 free
dom 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 dis
tinguishable 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
labor 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.
Observations on the Third Antinomy
ON THE THESIS ON THE ANTITHESIS
The transcendental idea of
freedom is far from constitut
ing the entire content of the
psychological conception so
termed, which is for the most
part empirical. It merely pre-
The assertor of the all-suf
ficiency of nature in regard
to causality (transcendental
Physiocracy} , in opposition to
the doctrine of freedom, would
defend his view of the ques-
2S4
KANT
sents us with the conception of
spontaneity of action, as the
proper ground for imputing
freedom to the cause of a cer
tain 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 uncon
ditioned causality. That ele
ment in the question of the
freedom of the will, which has
for so long a time placed spec
ulative reason in such perplex
ity, is properly only trans
cendental, 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 in
quiry ; for in the case of natu
ral 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 compre
hending 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
tion somewhat in the following
manner. He would say, in an
swer to the sophistical argu
ments of the opposite jparty:
// you do not accept a mathe
matical first, in relation to
time, you have no need to seek
a dynamical first, in regQrjj
causalit^J^iho compelled you
To" imagine an absolutely pri
mal condition of the world,
and therewith an absolute be
ginning of the gradually pro
gressing successions of phe
nomena — and, as some foun
dation 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 qf pypTtence ^renders
such a supposition__gurte nec^
. essary— ffiere is no difficulty
also, that the
changes in_' the^co,ndiiion<;
these substances have always
existed ; and, consequently,
thata^first beginning, mathe
matical or dynamical, is by no
means required. The possi
bility of such an infinite deri
vation, 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 al
so the existence of many fun
damental properties of natural
CRITIQUE OF PURE REASON
255
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 — al
though we are unable to ex
plain how it can exist — we feel
ourselves authorized to admit,
even in the midst of the natu
ral course of events, a begin
ning, as regards causality, of
different successions of phe
nomena, 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 com
mon misunderstanding, and to
suppose that, because a suc
cessive 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 begin
ning in relation la time, but
as regards causality alone.
"When, for example, I, com
pletely of my own free will,
and independently of the nec
essarily determinative influ
ence of natural causes, rise
from my chair, there com
mences with this event, includ
ing its material consequences
in infinitum, an absolutely new
series ; although, in relation to
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 insupera
ble difficulties. For if experi
ence did not teach you that it
was real, you never could con
ceive a priori the possibility
of this ceaseless sequence of
being and non-being.
But if the existence of a
transcendental faculty of free
dom 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 assump
tion, that, over and above the
complete content of all possi
ble intuitions, there still exists
an object which cannot be pre
sented in any possible percep
tion. But, to attribute to sub
stances in the world itself
such a faculty, is quite inad
missible ; for, in this case, the
connection of phenomena re
ciprocally determining and de
termined according to general
laws, which is termed nature,
and along with it the criteria
of empirical truth, which en
able us to distinguish experi
ence from mere visionary
dreaming, would almost en
tirely disappear. In proximity
with such a lawless faculty of
freedom, a system of nature
256
KANT
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 con
tinuations of it; on the con
trary, 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 causal
ity, if not in relation to time,
an absolutely primal begin
ning 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 them
selves obliged, when con
structing a theory of the mo
tions of the universe, to ac
cept 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
comprehensible.
is hardly cogitable; for the
laws of the latter would be
continually subject to the in
trusive influences of the for
mer, and the course of the
phenomena, which would oth
erwise proceed regularly and
uniformly, would become
thereby confused and discon
nected.
CRITIQUE OF PURE REASON
257
FOURTH CONFLICT OF THE TRANSCENDENTAL IDEAS
Thesis
There exists either in, or in con
nection with the world — either as a
part of it, or as the cause of it — an
absolutely necessary being.
PROOF
The world of sense, as the sum-
total of all phenomena, contains
a series of changes. For, with
out such a series, the mental rep
resentation of the series of time
itself, as the condition of the pos
sibility 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 con
dition 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 be
longs 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 im
possible. 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 pre-
* Objectively, time, as the formal con
dition of the possibility of change, pre
cedes all changes; but subjectively, and
in consciousness, the representation of
time, like every other, is given solely
by occasion of perception.
'7
Antithesis
An absolutely necessary being
does not exist, either in the world
or out of it— as its cause.
PROOF
Grant that either the world it
self is necessary, or that there is
contained in it a necessary exist
ence. Two cases are possible.
First, there must either be in the
series of cosmical changes a be
ginning, which is unconditionally
necessary and therefore uncaused
— which is at variance with the
dynamical law of the deter
mination of all phenomena in
time; or secondly, the series itself
is without beginning, and al
though contingent and con
ditioned in all its parts, is never
theless 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 hand, 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 orig
inate or begin t the existence of
the latter and their series. In this
case it must also begin to act, arid
its causality would therefore be
long to time, and consequently to
the sum-total of phenomena, that
is, to the world. It follows that
t 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 sec
ond is passive — the causality in the cause
itself beginning to operate (/JO- I rea
son here from the first to the second.
258
KANT
ceding, in which the thing that
begins to be was not in existence.
The causality of the necessary
cause of changes, and con
sequently 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 abso
lutely necessary — whether it be
the whole cosmical series itself, or
,only a part of it.
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 neces
sary being.
Observations on the Fourth Antinomy
ON THE THESIS
To demonstrate the exist
ence of a necessary being, I
cannot be permitted in this
place to employ any other than
the cosmological argument,
which ascends from the condi
tioned in phenomena to the
unconditioned in conception —
the unconditioned being con
sidered the necessary condi
tion of the absolute totality of
the series. The proof, from
the mere idea of a supreme
being, belongs to another
principle of reason, and re
quires separate discussion.
The pure cosmological
proof demonstrates the exist
ence of a necessary being, but
at the same time leaves it quite
unsettled, whether this being
is the world itself, or quite dis
tinct from it. To establish the
ON THE ANTITHESIS
The difficulties which meet
us, in our attempt to rise
through the series of phenom
ena to the existence of an ab
solutely 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 ob
jections must not be ontologi-
cal, but must be directed
against the causal connection
with a series of phenomena of
a condition which is itself un
conditioned. 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 con
clude with an empirically
unconditioned condition, and
259
truth of the latter view, prin
ciples are requisite, which are
not cosmological, and do not
proceed in the series of phe
nomena. We should require
to introduce into our proof
conceptions of contingent be
ings — regarded merely as ob
jects of the understanding,
and also a principle which en
ables 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 unhap
pily 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 i
in it according to empirical '<
laws of causality, we are not at I
liberty to break off from this
mode of demonstration and to
pass over to something which j
is not itself a member of the
series. The condition must be-!
taken in exactly the same sig
nification 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 em
pirical employment of the un
derstanding, the supreme con
dition or cause must close the
regressive series according to
that the cosmological argu
ment from the contingency of
the cosmical state — a contin
gency alleged to arise from
change — does not justify us in
accepting a first cause, that is,
a prime originator of the cos
mical series.
The reader will observe in
this antinomy a very remark
able contrast. The very same
grounds of proof which estab
lished in the thesis the exist
ence of a supreme being, dem
onstrated in the antithesis —
and with equal strictness — the
non-existence of such a being.
We found, first, that a neces
sary being exists, because the
whole time past contains the
series of all conditions, and
with it, therefore, the uncon
ditioned (the necessary) ; sec
ondly, that there does not exist
any necessary being, for the
same reason, that thq whole
time past contains the series
of all conditions — which are
themselves therefore, in the
aggregate, conditioned. The
cause of this seeming incon
gruity is as follows. We at
tend, 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 deter-
260
KANT
the laws of sensibility, and
consequently must belong to
the series of time. It follows
that this necessary existence
must be regarded as the high
est member of the cosmical
series.
Certain philosophers have,
nevertheless, allowed them
selves the liberty of making
such a saltus (perdficuns et?
a\Xo 7«/o<?). From the changes
in the world they have con
cluded their empirical contin
gency, that is, their depend
ence on empirically deter
mined 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 begin
ning or any highest member,
they passed suddenly from the
empirical conception of con
tingency to the pure category,
which presents us with a
series — not sensuous, but in
tellectual — whose complete
ness does certainly rest upon
the existence of an absolutely
necessary cause. Nay, more,
this intellectual series is not
tied to any sensuous condi
tions ; and is therefore free
from the condition of time,
which requires it spontaneous
ly to begin its causality in
time. — But such a procedure
is perfectly inadmissible, as
will be made plain from what
follows.
mined 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 every
thing that is unconditioned or
absolutely necessary disap
pears. 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 re
garded the controversy be-
between two celebrated astron
omers, which arose from a
similar difficulty as to the
choice of a proper standpoint,
as a phenomenon of sufficient
importance to warrant a sep
arate treatise on the subject.
The one concluded : the moon
revolves on its own axis, be
cause 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 per
fectly correct, according to the
point of view from which the
motions of the moon were con
sidered.
CRITIQUE OF PURE REASON
»6i
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 resl = non-A. Now it can
not be concluded from the fact
that a state opposite to the
state A follows it, that the con
tradictory opposite of A is
possible ; and that A is there
fore 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 fol-
Ipws from what has been said,
})
-32 KANT
that the succession of opposite
determinations, that is,
change, does not demonstrate
the fact of contingency as rep
resented in the conceptions of
the pure understanding; and
that it cannot, therefore, con
duct us to the fact of the ex
istence of a necessary being.
Change proves merely em
pirical 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.
Sec. III. — Of the Interest of Reason in these Self-contra
dictions
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 prog
ress in the empirical synthesis, is necessarily conducted to them,
when it endeavors 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 nat
ural 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
CRITIQUE OF PURE REASON 263
pretensions. They have, besides, in conformity with the charac
ter of a transcendental philosophy, been freed from every empir
ical element; although the full splendor of the promises they
hold out, and the anticipations they excite, manifest themselves
only when in connection with empirical cognitions. In the ap
plication 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, philos
ophy 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 noth
ing 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 high
est 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 ex
pectations 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 investiga
tions, 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
honor nor her safety will permit her to draw back. Nor can
264 KANT
she regard these conflicting trains of reasoning with indiffer
ence 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 alto
gether 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 insti
tuted 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 prop
ositions 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 charac
teristic, the dogmatism of pure reason.
On the side of dogmatism, or of the thesis, therefore, in the
determination of the cosmological ideas, we find:
CRITIQUE OF PURE REASON 265
1. A practical interest, which must be very dear to every
right-thinking man. That the world has a beginning — that the
nature of my thinking self is simple, and therefore indestruc
tible — 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 com
pletely a priori the entire chain of conditions, and understand
the derivation of the conditioned — beginning from the uncondi
tioned. 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 questions respecting the conditions of its syn
thesis — except such as must be supplemented by another ques
tion, 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 favor. 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 out 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 de
parture 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 deter
mination of the cosmological ideas :
i. 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
266 KANT
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
support.
2. But empiricism, in compensation, holds out to reason, in
its speculative interests, certain important advantages, far ex
ceeding 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 experi
ence, 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 it
self, 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 pretense 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, where 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 in
terests 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 mathe
matical thought — which he can determine synthetically in intui
tion, to those which neither sense nor imagination can ever pre
sent in concrete; 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 proced-
CRITIQUE OF PURE REASON 267
tire 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 pre
sumption 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 con
venient for itself, to break the thread of our physical investiga
tions, and, under pretense 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, ex
perience. 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 sci
ence and insight. For speculative cognition cannot find an ob
jective basis any other where than in experience ; and, when we
overstep its limits, our synthesis, which requires ever new cog
nitions independent of experience, has no substratum of intui
tion upon which to build.
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 re
ceives an irreparable injury.
And this constitutes the opposition between Epicureanism *
and Platonism.
* It is, however, still a matter of standing. If, indeed, they were nothing
doubt whether Epicurus ever propound- more than maxims for the speculative
ed these principles as directions for the exercise of reason, he gives evidence
objective employment of the under- therein of a more genuine philosophic
268 KANT
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 prac
tical, but, in relation to everything regarding which we can
attain to speculative cognition, permits reason to append ideal
istic 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 re
ceive it with pleasure — promising as it does, to satisfy it with
out passing the bounds of experience and its connected order ;
while transcendental dogmatism obliges it to rise to concep
tions, 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 advan
tage of it. If it understands little or nothing about these trans
cendental conceptions, no one can boast of understanding any
more; and although it may not express itself in so scholasti-
cally correct a manner as others, it can busy itself with reason
ing 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 can
not be established, nothing is more usual with the common un-
spirit than any of the philosophers of cause distinct from the world to account
antiquity. That, in the explanation of for a phenomenon or for the world it-
phenomena, we must proceed as if the self — are principles for the extension of
field of inquiry had neither limits in speculative philosophy, and the dis-
spice nor commencement in time; thai cpvery of the true sources of the prin-
we mus' be satisfied with the teaching ciples of morals, which, however little
of experience in reference to the ma- conformed to in the present day, are
tcrial of which the world is composed; undoubtedly correct. At the same time,
that we must not look for any other anyone desirous of ignoring, in mere
mode of the origination of events than speculation, these dogmatical proposi-
that which is determined by the unalter- tions, need not for that reason be ac-
able laws of nature; and finally, that we cused of denying them,
must not employ the hypothesis of a
CRITIQUE OF PURE REASON 269
derstanding. 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
favor 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 comple
tion 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 them
selves 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 uncon
ditioned 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 recommen
dation for the assertions of the thesis in our antinomy.
But if anyone could free himself entirely from all considera
tions 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. To-day, he would
feel convinced that the human will is free ; to-morrow, consid-
2 70 KANT
ering 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 prac
tical 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 ail partiality, and frankly to communicate its observa
tions for the judgment and opinion of others ; so no one can be
blamed for, much less prevented from placing both parties on
their trial, with permission to defend themselves, free from in
timidation, before a sworn jury of equal condition with them
selves — the condition of weak and fallible men.
Sec. 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 philos
opher of extravagant boasting and self-conceit, and at once
to destroy the confidence that might otherwise have been re
posed 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 un
avoidable 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 zve cannot knew. On the other hand,
in our investigations of the phenomena of nature, much must
remain uncertain, and many questions continue insoluble; be
cause what we know of nature is far from being sufficient to
explain all the phenomena that are presented to our observa
tion. 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
CRITIQUE OF PURE REASON 271
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 una
voidable 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 con
ception.
But, in transcendental philosophy, it is only the cosmological
questions, to which we can demand a satisfactory answer in re
lation to the constitution of their object ; and the philosopher is
not permitted to avail himself of the pretext of necessary igno
rance and impenetrable obscurity. These questions relate solely
to the cosmological ideas. For the object must be given in ex
perience, and the question relates to the adequateness of the ob
ject 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 im
possible.* The cosmological ideas alone possess 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
" The question, what is the constitu- not given as an object, in which, more-
tion of a transcendental object, is un- over, none of the categories — and it is
answerable — we are unable to say what to them that the question is properly
it is; but we can perceive that the ques- directed — find any conditions of its ap-
tion itself is nothing; because it does not plication. Here, therefore, is a case
relate to any object that can be pre- where no answer is the only proper
sented to us. For this reason, \ve must answer. _ For a question regarding the
consider all the questions raised in constitution of a something, which can-
transcendental psychology as answer- not be cogitated by any determined
able, and as really answered; for they predicate — being completely beyond the
relate to the transcendental subject of sphere of objects and experience, is
all internal phenomena, which is not perfectly null and void,
itself phenomenon, and consequently
2?2 KANT
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 cosmo-
logical question need not be sought out of the idea, for the ques
tion does not regard an object in itself. The question in relation
to a possible experience, is not, what can be given in an experi
ence in concrete — 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.
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
domestic^), although, up to a certain time, these answers may
not have been discovered. There are, in addition to trans
cendental philosophy, only two pure sciences of reason ; the one
with a speculative, the other with a practical content — pure
mathematics and pure ethics. Has anyone ever heard it al
leged 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 phys
ical 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 con
sequently a satisfactory explanation cannot be expected. The
questions of transcendental analytic, which relate to the de
duction of our pure cognition, are not to be regarded as of the
same kind as those mentioned above ; for we are not at present
CRITIQUE OF PURE REASON 273
treating- of the certainty of judgments in relation to the origin
of our conceptions, but only of that certainty in relation to ob
jects.
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 con
fession that it is beyond the power of our reason to decide,
whether the world has existed from all eternity or had a begin
ning — whether it is infinitely extended, or enclosed within cer
tain limits — whether anything in the world is simple, or whether
everything must be capable of infinite divisibility — whether free
dom can originate phenomena, or whether everything is abso
lutely 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 con
ditioned 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 re
gard 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 diffi
culties? Are you seeking for an explanation of certain phe
nomena ; and do you expect these ideas to give you the principles
or the rules of this explanation ? Let it be granted, that all na
ture was laid open before you ; that nothing was hid from your
senses and your consciousness. Still, you could not cognize in
concrete the object of your ideas in any experience. For what
is demanded, is, not only this full and complete intuition, but
18
274
KANT
also a complete synthesis and the consciousness of its absolute
totality ; and this is not possible by means of any empirical cog
nition. 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 uncondi
tioned ; nor can you decide whether this unconditioned is to be
placed in an absolute beginning of the synthesis, or in an abso
lute totality of the series without beginning. A whole, in the
empirical signification of the term, is always merely compara
tive. The absolute whole of quantity (the universe), of di
vision, of derivation, of the condition of existence, with the
question — whether it is to be produced by a 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 con
sist 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 ad
mit of explanation, only in so far as the conditions of that ex
planation 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 expla
nations of this whole beyond itself, in other pereceptions. The
explanation of this whole is the proper object of the trans
cendental problems of pure reason.
Although, therefore, the solution of these problems is unat
tainable through experience, we must not permit ourselves to
say, that it is uncertain how the object of our inquiries is con
stituted. 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 fall
ing into the amphiboly of regarding our idea as a representa
tion 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 con
sider the question objectively, but proceeds by inquiring into
the basis of the cognition upon which the question rests.
CRITIQUE OF PURE REASON 275
Sec. 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 before
hand that, be the answer what it may, it would only serve to
increase our ignorance, to throw us from one incomprehensi
bility 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 ad
vantage we shall gain, if the answer is to favor 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 dis
covering 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 rea
son 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 re
move the presumptuous notions of philosophy and their con
sequence — 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
favored, it must either be too great or too small for every con
ception of the understanding; — I would be able to comprehend
how the idea, which relates to an object of experience — an expe
rience 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 inade
quate, 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
276
KANT
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 undertaking. For, as a beginning
presupposes a time preceding, it cannot be unconditioned ; and
the law of the empirical employment of the understanding im
poses 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-sub-
sistent 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 con
ception. Consequently, a finite world is too small for our con
ception.
Secondly, if every phenomenon (matter) in space consists
of an infinite number of parts, the regress of the division is al
ways 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 mem
ber at which we have discontined our division still admits a re
gress to many more parts contained in the object.
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 neces-
CRITIQUE OF PURE REASON 277
sary 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 in
finite 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 concep
tion, and unattainable by the continued regress of any synthesis.
But if we believe that everything in the world — be it condi
tion 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 de
pends.
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 man
ner exactly the reverse of this, and, instead of accusing the
cosmological idea of overstepping or of falling short of its true
aim — possible experience, say that, in the first case, the empiri
cal 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 experi
ence can alone give reality to our conceptions ; without it a con
ception 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 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 cos
mological ideas, and all the conflicting sophistical assertions
connected with them, are based upon a false and fictitious con
ception of the mode in which the object of these ideas is pre
sented to us ; and this suspicion will probably direct us how to
278 KANT
expose the illusion that has so long led us astray from the
truth.
Sec. VI. — Transcendental Idealism as the Key to the Solu
tion 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 hu
man thought. This doctrine I call Transcendental Idealism*
The realist in the transcendental sense regards these modifica
tions of our sensibility — these mere representations, as things
subsisting in themselves.
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 ex
tended in it, and thus leaves us without a sufficient criterion of
reality and illusion. The supporters of this theory find no dif
ficulty 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 ex
istence of its object as a thing in itself.
Transcendental idealism allows that the objects of external
intuition — as intuited in space, and all changes in time — as rep
resented by the internal sense, are real. For, as space is the
form of that intuition which we call external, and without ob
jects 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 pre
sented to the sensibility of this, to us, unknown being. This
* I have elsewhere termed this theory To avoid ambiguity, it seems advisable
formal idealism, to distinguish it from in many cases to employ this term in-
tnaterial idealism, which doubts or de- stead of that mentioned in the text,
nies the existence of external things.
CRITIQUE OF PURE REASON 279
internal phenomenon cannot be admitted to be a self-subsist
ing thing; for its condition is time, and time cannot be the
condition of a thing in itself. But the empirical truth of phe
nomena 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 inhabi
tants 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 experi
ence, 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 progres
sion from it to other possible perceptions. For phenomena, as
mere representations, are real only in perception ; and percep
tion is, in fact, nothing but the reality of an empirical represen
tation, that is, a phenomenon. To call a phenomenon a real
thing prior to perception, means either, that -.ve 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 them
selves, 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 representa
tions, the relation of which to each other is a pure intuition of
space and time — the pure forms of sensibility. These represen
tations, in so far as they are connected and determinable in
this relation (in space and time) according to laws of the unity
* Dinge an sich, Sachen an sich.
28o KANT
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 con
dition 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 time.
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 noth
ing 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 ex
isted prior to my experience ; this means only that I must begin
with the perception present to me, and follow the track indi
cated, until I discover them in some part or region of experi
ence. The cause of the empirical condition of this progression
— and consequently at what member therein I must stop, and
CRITIQUE OF PURE REASON 281
at what point in the regress I am to find this member — is trans
cendental, and hence necessarily incognizable. But with this
we have not to do ; our concern is only with the law of progres
sion 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 the
ories 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 conceptions.
Sec. VII — Critical Solution of the Cosmological Problem
The antinomy of pure reason is based upon the following dia
lectical argument : If that which is conditioned is given, the
whole series of its conditions is also given; but sensuous ob
jects are given as conditioned; consequently. . . . This syllo
gism, the major of which seems so natural and evident, intro
duces 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 em
barrassment. Before proceeding to expose the fallacy in this
dialectical argument, it will be necessary to have a correct un
derstanding 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, analyt
ical, and has nothing to fear from transcendental criticism. It
282 KANT
is a logical postulate of reason : to pursue, as far as possible,
the connection of a conception with its conditions.
If, in the second place, both the conditioned and the condi
tion 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 un
derstanding merely, which represents things as they are, with
out 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 con
ditions. 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 signifi
cation 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 figures 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
CRITIQUE OF PURE REASON 283
this is nothing more than the logical requirement of complete
and satisfactory premises 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 be
tween 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 limita
tions 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 phe
nomena.
After this proof of the viciousness of the argument com
monly employed in maintaining cosmological assertions, both
parties may now be justly dismissed, as advancing claims with
out 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 be
ginning, 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 con
tinues, 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
KANT
284
none. This mode of adjusting a dispute which cannot be de
cided 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 ex
hibiting 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 criticised his mode of discussion, that
his purpose was to deny completely both of two self-contradic
tory propositions — which is absurd. But I cannot believe that
there is any justice in this accusation. The first of these propo
sitions I shall presently consider in a more detailed manner.
With regard to the others, if by the word 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 judgments presuppose a contingent
impossible, or arbitrary condition, both — in spite of their oppo
sition (which is, however, not properly or really a contradic
tion) — fall away ; because the condition, which insured the
validity of both, has itself disappeared.
If we say : everybody has either a good or a bad smell, we
have omitted a third possible judgment — 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- suave olens") , both judgments are contradictorily op
posed ; and the contradictory opposite of the former judgment
— some bodies are not good-smelling — embraces also those bod
ies which have no smell at all. In the preceding pair of opposed
judgments (per disparata), the contingent condition of the con
ception of body (smell) attached to both conflicting statements;
CRITIQUE OF PURE REASON 285
instead of having been omitted in the latter, which is conse
quently not the contradictory opposite of the former.
If, accordingly, we say : the world is either infinite in exten
sion, 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 judg
ment, we deny its infinite and consequently, perhaps, its inde
pendent existence; in the other, we append to the world, re
garded 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 op
posed judgments 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 perma
nent quantity, whether I deny the infinite or the finite regress
in the series of its phenomena. But if we dismiss this assump
tion — 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 given
completely or as a whole ; and it is, therefore, not an uncon
ditioned whole, and does not exist as such, either with an in
finite, 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
286 KANT
to the others. The series of conditions is discoverable only in
the regressive synthesis itself, and not in the phenomenon con
sidered as a thing in itself — given prior to all regress. Hence
I am compelled to say : the aggregate of parts in a given phe
nomenon 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 uncondi
tioned and necessary existence, which can never be regarded
as in itself, and in its totality, either as finite or as infinite ; be
cause, 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 ab
solute totality — admissible only as a condition of things in them
selves, 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 dog
matical addition, but as presenting to us another material sup
port 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 Transcendental ^Esthetic. The proof would
proceed in the following dilemma. If the world is a whole ex
isting 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 transcenden
tal ideality.
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 judgments which follow
CRITIQUE OF PURE REASON 287
make 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 favor 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 judgments on these subjects
of thought.
Sec. 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 them
selves (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 abso
lutely unconditioned. It is, therefore, not a principle of the
possibility of experience or of the empirical cognition of sensu
ous 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
288 KANT
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 con
ditions, as existing in itself and given in the object, is a consti
tutive cosmological principle. This distinction will at once
demonstrate the falsehood of the constitutive principle, and pre
vent us from attributing (by a transcendental subreptio) objec
tive 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 pro
ceeded with in order to attain to the complete conception of
the object. If it gave us any information in respect to the for
mer 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 re
garded 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 unat-
tained and unattainable. For the absolutely unconditioned can
not be discovered in the sphere of experience.
We now proceed to determine clearly our notion of a synthe
sis which can never be complete. There are two terms com
monly 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 in-
finitum. The philosophers prefer the expression progressus in
indefinitum. Without detaining the reader with an examina-
CRITIQUE OF PURE REASON 289
tion of the reasons for such a distinction, or with remarks on the
right or wrong use of the terms, I shall endeavor clearly to
determine these conceptions, so far as is necessary for the pur
pose of 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 pro
gressus 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 ex
pression 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 al
ways 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 con
ditions, 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 — or
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 mem
ber 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,
19
KANT
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 abso
lutely unconditioned member of the series. But as the mem
bers 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 em
pirical 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 in
finity. 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, be
cause no member of the series is given as absolutely conditioned,
and thus a higher member is possible, and an inquiry with re
gard 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 iw
CRITIQUE OF PURE REASON 291
quire for others, inasmuch as experience presents no absolute
limitation of the regress. For, either you do not possess a per
ception 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 frorrj
that which is limited by it), and it is incumbent on you to con
tinue 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.
Sec. 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 re
specting 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 condi
tion to condition, in order to discover, in conformity with the
rule of reason, a full and correct answer to the questions pro
posed 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 sub
jective signification which we have shown to be its only true
sense, may be guaranteed as a principle of the unceasing ex
tension 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
292 KANT
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 prob
lems, 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 impossible.
Now this proposition, which declares that every condition at
tained in the empirical regress must itself be considered empiric
ally 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 ex
perience, 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 re-
gressus in infinitum or in indefinitwn.
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 magni
tude of the regress from the quantity or magnitude of the world,
* The cosmical series can neither be limited), it is evident that we cannot
greater nor smaller than the possible regard the world as either finite or in-
empirical regress, upon which its con- finite, because the regress, which gives
ception is based. And as this regress us the representation of the world, is
cannot be a determinate infinite regress, neither finite nor infinite,
still less a determinate finite (absolutely
CRITIQUE OF PURE REASON 293
and determine the former by means of the latter ; on the con
trary, I must first of all form a conception of the quantity or
magnitude of the world from the magnitude of the empirical re
gress. But of this regress I know nothing more, than that I
ought to proceed from every given member of the series of con
ditions 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 em
pirical synthesis ; it would consequently determine the cosmical
quantity prior to the regress (although only in a negative man
ner) — 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
endeavor to attain to a conception of the quantity of the uni
verse, in conformity with the rule which determines the empiri
cal regress in it. But this rule merely requires us never to admit
an absolute limit to our series — how far soever we may have pro
ceeded 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, there
fore, the regressus in indefinitum, which, as not determining a
quantity in the object, is clearly distinguishable from the re
gressus in infinitum.
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 em
pirical ; but we cannot apply the conception of an infinite quan
tity to the world as an object of the senses. I cannot say, the
regress from a given perception to every thing 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,
294 KANT
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 impos
sible ; because it has no content. Consequently, an absolute cos-
mical limit is empirically, and therefore absolutely, impossible.*
From this follows the affirmative answer : The regress in the
series of phenomena — as a determination of the cosmical quan
tity, proceeds in indefinitum. This is equivalent to saying — the
world of sense has no absolute quantity, but the empirical re
gress (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, never
theless, 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. Conse
quently phenomena in the world are conditionally limited, but
* The reader will remark that the to all regress, and a determined position
proof presented above is very different in space and time was denied to it — if
from the dogmatical demonstration it was not considered as occupying all
given in the antithesis of the first an- time and all space. Hence our con-
tinomy. In that demonstration, it was elusion differed from that given above;
taken for granted that the world is a for we inferred in the antithesis the
thing in itself— given in its totality prior actual infinity of the world.
CRITIQUE OF PURE REASON 295
the world itself is not limited, either conditionally or uncon
ditionally.
For this reason, and because neither the world nor the cos-
mical series of conditions to a given conditioned can be com
pletely given, our conception of the cosmical quantity is given
only in and through the regress and not prior to it — in a collec
tive 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 the purpose of pre
senting to us a quantity — realized only in and through the re
gress 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 divison 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 regressns in indefinitum,
as happened in the case of the preceding cosmological idea, the
regress in which proceeded from the conditioned to the con
ditions not given contemporaneously and along with it, but dis
coverable only through the empirical regress. We are not, how
ever, 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 con
tained only in the progressing decomposition — in the regress it
self, 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
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KANT
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 pos
sibility of the body as an extended whole. A body is conse
quently 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 sub
stance 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 hand, that when all composition in matter is annihil
ated 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 con
junction 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 occu
pation or filling of space, it is not applicable to a whole consisting
of a number of distinct parts and constituting a quantum discre-
tum — that is to say, an organized body. It cannot be admitted
that every part in an organized whole is itself organized, and
that, in analyzing it to infinity, we must always meet with or
ganized parts; although we may allow that the parts of the
matter which we decompose in infinitum, may be organized.
CRITIQUE OF PURE REASON 297
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, there
fore, 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 divisi
bility 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 al
though, so far as our experience of this or that body has ex
tended, we may not have discovered any inorganic part, such
parts must exist in possible experience. But how far the trans
cendental 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 endeavored to show the ground of this self-contradiction
on the part of reason, and the only means of bringing it to a con
clusion — 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 rela
tions of space and time — which is the usual supposition of the
common understanding. In this respect, all dialectical represen-
298
KANT
tations of totality, in the series of conditions to a given con
ditioned, were perfectly homogeneous. The condition was al
ways 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 differ
ence existing between the conceptions of the understanding
which reason endeavors to raise to the rank of ideas — two of
these indicating a mathematical, and two a dynamical synthesis
of phenomena. Hitherto, it was not 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 dyna
mical 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 hypotheses ; in the present case the
hope appears of discovering a hypothesis which may be consist
ent 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 ex
tension, and whether they are adequate with ideas, the series of
conditions may be regarded as all homogeneous. But the con
ception of the understanding which lies at the basis of these
ideas, contains either a synthesis of the homogeneous (presup~
CRITIQUE OF PURE REASON 299
posed in every quantity — in its composition as well as in its
division) or of the heterogeneous, which is the case in the dy
namical 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 phe
nomena, arises a result which we should not have expected from
an antinomy. In former cases, the result was that both contra
dictory 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 phe
nomena 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.
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 caus
ality 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
* For the understanding cannot admit tioned phenomenon, without breaking
among phenomena a condition which is the series of empirical conditions, such
itself empirically unconditioned. But if a condition may be admissible as em
it is possible to cogitate an intelligible pirically unconditioned, and the empirical
condition — one which is not a member regress continue regular, unceasing, and
of the series of phenomena— for a condi- intact.
300 KANT
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 cause.
We must understand, on the contrary, by the term freedom,
in the cosmological sense, a faculty of the spontaneous origin
ation of a state ; the causality of which, therefore, is not subor
dinated 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 hap
pened, must also have a cause. In this view of the case, the
whole field of experience, how far soever it may extend, con
tains nothing that is not subject to the laws of nature. But, as
we cannot by this means attain to an absolute totality of con
ditions 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, accord
ing 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 ques
tion 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 patho
logically 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, phe
nomena, 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 transcen-
CRITIQUE OF PURE REASON 301
dental 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 op
position to the power of natural causes, and capable, conse
quently, 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 transcen
dental 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 it
self, 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 to
gether 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 ad
mits of no exception. The question, therefore, is : Whether an
effect, determined according to the laws of nature, can at the
* Probably an error of the press, and that we should read psychological. — ED.
302 KANT
same time be produced by a free agent, or whether freedom
and nature mutually exclude each other? And here, the com
mon, but fallacious hypothesis of the absolute reality of phenom
ena manifests its injurious influence in embarrassing the pro
cedure 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 condi
tioned, 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 repre
sentations, connected with each other in accordance with em
pirical laws, they must have a ground which is not phenomena
But the causality of such an intelligible cause is not determined
or determinable by phenomena ; although its effects, as phe
nomena, 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 ap
pear in the highest degree subtle and obscure. The sequel will
explain. It is sufficient, at present, to remark that, as the com
plete 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 Necessity
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 re
garded 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—
CRITIQUE OF PURE REASON 303
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 two- fold manner of cogitating a power residing in a sensu
ous 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 deter
mines 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, al
though 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 charac
ter, 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, constitutes a series in the order of nature. This sen
suous 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 subordi
nate 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 con
sequently 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 em
304 KANT
pirical character; for we always find ourselves compelled tc
place, in thought, a transcendental object at the basis of phe
nomena, although we can never know what this object is in it
self.
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 preced
ing phenomena. External phenomena must be capable of in
fluencing 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 determina
tion of these actions must be presented to us by experience.
In virtue of its intelligible character, on the other hand, (al
though we possess only a general conception of this character),
the subject must be regarded as free from all sensuous influ
ences, 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 this necessity exists only in the world of phenom
ena. 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 com
plete and absolute signification of these terms, can exist, with
out contradiction or disagreement, in the same action.
Exposition of the Cosmological Idea of Freedom in harmony
with the 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 con-
CRITIQUE OF PURE REASON 305
ception of the course which reason must adopt in the solution.
1 shall now proceed to exhibit the several momenta of this solu
tion, and to consider them in their order.
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 orig
inated), must have itself a phenomenal cause, by which it is de
termined, and, consequently, that 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 con
nected system of phenomena or nature, is a law of the under
standing, 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 ex
perience, 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 ideal
ism, 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 contra
dictory and incompatible ?
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 preced
ing state, in which its cause existed. Thus everything that hap
pens is but a continuation of a series, and an absolute begin
ning 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 — an action
which forms an absolute beginning, is beyond the causal power
of phenomena.
Now, is it absolutely necessary that, granting that all effects
306
KANT
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 phe
nomenal world must be connected with an empirical cause, ac
cording to the universal law of nature, this empirical causality
may be itself the effect of a non-empirical and intelligible causal
ity — 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 <.
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 condi
tions of natural events, that is to say, their causes. This bein^
admitted as unexceptionably valid, the requirements of the un
derstanding, 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, with
out 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 per
fect accordance with the laws of empirical causality. Thus the
acting subject, as a causal phenomenon, would continue to pre
serve 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 direc
tions of nature alone, we need not trouble ourselves about the
relation in which the transcendental subject, which is com
pletely 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
CRITIQUE OF PURE REASON 307
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 ap
ply 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 natu
ral phenomena. We remark this empirical character in his ac
tions, which reveal the presence of certain powers and faculties.
If we consider inanimate, or merely animal nature, we can dis
cover no reason for ascribing to ourselves any other than a
faculty which is determined in a purely sensuous manner. Bu1
man, to whom nature reveals herself only through sense, cog
nizes 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 — intel
ligible, because its action cannot be ascribed to sensuous recep
tivity. These faculties are understanding and reason. The
latter, especially, is in a peculiar manner distinct from all em
pirically-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 non-empirical.
That reason possesses the faculty of causality, or that at least
we are compelled so to represent it, is evident from the impera
tives, which in the sphere of the practical we impose on many
of our executive powers. The words / ought express a species
of necessity, and imply a connection with grounds which nature
does not and cannot present to the mind of man. Understand
ing knows nothing in nature but that ivhich 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,
3o8
KANT
has neither application nor meaning. The question, what ought
to happen in the sphere of nature, is just as absurd as the ques
tion, 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 ac
tion, the ground of which is a pure conception ; while the ground
of a merely natural action is, on the contrary, always a phe
nomenon. 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 deter
mination of the will itself, they relate to its effect alone, and the
consequences of the effect in the world of phenomena. What
ever number of motives nature may present to my will, what
ever 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 stand
ard, gives permission or prohibition. Be the object what it
may, purely sensuous — as pleasure, or presented by pure rea
son — 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, rear
ranges 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 presup
poses 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 experi
ence.
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 vari-
CRITIQUE OF PURE REASON 309
ous 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 phe
nomena 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 char
acter, 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 re
lation 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 em
pirical causes, but by the act of the will upon grounds of reason.
Now, granting that reason stands in a causal relation to phe
nomena ; 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 char
acter is itself determined by the intelligible character. The lat
ter we cannot cognize ; we can only indicate it by means of phe-
3io KANT
nomena, 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 ac
cordance with empirical laws. That is to say, not the condi
tions 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 pro
ducing 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 justi
fied in saying — If reason stands in a causal relation to phe
nomena, it is a faculty which originates the sensuous condition
of an empirical series of effects. For the condition, which re
sides 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
subject to any sensuous condition, or to any time-determination
by a preceding cause.
But, in another respect, the same cause belongs also to the se
ries 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 voli
tion 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 undeter
mined cause of an event in time cannot exist. For this reason
no given action can have an absolute and spontaneous origina
tion, 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
* The real morality of actions — their how much is to be ascribed to nature
merit or demerit, and even that of our and to blameless error, or to a happy
own conduct, is completely unknown to constitution of temperament (merito
Us. _ Our estimates can relate only to fortune?), no one can discover, nor, for
their empirical character. How much this reason, determine with perfect
is the result of the action of free-will, justice.
CRITIQUE OF PURE REASON 311
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 ac
tions 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 sen
suous schema, knows no before or after; and every action, irre
spective of the time-relation in which it stands with other phe
nomena, 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 condi
tions, foi 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 uncon
ditioned 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 ex
ample, 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 trans
cendental propositions. Let us take a voluntary action — for ex
ample, 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 orig
inated, and the blame of which and of the evil consequences aris
ing from it, is imputed to the offender. We at first proceed to
examine the empirical character of the offence, and for this pur
pose we endeavor 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 for
getting also the occasioning causes which prevailed at the mo-
3i2 KANT
ment 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 circum
stances, we do not the less blame the offender. We do not
blame him for his unhappy disposition, nor for the circum
stances 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 deter
mined the behavior 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 favored or opposed the action
of this causality, the offence is estimated according to its intel
ligible character — the offender is decidedly worthy of blame, the
moment he utters a falsehood. It follows that we regard rea
son, in spite of the empirical conditions of the act, as completely
free, and therefore, as in the present case, culpable.
The above judgment is complete evidence that we are accus
tomed to think that reason is not affected by sensuous condi
tions, 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 phenom
ena 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 con
ditions, determining, but not determinable. Hence we cannot
ask: Why did not reason determine itself in a different man
ner ? 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
CRITIQUE OF PURE REASON 313
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 false
hood, 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 phe
nomena 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 ac
tion 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 un
conditioned 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 rea
son 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 free
dom 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 rela
tion to a different kind of conditions 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 argu
ment 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 ac
cordance with its laws, must ever be unsuccessful. Nay, more,
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I have not even aimed at demonstrating the possibility of free
dom ; for this too would have been a vain endeavor, 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 con
ceptions. Freedom has been considered in the foregoing re
marks only as a transcendental idea, by means of which reason
aims at originating a series of conditions in the world of phe
nomena 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 solve.
IV7. — 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
endeavor is 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 ex
istences cannot embrace an unconditioned member, the exist
ence 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 dy
namical 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 condi
tions of its series parts of the series, and to be consequently
regarded as homogeneous, and for this neason, as consisting,
CRITIQUE OF PURE REASON 315
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 ex
ists 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 em
pirically 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 phe
nomenon) 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 in
telligible and as existing entirely apart from the world of sense
(as an ens e.vtramundanum) ; for otherwise it would be sub
ject 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 pos
sesses 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 deduc
ing any existence from a condition which lies out of and beyond
the empirical series, or in regarding any existence as inde
pendent 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.
KANT
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 condi
tion of the existence of 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 hand, to set bounds to the law of the
purely empirical understanding, and to protest against any at
tempts on its part at deciding on the possibility of things, or de
claring 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 hy
pothesis of a necessary, although purely intelligible condition,
that no real contradiction exists between them, and that, conse
quently, 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 na
ture. 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, more
over, from the contingency of the latter, conflicts neither with
the unlimited nature of the empirical regress, nor with the com-
CRITIQUE OF PURE REASON 317
plete contingency of phenomena. And the demonstration of
this was the only thing necessary for the solution of this appar
ent antinomy. For if the condition of every conditioned — as re
gards 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, neces
sarily falls, must, therefore, continue to exist ; or the uncondi
tioned 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, un
conditionally necessary.
The empirical employment of reason is not affected by the
assumption of a purely intelligible being ; it continues its opera
tions on the principle of the contingency of all phenomena, pro
ceeding from empirical conditions to still higher and higher
conditions, themselves empirical. Just as little does this regu
lative principle exclude the assumption of an intelligible cause,
when the question regards merely the pure employment of rea
son — in relation to ends or aims. For, in this case, an intel
ligible cause signifies merely the transcendental and to us un
known ground of the possibility of sensuous phenomena, and
its existence necessary and independent of all sensuous condi
tions, is not inconsistent with the contingency of phenomena,
or with the unlimited possibility of regress which exists in the
series of empirical conditions.
Concluding Remarks on the Antinomy of Pure Reason
So long as the object of our rational conceptions is the to
tality of conditions in the world of phenomena, and the satis
faction, 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 ex
perience, 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
3i8 KANT
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 infernal nature, for it
has no connection with empirical conceptions ; nor are we justi
fied in affirming the existence of any such object. It is,
consequently, a mere product of the mind alone. Of all the cos-
mological ideas, however, it is that occasioning the fourth anti
nomy which compels us to venture upon this step. For the
existence of phenomena, always conditioned and never self-sub-
sistent, requires us to look for an object different from phenom
ena — an intelligible object, with which all contingency must
cease. But, as we have allowed ourselves to assume the ex
istence 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 con
ceptions. 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 con
ceptions of it, all our conceptions of intelligible things. This we
propose to attempt in the following chapter.
CHAPTER III
The Ideal of Pure Reason
Sec. 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 con
ditions of objective reality do not exist in these conceptions,
which contain, in fact, nothing but the mere form of thought.
CRITIQUE OF PURE REASON 319
They may, however, when applied to phenomena, be presented
in concreto; for it is phenomena that present to them the ma
terials 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 ob
jective 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 com
pletely attain.
But still further removed than the idea from objective reality
is the Ideal, by which term I understand the idea, not in con
creto, but in individuo — as an individual thing, determinable or
determined by the idea alone. The idea of humanity in its com
plete 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 con
form 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 per
fect 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 conse
quently when we attend merely to their form, they may be con
sidered 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 con-
320 KANT
duct of this wise and divine man serves us as a standard of ac
tion, with which we may compare and judge ourselves, which
may help us to reform ourselves, although the perfection it de
mands can never be attained by us. Although we cannot con
cede objective reality to these ideals, they are not to be con
sidered as chimeras ; on the contrary, they provide reason with
a standard, which enables it to estimate, by comparison, the de
gree of incompleteness in the objects presented to it. But to
aim at realizing the ideal in an example in the world of experi
ence — 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 break
ing 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 un
real.
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 imitation or for criticism. Very different is the
nature of the ideals of the imagination. Of these it is impos
sible to present an intelligible conception; they are a kind of
monogram, drawn according to no determinate rule, and form
ing rather a vague picture — the production of many diverse ex
periences — 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 im
properly, 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 determina
tion 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.
Sec. II. — Of the Transcendental Ideal — Prototypon Transcen-
dentale
Every conception is, in relation to that which is not contained
in it, undetermined and subject to the principle of determin-
ability. This principle is, that of every tzvo contradictorily op-
CRITIQUE OF PURE REASON 321
posed predicates, only one can belong to a conception. It is
a purely logical principle, itself based upon the principle of con
tradiction; 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 sub
ject 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 pred
icates of things, and, while presupposing this sum as an a priori
condition, presents to the mind everything as receiving the pos
sibility 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 therefore to 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 of
analytical representation, which announces that one of two con
tradictory 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.
The proposition, everything which exists is completely deter
mined, means not only that one of every pair of given contradic
tory attributes, but that one of all possible attributes, is always
predicable of the thing ; in it the predicates are not merely com
pared logically with each other, but the thing itself is transcen-
dentally 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 de
termination is consequently a conception which cannot be pre
sented in its totality in concreto, and is therefore based upon an
* Principium determinations omnimoda. things, from the identity of the ground
— Tr. of their complete determination. The
t Thus this principle declares every- determinability of every conception is sub-
thing to possess a relation to a com- ordinate to the universality (Allgemein-
mon correlate — the sum-total of possi- heit universalitas) of the principle of
bility, which, if discovered to exist in excluded middle; the determination of a
the idea of one individual thing, would thing to the totality (Allheit, universitas)
establish the affinity of all possible of all possible predicates.
322 KANT
idea, which has its seat in the reason — the faculty which pre
scribes to the understanding the laws of its harmonious and
perfect exercise.
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 con
ception 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 com
pletely 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 logi
cally, 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 judgment, and is consequently
quite insufficient to present to the mind the content of a concep
tion. The expression not moral, 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 oppo
site negation, on the other hand, indicates a mere want, or
privation, or absence, and, where such negations alone are at
tached to a representation, the non-existence of anything cor
responding 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
* The investigations and calculations tant lesson we have received from them
of astronomers have taught us much is the discovery of the abyss of our
that is wonderful; but the most impor- ignorance in relation to the universe —
CRITIQUE OF PURE REASON 323
man has no conception of his ignorance, because he has no con
ception of knowledge. All conceptions of negatives are accord
ingly 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.
If, therefore, a transcendental substratum lies at the foun
dation 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 realitdtis).
In this view, negations are nothing but limitations — a term
which could not, with propriety, be applied to them, if the un
limited (the all) did not form the true basis of our conception.
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 indi
vidual being, inasmuch as it is determined by that predicate of
all possible contradictory predicates, which indicates and be
longs 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 possi
bility — a condition on which must rest the cogitation of all ob
jects 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 represen
tation 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 experi
ence, we cannot know any determinate kinds of reality, stand
ing under the former as the genus. The transcendental prin
ciple 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,
an ignorance, the magnitude of which This discovery of our deficiencies must
reason, without the information thus produce a great change in the determina-
derived, could never have conceived. tion of the aims of human reason.
324 KANT
but one which comprehends them all within itself. The com
plete 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 syllo
gism and the determination of the object 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 deter
mination of all possible things, takes a course in exact analogy
with that which it pursues in disjunctive syllogisms — a proposi
tion 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 reason
ing employed by the human mind.
It is self-evident that reason, in cogitating the necessary com
plete 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 unconditioned to
tality of complete determination, the conditioned, that is, the
totality of limited things. 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 de
rived — except that of the thing which contains in itself all real
ity, 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 realissi-
mum — are mere limitations of a greater and a higher — nay,
the highest reality ; and they consequently presuppose this real
ity, 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
CRITIQUE OF PURE REASON 325
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 per
fect 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 limi
tation, 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, may be with pro
priety regarded as belonging to this series of effects, while they
could not have formed parts of the idea, considered as an aggre
gate. 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 overstepping 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 objec
tive 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
326
KANT
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 dia
lectic of reason ; we must also endeavor to discover the sources
of this dialectic, that we may have it in our power to give a ra
tional explanation of this illusion, as a phenomenon of the
human mind. For the ideal, of which we are at present speak
ing, 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 exist
ing 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 ele
ment 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 sensu
ous 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 consti
tutes the thing itself — the real in a phenomenon, must be given,
and that, in which the real of all phenomena is given, is experi
ence, 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 prin
ciple of our conceptions of the possibility of things, as phenom
ena, by leaving out this limitative condition, to be a transcen
dental principle of the possibility of things in general.
We proceed afterwards to hypostatize this idea of the sum
CRITIQUE OF PURE REASON 327
total of all reality, by changing the distributive unity of the em
pirical 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 subrep
tion, 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.*
Sec. Ill — Of the Arguments employed by Speculative Reason
to prove a Supreme Being's Existence
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 concep
tions, the idealistic and factitious nature of such a presupposi
tion 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 unedu
cated, although the path at first entered it does not always con
tinue 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 un
worthy 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 con-
* This ideal of the ens realissimum — themselves, but upon the connection of
although merely a mental representa- the variety of phenomena by the under-
tion — is first objectivized, that is, has an standing in a consciousness, and thus the
objective existence attributed to it, then unity of the supreme reality and the
hypostatiscd, and finally, by the natural complete determinability of all things,
progress of reason to the completion of seem to reside in a supreme under-
unity, personified, as we shall show ores- standing, and consequently in a con-
ently. For the regulative unity of ex- scious intelligence,
perience is not based upon phenomena
328
KANT
dition 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 un
conditionally. 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 at
tribute of absolute necessity, not for the purpose of inferring
a priori, from the conception of such a being, its objective exist
ence (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,
wrhich is all-sufficient as a condition, seems to be the being of
which we can justly predicate absolute necessity — for this rea
son, that, possessing the conditions of all that is possible, it does
not and cannot itself require any condition. And thus it satis
fies, in one respect at least, the requirements of the conception of
absolute necessity. In this view, it is superior to all other con
ceptions, 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 d 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,
CRITIQUE OF PURE REASON 329
for we find that we cannot do without the existence of a neces
sary 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 rea
son. 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 satisfac
tory, if we admit the existence of a necessary being, and con
sider 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 favor 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 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 con
ditions of other things, to be absolutely unconditioned ; and ad
mitting too, that we have thus discovered the conception of a
thing to which may be attributed, without inconsistency, abso
lute necessity — it does not follow from all this that the concep
tion of a limited being, in which the supreme reality does not
reside, is therefore incompatible with the idea of absolute neces-
33° KANT
sity. For, although I do not discover the element of the uncon
ditioned 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 neces
sary, although we are unable to infer this from the general con
ception 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 result.
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 responsibili
ties 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 sup
position 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, accord
ing to the standard of reason, preponderate over and are su
perior to any claims that may be advanced from any other
quarter. The equilibrium of doubt would in this case be de
stroyed by a practical addition ; indeed, Reason would be com
pelled to condemn herself, if she refused to comply with the
demands of the judgment, no superior to which we know — how
ever defective her understanding of the grounds of these de
mands 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 ap
preciate 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
CRITIQUE OF PURE REASON 331
reality. This highest cause, then, we regard as absolutely neces
sary, 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 deter
minate 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 su
preme cause is concluded from a priori conceptions alone. The
first is the physico-theological argument, the second the cosmo-
logical, 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 em
pirical, 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 wrhich reason, in the progress of its development, at
tains 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 transcen
dental idea of reason which guides it in its pilgrimage, and is the
goal of all its struggles. I shall therefore begin with an exami
nation of the transcendental argument, and afterwards inquire,
what additional strength has accrued to this mode of proof from
the addition of the empirical element.
Sec. 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 in
dicate a certain unattainable perfection, and rather limits the
332 KANT
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 understand
ing 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 con
ceiving, whether — and how — a being of this nature is even
cogitable, not to mention that its existence is actually demon
strable. A verbal definition of the conception is certainly easy
enough ; it is something, the non-existence of which is impos
sible. But does this definition throw any light upon the con
ditions 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 under
standing 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 some
thing, or really of nothing at all.
Nay, more, this chance-conception, now become so current,
many have endeavored 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 excep
tion, from judgments, and not from things. But the uncon
ditioned necessity of a judgment does not form the absolute
necessity of a thing. On the contrary, the absolute necessity of
a judgment is only a conditioned necessity of a thing, or of the
predicate in a judgment. 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 concep
tion of a thing, the content of which was made to embrace ex
istence, we believed ourselves safe in concluding that, because
CRITIQUE OF PURE REASON 333
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 judgment, 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 con
tradiction 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 ab
solutely 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 judgment.
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 judgment
there cannot exist the least self-contradiction.
You have thus seen, that when the predicate of a judgment
is annihilated in thought along with the subject, no internal con
tradiction can arise, be the predicate what it may. There is no
possibility of evading the conclusion — you find yourselves com
pelled 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 be
hind a contradiction ; and contradiction is the only criterion of
impossibility, in the sphere of pure a priori conceptions.
Against these general considerations, the justice of which
no one can dispute, one argument is adduced, which is regarded
334 KANT
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 ad
mitting 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.
I answer: It is absurd to introduce — under whatever term
disguised — into the conception of a thing, which is to be cogi
tated 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 tau
tology. 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 con
tradiction — a property which is the characteristic of analytical
propositions, alone.
* A conception is always possible, if demonstrated; and a proof of this kind
from the nihil negativum. But it may remark may be serviceable as a warning
be, notwithstanding, an empty concep- against concluding, from the possibility
tion, unless the objective reality of this of a conception — which is logical, the
synthesis, by which it is generated, is possibility of a thing— which is real.
CRITIQUE OF PURE REASON 335
I should have a reasonable hope of putting an end forever
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 de
termination of a thing) resists almost all the endeavors 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 judgment. But the
determination of a conception is a predicate, which adds to
and enlarges the conception. It must not, therefore, be con
tained in the conception.
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 deter
minations in it. Logically, it is merely the copula of a judg
ment. The proposition, God is omnipotent, contains two con
ceptions, 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 con
ception. 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 con
ception 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 con
ception, 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 concep-
336
KANT
tion, 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 cogi
tated 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 concep
tion 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 pos
sible real content of my conception, there is a defect in its rela
tion to my mental state, that is, I am ignorant whether the cog
nition of the object indicated by the conception is possible a
posteriori. And here the cause of the present difficulty be
comes apparent. If the question regarded an object of sense
merely, it would be impossible for me to confound the con
ception 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 concep
tion, although a possible perception has been added to the ex
perience 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 distin
guish 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 ex
istence of objects of pure thought, because it must be cognized
CRITIQUE OF PURE REASON 337
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 ex
perience — 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 exist
ence 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 judgment cannot be formed,
because these realities are not presented to us specifically ; and
even if this were to happen, a judgment would still be impos
sible, because the criterion of the possibility of synthetical cog
nitions 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-account.
Sec. 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.
22
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This conception was thought to be found in the idea of an ens
realissimum, and thus this idea was employed for the attain
ment 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
course; 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 high
est reality; but, instead of reasoning from this highest reality
to a necessary existence, like the preceding argument, it con
cludes 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 per
suade 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 sub
ject 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 com
pletely a priori, or ontological. The object of all possible ex
perience being the world, it is called the cosmological proof.
It contains no reference to any peculiar property of sensuous
* This inference is too well known to contingent, must also have a cause;
require more detailed discussion. It is and so on, till the series of subordinated
based upon the spurious transcendental causes must end with an absolutely
law of causality, that everything which necessary cause, without which it would
is contingent has a cause, which, if itself not possess completeness.
CRITIQUE OF PURE REASON 339
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 consid
eration of the peculiar constitution of our sensuous world.
The proof proceeds thus: — A necessary being can be deter
mined 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 rea-
lissimum is the only conception, by and in which we can cogitate
a necessary being. Consequently, a supreme being necessarily
exists.
In this cosmological argument are assembled so many so
phistical 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 our
selves 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 conceptions, 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
340 KANT
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 argu
ment, and which is now employed in the support of the cosmo-
logical 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 rcalissimum 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 char
acter, 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 possi
bility 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 like
wise an ens realissimum, is correct (and it is this which con
stitutes the nervus probandi of the cosmological argument),
it must, like all affirmative judgments, 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
CRITIQUE OF PURE REASON 341
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 addi
tional 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 investi
gate the fallacies residing therein.
The following fallacies, for example, are discoverable in this
mode of proof: I. The transcendental principle, Everything
that is contingent must have a cause — a principle without
significance, except in the sensuous world. For the purely in
tellectual conception of the contingent cannot produce any syn
thetical proposition, like that of causality, which is itself with
out 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 impossi
bility of an infinite ascending series of causes in the world of
sense a first cause is inferred ; — a conclusion which the prin
ciples 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 com
pletion 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 conception,
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 transcenden
tal, 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 neces-
342 KANT
sity of proving the existence of a necessary being a 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 possi
bility 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 unfortu
nately 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 further than the point from
which I set out. The conception of a Supreme Being satisfies
all questions d 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 concep
tion does not satisfy the question regarding its existence — which
was the purpose of all our inquiries ; and, although the exist
ence of a necessary being were admitted, we should find it im
possible 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-suffi
cient 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 enuncia-
CRITIQUE OF PURE REASON 343
tion of an admissible hypothesis, but the boldest declaration
of an apodictic 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 trem
bles 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 meas
ures the duration of things, it does not support them. We can
not 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 ; but whence
then am I? Here all sinks away from under us ; and the great
est, 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 in
scrutable ; on the contrary, it must, as a mere idea, be based on
the constitution of reason itself, and on this account must be
344
capable of explanation and solution. For the very essence of
reason consists in its ability to give an account of all our con
ceptions, 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 trans
cendental arguments, of the dialectical, but natural, illusion,
which connects the conceptions of necessity and supreme real
ity, 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 someone 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 pro
ceed 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 abso
lutely 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 beginning.
CRITIQUE OF PURE REASON 345
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 infer
ence is, that necessity and contingency are not properties of
things themselves — otherwise an internal contradiction would
result; that consequently neither of these principles are objec
tive, but merely subjective principles of reason — the one re
quiring 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 ex
isted a necessary primal basis of all existing things, solely for
the purpose of introducing systematic unity into your knowl
edge, 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 fur
ther 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 any
thing which is empirically given should be absolutely necessary.
It follows from this, that you must accept the absolutely nec
essary 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
world, the second rule requiring you to regard all empirical
causes of unity as themselves deduced.
The philosophers of antiquity regarded all the forms of nat
ure as contingent; while matter was considered by them, in
accordance with the judgment of the common reason of man
kind, as primal and necessary. But if they had regarded mat
ter, not relatively — as the substratum of phenomena, but abso
lutely 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 ex-
346
KANT
istence ; 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, there
fore, have been at the foundation of this opinion. In fact, ex
tension and impenetrability — which together constitute our con
ception of matter — form the supreme empirical principle of the
unity of phenomena, and this principle, in so far as it is empiri
cally unconditioned, possesses the property of a regulative prin
ciple. But, as every determination of matter which constitutes
what is real in it — and consequently impenetrability — is an ef
fect, 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 de
rived unity. For every one of its real properties, being derived,
must be only conditionally necessary, and can therefore be an
nihilated 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 nec
essary being; and we can at the same time, strive without
ceasing towards the attainment of completeness for our deduc
tion, just as if such a being — the supreme condition of all ex
istences — 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 enounce-
ment of the existence of a being in itself necessary, is nothing
more than a regulative principle of reason, requiring us to re
gard 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 explana
tion of phenomena. We cannot, at the same time, avoid regard
ing, by a transcendental subreptio, this formal principle as con
stitutive, and hypostatizing this unity. Precisely similar is the
case with our notion of space. Space is the primal condition of
CRITIQUE OF PURE REASON 347
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 em
ployment 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 con
dition, as absolutely necessary, and that in this way a regula
tive 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.
Sec. 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 experi
ence 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 un-
348 KANT
conditioned among things that are conditioned, while examples,
nay, even guidance, is denied us by the laws of empirical syn
thesis.
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 disen
gage 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 ad
ditions 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 on the other,
whether we regard the world in its greatest or its least manifes
tations — even after we have attained to the highest summit of
knowledge which our weak minds can reach, we find that lan
guage 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 dis
solves into an astonishment without the 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 noth
ingness, unless we admit that, besides this infinite chain of con
tingencies, there exists something that is primal and self-sub-
sistent — 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 hu
man mind, what is there to prevent us from attributing to it
such a degree of perfection as to place it above the sphere of
CRITIQUE OF PURE REASON 349
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 prin
ciples, which is free from self-contradiction, which even con
tributes to the extension of the employment of reason in experi
ence, 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 dis
covered them, and extends our knowledge of nature, by direct
ing our attention to a unity, the principle of which lies beyond
nature. This knowledge of nature again re-acts upon this idea
— its cause ; and thus our belief in a divine author of the uni
verse 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, al
though 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 argu
ment advances to demonstrative certainty and to a reception
upon its own merits, apart from favor or support by other argu
ments. Nor can it injure the cause of morality to endeavor 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
35° KANT
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 introduc
tion, and that, consequently, this argument contains the only
possible ground of proof (possessed by speculative reason) for
the existence of this being.
The chief momenta in the physico-theological argument are
as follows: I. We observe in the world manifest signs of an
arrangement full of purpose, executed with great wisdom, and
existing in a 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, what
ever 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-power
ful 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 favors, 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 rea
son) is derivable from another and superhuman art — a conclu
sion 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
CRITIQUE OF PURE REASON 351
and modes of origination 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 indemon
strable principles of explanation which she does not knowTj
According to the physico-theological argument, the'"connec-
tion and harmony existing in the world evidence the contin
gency of the form merely, but not of the matter, that is, of the
substance of the world. To establish the truth of the latter opin
ion, 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 capa
bilities of the material with which he works, but not of a creator
of the world, to whom all things are subject. Thus this argu
ment is utterly insufficient for the task before us — a demonstra
tion 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 ex
istence 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 posses
ses all power, wisdom, and so on, in one word, all perfection —
the conception, that is, of an all-sufficient being. For the predi
cates of very great, astonishing, or immeasurable power and ex
cellence, 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 ob
ject 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 alone.
352 KANT
Now it cannot be expected that anyone 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 deter
minate conception of a supreme cause of the world, and is there
fore 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 em
ploy to bridge the abyss ?
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 ar
gument on empirical grounds, and proceed to infer the con
tingency 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 there
of — the conception of an all-embracing reality. Thus the
physico-theological, failing in its undertaking, recurs in its em
barrassment to the cosmological argument; and, as this is
merely the ontological argument in disguise, it executes its de
sign solely by the aid of pure reason, although it at first pro
fessed 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 ob
servers 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 ob
ject, 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. Gain-
CRITIQUE OF PURE REASON 353
ing, 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 Su
preme 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 exer
cise of the understanding is possible at all.
Sec. 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 trans
cendental 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 natu
ral theology also, a Theist. The former admits that we can cog
nize 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 zvorld — whether by the neces
sity of his nature, or as a free agent, is left undetermined ; the
latter considers this being as the author of the world.
23
354
KANT
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 endeavors 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.*
As we are wont to understand by the term Go d 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 in
terest to humanity, we might, in strict rigor, 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 cer
tain 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 intel-
ligentia). We shall now proceed to investigate the sources of
all these attempts of reason to establish the existence of a Su
preme Being.
It may be sufficient in this place to define theoretical knowl
edge 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 hap
pen. 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
* Not theological ethics; for this sci- theology, on the contrary, is the ex-
ence contains ethical laws, which pre- pression of a conviction of the existence
suppose the existence of a Supreme of a Supreme Being, founded upon
Governor of the world; while Moral- ethical laws.
CRITIQUE OF PURE REASON 355
absolutely necessary, or such a condition may be arbitrarily pre
supposed. 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 exist
ence 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 condi
tion, is itself cognized a priori as absolutely necessary. We shall
at some future time show that the moral laws not merely pre
suppose the existence of a Supreme Being, but also, as them
selves 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 experi
ence, is always cogitated as contingent. For this reason its con
dition 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 ob
ject 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 — as likewise that of the
contingent — loses, in this speculative mode of employing it, all
356
KANT
significance, for its objective reality and meaning are compre
hensible 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 pro
ceeding not in the natural, but in the speculative method. For
the principle of the former announces, not that things themselves
or substances, but only that which happens or their states — as
empirically contingent, have a cause : the assertion that the ex
istence of substance itself is contingent is not justified by ex
perience, 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 judgment 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 the
ology by the aid of speculation alone are fruitless, that the prin
ciples 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 trans-
cendentally, and of this the understanding is quite incapable. If
the empirical law of causality is to conduct us to a Supreme Be
ing, 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 pro
cedure? Certainly not the conception of a Supreme Being, be
cause experience never presents us with the greatest of all pos
sible 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 ab
solutely necessary being, this can be admitted only from favor,
CRITIQUE OF PURE REASON 357
and cannot be regarded as the result of irresistible demonstra
tion. The physico-theological proof may add weight to others
— if other proofs there are — by connecting speculation with ex
perience; but in itself it rather prepares the mind for theo
logical cognition, and gives it a right and natural direction, than
establishes a sure foundation for theology.
It is now perfectly evident that transcendental questions ad
mit 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 experi
ence — 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 im
manence in the field of experience, that is, their relation to ob
jects of empirical cognition, or phenomena. Thus all transcen
dental 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-honored arguments, he at least cannot decline
answering the question — how he can pass the limits of all pos
sible 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 my
self 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
358
KANT
point where experience abandons us, and no means exist of
guaranteeing the objective reality of our conceptions. In what
ever way the understanding may have attained to a conception,
the existence of the object of the conception cannot be discov
ered 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 high
est 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 summum, and
eliminating from it all limitations or admixture of empirical ele
ments.
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 im
portance 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 overthrow
all contradictory assertions — be they atheistic, deistic, or an
thropomorphic. This is of course very easy ; as the same argu
ments 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 re
gard as analogical with the dynamical qualities of a thinking
being, or that, as the anthropomorphists would have us believe,
CRITIQUE OF PURE REASON 359
it is subject to all the limitations which sensibility imposes upon
those intelligences which exist in the world of experience.
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 determina
tion 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, omnipres
ence — free from the conditions of space, omnipotence and others,
are pure transcendental predicates ; and thus the accurate con
ception of a Supreme Being, which every theology requires, is
furnished by transcendental theology alone.
APPENDIX
The Transcendental Dialectic
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 im
portant 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
36°
KANT
their true direction and aim. We are entitled to suppose, there
fore, that there exists a mode of employing transcendental
ideas which is proper and immanent; although, when we mis
take 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; immanently, when it is applied solely to
the employment of the understanding in the sphere of expe
rience. Thus all errors of subreptio — of misapplication, are
to be ascribed to defects of judgment, and not to understand
ing or reason.
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 mere
ly 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 conceptions 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 destina
tion. 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 con
ceptions of objects, and that, when thus considered, they as
sume a fallacious and dialectical character. But, on the other
hand, they are capable of an admirable and indispensably neces
sary 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.
CRITIQUE OF PURE REASON 361
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 ex
perience — 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 un
avoidable, 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 accord
ing to a principle. This unity presupposes an idea — the idea
of the form of a whole (of cognition), preceding the de
terminate 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 understand
ing 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 defec
tive 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 discov
ered. 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
362 KANT
former, or the machines employed by them in their opera
tions — 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
philosophers.
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 judgment should subsume the particular
under the general, the particular being thus necessarily de
termined. I shall term this the demonstrative or apodictic em
ployment 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 univer
sality is inferred, and at the same time, all the causes which
have not, or cannot be presented to our observations, are con
cluded 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 consti
tutive. 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 there
fore the systematic unity of cognitions ; and this unity is the
criterion of the truth of a rule. On the other hand, this syste
matic 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
CRITIQUE OF PURE REASON 363
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 insure the most complete con
sistency and connection that can be attained. But the asser
tion 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 refer
ence to the interest of reason, and that we are justified in de
claring all possible cognitions — empirical and others — to pos
sess 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 sys
tematic 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 discov
ering the hidden identity which exists. We must inquire, for
example, whether or not imagination (connected with con
sciousness), memory, wit, and analysis are not merely different
forms of understanding and reason. The idea of a fundamental
poiver, 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
KANT
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
cases.
These relatively fundamental powers must again be com
pared 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
apodictic or necessary principle. For, without having at
tempted to discover the unity of the various powers existing in
nature, nay, even after all our attempts have failed, we notwith
standing 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 sub
ordinate 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 prin
ciple, by which such a systematic unity — as a property of objects
themselves — is regarded as necessary 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
CRITIQUE OF PURE REASON 365
is not comf ormable 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, not with
out 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 cri
terion, 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 dif
ferent forms in the principles of philosophers, although they
have neither recognized it nor confessed to themselves its pres
ence. 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 con
ceptions, 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 phil
osophers in the well-known scholastic maxim, which forbids us
unnecessarily to augment the number of entities or principles
(entia prater 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 discover
ing 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, has been always pur
sued with so much zeal, that thinkers have found it necessary
rather to moderate the desire than encourage it. It was con
sidered a great step when chemists were able to reduce all salts
to two main genera — acids and alkalis; and they regard this
366
KANT
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 endeavored to
reduce to three, and afterwards to two; but still, not content
with this advance, they cannot but think that behind these diver
sities 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 founda
tion, 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 wfiich I mean objects presented to
our senses), presupposes a transcendental principle. In accord
ance with this principle, homogeneity is necessarily presupposed
in the variety of phenomena (although we are unable to deter
mine 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 understand
ing to attend to the one no less than to the other. This principle
(of the faculty of distinction) acts as a check upon the levity of
the former (the faculty of wit) ; and reason exhibits in this re
spect a double and conflicting interest — on the one hand the
interest in the extent (the interest of generality) in relation to
CRITIQUE OF PURE REASON 367
genera, on the other that of the content (the interest of individu
ality) 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 it
self likewise in the habits of thought peculiar to natural philo
sophers, 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
principles.
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 con
ception 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 sub-species; 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 ex
pressed : — Entium varietates non temere sunt minuenda.
But it is easy to see that this logical law would likewise be
without sense or application, were it not based upon a transcen
dental law of specification, which certainly does not require that
the differences existing in phenomena should be infinite in num
ber, for the logical principle, which merely maintains the inde-
terminateness 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
368
KANT
sub-species to every species, and minor differences in every dif
ference. 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 had 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 appli
cation. 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 dis
covered by obeying the anticipatory law of reason, which im
poses upon the understanding the task of discovering the differ
ences 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 un
derstanding, were not the phenomena included under these con
ceptions 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, I. by the principle of the homogen
eity 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 con
ceptions, 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 specifi
cation, 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
CRITIQUE OF PURE REASON 369
genera, as well as in the descent to lower species. For all diver
sities 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 determination.
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 stand-point of a spec
tator, has a certain horizon, which may be said to enclose a num
ber 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 (sub-species), but not of
points (individuals), which possess no extent. But different
horizons or genera, which include under them so many concep
tions, 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 con
tains under itself all differences and varieties, as genera, species,
and sub-species.
To this highest stand-point 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 concep
tions, 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 prin
ciple : 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 con
tinuum 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
24
370 KANT
which from each of the former is always smaller than the differ
ence 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 indi
viduals. The third unites both the former, by enouncing the
fact of homogeneity as existing even in the most various diver
sity, 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 con-
tinui 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 pur
pose 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 far
ther, 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 pur
pose 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, inas-
* Not quanta continua, like space or a line.
CRITIQUE OF PURE REASON 371
much 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 indi
cation 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 comformable 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 ex
perience or empirical notions. The affinity of the diverse, not
withstanding 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 obser
vation 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 pro
duced to an indefinite extent. Thus these principles conduct us
to a unity in the genera of the forms of these orbits, and, pro
ceeding further, to a unity as regards the cause of the motions of
the heavenly bodies — that is, gravitation. But we go on ex
tending our conquests over nature, and endeavor 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 hyper
bolic paths of comets, pursuing which, these bodies leave our
solar system, and, passing from sun to sun, unite the most dis
tant 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
373 KANT
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 mathemati
cal term), that is, continually approximate, without ever being
able to attain to them, they possess, notwithstanding, as a priori
synthetical propositions, objective though undetermined valid
ity, and are available as rules for possible experience. In the
elaboration of our experience, they may also be employed with
great advantage, as heuristic * principles. A transcendental
deduction of them cannot be made ; such a deduction being al
ways impossible in the case of ideas, as has been already shown.
We distinguished, in the Transcendental Analytic, the dyna
mical principles of the understanding, which are regulative prin
ciples 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, pos
sible a priori. But the principles of pure reason cannot be con
stitutive even in regard to empirical conceptions, because no
sensuous schema corresponding to them can be discovered, and
they cannot therefore have an object in concrete. Now, if I
grant that they cannot be employed in the sphere of experience,
as constitutive principles, how shall I secure for them employ
ment 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 con
ditions 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 ma.rimum of the division and
* From the Greek evptoxw.
CRITIQUE OF PURE REASON 373
the connection of our cognition in one principle. For we may
have a determinate notion of a maximum and an absolutely per
fect, 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 under
standing 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 objec
tive reality and validity in relation to experience. But they will
not aim at determining our knowledge in regard to any em
pirical object; they will merely indicate the procedure, follow
ing which, the empirical and determinate exercise of the under
standing 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 prin
ciples.
When principles which are really regulative are regarded as
constitutive, and employed as objective principles, contradic
tions 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 be
tween her maxims merely indicates a difference in, and a recip
rocal limitation of, the methods by which this interest is satisfied.
This reasoner has at heart the interest of diversity — in accord
ance with the principle of specification ; another, the interest of
unity — in accordance with the principle of aggregation. Each
374 KANT
believes that his judgment 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 circum
stances — 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 two-fold 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 hindrances in the
way of the advancement of truth, until some means is dis
covered 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 f
— 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
•Leibnitz, " Nouveaux Essais," Liv. t Bonnet, "Betrachtungen iiber die
>"• ch. 6. Natur," pp. 29—85.
CRITIQUE OF PURE REASON 375
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 ex
tends — as really existing in nature, is beyond doubt a legitimate
and excellent principle of reason — a principle which extends
further 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 legiti
mate 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 criti
cise and to blame its procedure.
We cannot employ an a priori conception with certainty, until
we have made a transcendental deduction thereof. 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 ratio cinantis} , 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 labors 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 de
termine 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 arid indirect manner, by means of their relation to the
376
KANT
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 prop
erly 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, cosmologi-
qaj, 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 em
pirical cognition, without ever being inconsistent or in opposi
tion with it — it must be a necessary maximoi reason to regulate
its procedure according to these ideas. And this forms the
transcendental deduction of all speculative ideas, not as consti
tutive principles of the extension of our cognition beyond the
limits of our experience, but as regulative principles of the sys
tematic 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 alone.
I shall make this plainer. Guided by the principles involved
in these ideas, we must, in the first place, so connect all the phe
nomena, 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, in
ternal as well as external, as if they belonged to a chain infinite
and without any prime or supreme member, while we do not. on
CRITIQUE OF PURE REASON 377
this account, deny the existence of intelligible grounds of these
phenomena, although we never employ them to explain phenom
ena, for the simple reason that they are not objects of our cog
nition. Thirdly, in the sphere of theology, we must regard the
whole_sy_stem 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_frpjmjthat 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 admitting these ideas/'
to possess an objective and hyperbolic existence, except the cos-V
mological ideas, which lead reason into an antinomy : the psy-i
chological and theological ideas are not antinomial. They con
tain no contradiction ; and how then can any one dispute their
objective reality, since he who denies it knows as little about
their possibility, as we who affirm ? And yet, when we wish to
admit the existence of a thing, it is not sufficient to convince
ourselves that there is no positive obstacle in the way; for it
cannot be allowable to regard mere creations of thought, which
transcend, though they do not contradict, all our conceptions,
as real and determinate objects, solely upon the authority of a
speculative reason striving to compass its own aims. They can
not, therefore, be admitted to be real in themselves ; they can
only possess a comparative reality — that of a schema of the
regulative principle of the systematic unity of all cognition.
They are to be regarded not as actual things, but as in some
measure analogous to them. We abstract from the object
of the idea all the conditions which limit the exercise of our
understanding, but which, on the other hand, are the sole con
ditions of our possessing a determinate conception of any given
thing. And thus we cogitate a something, of the real nature of
which we have not the least conception, but which we represent
372
KANT
to ourselves as standing in a relation to the whole system of phe
nomena, analogous to that in which phenomena stand to each
other.
By admitting these ideal beings, we do not really extend our
cognitions beyond the objects of possible experience ; we extend
merely the empirical unity of our experience, by the aid of
systematic unity, the schema of which is furnished by the idea,
which is therefore valid — not as a constitutive, but as a regula
tive principle. For although we posit a thing corresponding to
the idea — a something, an actual existence, we do not on that
account aim at the extension of our cognition by means of trans
cendent conceptions. This existence is purely ideal, and not
objective; it is the mere expression of the systematic unity
which is to be the guide of reason in the field of experience.
There are no attempts made at deciding what the ground
of this unity may be, or what the real nature of this imaginary
being.
Thus the transcendental and only determinate conception of
God, which is presented to us by speculative reason, is in the
strictest sense deistic. In other words, reason does not assure
us of the objective validity of the conception ; it merely gives us
the idea of something, on which the supreme and necessary unity
of all experience is based. This something we cannot, following
the analogy of a real substance, cogitate otherwise than as the
cause of all things operating in accordance with rational laws,
if we regard it as an individual object ; although we should rest
contented with the idea alone as a regulative principle of reason,
and make no attempt at completing the sum of the conditions
imposed by thought. This attempt is, indeed, inconsistent with
the grand aim of complete systematic unity in the sphere of
cognition — a unity to which no bounds are set by reason.
Hence it happens that, admitting a divine being, I can have
no conception of the internal possibility of its perfection, or of
the necessity of its existence. The only advantage of this ad
mission is, that it enables me to answer all other questions re
lating to the contingent, and to give reason the most complete
satisfaction as regards the unity which it aims at attaining in
the world of experience. But I cannot satisfy reason with re
gard to this hypothesis itself ; and this proves that it is not its
intelligence and insight into the subject, but its speculative in
terest alone which induces it to proceed from a point lying far
CRITIQUE OF PURE REASON 379
beyond the sphere of our cognition, for the purpose of being
able to consider all objects as parts of a systematic whole.
Here a distinction presents itself, in regard to the way in
which we may cogitate a presupposition — a distinction which is
somewhat subtle, but of great importance in transcendental
philosophy. I may have sufficient grounds to admit something,
or the existence of something, in a relative point of view (sup-
positio relative,}, without being justified in admitting it in an
absolute sense (suppositio absoluta). This distinction is un
doubtedly requisite, in the case of a regulative principle, the
necessity of which we recognize, though we are ignorant of the
source and cause of that necessity, and which we assume to be
based upon some ultimate ground, for the purpose of being able
to cogitate the universality of the principle in a more deter
minate way. For example, I cogitate the existence of a being
corresponding to a pure transcendental idea. But I cannot
admit that this being exists absolutely and in itself, because all
of the conceptions, by which I can cogitate an object in a de
terminate manner, fall short of assuring me of its existence;
nay, the conditions of the objective validity of my conceptions
are excluded by the idea — by the very fact of its being an idea.
The conceptions of reality, substance, causality, nay, even that
of necessity in existence, have no significance out of the sphere
of empirical cognition, and cannot, beyond that sphere, de
termine any object. They may, accordingly, be employed to
explain the possibility of things in the world of sense, but they
are utterly inadequate to explain the possibility of the universe
itself considered as a whole ; because in this case the ground of
explanation must lie out of and beyond the world, and cannot,
therefore, be an object of possible experience. Now, I may
admit the existence of an incomprehensible being of this nature
— the object of a mere idea, relatively to the world of sense ; al
though I have no ground to admit its existence absolutely and in
itself. For if an idea (that of a systematic and complete unity,
of which I shall presently speak more particularly) lies at the
foundation of the most extended empirical employment of
reason, and if this idea cannot be adequately represented in con-
crcto, although it is indispensably necessary for the approxima
tion of empirical unity to the highest possible degree — I am not
only authorized, but compelled to realize this idea, that is, to
posit a real object corresponding thereto. But I cannot profess
38o
KANT
to know this object ; it is to me merely a something, to which,
as the ground of systematic unity in cognition, I attribute such
properties as are analogous to the conceptions employed by the
understanding in the sphere of experience. Following the
analogy of the notions of reality, substance, causality, and neces
sity, I cogitate a being, which possesses all these attributes in
the highest degree; and, as this idea is the offspring of my
reason alone, I cogitate this being as self-subsistent reason,
and as the cause of the universe operating by means of ideas
of the greatest possible harmony and unity. Thus I abstract
all conditions that would limit my idea, solely for the purpose
of rendering systematic unity possible in the world of empirical
diversity, and thus securing the widest possible extension for
the exercise of reason in that sphere. This I am enabled to do,
by regarding all connections and relations in the world of sense,
as if they were the dispositions of a supreme reason, of which
our reason is but a faint image. I then proceed to cogitate
this Supreme Being by conceptions which have, properly, no
meaning or application, except in the world of sense. But as
I am authorized to employ the transcendental hypothesis of such
a being in a relative respect alone, that is, as the substratum of
the greatest possible unity in experience — I may attribute to a
being which I regard as distinct from the world, such properties
as belong solely to the sphere of sense and experience. For I do
not desire, and am not justified in desiring, to cognize this object
of my idea, as it exists in itself; for I possess no conceptions
sufficient for this task, those of reality, substance, causality,
nay, even that of necessity in existence, losing all significance,
and becoming merely the signs of conceptions, without content
and without applicability, when I attempt to carry them beyond
the limits of the world of sense. I cogitate merely the relation
of a perfectly unknown being to the greatest possible systematic
unity of experience, solely for the purpose of employing it as
the schema of the regulative principle which directs reason in
its empirical exercise.
It is evident, at the first view, that we cannot presuppose the
reality of this transcendental object, by means of the conceptions
of reality, substance, causality, and so on ; because these con
ceptions cannot be applied to anything that is distinct from the
world of sense. Thus the supposition of a Supreme Being or
cause is purely relative ; it is cogitated only in behalf of the sys-
CRITIQUE OF PURE REASON 381
tematic unity of experience ; such a being is but a something, of
whose existence in itself we have not the least conception.
Thus, too, it becomes sufficiently manifest, why we required the
idea of a necessary being in relation to objects given by sense,
although we can never have the least conception of this being,
or of its absolute necessity.
And now we can clearly perceive the result of our transcen
dental dialectic, and the proper aim of the ideas of pure reason
— which become dialectical solely from misunderstanding and
inconsiderateness. Pure reason is, in fact, occupied with itself,
and not with any object. Objects are not presented to it to be
embraced in the unity of an empirical conception ; it is only the
cognitions of the understanding that are presented to it, for the
purpose of receiving the unity of a rational conception, that is,
of being connected according to a principle. The unity of rea
son is the unity of system ; and this systematic unity is not an
objective principle, extending its dominion over objects, but a
subjective maxim, extending its authority over the empirical
cognition of objects. The systematic connection which reason
gives to the empirical employment of the understanding, not
only advances the extension of that employment, but ensures its
correctness, and thus the principle of a systematic unity of this
nature is also objective, although only in an indefinite respect
(principium vagum). It is not, however, a constitutive prin
ciple, determining an object to which it directly relates ; it is
merely a regulative principle or maxim, advancing and
strengthening the empirical exercise of reason, by the opening
up of new paths of which the understanding is ignorant, while
it never conflicts with the laws of its exercise in the sphere of
experience.
But reason cannot cogitate this systematic unity, without at
the same time cogitating an object of the idea — an object that
cannot be presented in any experience, which contains no con
crete example of a complete systematic unity. This being (ens
rationis ratiocinate?) is therefore a mere idea, and is not assumed
to be a thing which is real absolutely and in itself. On the con
trary, it forms merely the problematical foundation of the con
nection which the mind introduces among the phenomena of the
sensuous world. We look upon this connection, in the light of
the above-mentioned idea, as if it drew its origin from the sup
posed being which corresponds to the idea. And yet all we aim
382 KANT
at is the possession of this idea as a secure foundation for the
systematic unity of experience — a unity indispensable to reason,
advantageous to the understanding, and promotive of the inter
ests of empirical cognition.
We mistake the true meaning of this idea, when we regard
it as an announcement, or even as a hypothetical declaration of
the existence of a real thing, which we are to regard as the origin
or ground of a systematic constitution of the universe. On the
contrary, it is left completely undetermined what the nature or
properties of this so-called ground may be. The idea is merely
to be adopted as a point of view, from which this unity, so es
sential to reason and so beneficial to the understanding, may be
regarded as radiating. In one word, this transcendental thing
is merely the schema of a regulative principle, by means of
which Reason, so far as in her lies, extends the dominion of sys
tematic unity over the whole sphere of experience.
The first object of an idea of this kind is the Ego, considered
merely as a thinking nature or soul. If I wish to investigate
the properties of a thinking being, I must interrogate experi
ence. But I find that I can apply none of the categories to this
object, the schema of these categories, which is the condition of
their application, being given only in sensuous intuition. But I
cannot thus attain to the cognition of a systematic unity of all
the phenomena of the internal sense. Instead, therefore of an
empirical conception of what the soul really is, reason takes the
conception of the empirical unity of all thought, and, by cogitat
ing this unity as unconditioned and primitive, constructs the
rational conception or idea of a simple substance which is in
itself unchangeable, possessing personal identity, and in con
nection with other real things external to it ; in one word, it
constructs the idea of a simple self-subsistent intelligence. But
the real aim of reason in this procedure is the attainment of
principles of systematic unity for the explanation of the phe
nomena of the soul. That is, reason desires to be able to repre
sent all the determinations of the internal sense, as existing in
one subject, all powers as deduced from one fundamental power,
all changes as mere varieties in the condition of a being which is
permanent and always the same, and all phenomena in space as
entirely different in their nature from the procedure of thought.
Essential simplicity (with the other attributes predicated of the
Ego) is regarded as the mere schema of this regulative prin-
CRITIQUE OF PURE REASON 383
ciple ; it is not assumed that it is the actual ground of the proper
ties of the soul. For these properties may rest upon quite dif
ferent grounds, of which we are completely ignorant; just as
the above predicates could not give us any knowledge of the
soul as it is in itself, even if we regarded them as valid in re
spect of it, inasmuch as they constitute a mere idea, which can
not be represented in concrete. Nothing but good can result
from a psychological idea of this kind, if we only take proper
care not to consider it as more than an idea ; that is, if we regard
it as valid merely in relation to the employment of reason, in
the sphere of the phenomena of the soul. Under the guidance
of this idea, or principle, no empirical laws of corporeal phe
nomena are called in to explain that which is a phenomenon of
the internal sense alone ; no windy hypotheses of the generation,
annihilation, and palingenesis of souls are admitted. Thus the
consideration of this object of the internal sense is kept pure,
and unmixed with heterogeneous elements ; while the investiga
tion of reason aims at reducing all the grounds of explanation
employed in this sphere of knowledge to a single principle. All
this is best effected, nay, cannot be effected otherwise than by
means of such a schema, which requires us to regard this ideal
thing as an actual existence. The psychological idea is there
fore meaningless and inapplicable, except as the schema of a
regulative conception. For, if I ask whether the soul is not
really of a spiritual nature, — it is a question which has no mean
ing. From such a conception has been abstracted, not merely
all corporeal nature, but all nature, that is, all the predicates of
a possible experience ; and consequently, all the conditions
which enable us to cogitate an object to this conception have
disappeared. But, if these conditions are absent, it is evident
that the conception is meaningless.
The second regulative idea of speculative reason is the con
ception of the universe. For nature is properly the only object
presented to us, in regard to which reason requires regulative
principles. Nature is two-fold — thinking and corporeal nature.
To cogitate the latter in regard to its internal possibility, that is,
to determine the application of the categories to it, no idea is
required — no representation which transcends experience. In
this sphere, therefore, an idea is impossible, sensuous intuition
being our only guide; while, in the sphere of psychology, we
require the fundamental idea ( I ) , which contains a priori a cer-
384
KANT
tain form of thought, namely, the unity of the Ego. Pure rea
son has therefore nothing left but nature in general, and the
completeness of conditions in nature in accordance with some
principle. The absolute totality of the series of these conditions
is an idea, which can never be fully realized in the empirical ex
ercise of reason, while it is serviceable as a rule for the pro
cedure of reason in relation to that totality. It requires us, in
the explanation of given phenomena (in the regress or ascent in
the series), to proceed, as if the series were infinite in itself, that
is, were prolonged in indefinitum; while, on the other hand,
where reason is regarded as itself the determining cause (in the
region of freedom), we are required to proceed as if we had not
before us an object of sense, but of the pure understanding. In
this latter case, the conditions do not exist in the series of phe
nomena, but may be placed quite out of and beyond it, and the
series of conditions may be regarded as if it had an absolute be
ginning from an intelligible cause. All this proves that the cos-
mological ideas are nothing but regulative principles, and not
constitutive; and that their aim is not to realize an actual to
tality in such series. The full discussion of this subject will be
found in its proper place in the chapter on the antinomy of pure
reason.
The third idea of pure reason, containing the hypothesis of a
being which is valid merely as a relative hypothesis, is that of
the one and all-sufficient cause of all cosmological series, in
other words, the idea of God. We have not the slightest ground
absolutely to admit the existence of an object corresponding to
this idea; for what can empower or authorize us to affirm the
existence of a being of the highest perfection — a being whose
existence is absolutely necessary, merely because we possess the
conception of such a being? The answer is, — it is the existence
of the world which renders this hypothesis necessary. But this
answer makes it perfectly evident, that the idea of this being,
like all other speculative ideas, is essentially nothing more than
a demand upon reason that it shall regulate the connection which
it and its subordinate faculties introduce into the phenomena of
the world by principles of systematic unity, and consequently,
that it shall regard all phenomena as originating from one all-
embracing being, as the supreme and all-sufficient cause. From
this it is plain that the only aim of reason in this procedure is
the establishment of its own formal rule for the extension of
CRITIQUE OF PURE REASON 385
its dominion in the world of experience ; that it does not aim
at an extension of its cognition beyond the limits of experience;
and that, consequently, this idea does not contain any constitu
tive principle.
The highest formal unity, which is based upon ideas alone,
is the unity of all things — a unity in accordance with an aim or
purpose ; and the speculative interest of reason renders it neces
sary to regard all order in the world, as if it originated from
the intention and design of a supreme reason. This principle
unfolds to the view of reason in the sphere of experience new
and enlarged prospects, and invites it to connect the phenomena
of the world according to teleological laws, and in this way to
attain to the highest possible degree of systematic unity. The
hypothesis of a supreme intelligence, as the sole cause of the
universe — an intelligence which has for us no more than an
ideal existence, is accordingly always of the greatest service
to reason. Thus, if we presuppose, in relation to the figure of
the earth (which is round, but somewhat flattened at the
poles),* or that of mountains or seas, wise designs on the part
of an author of the universe, we cannot fail to make, by the light
of this supposition, a great number of interesting discoveries.
If we keep to this hypothesis, as a principle which is purely regu
lative, even error cannot be very detrimental. For, in this case,
error can have no more serious consequences than that, where
we expected to discover a teleological connection (nexus
nnalis), only a mechanical or physical connection appears. In
such a case, we merely fail to find the additional form of unity
we expected, but we do not lose the rational unity which the
mind requires in its procedure in experience. But even a mis
carriage of this sort cannot affect the law in its general and
teleological relations. For although we may convict an anatom
ist of an error, when he connects the limb of some animal with a
certain purpose ; it is quite impossible to prove in a single case,
that any arrangement of nature, be it what it may, is entirely
without aim or design. And thus medical physiology, by the aid
* The advantages which a circular able degree in a short time. The great
form, in the case of the earth, has over protuberance of the earth under the
every other, are well known. But few equator serves to overbalance the im-
are aware that the slight flattening at petus of all other masses of earth, and
the poles, which gives it the figure of thus to preserve the axis of the earth,
a spheroid, is the only cause which pre- so far as we can observe, in its present
vents the elevations of continents or position. And yet this wise arrange-
even of mountains, perhaps thrown up ment has been unthinkingly explained
by some internal convulsion, from con- from the equilibrium of the formerly
tinually altering the position of the axis fluid mass.
of the earth— and that to some consider-
25
386 KANT
of a principle presented to it by pure reason, extends its very
limited empirical knowledge of the purposes of the different
parts of an organized body so far, that it my be asserted with
the utmost confidence, and with the approbation of all reflecting
men, that every organ or bodily part of an animal has its use and
answers a certain design. Now, this is a supposition, which, if
regarded as of a constitutive character, goes much farther than
any experience or observation of ours can justify. Hence it is
evident that it is nothing more than a regulative principle of
reason, which aims at the highest degree of systematic unity, by
the aid of the idea of a causality according to design in a su
preme cause — a cause which it regards as the highest intelli
gence.
If, however, we neglect this restriction of the idea to a purely
regulative influence, reason is betrayed into numerous errors.
For it has then left the ground of experience, in which alone are
to be found the criteria of truth, and has ventured into the
region of the incomprehensible and unsearchable, on the heights
of which it loses its power and collectedness, because it has com
pletely severed its connection with experience.
The first error which arises from our employing the idea of a
Supreme Being as a constitutive (in repugnance to the very
nature of an idea), and not as a regulative principle, is the error
of inactive reason (ignava ratio *). We may so term every
principle which requires us to regard our investigations of na
ture as absolutely complete, and allows reason to cease its
inquiries, as if it had fully executed its task. Thus the psycho
logical idea of the Ego, when employed as a constitutive prin
ciple for the explanation of the phenomena of the soul, and for
the extension of our knowledge regarding this subject beyond
the limits of experience — even to the condition of the soul after
death, is convenient enough for the purposes of pure reason,
but detrimental and even ruinous to its interests in the sphere
of nature and experience. The dogmatizing spiritualist explains
the unchanging unity of our personality through all changes of
condition from the unity of a thinking substance, the interest
which we take in things and events that can happen only after
our death, from a consciousness of the immaterial nature of our
* This was the term applied by the has received this appellation, because, if
old dialecticians to a sophistical argu- followed, it puts an end to the employ
ment, which ran thus: If it is your ment of reason in the affairs of life,
fate to die of this disease, you will die, For a similar reason I have applied this
whether you employ a physician or not. designation to the sophistical argument
Cicero says that this mode of reasoning of pure reason.
CRITIQUE OF PURE REASON 387
thinking subject, and so on. Thus he dispenses with all em
pirical investigations into the cause of these internal phenomena,
and with all possible explanations of them upon purely natural
grounds; while, at the dictation of a transcendent reason, he
passes by the immanent sources of cognition in experience,
greatly to his own ease and convenience, but to the sacrifice of all
genuine insight and intelligence. These prejudicial conse
quences become still more evident, in the case of the dogmatical
treatment of our idea of a Supreme Intelligence, and the theo
logical system of nature (physico-theology) which is falsely
based upon it. For, in this case, the aims which we observe in
nature, and often those which we merely fancy to exist, make
the investigation of causes a very easy task, by directing us to
refer such and such phenomena immediately to the unsearchable
will and counsel of the Supreme Wisdom, while we ought to
investigate their causes in the general laws of the mechanism of
matter. We are thus recommended to consider the labor of
reason as ended, when we have merely dispensed with its em
ployment, which is guided surely and safely, only by the order
of nature and the series of changes in the world — which are
arranged according to immanent and general laws. This error
may be avoided, if we do not merely consider from the view
point of final aims certain parts of nature, such as the division
and structure of a continent, the constitution and direction of
certain mountain-chains, or even the organization existing in
the vegetable and animal kingdoms, but look upon this sys
tematic unity of nature in a perfectly general way, in relation
to the idea of a Supreme Intelligence. If we pursue this ad-
, vice, we lay as a foundation for all investigation the conformity
to aims of all phenomena of nature in accordance with universal
laws, for which no particular arrangement of nature is exempt,
but only cognized by us with more or less difficulty; and we
possess a regulative principle of the systematic unity of a
teleological connection, which we do not attempt to anticipate
or predetermine. All that we do, and ought to do, is to follow
out the physico-mechanical connection in nature according to
general laws, with the hope of discovering, sooner or later, the
teleological connection also. Thus, and thus only, can the prin
ciple of final unity aid in the extension of the employment of
reason in the sphere of experience, without being in any case
detrimental to its interests.
388 KANT
The second error which arises from the misconception of the
principle of systematic unity is that of perverted reason (per-
versa ratio, va-repov irporepov rationis) . The idea of systematic
unity is available as a regulative principle in the connection of
phenomena according to general natural laws ; and, how far
soever we have to travel upon the path of experience to dis
cover some fact or event, this idea requires us to believe that
we have approached all the more nearly to the completion of
its use in the sphere of nature, although that completion can
never be attained. But this error reverses the procedure of
reason. We begin by hypostatizing the principle of systematic
unity, and by giving an anthropomorphic determination to the
conception of a Supreme Intelligence, and then proceed forcibly
to impose aims upon nature. Thus not only does teleology,
which ought to aid in the completion of unity in accordance
with general laws, operate to the destruction of its influence,
but it hinders reason from attaining its proper aim, that is, the
proof, upon natural grounds, of the existence of a supreme in
telligent cause. For, if we cannot presuppose supreme finality
in nature d priori, that is, as essentially belonging to nature,
how can we be directed to endeavor to discover this unity, and,
rising gradually through its different degrees, to approach the
supreme perfection of an author of all — a perfecton which is
absolutely necessary, and therefore cognizable d priori? The
regulative principle directs us to presuppose systematic unity
absolutely, and, consequently, as following from the essential
nature of things — but only as a unity of nature, not merely cog
nized empirically, but presupposed d priori, although only in an
indeterminate manner. But if I insist on basing nature upon
the foundation of a supreme ordaining Being, the unity of
nature is in effect lost. For, in this case, it is quite foreign
and unessential to the nature of things, and cannot be cognized
from the general laws of nature. And thus arises a vicious cir
cular argument, what ought to have been proved having been
presupposed.
To take the regulative principle of systematic unity in nature
for a constitutive principle, and to hypostatize and make a cause
out of that which is properly the ideal ground of the consistent
and harmonious exercise of reason, involves reason in inex
tricable embarrassments. The investigation of nature pursues
its own path under the guidance of the chain of natural causes,
CRITIQUE OF PURE REASON 389
in accordance with the general laws of nature, and ever follows
the light of the idea of an author of the universe — not for the
purpose of deducing the finality, which it constantly pursues,
from this Supreme Being, but to attain to the cognition of his
existence from the finality which it seeks in the existence of the
phenomena of nature, and, if possible, in that of all things — to
cognize this being, consequently, as absolutely necessary.
Whether this latter purpose succeed or not, the idea is and must
always be a true one, and its employment, when merely regula
tive, must always be accompanied by truthful and beneficial
results.
Complete unity, in conformity with aims, constitutes abso
lute perfection. But if we do not find this unity in the nature
of the things which go to constitute the world of experience,
that is, of objective cognition, consequently in the universal and
necessary laws of nature, how can we infer from this unity the
idea of the supreme and absolutely necessary perfection of a
primal being, which is the origin of all causality ? The greatest
systematic unity, and consequently teleological unity, consti
tutes the very foundation of the possibility of the most extended
employment of human reason. The idea of unity is therefore
essentially and indissolubly connected with the nature of our
reason. This idea is a legislative one ; and hence it is very
natural that we should assume the existence of a legislative
reason corresponding to it, from which the systematic unity
of nature — the object of the operations of reason — must be
derived.
In the course of our discussion of the antinomies, we stated
that it is always possible to answer all the questions which pure
reason may raise ; and that the plea of the limited nature of our
cognition, which is unavoidable and proper in many questions
regarding natural phenomena, cannot in this case be admitted,
because the questions raised do not relate to the nature of things,
but are necessarily originated by the nature of reason itself,
and relate to its own internal constitution. We can now estab
lish this assertion, which at first sight appeared so rash, in rela
tion to the two questions in which reason takes the greatest
interest, and thus complete our discussion of the dialectic of
pure reason.
If, then, the question is asked, in relation to transcendental
39o KANT
theology ; * first, whether there is anything distinct from the
world, which contains the ground of cosmical order and con
nection according to general laws? The answer is, Certainly.
For the world is a sum of phenomena; there must therefore
be some transcendental basis of these phenomena, that is, a
basis cogitable by the pure understanding alone. If, secondly,
the question is asked, whether this being is substance, whether
it is of the greatest reality, whether it is necessary, and so forth ?
I answer that this question is utterly without meaning. For all
the categories which aid me in forming a conception of an
object, cannot be employed except in the world of sense, and
are without meaning, when not applied to objects of actual or
possible experience. Out of this sphere, they are not properly
conceptions, but the mere marks or indices of conceptions, which
we may admit, although they cannot, without the help of ex
perience, help us to understand any subject or thing. If, thirdly,
the question is, whether we may not cogitate this being, which
is distinct from the world, in analogy with the objects of ex
perience? The answer is, undoubtedly, but only as an ideal,
and not as a real object. That is, we must cogitate it only as
an unknown substratum of the systematic unity, order, and
finality of the world — a unity which reason must employ as
the regulative principle of its investigation of nature. Nay,
more, we may admit into the idea certain anthropomorphic ele
ments, which are promotive of the interests of this regulative
principle. For it is no more than an idea, which does not relate
directly to a being distinct from the world, but to the regulative
principle of the systematic unity of the world, by means, how
ever, of a schema of this unity — the schema of a Supreme In
telligence, who is the wisely designing author of the universe.
What this basis of cosmical unity may be in itself, we know
not — we cannot discover from the idea; we merely know how
we ought to employ the idea of this unity, in relation to the
systematic operation of reason in the sphere of experience.
But, it will be asked again, can we on these grounds, admit
the existence of a wise and omnipotent author of the world?
Without doubt; and not only so, but we must assume the ex-
* After what has been said of the psy- tematic unity of all the various phenom-
chological idea of the Ego and its proper ena of the internal sense is hypostatised.
employment as a regulative principle The procedure is in this case very
of the operations of reason, I need not similar to that which has been discussed
enter into details regarding the trans- in our remarks on the theological ideal,
cendental illusion by which the sys-
CRITIQUE OF PURE REASON 391
istence of such a being. But do we thus extend the limits of
our knowledge beyond the field of possible experience? By
no means. For we have merely presupposed a something, of
which we have no conception, which we do not know as it is
in itself; but, in relation to the systematic disposition of the
universe, which we must presuppose in all our observation of
nature, we have cogitated this unknown being in analogy with
an intelligent existence (an empirical conception), that is to
say, we have endowed it with those attributes, which, judging
from the nature of our own reason, may contain the ground
of such a systematic unity. This idea is therefore valid only
relatively to the employment in experience of our reason. But
if we attribute to it absolute and objective validity, we overlook
the fact that it is merely an ideal being that we cogitate ; and,
by setting out from a basis which is not determinable by con
siderations drawn from experience, we place ourselves in a posi
tion which incapacitates us from applying this principle to the
empirical employment of reason.
But, it will be asked further, can I make any use of this
conception and hypothesis in my investigations into the world
and nature? Yes, for this very purpose was the idea estab
lished by reason as a fundamental basis. But may I regard
certain arrangements, which seemed to have been made in con
formity with some fixed aim, as the arrangements of design,
and look upon them as proceeding from the divine will, with
the intervention, however, of certain other particular arrange
ments disposed to that end? Yes, you may do so; but at the
same time you must regard it as indifferent, whether it is as
sarted that divine wisdom has disposed all things in conformity
with his highest aims, or that the idea of supreme wisdom is
a regulative principle in the investigation of nature, and at the
same time a principle of the systematic unity of nature accord
ing to general laws, even in those cases where we are unable
to discover that unity. In other words, it must be perfectly
indifferent to you, whether you say, when you have discovered
this unity — God has wisely willed it so, or, nature has wisely
arranged this. For it was nothing but the systematic unity,
which reason requires as a basis for the investigation of nature,
that justified you in accepting the idea of a supreme intelligence
as a schema for a regulative principle; and, the further you
advance in the discovery of design and finality, the more certain
392 KANT
the validity of your idea. But, as the whole aim of this regu
lative principle was the discovery of a necessary and systematic
unity in nature, we have, in so far as we attain this, to attribute
our success to the idea of a Supreme Being ; while, at the same
time, we cannot, without involving ourselves in contradictions,
overlook the general laws of nature, as it was in reference to
them alone that this idea was employed. We cannot, I say,
overlook the general laws of nature, and regard this conformity
to aims observable in nature as contingent or hyperphysical in
its origin; inasmuch as there is no ground which can justify
us in the admission of a being with such properties distinct from
and above nature. All that we are authorized to assert is, that
this idea may be employed as a principle, and that the properties
of the being which is assumed to correspond to it may be re
garded as systematically connected in analogy with the causal
determination of phenomena.
For the same reasons we are justified in introducing into the
idea of the supreme cause other anthropomorphic elements (for
without these we could not predicate anything of it) ; we may
regard it as allowable to cogitate this cause as a being with
understanding, the feelings of pleasure and displeasure, and
faculties of desire and will corresponding to these. At the same
time, we may attribute to this being infinite perfection — a per
fection which necessarily transcends that which our knowledge
of the order and design in the world would authorize us to pred
icate of it. For the regulative law of systematic unity requires
us to study nature on the supposition that systematic and final
unity in infinitum is everywhere discoverable, even in the high
est diversity. For, although we may discover little of this cos-
mical perfection, it belongs to the legislative prerogative of rea
son, to require us always to seek for and to expect it ; while it
must always be beneficial to institute all inquiries into nature
in accordance with this principle. But it is evident that, by this
idea of a supreme author of all, which I place as the foundation
of all inquiries into nature, I do not mean to assert the existence
of such a being, or that I have any knowledge of its existence ;
and, consequently, I do not really deduce anything from the
existence of this being, but merely from its idea, that is to say,
from the nature of things in this world, in accordance with this
idea. A certain dim consciousness of the true use of this idea
seems to have dictated to the philosophers of all times the mod-
CRITIQUE OF PURE REASON 393
erate language used by them regarding the cause of the world.
We find them employing the expressions, wisdom and care of
nature, and divine wisdom, as synonymous — nay, in purely spec
ulative discussions, preferring the former, because it does not
carry the appearance of greater pretensions than such as we
are entitled to make, and at the same time directs reason to its
proper field of action — nature and her phenomena.
Thus, pure reason, which at first seemed to promise us noth
ing less than the extension of our cognition beyond the limits
of experience, is found, when thoroughly examined, to contain
nothing but regulative principles, the virtue and function of
which is to introduce into our cognition a higher degree of
unity than the understanding could of itself. These principles,
by placing the goal of all our struggles at so great a distance,
realize for us the most thorough connection between the dif
ferent parts of our cognition, and the highest degree of syste
matic unity. But, on the other hand, if misunderstood and
employed as constitutive principles of transcendent cognition,
they become the parents of illusions and contradictions, while
pretending to introduce us to new regions of knowledge.
Thus all human cognition begins with intuitions, proceeds
from thence to conceptions, and ends with ideas. Although it
possesses in relation to all three elements, a priori sources of
cognition, which seemed to transcend the limits of all experi
ence, a thorough-going criticism demonstrates, that speculative
reason can never, by the aid of these elements, pass the bounds
of possible experience, and that the proper destination of this
highest faculty of cognition, is to employ all methods, and all
the principles of these methods, for the purpose of penetrating
into the innermost secrets of nature, by the aid of the principles
of unity (among all kinds of which teleological unity is the
highest), while it ought not to attempt to soar above the sphere
of experience, beyond which there lies nought for us but the
void inane. The critical examination, in our Transcendental
Analytic, of all the propositions which professed to extend cog
nition beyond the sphere of experience, completely demon
strated that they can only conduct us to a possible experience.
If we were not distrustful even of the clearest abstract theorems,
if we were not allured by specious and inviting prospects to
394
escape from the constraining power of their evidence, we might
spare ourselves the laborious examination of all the dialectical
arguments which a transcendent reason adduces in support of
its pretensions ; for we should know with the most complete cer
tainty that, however honest such professions might be, they are
null and valueless, because they relate to a kind of knowledge
to which no man can by any possibility attain. But, as there
is no end to discussion, if we cannot discover the true cause
of the illusions by which even the wisest are deceived, and as
the analysis of all our transcendent cognition into its elements
is of itself of no slight value as a psychological study, while it
is a duty incumbent on every philosopher — it was found neces
sary to investigate the dialectical procedure of reason in its
primary sources. And as the inferences of which this dialectic
is the parent, are not only deceitful, but naturally possess a pro
found interest for humanity, it was advisable at the same time,
to give a full account of the momenta of this dialectical pro
cedure, and to deposit it in the archives of human reason, as
a warning to all future metaphysicians to avoid these causes
of speculative error.
TRANSCENDENTAL DOCTRINE
OF
METHOD
INTRODUCTION
IF we regard the sum of the cognition of pure speculative
reason as an edifice, the idea of which, at least, exists in
the human mind, it may be said that we have in the Trans
cendental Doctrine of Elements examined the materials and
determined to what edifice these belong, and what its height
and stability. We have found, indeed, that, although we had
purposed to build for ourselves a tower which should reach to
Heaven, the supply of materials sufficed merely for a habitation,
which was spacious enough for all terrestrial purposes, and
high enough to enable us to survey the level plain of experience,
but that the bold undertaking designed necessarily failed for
want of materials — not to mention the confusion of tongues,
which gave rise to endless disputes among the laborers on the
plan of the edifice, and at last scattered them over all the
world, each to erect a separate building for himself, according
to his own plans and his own inclinations. Our present task
relates not to the materials, but to the plan of an edifice ; and,
as we have had sufficient warning not to venture blindly upon
a design which may be found to transcend our natural powers,
while, at the same time, we cannot give up the intention of
erecting a secure abode for the mind, we must proportion our
design to the material which is presented to us, and which is,
at the same time, sufficient for all our wants.
I understand, then, by the transcendental doctrine of method,
the determination of the formal conditions of a complete sys
tem of pure reason. We shall accordingly have to treat of the
Discipline, the Canon, the Architectonic, and, finally, the His
tory of pure reason. This part of our Critique will accomplish,
from the transcendental point of view, what has been usually
attempted, but miserably executed, under the name of practical
logic. It has been badly executed, I say, because general logic,
not being limited to any particular kind of cognition (not even
to the pure cognition of the understanding) nor to any par-
397
398 KANT
ticular objects, it cannot, without borrowing from other
sciences, do more than present merely the titles or signs of
possible methods and the technical expressions, which are em
ployed in the systematic parts of all sciences ; and thus the
pupil is made acquainted with names, the meaning and applica
tion of which he is to learn only at some future time.
CHAPTER I
The Discipline of Pure Reason
Negative judgments — those which are so not merely as re
gards their logical form, but in respect of their content — are
not commonly held in especial respect. They are, on the con
trary, regarded as jealous enemies of our insatiable desire for
knowledge; and it almost requires an apology to induce us to
tolerate, much less to prize and to respect them.
All propositions, indeed, may be logically expressed in a
negative form ; but, in relation to the content of our cognition,
the peculiar province of negative judgments is solely to prevent
error. For this reason, too, negative propositions, which are
framed for the purpose of correcting false cognitions where
error is absolutely impossible, are undoubtedly true, but inane
and senseless ; that is, they are in reality purposeless, and for
this reason often very ridiculous. Such is the proposition of
the schoolman, that Alexander could not have subdued any
countries without an army.
But where the limits of our possible cognition are very much
contracted, the attraction to new fields of knowledge great,
the illusions to which the mind is subject of the most deceptive
character, and the evil consequences of error of no inconsidera
ble magnitude — the negative element in knowledge, which is
useful only to guard us against error, is of far more importance
than much of that positive instruction which makes additions
to the sum of our knowledge. The restraint which is employed
to repress, and finally to extirpate the constant inclination to
depart from certain rules, is termed Discipline. It is distin
guished from culture, which aims at the formation of a certain
degree of skill, without attempting to repress or to destroy any
other mental power, already existing. In the cultivation of a
CRITIQUE OF PURE REASON 399
talent, which has given evidence of an impulse towards self-
development, discipline takes a negative,* culture and doctrine,
a positive part.
That natural dispositions and talents (such as imagination
and wit), which ask a free and unlimited development, require
in many respects the corrective influence of discipline, every
one will readily grant. But it may well appear strange, that
reason, whose proper duty it is to prescribe rules of discipline
to all the other powers of the mind, should itself require this
corrective. It has, in fact, hitherto escaped this humiliation,
only because, in presence of its magnificent pretensions and
high position, no one could readily suspect it to be capable of
substituting fancies for conceptions, and words for things.
Reason, when employed in the field of experience, does not
stand in need of criticism, because its principles are subjected
to the continual test of empirical observations. Nor is criti
cism requisite in the sphere of mathematics, where the con
ceptions of reason must always be presented In concrete in pure
intuition, and baseless or arbitrary assertions are discovered
without difficulty. But where reason is not held in a plain
track by the influence of empirical or of pure intuition, that
is, when it is employed in the transcendental sphere of pure
conceptions, it stands in great need of discipline, to restrain
its propensity to overstep the limits of possible experience, and
to keep it from wandering into error. In fact, the utility of
the philosophy of pure reason is entirely of this negative char
acter. Particular errors may be corrected by particular ani
madversions, and the causes of these errors may be eradicated
by criticism. But where we find, as in the case of pure reason,
a complete system of illusions and fallacies, closely connected
with each other and depending upon grand general principles,
there seems to be required a peculiar and negative code of
mental legislation, which, under the denomination of a disci
pline, and founded upon the nature of reason and the objects of
its exercise, shall constitute a system of thorough examination
and testing, which no fallacy will be able to withstand or escape
from, under whatever disguise or concealment it may lurk.
* I am well aware that, in the Ian- latter, as the communication of knowl-
guage of the schools, the term discipline edge, and the nature of things itself de-
is usually employed as synonymous with mands the appropriation of the most
instruction. But there are so many cases suitable expressions for this distinction,
in which it is necessary to distinguish that it is my desire that the_former term
the notion of the former, as a course should never be employed in any other
of corrective training, from that of the than a negative signification.
400 KANT
But the reader must remark that, in this the second division
of our Transcendental Critique, the discipline of pure reason
is not directed to the content, but to the method of the cognition
of pure reason. The former task has been completed in the
Doctrine of Elements. But there is so much similarity in the
mode of employing the faculty of reason, whatever be the
object to which it is applied, while, at the same time, its employ
ment in the transcendental sphere is so essentially different in
kind from every other, that, without the warning negative in
fluence of a discipline specially directed to that end, the errors
are unavoidable which spring from the unskilful employment
of the methods which are originated by reason but which are
out of place in this sphere.
Section I. — The Discipline of Pure Reason in the sphere of
Dogmatism
The science of Mathematics presents the most brilliant ex
ample of the extension of the sphere of pure reason without
the aid of experience. Examples are always contagious ; and
they exert an especial influence on the same faculty, which natu
rally flatters itself that it will have the same good fortune in
other cases, as fell to its lot in one fortunate instance. Hence
pure reason hopes to be able to extend its empire in the trans
cendental sphere with equal success and security, especially
when it applies the same method which was attended with such
brilliant results in the science of Mathematics. It is, there
fore, of the highest importance for us to know, whether the
method of arriving at demonstrative certainty, which is termed
mathematical, be identical with that by which we endeavor to
attain the same degree of certainty in philosophy, and which
is termed in that science dogmatical.
Philosophical cognition is the cognition of reason by means
of conceptions; mathematical cognition is cognition by means
of the construction of conceptions. The construction of a con
ception is the presentation a priori of the intuition which cor
responds to the conception. For this purpose a non-empirical
intuition is requisite, which, as an intuition, is an individual
object; while, as the construction of a conception (a general
representation), it must be seen to be universally valid for all
the possible intuitions which rank under that conception. Thus
I construct a triangle, by the presentation of the object which
CRITIQUE OF PURE REASON 401
corresponds to this conception, either by mere imagination —
in pure intuition, or upon paper — in empirical intuition, in both
cases completely a priori, without borrowing the type of that
figure from any experience. The individual figure drawn upon
paper is empirical; but it serves, notwithstanding, to indicate
the conception, even in its universality, because in this empirical
intuition we keep our eye merely on the act of the construction
of the conception, and pay no attention to the various modes
of determining it, for example, its size, the length of its sides,
the size of its angles, these not in the least affecting the essential
character of the conception.
Philosophical cognition, accordingly, regards the particular
only in the general ; mathematical the general in the particular,
nay, in the individual. This is done, however, entirely a priori
and by means of pure reason, so that, as this individual figure
is determined under certain universal conditions of construction,
the object of the conception, to which this individual figure cor
responds as its schema, must be cogitated as universally de
termined.
The essential difference of these two modes of cognition
consists, therefore, in this formal quality; it does not regard
the difference of the matter or objects of both. Those thinkers
who aim at distinguishing philosophy from mathematics by
asserting that the former has to do with quality merely, and
the latter with quantity, have mistaken the effect for the cause.
The reason why mathematical cognition can relate only to quan
tity, is to be found in its form alone. For it is the conception
of quantities only that is capable of being constructed, that is,
presented a priori in intuition ; while quantities cannot be given
in any other than an empirical intuition. Hence the cognition
of qualities by reason is possible only through conceptions. No
one can find an intuition which shall correspond to the concep
tion of reality, except in experience; it cannot be presented to
the mind a priori, and antecedently to the empirical conscious
ness of reality. We can form an intuition, by means of the
mere conception of it, of a cone, without the aid of experience ;
but the color of the cone we cannot know except from experi
ence. I cannot present an intuition of a cause, except in an
example, which experience offers to me. Besides, philosophy,
as well as mathematics, treats of quantities ; as, for example, of
totality, infinity, and so on. Mathematics, too, treats of the
26
402 KANT
difference of lines and surfaces — as spaces of different quality,
of the continuity of extension — as a quality thereof. But, al
though in such cases they have a common object, the mode in
which reason considers that object is very different in philoso
phy from what it is in mathematics. The former confines itself
to the general conceptions; the latter can do nothing with a
mere conception, it hastens to intuition. In this intuition it
regards the conception in concrete, not empirically, but in an
a priori intuition, which it has constructed ; and in which, all
the results which follow from the general conditions of the
construction of the conception, are in all cases valid for the
object of the constructed conception.
Suppose that the conception of a triangle is given to a phi
losopher, and that he is required to discover, by the philosophi
cal method, what relation the sum of its angles bears to a right
angle. He has nothing before him but the conception of a
figure enclosed within three right lines, and, consequently, with
the same number of angles. He may analyze the conception
of a right line, of an angle, or of the number three as long as
he pleases, but he will not discover any properties not contained
in these conceptions. But, if this question is proposed to a
geometrician, he at once begins by constructing a triangle. He
knows that two right angles are equal to the sum of all the
contiguous angles which proceed from one point in a straight
line; and he goes on to produce one side of his triangle, thus
forming two adjacent angles which are together equal to two
right angles. He then divides the exterior of these angles, by
drawing a line parallel with the opposite side of the triangle,
and immediately perceives that he has thus got an exterior
adjacent angle which is equal to the interior. Proceeding in
this way, through a chain of inferences, and always on the
ground of intuition, he arrives at a clear and universally valid
solution of the question.
But mathematics does not confine itself to the construction
of quantities (quanta), as in the case of geometry; it occupies
itself with pure quantity also (quantitas), as in the case of
algebra, where complete abstraction is made of the properties
of the object indicated by the conception of quantity. In al
gebra, a certain method of notation by signs is adopted, and
these indicate the difference possible constructions of quantities,
the extraction of roots, and so on. After having thus denoted
CRITIQUE OF PURE REASON 403
the general conception of quantities, according to their different
relations, the different operations by which quantity or number
is increased or diminished are presented in intuition in accord
ance with general rules. Thus, when one quantity is to be
divided by another, the signs which denote both are placed in
the form peculiar to the operation of division ; and thus algebra,
by means of a symbolical construction of quantity, just as
geometry, with its ostensive or geometrical construction (a con
struction of the objects themselves), arrives at results which
discursive cognition cannot hope to reach by the aid of mere
conceptions.
Now, what is the cause of this difference in the fortune of
the philosopher and the mathematician, the former of whom
follows the path of conceptions, while the latter pursues that
of intuitions, wrhich he represents, a priori, in correspondence
with his conceptions. The cause is evident, from what has
been already demonstrated in the introduction to this Critique.
We do not, in the present case, want to discover analytical
propositions, which may be produced merely by analyzing our
conceptions — for in this the philosopher would have the ad
vantage over his rival ; we aim at the discovery of synthetical
propositions — such synthetical propositions, moreover, as can
be cognized a priori. I must not confine myself to that which
I actually cogitate in my conception of a triangle, for this is
nothing more than the mere definition ; I must try to go beyond
that, and to arrive at properties which are not contained in,
although they belong to, the conception. Now, this is im
possible, unless I determine the object present to my mind ac
cording to the conditions, either of empirical, or of pure in
tuition. In the former case, I should have an empirical
proposition (arrived at by actual measurement of the angles
of the triangle), which would possess neither universality nor
necessity ; but that would be of no value. In the latter, I pro
ceed by geometrical construction, by means of which I collect,
in a pure intuition, just as I would in an empirical intuition,
all the various properties which belong to the schema of a tri
angle in general, and consequently to its conception, and thus
construct synthetical propositions which possess the attribute
of universality.
It would be vain to philosophize upon the triangle, that is,
to reflect on it discursively; I should get no further than the
4o4
definition with which I had been obliged to set out. There
are certainly transcendental synthetical propositions which are
framed by means of pure conceptions, and which form the
peculiar distinction of philosophy; but these do not relate to
any particular thing, but to a thing in general, and enounce
the conditions under which the perception of it may become a
part of possible experience. But the science of mathematics
has nothing to do with such questions, nor with the question
of existence in any fashion; it is concerned merely with the
properties of objects in themselves, only in so far as these are
connected with the conception of the objects.
In the above example, we have merely attempted to show
the great difference which exists between the discursive em
ployment of reason in the sphere of conceptions, and its intuitive
exercise by means of the construction of conceptions. The
question naturally arises — what is the cause which necessitates
this twofold exercise of reason, and how are we to discover
whether it is the philosophical or the mathematical method
which reason is pursuing in an argument?
All our knowledge relates, finally, to possible intuitions, for
it is these alone that present objects to the mind. An a priori
or non-empirical conception contains either a pure intuition —
and in this case it can be constructed; or it contains nothing
but the synthesis of possible intuitions, which are not given
a priori. In this latter case, it may help us to form syntheti
cal a priori judgments, but only in the discursive method, by
conceptions, not in the intuitive, by means of the construction
of conceptions.
The only a priori intuition is that of the pure form of phe
nomena — space and time. A conception of space and time as
quanta may be presented a priori in intuition, that is, con
structed, either along with their quality (figure), or as pure
quantity (the mere synthesis of the homogeneous), by means
of number. But the matter of phenomena, by which things are
given in space and time, can be presented only in perception, a
posteriori. The only conception which represents a priori this
empirical content of phenomena, is the conception of a thing
in general ; and the a priori synthetical cognition of this con
ception can give us nothing more than the rule for the synthesis
of that which may be contained in the corresponding a pos
teriori perception ; it is utterly inadequate to present an a priori
CRITIQUE OF PURE REASON 405
intuition of the real object, which must necessarily be em
pirical.
Synthetical propositions, which relate to things in general,
an a priori intuition of which is impossible, are transcendental.
For this reason transcendental propositions cannot be framed
by means of the construction of conceptions ; they are a priori,
and based entirely on conceptions themselves. They contain
merely the rule, by which we are to seek in the world of per
ception or experience the synthetical unity of that which cannot
be intuited d priori. But they are incompetent to present any
of the conceptions which appear in them in an a priori intuition ;
these can be given only a posteriori, in experience, which, how
ever, is itself possible only through these synthetical principles.
If we are to form a synthetical judgment regarding a con
ception, we must go beyond it, to the intuition in which it is
given. If we keep to what is contained in the conception, the
judgment is merely analytical — it is merely an explanation of
what we have cogitated in the conception. But I can pass from
the conception to the pure or empirical intuition which cor
responds to it. I can proceed to examine my conception in
co ncreto, and to cognize, either d priori or d posteriori, what
I find in the object of the conception. The former — d priori
cognition — is rational-mathematical cognition by means of the
construction of the conception ; the latter — d posteriori cogni
tion — is purely empirical cognition, which does not possess the
attributes of necessity and universality. Thus I may analyze
the conception I have of gold ; but I gain no new information
from this analysis, J merely enumerate Jhe different properties
which I had connected with jhe notion indicated by the word.
My knowledge has gained in logical clearness and arrange
ment, but no addition has been made to it. But if I take the
matter which is indicated by this name, and submit it to the
examination of my senses, I am enabled to form several synthet
ical — although still empirical — propositions. The mathemati
cal conception of a triangle I should construct, that is, present
d priori in intuition, and in this way attain to rational-synthetical
cognition. But when the transcendental conception of reality,
or substance, or power is presented to my mind, I find that it
does not relate to or indicate either an empirical or pure intui
tion, but that it indicates merely the synthesis of empirical in
tuitions, which cannot of course be given d priori. The syn-
406 KANT
thesis in such a conception cannot proceed a priori — without
the aid of experience — to the intuition which corresponds to
the conception ; and, for this reason, none of these conceptions
can produce a determinative synthetical proposition, they can
never present more than a principle of the synthesis* of possible
empirical intuitions. A transcendental proposition is, there
fore, a synthetical cognition of reason by means of pure con
ceptions and the discursive method, and it renders possible all
synthetical unity in empirical cognition, though it cannot pre
sent us with any intuition a priori.
There is thus a twofold exercise of reason. Both modes
have the properties of universality and an a priori origin in
common, but are, in their procedure, of widely different charac
ter. The reason of this is, that in the world of phenomena, in
which alone objects are presented to our minds, there are two
main elements — the form of intuition (space and time), which
can be cognized and determined completely a priori, and the
matter or content — that which is presented in space and time,
and which, consequently, contains a something — an existence
corresponding to our powers of sensation. As regards the lat
ter, which can never be given in a determinate mode except by
experience, there are no a priori notions which relate to it, ex
cept the undetermined conceptions of the synthesis of possible
sensations, in so far as these belong (in a possible experience)
to the unity of consciousness. As regards the former, we can
determine our conceptions a priori in intuition, inasmuch as we
are ourselves the creators of the objects of the conceptions in
space and time — these objects being regarded simply as quanta.
In the one case, reason proceeds according to conceptions, and
can do nothing more than subject phenomena to these — which
can only be determined empirically, that is a posteriori — in con
formity, however, with those conceptions as the rules of all
empirical synthesis. In the other case, reason proceeds by the
construction of conceptions; and, as these conceptions relate
to an a priori intuition, they may be given and determined in
pure intuition a priori, and without the aid of empirical data.
* In the case of the conception of strictly according to conceptions; I can-
cause, I do really go beyond the em- not in a case of this kind employ the
pirical conception of an event — but not construction of conceptions, because the
to the intuition which presents this con- conception is merely a rule for the
ception in concrete, but only to the time- synthesis of perceptions, which are not
conditions, which may be found in pure intuitions, and which, therefore,
experience to correspond to the con- cannot be given a priori.
ception. My procedure is, therefore,
CRITIQUE OF PURE REASON 407
The examination and consideration of everything that exists in
space or time — whether it is a quantum or not, in how far the
particular something (which fills space or time) is a primary
substratum, or a mere determination of some other existence,
whether it relates to anything else — either as cause or effect,
whether its existence is isolated or in reciprocal connection with
and dependence upon others, the possibility of this existence,
its reality and necessity or their opposites — all these form part
of the cognition of reason on the ground of conceptions, and
this cognition is termed philosophical. But to determine a
priori an intuition in space (its figure), to divide time into
periods, or merely to cognize the quantity of an intuition in
space and time, and to determine it by number — all this is an
operation of reason by means of the construction of concep
tions, and is called mathematical.
The success which attends the efforts of reason in the sphere
of mathematics, naturally fosters the expectation that the same
good fortune will be its lot, if it applies the mathematical method
in other regions of mental endeavor besides that of quantities.
Its success is thus great, because it can support all its concep
tions by a priori intuitions, and in this way make itself a master,
as it were, over nature ; while pure philosophy, with its a priori
discursive conceptions, bungles about in the world of nature,
and cannot accredit or show any a priori evidence of the reality
of these conceptions. Masters in the science of mathematics
are confident of the success of this method ; indeed, it is a com
mon persuasion, that it is capable of being applied to any subject
of human thought. They have hardly ever reflected or philoso
phized on their favorite science — a task of great difficulty ; and
the specific difference between the two modes of employing the
faculty of reason has never entered their thoughts. Rules
current in the field of common experience, and which common
sense stamps everywhere with its approval, are regarded by
them as axiomatic. From what source the conceptions of
space and time, with which (as the only primitive quanta) they
have to deal, enter their minds, is a question which they do not
trouble themselves to answer; and they think it just as unneces
sary to examine into the origin of the pure conceptions of the
understanding and the extent of their validity. All they have
to do with them is to employ them. In all this they are per
fectly right, if they do not overstep the limits of the sphere of
408
KANT
nature. But they pass, unconsciously, from the world of sense
to the insecure ground of pure transcendental conceptions (in-
stabilis tellus, innabilis undo), where they can neither stand nor
swim, and where the tracks of their footsteps are obliterated
by time ; while the march of mathematics is pursued on a broad
and magnificent highway, which the latest posterity shall fre
quent without fear of danger or impediment.
As we have taken upon us the task of determining, clearly
and certainly, the limits of pure reason in the sphere of trans
cendentalism, and as the efforts of reason in this direction are
persisted in, even after the plainest and most expressive warn
ings, hope still beckoning us past the limits of experience into
the splendors of the intellectual world — it becomes necessary
to cut away the last anchor of this fallacious and fantastic hope.
We shall accordingly show that the mathematical method is
unattended in the sphere of philosophy by the least advantage
— except, perhaps, that it more plainly exhibits its own inad
equacy — that geometry and philosophy are two quite different
things, although they go hand in hand in the field of natural
science, and, consequently, that the procedure of the one can
never be imitated by the other.
The evidence of mathematics rests upon definitions, axioms,
and demonstrations. I shall be satisfied with showing that
none of these forms can be employed or imitated in philosophy
in the sense in which they are understood by mathematicians ;
and that the geometrician, if he employs his method in philos
ophy, will succeed only in building card-castles, while the em
ployment of the philosophical method in mathematics, can re
sult in nothing but mere verbiage. The essential business of
philosophy, indeed, is to mark out the limits of the science ; and
even the mathematician, unless his talent is naturally circum
scribed and limited to this particular department of knowledge,
cannot turn a deaf ear to the warnings of philosophy, or set him
self above its direction.
i. Of Definitions. — A definition is, as the term itself indi
cates, the representation, upon primary grounds, of the com
plete conception of a thing within its own limits.* Accord-
* The definition must describe the say, the limitation of the bounds of the
conception completely, that is, omit none conception must not be deduced from
of the marks or signs of which it is other conceptions, as in this case a proof
composed; within its own limits, that is, would be necessary, and the so-called
it mu£t be precise, and enumerate no definition would be incapable of taking
more signs than belong to the concep- its place at the head of all the judgments,
tion; and on primary grounds, that is to we have to form regarding an object,
CRITIQUE OF PURE REASON 409
ingly, an empirical conception cannot be defined, it can only be
explained. For, as there are in such a conception only a cer
tain number of marks or signs, which denote a certain class of
sensuous objects, we can never be sure that we do not cogitate
under the word which indicates the same object, at one time a
greater, at another a smaller number of signs. Thus, one per
son may cogitate in his conception of gold, in addition to its
properties of weight, color, malleability, that of resisting rust,
while another person may be ignorant of this quality. We em
ploy certain signs only so long as we require them for the sake
of distinction; new observations abstract some and add new
ones, so that an empirical conception never remains within per
manent limits. It is, in fact, useless to define a conception of this
kind. If, for example, we are speaking of water and its proper
ties, we do not stop at what we actually think by the word ivater,
but proceed to observation and experiment ; and the word, with
the few signs attached to it, is more properly a designation than
a conception of the thing. A definition in this case, would evi
dently be nothing more than a determination of the word. In
the second place, no a priori conception, such as those of sub
stance, cause, right, fitness, and so on, can be defined. For I
can never be sure, that the clear representation of a given con
ception (which is given in a confused state) has been fully
developed, until I know that the representation is adequate with
its object. But, inasmuch as the conception, as it is presented
to the mind, may contain a number of obscure representations,
which we do not observe in our analysis, although we employ
them in our application of the conception, I can never be sure
that my analysis is complete, while examples may make this
probable, although they can never demonstrate the fact. In
stead of the word definition, I should rather employ the term
exposition — a more modest expression, which the critic may
accept without surrendering his doubts as to the completeness
of the analysis of any such conception. As, therefore, neither
empirical nor a priori conceptions are capable of definition, we
have to see whether the only other kind of conceptions — arbi
trary conceptions — can be subjected to this mental operation.
Such a conception can always be defined ; for I must know thor
oughly what I wished to cogitate in it, as it was I who created
it, and it was not given to my mind either by the nature of my
understanding or by experience. At the same time, I cannot
4io KANT
say that, by such a definition, I have defined a real object. If
the conception is based upon empirical conditions, if, for ex
ample, I have a conception of a clock for a ship, this arbitrary
conception does not assure me of the existence or even of the
possibility of the object. My definition of such a conception
would with more propriety be termed a declaration of a project
than a definition of an object. There are no other conceptions
which can bear definition, except those which contain an arbi
trary synthesis, which can be constructed d priori. Conse
quently, the science of mathematics alone possesses definitions.
For the object here thought is presented d priori in intuition ;
and thus it can never contain more or less than the conception,
because the conception of the object has been given by the
definition — and primarily, that is, without deriving the defini
tion from any other source. Philosophical definitions are,
therefore, merely expositions of given conceptions, while math
ematical definitions are constructions of conceptions originally
formed by the mind itself ; the former are produced by analysis,
the completeness of which is never demonstratively certain, the
latter by a synthesis. In a mathematical definition the concep
tion is formed, in a philosophical definition it is only explained.
From this it follows :
a. That we must not imitate, in philosophy, the mathematical
usage of commencing with definitions — except by way of hy
pothesis or experiment. For, as all so-called philosophical defi
nitions are merely analyses of given conceptions, these concep
tions, although only in a confused form, must precede the
analysis ; and the incomplete exposition must precede the com
plete, so that we may be able to draw certain inferences from
the characteristics which an incomplete analysis has enabled us
to discover, before we attain to the complete exposition or defi
nition of the conception. In one word, a full and clear definition
ought, in philosophy, rather to form the conclusion than the
commencement of our labors.* In mathematics, on the con
trary, we cannot have a conception prior to the definition ; it is
all philosophical thought. But, as m- philosophy ad meltus esse. It is a dit-
completely defined conceptions may al- ficult task to construct a proper defint-
wavs be employed without detriment to tion. Jurists are still without a comJ
truth, so far as our analysis of the ele- plete definition of the idea of right.
CRITIQUE OF PURE REASON 411
the definition which gives us the conception, and it must for
this reason form the commencement of every chain of mathe
matical reasoning.
b. Mathematical definitions cannot be erroneous. For the
conception is given only in and through the definition, and thus
it contains only what has been cogitated in the definition. But
although a definition cannot be incorrect, as regards its content,
an error may sometimes, although seldom, creep into the form.
This error consists in a want of precision. Thus the common
definition of a circle — that it is a curved line, every point in
which is equally distant from another point called the centre —
is faulty, from the fact that the determination indicated by the
word curved is superfluous. For there ought to be a particular
theorem, which may be easily proved from the definition, to the
effect that every line, which has all its points at equal distances
from another point, must be a curved line — that is, that not
even the smallest part of it can be straight. Analytical defini
tions, on the other hand, may be erroneous in many respects,
either by the introduction of signs which do not actually
exist in the conception, or by wanting in that completeness
which forms the essential of a definition. In the latter case, the
definition is necessarily defective, because we can never be fully
certain of the completeness of our analysis. For these reasons,
the method of definition employed in mathematics cannot be
imitated in philosophy.
2. Of Axioms. These, in so far as they are immediately
certain, are a priori synthetical principles. Now, one concep
tion cannot be connected synthetically and yet immediately with
another; because, if we wish to proceed out of and beyond a
conception, a third mediating cognition is necessary. And, as
philosophy is a cognition of reason by the aid of conceptions
alone, there is to be found in it no principle which deserves to
be called an axiom. Mathematics, on the other hand, may pos
sess axioms, because it can always connect the predicates of
an object a priori, and without any mediating term, by means
of the construction of conceptions in intuition. Such is the
case with the proposition, three points can always lie in a plane.
On the other hand, no synthetical principle which is based upon
conceptions, can ever be immediately certain (for example, the
proposition, Everything that happens has a cause), because I
require a mediating term to connect the two conceptions of event
4i2 KANT
and cause — namely, the condition of time-determination in an
experience, and I cannot cognize any such principle immediately
and from conceptions alone. Discursive principles are, accord
ingly, very different from intuitive principles or axioms. The
former always require deduction, which in the case of the latter
may be altogether dispensed with. Axioms are, for this reason,
always self-evident, while philosophical principles, whatever
may be the degree of certainty they possess, cannot lay any
claim to such a distinction. No synthetical proposition of pure
transcendental reason can be so evident, as is often rashly
enough declared, as the statement, twice two are four. It is
true that in the Analytic I introduced into the list of principles
of the pure understanding, certain axioms of intuition ; but the
principle there discussed was not itself an axiom, but served
merely to present the principle of the possibility of axioms in
general, while it was really nothing more than a principle based
upon conceptions. For it is one part of the duty of transcenden
tal philosophy to establish the possibility of mathematics itself.
Philosophy possesses, then, no axioms, and has no right to im
pose its a priori principles upon thought, until it has established
their authority and validity by a thorough-going deduction.
3. Of Demonstrations. Only an apodictic proof, based upon
intuition, can be termed a demonstration. Experience teaches
us what is, but it cannot convince us that it might have been
otherwise. Hence a proof upon empirical grounds cannot be
apodictic. A priori conceptions, in discursive cognition, can
never produce intuitive certainty or evidence, however certain
the judgment they present may be. Mathematics alone, there
fore, contains demonstrations, because it does not deduce its
cognition from conceptions, but from the construction of con
ceptions, that is, from intuition, which can be given a priori in
accordance with conceptions. The method of algebra, in equa
tions, from which the correct answer is deduced by reduction,
is a kind of construction — not geometrical, but by symbols — in
which all conceptions, especially those of the relations of quan
tities, are represented in intuition by signs ; and thus the con
clusions in that science are secured from errors by the fact that
every proof is submitted to ocular evidence. Philosophical
cognition does not possess this advantage, it being required
to consider the general always in abstract o (by means of con
ceptions), while mathematics can always consider it in concreto
CRITIQUE OF PURE REASON 413
(in an individual intuition), and at the same time by means of
a priori representation, whereby all errors are rendered manifest
to the senses. The former — discursive proofs — ought to be
termed acroamatic proofs, rather than demonstrations, as only
words are employed in them, while demonstrations proper, as
the term itself indicates, always require a reference to the in
tuition of the object.
It follows from all these considerations, that it is not consonant
with the nature of philosophy, especially in the sphere of pure
reason, to employ the dogmatical method, and to adorn itself
with the titles and insignia of mathematical science. It does
not belong to that order, and can only hope for a fraternal union
with that science. Its attempts at mathematical evidence are
vain pretensions, which can only keep it back from its true aim,
which is to detect the illusory procedure of reason when trans
gressing its proper limits, and by fully explaining and analyz
ing our conceptions, to conduct us from the dim regions of
speculation, to the clear region of modest self-knowledge. Rea
son must not, therefore, in its transcendental endeavors, look
forward with such confidence, as if the path it is pursuing led
straight to its aim, nor reckon with such security upon its
premises, as to consider it unnecessary to take a step back, or
to keep a strict watch for errors, which, overlooked in the prin
ciples, may be detected in the arguments themselves — in which
case it may be requisite either to determine these principles with
greater strictness, or to change them entirely.
I divide all apodictic propositions, whether demonstrable or
immediately certain, into dogmata and mathemata. A direct
synthetical proposition, based on conceptions, is a dogma; i
proposition of the same kind, based on the construction of con
ceptions, is a mathema. Analytical judgments do not teach us
any more about an object, than what was contained in the con
ception we had of it ; because they do not extend our cognition
beyond our conception of an object, they merely elucidate the
conception. They cannot therefore be with propriety termed
dogmas. Of the two kinds of a priori synthetical propositions
above-mentioned, only those which are employed in philosophy
can, according to the general mode of speech, bear this name ;
those of arithmetic or geometry would not be rightly so denom
inated. Thus the customary mode of speaking confirms the
explanation given above, and the conclusion arrived at, that only
4i4 KANT
those judgments which are based upon conceptions, not on the
construction of conceptions, can be termed dogmatical.
Thus, pure reason, in the sphere of speculation, does not
contain a single direct synthetical judgment based upon con
ceptions. By means of ideas, it is, as we have shown, incapable
of producing synthetical judgments, which are objectively valid ;
by means of the conceptions of the understanding, it establishes
certain indubitable principles, not, however, directly on the basis
of conceptions, but only indirectly by means of the relation
of these conceptions to something of a purely contingent nature,
namely, possible experience. When experience is presupposed,
these principles are apodictically certain, but in themselves, and
directly, they cannot even be cognized a priori. Thus the given
conceptions of cause and event will not be sufficient for the
demonstration of the proposition, every event has a cause. For
this reason, it is not a dogma; although from another point of
view — that of experience, it is capable of being proved to
demonstration. The proper term for such a proposition is prin
ciple, and not theorem (although it does require to be proved),
because it possesses the remarkable peculiarity of being the con
dition of the possibility of its own ground of proof, that is, ex
perience, and of forming a necessary presupposition in all em
pirical observation.
If then, in the speculative sphere of pure reason, no dogmata
are to be found; all dogmatical methods, whether borrowed
from mathematics, or invented by philosophical thinkers, are
alike inappropriate and inefficient. They only serve to conceal
errors and fallacies, and to deceive philosophy, whose duty it is
to see that reason pursues a safe and straight path. A philo
sophical method may, however, be systematical. For our reason
is, subjectively considered, itself a system, and, in the sphere of
mere conceptions, a system of investigation according to prin
ciples of unity, the material being supplied by experience alone.
But this is not the proper place for discussing the peculiar
method of transcendental philosophy, as our present task is
simply to examine whether our faculties are capable of erecting
an edifice on the basis of pure reason, and how far they may
proceed with the materials at their command.
CRITIQUE OF PURE REASON 415
Section II.— The Discipline of Pure Reason in Polemics
Reason must be subject, in all its operations,to criticism, which
must always be permitted to exercise its functions without re
straint ; otherwise its interests are imperilled, and its influence
obnoxious to suspicion. There is nothing, however useful, how
ever sacred it may be, that can claim exemption from the search
ing examination of this supreme tribunal, which has no respect
of persons. The very existence of reason depends upon this
freedom ; for the voice of reason is not that of a dictatorial and
despotic power, it is rather like the vote of the citizen of a free
state, every member of which must have the privilege of giving
free expression to his doubts, and possess even the right of veto.
But while reason can never decline to submit itself to the
tribunal of criticism, it has not always cause to dread the judg
ment of this court. Pure reason, however, when engaged in the
sphere of dogmatism is not so thoroughly conscious of a strict
observance of its highest laws, as to appear before a higher
judicial reason with perfect confidence. On the contrary, it
must renounce its magnificent dogmatical pretensions in philos
ophy.
Very different is the case, when it has to defend itself, not
before a judge, but against an equal. If dogmatical assertions
are advanced on the negative side, in opposition to those made
by reason on the positive side, its justification Kar avdpwirov
is complete, although the proof of its propositions is Kar a\rj-
detav unsatisfactory.
By the polemic of pure reason I mean the defence of its
propositions made by reason, in opposition to the dogmatical
counter-propositions advanced by other parties. The question
here is not whether its own statements may not also be false ; it
merely regards the fact that reason proves that the opposite can
not be established with demonstrative certainty, nor even as
serted with a higher degree of probability. Reason does not
hold her possessions upon sufferance ; for, although she cannot
show a perfectly satisfactory title to them, no one can prove that
she is not the rightful possessor.
It is a melancholy reflection, that reason, in its highest exer
cise, falls into an antithetic ; and that the supreme tribunal for
the settlement of differences, should not be at union with itself.
It is true that we had to discuss the question of an apparent
4i6 KANT
antithetic, but we found that it was based upon a misconception.
In conformity with the common prejudice, phenomena were
regarded as things in themselves, and thus an absolute com
pleteness in their synthesis was required in the one mode or in
the other (it was shown to be impossible in both) ; a demand
entirely out of place in regard to phenomena. There was, then,
no real self-contradiction of reason in the propositions — the
series of phenomena given in themselves has an absolutely first
beginning, and, this series is absolutely and in itself without be
ginning. The two propositions are perfectly consistent with
each other, because phenomena as phenomena, are in themselves
nothing, and consequently the hypothesis that they are things
in themselves, must lead to self-contradictory inferences.
But there are cases in which a similar misunderstanding can
not be provided against, and the dispute must remain unsettled.
Take, for example, the theistic proposition : There is a Supreme
Being ; and on the other hand, the atheistic counter-statement :
There exists no Supreme Being; or, in psychology: Every
thing that thinks, possesses the attribute of absolute and per
manent unity, which is utterly different from the transitory
unity of material phenomena; and the counter proposition:
The soul is not an immaterial unity, and its nature is transitory,
like that of phenomena. The objects of these questions contain
no heterogeneous or contradictory elements, for they relate to
things in themselves, and not to phenomena. There would
arise indeed, a real contradiction, if reason came forward with
a statement on the negative side of these questions alone. As
regards the criticism to which the grounds of proof on the
affirmative side must be subjected, it may be freely admitted,
without necessitating the surrender of the affirmative proposi
tions, which have, at least, the interest of reason in their favor — •
an advantage which the opposite party cannot lay claim to.
I cannot agree with the opinion of several admirable thinkers
— Sulzer among the rest — that in spite of the weakness of the
arguments hitherto in use, we may hope, one day, to see suffi
cient demonstrations of the two cardinal propositions of pure
reason — the existence of a Supreme Being, and the immortality
of the soul. I am certain, on the contrary, that this will never
be the case. For on what ground can reason base such syn
thetical propositions, which do not relate to the objects of
experience and their internal possibility ? — But it is also demon-
CRITIQUE OF PURE REASON 417
stratively certain that no one will ever be able to maintain the
contrary with the least show of probability. For, as he can
attempt such a proof solely upon the basis of pure reason, he is
bound to prove that a Supreme Being, and a thinking subject
in the character of a pure intelligence, are impossible. But
where will he find the knowledge which can enable him to
enounce synthetical judgments in regard to things which tran
scend the region of experience ? We may, therefore, rest assured
that the opposite never will be demonstrated. We need not,
then, have recourse to scholastic arguments; we may always
admit the truth of those propositions which are consistent with
the speculative interests of reason in the sphere of experience,
and form, moreover, the only means of uniting the speculative
with the practical interest. Our opponent, who must not be
considered here as a critic solely, we can be ready to meet with
a non liquet which cannot fail to disconcert him ; while we can
not deny his right to a similar retort, as we have on our side
the advantage of the support of the subjective maxim of reason,
and can therefore look upon all his sophistical arguments with
calm indifference.
From this point of view, there is properly no antithetic of
pure reason. For the only arena for such a struggle would
be upon the field of pure theology and psychology; but on
this ground there can appear no combatant whom we need to
fear. Ridicule and boasting can be his only weapons; and
these may be laughed at, as mere child's play. This considera
tion restores to Reason her courage ; for what source of confi
dence could be found, if she, whose vocation it is to destroy
error, were at variance with herself and without any reasonable
hope of ever reaching a state of permanent repose ?
Everything in nature is good for some purpose. Even poi
sons are serviceable : they destroy the evil effects of other
poisons generated in our system, and must always find a place
in every complete pharmacopoeia. The objections raised against
the fallacies and sophistries of speculative reason, are objections
given by the nature of this reason itself, and must therefore have
a destination and purpose which can only be for the good of
humanity. For what purpose has Providence raised many ob
jects, in which we have the deepest interest, so far above us,
that we vainly try to cognize them with certainty, and our pow
ers of mental vision are rather excited than satisfied by the
27
4i8 KANT
glimpses we may chance to seize ? It is very doubtful whether
it is for our benefit to advance bold affirmations regarding sub
jects involved in such obscurity; perhaps it would even be
detrimental to our best interests. But it is undoubtedly always
beneficial to leave the investigating, as well as the critical rea
son, in perfect freedom, and permit it to take charge of its own
interests, which are advanced as much by its limitation, as by
its extension of its views, and which always suffer by the in
terference of foreign powers forcing it, against its natural ten
dencies, to bend to certain preconceived designs.
Allow your opponent to say what he thinks reasonable, and
combat him only with the weapons of reason. Have no anxiety
for the practical interests of humanity — these are never imper
illed in a purely speculative dispute. Such a dispute serves
merely to disclose the antinomy of reason, which, as it has its
source in the nature of reason, ought to be thoroughly investi
gated. Reason is benefited by the examination of a subject on
both sides, and its judgments are corrected by being limited.
It is not the matter that may give occasion to dispute, but the
manner. For it is perfectly permissible to employ, in the pres
ence of reason, the language of a firmly rooted faith, even after
we have been obliged to renounce all pretensions to knowledge.
If we were to ask the dispassionate David Hume — a philos
opher endowed, in a degree that few are, with a well-balanced
judgment: What motive induced you to spend so much labor
and thought in undermining the consoling and beneficial per
suasion that Reason is capable of assuring us of the existence,
and presenting us with a determinate conception of a Supreme
Being? — His answer would be: Nothing but the desire of
teaching Reason to know its own powers better, and, at the
same time, a dislike of the procedure by which that faculty was
compelled to support foregone conclusions, and prevented from
confessing the internal weaknesses which it cannot but feel
when it enters upon a rigid self-examination. If, on the other
hand, we were to ask Priestley — a philosopher who had no taste
for transcendental speculation, but was entirely devoted to the
principles of empiricism — what his motives were for overturn
ing those two main pillars of religion — the doctrines of the free
dom of the will and the immortality of the soul (in his view the
hope of a future life is but the expectation of the miracle of
resurrection) — this philosopher, himself a zealous and pious
CRITIQUE OF PURE REASON 419
teacher of religion, could give no other answer than this: I
acted in the interest of reason, which always suffers, when
certain objects are explained and judged by a reference to other
supposed laws than those of material nature — the only laws
which we know in a determinate manner. It would be unfair
to decry the latter philosopher, who endeavored to harmonize
his paradoxical opinions with the interests of religion, and to
undervalue an honest and reflecting man, because he finds him
self at a loss the moment he has left the field of natural science.
The same grace must be accorded to Hume, a man not less
well-disposed, and quite as blameless in his moral character,
and who pushed his abstract speculations to an extreme length,
because, as he rightly believed, the object of them lies entirely
beyond the bounds of natural science, and within the sphere of
pure ideas.
What is to be done to provide against the danger which
seems in the present case to menace the best interests of human
ity? The course to be pursued in reference to this subject is
a perfectly plain and natural one. Let each thinker pursue his
own path ; if he shows talent, if he gives evidence of profound
thought, in one word, if he shows that he possesses the power
of reasoning — reason is always the gainer. If you have re
course to other means, if you attempt to coerce reason, if you
raise the cry of treason to humanity, if you excite the feelings
of the crowd, which can neither understand nor sympathize with
such subtle speculations — you will only make yourselves ridicu
lous. For the question does not concern the advantage or disad
vantage which we are expected to reap from such inquiries ; the
question is merely, how far reason can advance in the field of
speculation, apart from all kinds of interest, and whether we
may depend upon the exertions of speculative reason, or must
renounce all reliance on it. Instead of joining the combatants,
it is your part to be a tranquil spectator of the struggle — a labo
rious struggle for the parties engaged, but attended, in its prog
ress as well as in its results, with the most advantageous conse
quences for the interests of thought and knowledge. It is absurd
to expect to be enlightened by Reason, and at the same time to
prescribe to her what side of the question she must adopt.
Moreover, reason is sufficiently held in check by its own power,
the limits imposed on it by its own nature are sufficient ; it is
unnecessary for you to place over it additional guards, as if its
420
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power were dangerous to the constitution of the intellectual
state. In the dialectic of reason there is no victory gained,
which needs in the least disturb your tranquillity.
The strife of dialectic is a necessity of reason, and we cannot
but wish that it had been conducted long ere this with that per
fect freedom which ought to be its essential condition. In this
case, we should have had at an earlier period a matured and pro
found criticism, which must have put an end to all dialectical
disputes, by exposing the illusions and prejudices in which they
originated.
There is in human nature an unworthy propensity — a pro
pensity which, like everything that springs from nature, must
in its final purpose be conducive to the good of humanity —
to conceal our real sentiments, and to give expression only to
certain received opinions, which are regarded as at once safe
and promotive of the common good. It is true, this tendency,
not only to conceal our real sentiments, but to profess those
which may gain us favor in the eyes of society, has not only
civilised, but, in a certain measure, moralised us; as no one
can break through the outward covering of respectability, honor,
and morality, and thus the seemingly good examples which we
see around us, form an excellent school for moral improvement,
so long as our belief in their genuineness remains unshaken.
But this disposition to represent ourselves as better than we
are, and to utter opinions which are not our own, can be nothing
more than a kind of provisionary arrangement of nature to lead
us from the rudeness of an uncivilized state, and to teach us
how to assume at least the appearance and manner of the good
we see. But when true principles have been developed, and
have obtained a sure foundation in our habit of thought, this
conventionalism must be attacked with earnest vigor, otherwise
it corrupts the heart, and checks the growth of good dispositions
with the mischievous weed of fair appearances.
I am sorry to remark the same tendency to misrepresentation
and hypocrisy in the sphere of speculative discussion, where
there is less temptation to restrain the free expression of
thought. For what can be more prejudicial to the interests of
intelligence, than to falsify our real sentiments, to conceal the
doubts which we feel in regard to our statements, or to maintain
the validity of grounds of proof which we well know to be in
sufficient? So long as mere personal vanity is the source of
CRITIQUE OF PURE REASON 421
these unworthy artifices — and this is generally the case in specu
lative discussions, which are mostly destitute of practical in
terest, and are incapable of complete demonstration — the vanity
of the opposite party exaggerates as much on the other side ;
and thus the result is the same, although it is not brought about
so soon as if the dispute had been conducted in a sincere and
upright spirit. But where the mass entertains the notion that
the aim of certain subtle speculators is nothing less than to
shake the very foundations of public welfare and morality — it
seems not only prudent, but even praiseworthy, to maintain
the good cause by illusory arguments, rather than to give to our
supposed opponents the advantage of lowering our declarations
to the moderate tone of a merely practical conviction, and of
compelling us to confess our inability to attain to apodictic
certainty in speculative subjects. But we ought to reflect that
there is nothing in the world more fatal to the maintenance of
a good cause than deceit, misrepresentation, and falsehood.
That the strictest laws of honesty should be observed in the
discussion of a purely speculative subject, is the least require
ment that can be made. If we could reckon with security even
upon so little, the conflict of speculative reason regarding the
important questions of God, immortality, and freedom, would
have been either decided long ago, or would very soon be
brought to a conclusion. But, in general, the uprightness
of the defense stands in an inverse ratio to the goodness of the
cause ; and perhaps more honesty and fairness are shown by
those who deny, than by those who uphold these doctrines.
I shall persuade myself, then, that I have readers who do
not wish to see a righteous cause defended by unfair argu
ments. Such will now recognize the fact that, according to
the principles of this Critique, if we consider not what is, but
what ought to be the case, there can be really no polemic of
pure reason. For how can two persons dispute about a thing,
the reality of which neither can present in actual or even in
possible experience ? Each adopts the plan of meditating on his
idea for the purpose of drawing from the idea, if he can, what
is more than the idea, that is, the reality of the object which
it indicates. How shall they settle the dispute, since neither is
able to make his assertions directly comprehensible and certain,
but must restrict himself to attacking and confuting those of
his opponent? All statements enounced by pure reason tran-
422
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scend the conditions of possible experience, beyond the sphere
of which we can discover no criterion of truth, while they are
at the same time framed in accordance with the laws of the
understanding, which are applicable only to experience; and
thus it is the fate of all such speculative discussions, that while
the one party attacks the weaker side of his opponent, he in
fallibly lays open his own weaknesses.
The critique of pure reason may be regarded as the highest
tribunal for all speculative disputes; for it is not involved in
these disputes, which have an immediate relation to certain ob
jects and not to the laws of the mind, but is instituted for the
purpose of determining the rights and limits of reason.
Without the control of criticism reason is, as it were, in a state
of nature, and can only establish its claims and assertions by
war. Criticism, on the contrary, deciding all questions accord
ing to the fundamental laws of its own institution, secures to
us the peace of law and order, and enables us to discuss all
differences in the more tranquil manner of a legal process. In
the former case, disputes are ended by victory, which both sides
may claim, and which is followed by a hollow armistice ; in the
latter, by a sentence, which, as it strikes at the root of all specu
lative differences, insures to all concerned a lasting peace. The
endless disputes of a dogmatizing reason compel us to look for
some mode of arriving at a settled decision by a critical investi
gation of reason itself; just as Hobbes maintains that the state
of nature is a state of injustice and violence, and that we must
leave it and submit ourselves to the constraint of law, which
indeed limits individual freedom, but only that it may consist
with the freedom of others and with the common good of all.
This freedom will, among other things, permit of our openly
stating the difficulties and doubts which we are ourselves un
able to solve, without being decried on that account as turbu
lent and dangerous citizens. This privilege forms part of the
native rights of human reason, which recognizes no other judge
than the universal reason of humanity ; and as this reason is the
source of all progress and improvement, such a privilege is to
be held sacred and inviolable. It is unwise, moreover, to de
nounce as dangerous, any bold assertions against, or rash at
tacks upon, an opinion which is held by the largest and most
moral class of the community ; for that would be giving them
an importance which they do not deserve. When I hear that
CRITIQUE OF PURE REASON 423
the freedom of the will, the hope of a future life, and the ex
istence of God have been overthrown by the arguments of some
able writer, I feel a strong desire to read his book ; for I expect
that he will add to my knowledge, and impart greater clearness
and distinctness to my views by the argumentative power shown
in his writings. But I am perfectly certain, even before I have
opened the book, that he has not succeeded in a single point,
not because I believe I am in possession of irrefutable demon
strations of these important propositions, but because this tran
scendental critique, which has disclosed to me the power and
the limits of pure reason, has fully convinced me that, as it is
insufficient to establish the affirmative, it is as powerless, and
even more so, to assure us of the truth of the negative answer to
these questions. From what source does this free-thinker derive
his knowledge that there is, for example, no Supreme Being?
This proposition lies out of the field of possible experience, and,
therefore, beyond the limits of human cognition. But I would
not read at all the answer which the dogmatical maintainer of
the good cause makes to his opponent, because I know well
beforehand, that he will merely attack the fallacious grounds
of his adversary, without being able to establish his own asser
tions. Besides, a new illusory argument, in the construction of
which talent and acuteness are shown, is suggestive of new ideas
and new trains of reasoning, and in this respect the old and
everyday sophistries are quite useless. Again, the dogmatical
opponent of religion gives employment to criticism, and enables
us to test and correct its principles, while there is no occasion
for anxiety in regard to the influence and results of his rea
soning.
But, it will be said, must we not warn the youth intrusted
to academical care against such writings, must we not pre
serve them from the knowledge of these dangerous assertions,
until their judgment is ripened, or rather until the doctrines
which we wish to inculcate are so firmly rooted in their minds
as to withstand all attempts at instilling the contrary dogmas,
from whatever quarter they may come?
If we are to confine ourselves to the dogmatical procedure
in the sphere of pure reason, and find ourselves unable to settle
such disputes otherwise than by becoming a party in them, and
setting counter-assertions against the statements advanced by
our opponents, there is certainly no plan more advisable for the
424 KANT
moment, but, at the same time, none more absurd and inefficient
for the future, than this retaining of the youthful mind under
guardianship for a time, and thus preserving it — for so long at
least — from seduction into error. But when, at a later period,
either curiosity, or the prevalent fashion of thought, places such
writings in their hands, will the so-called convictions of their
youth stand firm? The young thinker, who has in his armory
none but dogmatical weapons with which to resist the attacks of
his opponent, and who cannot detect the latent dialectic which
lies in his own opinions as well as in those of the opposite party,
sees the advance of illusory arguments and grounds of proof
which have the advantage of novelty, against as illusory
grounds of proof destitute of this advantage and which, per
haps, excite the suspicion that the natural credulity of his youth
has been abused by his instructors. He thinks he can find no
better means of showing that he has outgrown the discipline
of his minority, than by despising those well-meant warnings,
and, knowing no system of thought but that of dogmatism, he
drinks deep draughts of the poison that is to sap the principles
in which his early years were trained.
Exactly the opposite of the system here recommended ought
to be pursued in academical instruction. This can only be ef
fected, however, by a thorough training in the critical investi
gation of pure reason. For, in order to bring the principles
of this critique into exercise as soon as possible, and to demon
strate their perfect sufficiency, even in the presence of the high
est degree of dialectical illusion, the student ought to examine
the assertions made on both sides of speculative questions step
by step, and to test them by these principles. It cannot be a
difficult task for him to show the fallacies inherent in these
propositions, and thus he begins early to feel his own power of
securing himself against the influence of such sophistical ar
guments, which must finally lose, for him, all their illusory
power. And, although the same blows which overturn the edi
fice of his opponent are as fatal to his own speculative struct
ures, if such he has wished to rear ; he need not feel any sorrow
in regard to this seeming misfortune, as he has now before him
a fair prospect into the practical region, in which he may reason
ably hope to find a more secure foundation for a rational system.
There is, accordingly, no proper polemic in the sphere of
pure reason. Both parties beat the air and fight with their
CRITIQUE OF PURE REASON 425
own shadows, as they pass beyond the limits of nature, and
can find no tangible point of attack — no firm footing for their
dogmatical conflict. Fight as vigorously as they may, the shad
ows which they hew down, immediately start up again, like
the heroes in Walhalla, and renew the bloodless and unceasing
contest.
But neither can we admit that there is any proper sceptical
employment of pure reason, such as might be based upon the
principle of neutrality in all speculative disputes. To excite
reason against itself, to place weapons in the hands of the party
on the one side as well as in those of the other, and to remain
an undisturbed and sarcastic spectator of the fierce struggle that
ensues, seems, from the dogmatical point of view, to be a part
fitting only a malevolent disposition. But, when the sophist
evidences an invincible obstinacy and blindness, and a pride
which no criticism can moderate, there is no other practicable
course than to oppose to this pride and obstinacy similar feel
ings and pretensions on the other side, equally well or ill
founded, so that reason, staggered by the reflections thus forced
upon it, finds it necessary to moderate its confidence in such
pretensions, and to listen to the advices of criticism. But we
cannot stop at these doubts, much less regard the conviction
of our ignorance, not only as a cure for the conceit natural to
dogmatism, but as the settlement of the disputes in which reason
is involved with itself. On the contrary, scepticism is merely
a means of awakening reason from its dogmatic dreams, and
exciting it to a more careful investigation into its own powers
and pretensions. But, as scepticism appears to be the shortest
road to a permanent peace in the domain of philosophy, and
as it is the track pursued by the many who aim at giving a
philosophical coloring to their contemptuous dislike of all in
quiries of this kind, I think it necessary to present to my readers
this mode of thought in its true light.
Scepticism not a Permanent State for Human Reason
The consciousness of ignorance — unless this ignorance is
recognized to be absolutely necessary — ought, instead of form
ing the conclusion of my inquiries, to be the strongest motive
to the pursuit of them. All ignorance is either ignorance of
things, or of the limits of knowledge. If my ignorance is acci
dental and not necessary, it must incite me, in the first case,
426 KANT
to a dogmatical inquiry regarding the objects of which I am
ignorant ; in the second, to a critical investigation into the
bounds of all possible knowledge. But that my ignorance is
absolutely necessary and unavoidable, and that it consequently
absolves from the duty of all further investigation, is a fact
which cannot be made out upon empirical grounds — from ob
servation, but upon critical grounds alone, that is, by a thor
ough-going investigation into the primary sources of cognition.
It follows that the determination of the bounds of reason can
be made only on a priori grounds ; while the empirical limita
tion of reason, which is merely an indeterminate cognition of an
ignorance that can never be completely removed, can take place
only a posteriori. In other words, our empirical knowledge is
limited by that which yet remains for us to know. The former
cognition of our ignorance, which is possible only on a rational
basis, is a science; the latter is merely a perception, and we can
not say how far the inferences drawn from it may extend. If
I regard the earth, as it really appears to my senses, as a flat
surface, I am ignorant how far this surface extends. But
experience teaches me that, how far soever I go, I always see
before me a space in which I can proceed further; and thus
I know the limits — merely visual — of my actual knowledge of
the earth, although I am ignorant of the limits of the earth
itself. But if I have got so far as to know that the earth is
a sphere, and that its surface is spherical, I can cognize a priori
and determine upon principles, from my knowledge of a small
part of this surface — say to the extent of a degree — the diam
eter and circumference of the earth; and although I am ig
norant of the objects which this surface contains, I have a per
fect knowledge of its limits and extent.
The sum of all the possible objects of our cognition seems
to us to be a level surface, with an apparent horizon — that
which forms the limit of its extent, and which has been termed
by us the idea of unconditioned totality. To reach this limit
by empirical means is impossible, and all attempts to determine
it d priori according to a principle, are alike in vain. But all
the questions raised by pure reason relate to that which lies
beyond this horizon, or, at least, in its boundary line.
The celebrated David Hume was one of those geographers
of human reason who believe that they have given a sufficient
answer to all such questions, by declaring them to lie beyond
CRITIQUE OF PURE REASON 427
the horizon of our knowledge — a horizon which, however,
Hume was unable to determine. His attention especially was
directed to the principle of causality; and he remarked with
perfect justice, that the truth of this principle, and even the
objective validity of the conception of a cause, was not com
monly based upon clear insight, that is, upon a priori cognition.
Hence he concluded that this law does not derive its authority
from its universality and necessity, but merely from its general
applicability in the course of experience, and a kind of subjec
tive necessity thence arising, which he termed habit. From the
inability of reason to establish this principle as a necessary law
for the acquisition of all experience, he inferred the nullity of
all the attempts of reason to pass the region of the empirical.
This procedure, of subjecting the facta of reason to exam
ination, and, if necessary, to disapproval, may be termed the
censura of reason. This censura must inevitably lead us to
doubts regarding all transcendent employment of principles.
But this is only the second step in our inquiry. The first step
in regard to the subjects of pure reason, and which marks the
infancy of that faculty, is that of dogmatism. The second,
which we have just mentioned, is that of scepticism, and it gives
evidence that our judgment has been improved by experience.
But a third step is necessary — indicative of the maturity and
manhood of the judgment, which now lays a firm foundation
upon universal and necessary principles. This is the period of
criticism, in which we do not examine the facta of reason, but
reason itself, in the whole extent of its powers, and in regard
to its capability of a priori cognition; and thus we determine
not merely the empirical and ever-shifting bounds of our
knowledge, but its necessary and eternal limits. We demon
strate from indubitable principles, not merely our ignorance in
respect to this or that subject, but in regard to all possible
questions of a certain class. Thus scepticism is a resting-place
for reason, in which it may reflect on its dogmatical wanderings,
and gain some knowledge of the region in which it happens to
be, that it may pursue its way with greater certainty; but it
cannot be its permanent dwelling-place. It must take up its
abode only in the region of complete certitude, whether this
relates to the cognition of objects themselves, or to the limits
which bound all our cognition.
Reason is not to be considered as an indefinitely extended
4 28 KANT
plane, of the bounds of which we have only a general knowl
edge; it ought rather to be compared to a sphere, the radius
of which may be found from the curvature of its surface — that
is, the nature of a priori synthetical propositions — and, conse
quently, its circumference and extent. Beyond the sphere of
experience there are no objects which it can cognize ; nay, even
questions regarding such supposititious objects relate only to
the subjective principles of a complete determination of the
relations which exist between the understanding-conceptions
which lie within this sphere.
We are actually in possession of a priori synthetical cog
nitions, as is proved by the existence of the principles of the
understanding, which anticipate experience. If anyone cannot
comprehend the possibility of these principles, he may have
some reason to doubt whether they are really a priori; but he
cannot on this account declare them to be impossible, and affirm
the nullity of the steps whhch reason may have taken under
their guidance. He can only say : If we perceived their origin
and their authenticity, we should be able to determine the extent
and limits of reason; but, till we can do this, all propositions
regarding the latter are mere random assertions. In this view,
the doubt respecting all dogmatical philosophy, which proceeds
without the guidance of criticism, is well grounded; but we
cannot therefore deny to reason the ability to construct a sound
philosophy, when the way has been prepared by a thorough
critical investigation. All the conceptions produced, and all
the questions raised, by pure reason, do not lie in the sphere of
experience, but in that of reason itself, and hence they must
be solved, and shown to be either valid or inadmissible, by that
faculty. We have no right to decline the solution of such prob
lems, on the ground that the solution can be discovered only
from the nature of things, and under pretense of the limitation
of human faculties, for reason is the sole creator of all these
ideas, and is therefore bound either to establish their validity
or to expose their illusory nature.
The polemic of scepticism is properly directed against the dog
matist, who erects a system of philosophy without having exam
ined the fundamental objective principles on which it is based,
for the purpose of evidencing the futility of his designs, and
thus bringing him to a knowledge of his own powers. But, in
itself, scepticism does not give us any certain information in
CRITIQUE OF PURE REASON 439
regard to the bounds of our knowledge. All unsuccessful dog
matical attempts of reason are facta, which it is always useful
to submit to the censure of the sceptic. But this cannot help
us to any decision regarding the expectations which reason
cherishes of better success in future endeavors ; the investiga
tions of scepticism cannot, therefore, settle the dispute regard
ing the rights and powers of human reason.
Hume is perhaps the ablest and most ingenious of all sceptical
philosophers, and his writings have, undoubtedly, exerted the
most powerful influence in awakening reason to a thorough in
vestigation into its own powers. It will, therefore, well repay
our labors to consider for a little the course of reasoning which
he followed, and the errors into which he strayed, although set
ting out on the path of truth and certitude.
Hume was probably aware, although he never clearly devel
oped the notion, that we proceed in judgments of a certain class
beyond our conception of the object. I have termed this kind
of judgments synthetical. As regards the manner in which I
pass beyond my conception by the aid of experience, no doubts
can be entertained. Experience is itself a synthesis of percep
tions ; and it employs perceptions to increment the conception,
which I obtain by means of another perception. But we feel
persuaded that we are able to proceed beyond a conception, and
to extend our cognition d priori. We attempt this in two ways
— either, through the pure understanding, in relation to that
which may become an object of experience, or, through pure
reason, in relation to such properties of things, or of the exist
ence of things, as can never be presented in any experience.
This sceptical philosopher did not distinguish these two kinds
of judgments, as he ought to have done, but regarded this aug
mentation of conceptions, and, if we may so express ourselves,
the spontaneous generation of understanding and reason, inde
pendently of the impregnation of experience, as altogether im
possible. The so-called a priori principles of these faculties he
consequently held to be invalid and imaginary, and regarded
them as nothing but subjective habits of thought originating in
experience, and therefore purely empirical and contingent rules,
to which we attribute a spurious necessity and universality.
In support of this strange assertion, he referred us to the gen
erally acknowledged principle of the relation between cause
and effect. No faculty of the mind can conduct us from the
43o KANT
conception of a thing to the existence of something else ; and
hence he believed he could infer that, without experience, we
possess no source from which we can augment a conception,
and no ground sufficient to justify us in framing a judgment
that is to extend our cognition a priori. That the light of the
sun, which shines upon a piece of wax, at the same time melts
it, while it hardens clay, no power of the understanding could
infer from the conceptions which we previously possessed of
these substances ; much less is there any a priori law that could
conduct us to such a conclusion, which experience alone can
certify. On the other hand, we have seen in our discussion
of Transcendental Logic, that, although we can never proceed
immediately beyond the content of the conception which is
given us, we can always cognize completely a priori — in rela
tion, however, to a third term, namely, possible experience —
the law of its connection with other things. For example, if I
observe that a piece of wax melts, I can cognize a priori that
there must have been something (the sun's heat) preceding,
which this effect follows according to a fixed law ; although,
without the aid of experience, I could not cognize a priori and
in a determinate manner, either the cause from the effect, or the
effect from the cause. Hume was therefore wrong in inferring,
from the contingency of the determination according to law,
the contingency of the laiv itself; and the passing beyond the
conception of a thing to possible experience (which is an
a priori proceeding, constituting the objective reality of the con
ception), he confounded with our synthesis of objects in actual
experience, which is always, of course, empirical. Thus, too,
he regarded the principle of affinity, which, has its seat in the
understanding and indicates a necessary connection, as a mere
rule of association, lying in the imitative faculty of imagination,
which can present only contingent, and not objective connec
tions.
The sceptical errors of this remarkably acute thinker arose
principally from a defect, which was common to him with the
dogmatists, namely, that he had never made a systematic review
of all the different kinds of a priori synthesis performed by the
understanding. Had he done so, he would have found, to take
one example among many, that the principle of permanence
was of this character, and that it, as well as the principle of
causality, anticipates experience. In this way he might have
CRITIQUE OF PURE REASON 431
been able to describe the determinate limits of the d priori opera
tions of understanding and reason. But he merely declared the
understanding to be limited, instead of showing what its limits
were ; he created a general mistrust in the power of our facul
ties, without giving us any determinate knowledge of the
bounds of our necessary and unavoidable ignorance ; he exam
ined and condemned some of the principles of the understand
ing, without investigating all its powers with the completeness
necessary to criticism. He denies, with truth, certain powers to
the understanding, but he goes further, and declares it to be
utterly inadequate to the d priori extension of knowledge, al
though he has not fully examined all the powers which reside in
the faculty ; and thus the fate which always overtakes scepticism
meets him too. That is to say, his own declarations are doubted,
for his objections were based upon facta, which are contingent,
and not upon principles, which can alone demonstrate the neces
sary invalidity of all dogmatical assertions.
As Hume makes no distinction between the well-grounded
claims of the understanding and the dialectical pretensions of
reason, against which, however, his attacks are mainly directed,
reason does not feel itself shut out from all attempts at the
extension of d priori cognition, and hence it refuses, in spite of
a few checks in this or that quarter, to relinquish such efforts.
For one naturally arms one's self to resist an attack, and be
comes more obstinate in the resolve to establish the claims he
has advanced. But a complete review of the powers of reason,
and the conviction thence arising that we are in possession of
a limited field of action, while we must admit the vanity of
higher claims, puts an end to all doubt and dispute, and induces
reason to rest satisfied with the undisturbed possession of its
limited domain.
To the uncritical dogmatist, who has not surveyed the sphere
of his understanding, nor determined, in accordance with prin
ciples, the limits of possible cognition, who, consequently, is
ignorant of his own powers, and believes he will discover them
by the attempts he makes in the field of cognition, these attacks
of scepticism are not only dangerous, but destructive. For if
there is one proposition in his chain of reasoning which he can
not prove, or the fallacy in which he cannot evolve in accordance
with a principle, suspicion falls on all his statements, however
plausible they may appear.
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KANT
And thus scepticism, the bane of dogmatical philosophy, con
ducts us to a sound investigation into the understanding and
the reason. When we are thus far advanced, we need fear no
further attacks ; for the limits of our domain are clearly marked
out, and we can make no claims nor become involved in any
disputes regarding the region that lies beyond these limits.
Thus the sceptical procedure in philosophy does not present
any solution of the problems of reason, but it forms an excellent
exercise for its powers, awakening its circumspection, and in
dicating the means whereby it may most fully establish its
claims to its legitimate possessions.
Section III. — The Discipline of Pure Reason in Hypothesis
This critique of reason has now taught us that all its efforts
to extend the bounds of knowledge, by means of pure specu
lation, are utterly fruitless. So much the wider field, it may
appear, lies open to hypothesis ; as, where we cannot know with
certainty, we are at liberty to make guesses, and to form sup
positions.
Imagination may be allowed, under the strict surveillance of
reason, to invent suppositions; but, these must be based on
something that is perfectly certain — and that is the possibility
of the object. If we are well assured upon this point, it is
allowable to have recourse to supposition in regard to the real
ity of the object ; but this supposition must, unless it is utterly
groundless, be connected, as its ground of explanation, with that
which is really given and absolutely certain. Such a supposition
is termed a hypothesis.
It is beyond our power to form the least conception d priori
of the possibility of dynamical connection in phenomena ; and
the category of the pure understanding will not enable us to
excogitate any such connection, but merely helps us to under
stand it, when we meet with it in experience. For this reason
we cannot, in accordance with the categories, imagine or invent
any object or any property of an object not given, or that may
not be given in experience, and employ it in a hypothesis ; other
wise, we should be basing our chain of reasoning upon mere
chimerical fancies, and not upon conceptions of things. Thus,
we have no right to assume the existence of new powers, not
existing in nature — for example, an understanding with a non-
sensuous intuition, a force of attraction without contact, or some
433
new kind of substances occupying space, and yet without the
property of impenetrability ; and, consequently, we cannot as
sume that there is any other kind of community among sub
stances than that observable in experience, any kind of presence
than that in space, or any kind of duration than that in time.
In one word, the conditions of possible experience are for reason
the only conditions of the possibility of things ; reason cannot
venture to form, independently of these conditions, any concep
tions of things, because such conceptions, although not self-
contradictory, are without object and without application.
The conceptions of reason are, as we have already shown,
mere ideas, and do not relate to any object in any kind of ex
perience. At the same time, they do not indicate imaginary
or possible objects. They are purely problematical in their
nature, and, as aids to the heuristic exercise of the faculties,
form the basis of the regulative principles for the systematic
employment of the understanding in the field of experience.
If we leave this ground of experience, they become mere fic
tions of thought, and possibility of which is quite indemon
strable; and they cannot consequently be employed, as hy
potheses, in the explanation of real phenomena. It is quite
admissible to cogitate the soul as simple, for the purpose of
enabling ourselves to employ the idea of a perfect and necessary
unity of all the faculties of the mind as the principle of all our
inquiries into its internal phenomena, although we cannot cog
nize this unity in concrete. But to assume that the soul is a
simple substance (a transcendental conception) would be
enouncing a proposition which is not only indemonstrable —
as many physical hypotheses are, but a proposition which is
purely arbitrary, and in the highest degree rash. The simple
is never presented in experience; and, if by substance is here
meant the permanent object of sensuous intuition, the possibility
of a simple phenomenon is perfectly inconceivable. Reason
affords no good grounds for admitting the existence of intelli
gible beings, or of intelligible properties of sensuous things,
although — as we have no conception either of their possibility
or of their impossibility — it will always be out of our power to
affirm dogmatically that they do not exist.
In the explanation of given phenomena, no other things and
no other grounds of explanation can be employed, than those
which stand in connection with the given phenomena according
28
434 KANT
to the known laws of experience. A transcendental hypothesis,
in which a mere idea of reason is employed to explain the phe
nomena of nature, would not give us any better insight into
a phenomenon, as we should be trying to explain what we do
not sufficiently understand from known empirical principles,
by what we do not understand at all. The principle of such
a hypothesis might conduce to the satisfaction of reason, but
it would not assist the understanding in its application to ob
jects. Order and conformity to aims in the sphere of nature
must be themselves explained upon natural grounds and accord
ing to natural laws ; and the wildest hypotheses, if they are only
physical, are here more admissible than a hyperphysical hy
pothesis, such as that of a divine author. For such a hypothesis
would introduce the principle of ignava ratio, which requires us
to give up the search for causes that might be discovered in
the course of experience, and to rest satisfied with a mere idea.
As regards the absolute totality of the grounds of explanation
in the series of these causes, this can be no hindrance to the
understanding in the case of phenomena ; because, as they are
to us nothing more than phenomena, we have no right to look
for anything like completeness in the synthesis of the series
of their conditions.
Transcendental hypotheses are therefore inadmissible; and
we cannot use the liberty of employing, in the absence of physi
cal, hyperphysical grounds of explanation. And this for two
reasons ; first, because such hypotheses do not advance reason,
but rather stop it in its progress ; secondly, because this license
would render fruitless all its exertions in its own proper sphere,
which is that of experience. For, when the explanation of
natural phenomena happens to be difficult, we have constantly
at hand a transcendental ground of explanation, which lifts
us above the necessity of investigating nature ; and our in*
quiries are brought to a close, not because we have obtained all
the requisite knowledge, but because we abut upon a principle,
which is incomprehensible, and which, indeed, is so far back
in the track of thought, as to contain the conception of the
absolutely primal being.
The next requisite for the admissibility of a hypothesis is
its sufficiency. That is, it must determine a priori the conse
quences which are given in experience, and which are supposed
to follow from the hypothesis itself. If we require to employ
CRITIQUE OF PURE REASON 435
auxiliary hypotheses, the suspicion naturally arises that they
are mere fictions ; because the necessity for each of them re
quires the same justification as in the case of the original hy
pothesis, and thus their testimony is invalid. If we suppose
the existence of an infinitely perfect cause, we possess suffi
cient grounds for the explanation of the conformity to aims,
the order and the greatness which we observe in the universe ;
but we find ourselves obliged, when we observe the evil in the
world and the exceptions to these laws, to employ new hy
potheses in support of the original one. We employ the idea
of the simple nature of the human soul as the foundation
of all the theories we may form of its phenomena; but when
we meet with difficulties in our way, when we observe in the
soul phenomena similar to the changes which take place in
matter, we require to call in new auxiliary hypotheses. These
may, indeed, not be false, but we do not know them to be true,
because the only witness to their certitude is the hypothesis
which they themselves have been called in to explain.
We are not discussing the above-mentioned assertions re
garding the immaterial unity of the soul and the existence of
a Supreme Being, as dogmata, which certain philosophers pro
fess to demonstrate d priori, but purely as hypotheses. In the
former case, the dogmatist must take care that his arguments
possess the apodictic certainty of a demonstration. For the
assertion that the reality of such ideas is probable, is as absurd
as a proof of the probability of a proposition in geometry.
Pure abstract reason, apart from all experience, can either cog
nize a proposition entirely d priori, and as necessary, or it can
cognize nothing at all ; and hence the judgments it enounces
are never mere opinions, they are either apodictic certainties,
or declarations that nothing can be known on the subject.
Opinions and probable judgments on the nature of things
can only be employed to explain given phenomena, or they
may relate to the effect, in accordance with empirical laws, of
an actually existing cause. In other words, we must restrict
the sphere of opinion to the world of experience and nature.
Beyond this region opinion is mere invention; unless we are
groping about for the truth on a path not yet fully known,
and have some hopes of stumbling upon it by chance.
But, although hypotheses are inadmissible in answers to the
questions of pure speculative reason, they may be employed
436
KANT
in the defense of these answers. That is to say, hypotheses are
admissible in polemic, but not in the sphere of dogmatism. By
the defense of statements of this character, I do not mean an
attempt at discovering new grounds for their support, but
merely the refutation of the arguments of opponents. All a
priori synthetical propositions possess the peculiarity, that, al
though the philosopher who maintains the reality of the ideas
contained in the proposition, is not in possession of sufficient
knowledge to establish the certainty of his statements, his op
ponent is as little able to prove the truth of the opposite. This
equality of fortune does not allow the one party to be superior
to the other in the sphere of speculative cognition ; and it is this
sphere accordingly that is the proper arena of these endless
speculative conflicts. But we shall afterwards show that, in
relation to its practical exercise, Reason has the right of ad
mitting what, in the field of pure speculation, she would not be
justified in supposing, except upon perfectly sufficient grounds;
because all such suppositions destroy the necessary complete
ness of speculation — a condition which the practical reason,
however, does not consider to be requisite. In this sphere,
therefore, Reason is mistress of a possession, her title to which
she does not require to prove — which, in fact, she could not do.
The burden of proof accordingly rests upon the opponent. But
as he has just as little knowledge regarding the subject dis
cussed, and is as little able to prove the non-existence of the
object of an idea, as the philosopher on the other side is to
demonstrate its reality, it is evident that there is an advantage
on the side of the philosopher who maintains his proposition
as a practically necessary supposition (melior est conditio
possidentis). For he is at liberty to employ, in self-defense, the
same weapons as his opponent makes use of in attacking him ;
that is, he has a right to use hypotheses not for the purpose of
supporting the arguments in favor of his own propositions, but
to show that his opponent knows no more than himself regard
ing the subject under discussion, and cannot boast of any specu
lative advantage.
Hypotheses are, therefore, admissible in the sphere of pure
reason, only as weapons for self-defense, and not as supports
to dogmatical assertions. But the opposing party we must
always seek for in ourselves. For speculative reason is, in the
sphere of transcendentalism, dialectical in its own nature. The
CRITIQUE OF PURE REASON 437
difficulties and objections we have to fear lie in ourselves.
They are like old but never superannuated claims; and we
must seek them out, and settle them once and forever, if we are
to expect a permanent peace. External tranquillity is hollow
and unreal. The root of these contradictions, which lies in
the nature of human reason, must be destroyed ; and this can
only be done, by giving it, in the first instance, freedom to
grow, nay, by nourishing it, that it may send out shoots, and
thus betray its own existence. It is our duty, therefore, to try
to discover new objections, to put weapons in the hands of our
opponent, and to grant him the most favorable position in
the arena that he can wish. We have nothing to fear from
these concessions; on the contrary, we may rather hope that
we shall thus make ourselves master of a possession which
no one will ever venture to dispute.
The thinker requires, to be fully equipped, the hypotheses
of pure reason, which, although but leaden weapons (for they
have not been steeled in the armory of experience), are as
useful as any that can be employed by his opponents. If, ac
cordingly, we have assumed, from a non-speculative point of
view, the immaterial nature of the soul, and are met by the ob
jection that experience seems to prove that the growth and
decay of our mental faculties are mere modifications of the
sensuous organism — we can weaken the force of this objection,
by the assumption that the body is nothing but the fundamental
phenomenon, to which, as a necessary condition, all sensibility,
and consequently all thought, relates in the present state of
our existence ; and that the separation of soul and body forms
the conclusion of the sensuous exercise of our power of cog
nition, and the beginning of the intellectual. The body
would, in this view of the question, be regarded, not as the
cause of thought, but merely as its restrictive condition, as
promotive of the sensuous and animal, but as a hindrance to
the pure and spiritual life ; and the dependence of the animal
life on the constitution of the body, would not prove that the
whole life of man was also dependent on the state of the organ
ism. We might go still further, and discover new objections,
or carry out to their extreme consequences those which have
already been adduced.
Generation, in the human race as well as among the irra
tional animals, depends on so many accidents — of occasion,
KANT
of proper sustenance, of the laws enacted by the government
of a country, of vice even, that it is difficult to believe in the
eternal existence of a being, whose life has begun under cir
cumstances so mean and trivial, and so entirely dependent upon
our own control. As regards the continuance of the existence
of the whole race, we need have no difficulties, for accident in
single cases is subject to general laws; but, in the case of each
individual, it would seem as if we could hardly expect so won
derful an effect from causes so insignificant. But, in answer to
these objections, we may adduce the transcendental hypothesis,
that all life is properly intelligible, and not subject to changes
of time, and that it neither began in birth, nor will end in death.
We may assume that this life is nothing more than a sensuous
representation of pure spiritual life; that the whole world of
sense is but an image, hovering before the faculty of cognition
which we exercise in this sphere, and with no more objective
reality than a dream ; and that if we could intuite ourselves and
other things as they really are, we should see ourselves in a
world of spiritual natures, our connection with which did not
begin at our birth, and will not cease with the destruction of
the body. And so on.
We cannot be said to know what has been above asserted, nor
do we seriously maintain the truth of these assertions ; and the
notions therein indicated are not even ideas of reason, they are
purely fictitious conceptions. But this hypothetical procedure
is in perfect conformity with the laws of reason. Our opponent
mistakes the absence of empirical conditions for a proof of the
complete impossibility of all that we have asserted ; and we have
to show him that he has not exhausted the whole sphere of pos
sibility, and that he can as little compass that sphere by the laws
of experience and nature, as we can lay a secure foundation for
the operations of reason beyond the region of experience. Such
hypothetical defences against the pretensions of an opponent
must not be regarded as declarations of opinion. The philoso
pher abandons them, so soon as the opposite party renounces its
dogmatical conceit. To maintain a simply negative position in
relation to propositions which rest on an insecure foundation,
well befits the moderation of a true philosopher ; but to uphold
the objections urged against an opponent as proofs of the op
posite statement, is a proceeding just as unwarrantable and ar-
CRITIQUE OF PURE REASON 439
rogant as it is to attack the position of a philosopher who ad
vances affirmative propositions regarding such a subject.
It is evident, therefore, that hypotheses, in the speculative
sphere, are valid, not as independent propositions, but only rela
tively to opposite transcendent assumptions. For, to make the
principles of possible experience conditions of the possibility of
things in general is just as transcendent a procedure as to main
tain the objective reality of ideas which can be applied to no ob
jects except such as lie without the limits of possible experience.
The judgments enounced by pure reason must be necessary, or
they must not be enounced at all. Reason cannot trouble herself
with opinions. But the hypotheses we have been discussing are
merely problematical judgments, which can neither be confuted
nor proved; while, therefore, they are not personal opinions,
they are indispensable as answers to objections which are liable
to be raised. But we must take care to confine them to this func
tion, and guard against any assumption on their part of absolute
validity, a proceeding which would involve reason in inextric
able difficulties and contradictions.
Section IV. — The Discipline of Pure Reason in relation to
Proofs
It is a peculiarity which distinguishes the proofs of transcen
dental synthetical propositions from those of all other d priori
synthetical cognitions, that reason, in the case of the former,
does not apply its conceptions directly to an object, but is first
obliged to prove, & priori, the objective validity of these concep
tions and the possibility of their syntheses. This is not merely
a prudential rule, it is essential to the very possibility of the
proof of a transcendental proposition. If I am required to pass,
a priori, beyond the conception of an object, I find that it is ut
terly impossible without the guidance of something which is
not contained in the conception. In mathematics, it is a priori
intuition that guides my synthesis ; and, in this case, all our
conclusions may be drawn immediately from pure intuition. In
transcendental cognition, so long as we are dealing only with
conceptions of the understanding, we are guided by possible ex
perience. That is to say, a proof in the sphere of transcendental
cognition does not show that the given conception (that of an
event, for example,) leads directly to another conception (that
of a cause)— for this would be a saltus which nothing can jus-
440 KANT
tify; but it shows that experience itself, and consequently the
object of experience, is impossible without the connection indi
cated by these conceptions. It follows that such a proof must
demonstrate the possibility of arriving, synthetically and a
priori, at a certain knowledge of things, which was not con
tained in our conceptions of these things. Unless we pay par
ticular attention to this requirement, our proofs, instead of
pursuing the straight path indicated by reason, follow the tor
tuous road of mere subjective association. The illusory convic
tion, which rests upon subjective causes of association, and
which is considered as resulting from the perception of a real
and objective natural affinity, is always open to doubt and sus
picion. For this reason, all the attempts which have been made
to prove the principle of sufficient reason, have, according to the
universal admission of philosophers, been quite unsuccessful ;
and, before the appearance of transcendental criticism, it was
considered better, as this principle could not be abandoned to
appeal boldly to the common sense of mankind (a proceeding
which always proves that the problem, which reason ought to
solve, is one in which philosophers find great difficulties),
rather than attempt to discover new dogmatical proofs.
But, if the proposition to be proved is a proposition of pure
reason, and if I aim at passing beyond my empirical conceptions
by the aid of mere ideas, it is necessary that the proof should
first show that such a step in synthesis is possible (which it is
not), before it proceeds to prove the truth of the proposition
itself. The so-called proof of the simple nature of the soul
from the unity of apperception, is a very plausible one. But it
contains no answer to the objection, that, as the notion of abso
lute simplicity is not a conception which is directly applicable
to a perception, but is an idea which must be inferred — if at all
— from observation, it is by no means evident, how the mere fact
of consciousness, which is contained in all thought, although in
so far a simple representation, can conduct me to the conscious
ness and cognition of a thing which is purely a thinking sub
stance. When I represent to my mind the power of my body
as in motion, my body in this thought is so far absolute unity,
and my representation of it is a simple one; and hence I can
indicate this representation by the motion of a point, because I
have made abstraction of the size or volume of the body. But
I cannot hence infer that, given merely the moving power of a
CRITIQUE OF PURE REASON 441
body, the body may be cogitated as simple substance, merely
because the representation in my mind takes no account of its
content in space, and is consequently simple. The simple, in
abstraction, is very different from the objectively simple; and
hence the Ego, which is simple in the first sense, may, in the
second sense, as indicating the soul itself, be a very complex
conception, with a very various content. Thus it is evident, that
in all such arguments, there lurks a paralogism. We guess (for
without some such surmise our suspicion would not be excited
in reference to a proof of this character,) at the presence of the
paralogism, by keeping ever before us a criterion of the pos
sibility of those synthetical propositions which aim at proving
more than experience can teach us. This criterion is obtained
from the observation that such proofs do not lead us directly
from the subject of the proposition to be proved to the required
predicate, but find it necessary to presuppose the possibility of
extending our cognition a priori by means of ideas. We must,
accordingly, always use the greatest caution ; we require, before
attempting any proof, to consider how it is possible to extend
the sphere of cognition by the operations of pure reason, and
from what source we are to derive knowledge, which is not ob
tained from the analysis of conceptions, nor relates, by anticipa
tion, to possible experience. We shall thus spare ourselves
much severe and fruitless labor, by not expecting from reason
what is beyond its power, or rather by subjecting it to discipline,
and teaching it to moderate its vehement desires for the exten
sion of the sphere of cognition.
The first rule for our guidance is, therefore, not to attempt a
transcendental proof, before we have considered from what
source we are to derive the principles upon which the proof is
to be based, and what right we have to expect that our con
clusions from these principles will be veracious. If they are
principles of the understanding, it is vain to expect that we
should attain by their means to ideas of pure reason ; for these
principles are valid only in regard to objects of possible ex
perience. If they are principles of pure reason, our labor is
alike in vain. For the principles of reason, if employed as ob
jective, are without exception dialectical, and possess no valid
ity or truth, except as regulative principles of the systematic
employment of reason in experience. But when such delusive
proofs are presented to us, it is our duty to meet them with the
AA2 KANT
442
non liquet of a matured judgment ; and, although we are un
able to expose the particular sophism upon which the proof is
based, we have a right to demand a deduction of the principles
employed in it ; and, if these principles have their origin in pure
reason alone, such a deduction is absolutely impossible. And
thus it is unnecessary that we should trouble ourselves with the
exposure and confutation of every sophistical illusion ; we may,
at once, bring all dialectic, which is inexhaustible in the produc
tion of fallacies, before the bar of critical reason, which tests the
principles upon which all dialectical procedure is based. The
second peculiarity of transcendental proof is, that a transcen
dental proposition cannot rest upon more than a single proof.
If I am drawing conclusions, not from conceptions, but from
intuition corresponding to a conception, be it pure intuition, as
in mathematics, or empirical, as in natural science, the intuition
which forms the basis of my inferences, presents me with ma
terials for many synthetical propositions, which I can connect in
various modes, while, as it is allowable to proceed from differ
ent points in the intention, I can arrive by different paths at the
same proposition.
But every transcendental proposition sets out from a con
ception, and posits the synthetical condition of the possibility of
an object according to this conception. There must, therefore,
be but one ground of proof, because it is the conception alone
which determines the object; and thus the proof cannot con
tain anything more than the determination of the object accord
ing to the conception. In our Transcendental Analytic, for ex
ample, we inferred the principle, Every event has a cause, from
the only condition of the objective possibility of our concep
tion of an event. This is, that an event cannot be determined
in time, and consequently cannot form a part of experience, un
less it stands under this dynamical law. This is the only possible
ground for proof ; for our conception of an event possesses ob
jective validity, that is, is a true conception, only because the
law of causality determines an object to which it can refer.
Other arguments in support of this principle have been at
tempted — such as that from the contingent nature of a phenome
non ; but when this argument is considered, we can discover no
criterion of contingency, except the fact of an event — of some
thing happening, that is to say, the existence which is preceded
by the non-existence of an object, and thus we fall back on the
CRITIQUE OF PURE REASON 443
very thing to be proved. If the proposition, Every thinking be
ing is simple, is to be proved, we keep to the conception of the
Ego, which is simple, and to which all thought has a relation.
The same is the case with the transcendental proof of the ex
istence of a Deity, which is based solely upon the harmony and
reciprocal fitness of the conceptions of an ens realissimum and
a necessary being, and cannot be attempted in any other man
ner.
This caution serves to simplify very much the criticism of all
propositions of reason. When reason employs conceptions
alone, only one proof of its thesis is possible, if any. When,
therefore, the dogmatist advances with ten arguments in favor
of a proposition, we may be sure that not one of them is con
clusive. For if he possessed one which proved the proposition
he brings forward to demonstration — as must always be the
case with the propositions of pure reason — what need is there
for any more? His intention can only be similar to that of the
advocate, who had different arguments for different judges;
thus availing himself of the weakness of those who examine his
arguments, who, without going into any profound investiga
tion, adopt the view of the case which seems most probable at
first sight, and decide according to it.
The third rule for the guidance of pure reason in the conduct
of a proof is, that all transcendental proofs must never be apa-
gogic or indirect, but always ostensive or direct. The direct
or ostensive proof not only establishes the truth of the proposi
tion to be proved, but exposes the grounds of its truth ; the
apagogic, on the other hand, may assure us of the truth of the
proposition, but it cannot enable us to comprehend the grounds
of its possibility. The latter is, accordingly, rather an auxiliary
to an argument, than a strictly philosophical and rational mode
of procedure. In one respect, however, they have an advantage
over direct proofs, from the fact, that the mode of arguing by
contradiction, which they employ, renders our understanding of
the question more clear, and approximates the proof to the cer
tainty of an intuitional demonstration.
The true reason why indirect proofs are employed in differ
ent sciences, is this. When the grounds upon which we seek to
base a cognition are too various or too profound, we try whether
or not we may not discover the truth of our cognition from its
consequences. The modus ponens of reasoning from the truth
444 KANT
of its inferences to the truth of a proposition, would be admis
sible if all the inferences that can be drawn from it are known to
be true ; for in this case there can be only one possible ground
for these inferences, and that is the true one. But this is a quite
impracticable procedure, as it surpasses all our powers to dis
cover all the possible inferences that can be drawn from a pro
position. But this mode of reasoning is employed, under favor,
when we wish to prove the truth of a hypothesis ; in which case
we admit the truth of the conclusion — which is supported by
analogy — that, if all the inferences we have drawn and ex
amined agree with the proposition assumed, all other possible
inferences will also agree with it. But, in this way, an hy
pothesis can never be established as a demonstrated truth. The
modus tollens of reasoning from known inferences to the un
known proposition, is not only a rigorous, but a very easy mode
of proof. For, if it can be shown that but one inference from a
proposition is false, then the proposition must itself be false. In
stead, then, of examining, in an ostensive argument, the whole
series of the grounds on which the truth of a proposition rests,
we need only take the opposite of this proposition, and if one
inference from it be false, then must the opposite be itself false ;
and, consequently, the proposition which we wished to prove,
must be true.
The apagogic method of proof is admissible only in those
sciences where it is impossible to mistake a subjective repre
sentation for an objective cognition. Where this is possible, it
is plain that the opposite of a given proposition may contradict
merely the subjective conditions of thought, and not the objec
tive cognition; or it may happen that both propositions con
tradict each other only under a subjective condition, which is
incorrectly considered to be objective, and, as the condition is
itself false, both propositions may be false, and it will, conse
quently, be impossible to conclude the truth of the one from the
falseness of the other.
In mathematics such subreptions are impossible ; and it is in
this science, accordingly, that the indirect mode of proof has its
true place. In the science of nature, where all assertion is based
upon empirical intuition, such subreptions may be guarded
against by the repeated comparison of observations; but this
mode of proof is of little value in this sphere of knowledge. But
the transcendental efforts of pure reason are all made in the
CRITIQUE OF PURE REASON 445
sphere of the subjective, which is the real medium of all dialect
ical illusion ; and thus reason endeavors, in its premises, to im
pose upon us subjective representations for objective cognitions.
In the transcendental sphere of pure reason, then, and in the
case of synthetical propositions, it is inadmissible to support a
statement by disproving the counter-statement. For only two
cases are possible ; either, the counter-statement is nothing but
the announcement of the inconsistency of the opposite opinion
with the subjective conditions of reason, which does not affect
the real case (for example, we cannot comprehend the uncon
ditioned necessity of the existence of a being, and hence every
speculative proof of the existence of such a being must be op
posed on subjective grounds, while the possibility of this being
in itself cannot with justice be denied) ; or, both propositions,
being dialectical in their nature, are based upon an impossible
conception. In this latter case the rule applies — non entis nulla
sunt predicata; that is to say, what we affirm and what we
deny, respecting such an object, are equally untrue, and the
apagogic mode of arriving at the truth is in this case impossible.
If, for example, we presuppose that the world of sense is given
in itself in its totality, it is false, either that is infinite, or that it
is finite and limited in space. Both are false, because the hy
pothesis is false. For the notion of phenomena (as mere repre
sentations) which are given in themselves (as objects) is self-
contradictory ; and the infinitude of this imaginary whole would,
indeed, be unconditioned, but would be inconsistent (as every
thing in the phenomenal world is conditioned) with the uncon
ditioned determination and finitude of quantities which is pre
supposed in our conception.
The apagogic mode of proof is the true source of those illu
sions which have always had so strong an attraction for the
admirers of dogmatical philosophy. It may be compared to
a champion, who maintains the honor and claims of the party he
has adopted, by offering battle to all who doubt the validity of
these claims and the purity of that honor ; while nothing can be
proved in this way, except the respective strength of the com
batants, and the advantage, in this respect, is always on the side
of the attacking party. Spectators, observing that each party is
alternately conqueror and conquered, are led to regard the sub
ject of dispute as beyond the power of man to decide upon. But
446 KANT
such an opinion cannot be justified ; and it is sufficient to apply
to these reasoners the remark : —
" Non defensoribus istis
Tempus eget."
Each must try to establish his assertions by a transcendental
deduction of the grounds of proof employed in his argument,
and thus enable us to see in what way the claims of reason may
be supported. If an opponent bases his assertions upon sub
jective grounds, he may be refuted with ease ; not, however to
the advantage of the dogmatist, who likewise depends upon sub
jective sources of cognition, and is in like manner driven into a
corner by his opponent. But, if parties employ the direct
method of procedure, they will soon discover the difficulty, nay,
the impossibility of proving their assertions, and will be forced
to appeal to prescription and precedence ; or they will, by the
help of criticism, discover with ease the dogmatical illusions by
which they had been mocked, and compel reason to renounce
its exaggerated pretensions to speculative insight, and to con
fine itself within the limits of its proper sphere — that of prac
tical principles.
CHAPTER II
The Canon of Pure Reason
It is a humiliating consideration for human reason, that it is
incompetent to discover truth by means of pure speculation, but,
on the contrary, stands in need of discipline to check its devia
tions from the straight path, and to expose the illusions which
it originates. But, on the other hand, this consideration ought
to elevate and to give it confidence, for this discipline is exer
cised by itself alone, and it is subject to the censure of no other
power. The bounds, moreover, which it is forced to set to its
speculative exercise, form likewise a check upon the fallacious
pretensions of opponents; and thus what remains of its pos
sessions, after these exaggerated claims have been disallowed,
is secure from attack or usurpation. The greatest, and perhaps
the only, use of all philosophy of pure reason is, accordingly,
of a purely negative character. It is not an organon for the ex
tension, but a discipline for the determination of the limits of
CRITIQUE OF PURE REASON 447
its exercise ; and without laying claim to the discovery of new
truth, it has the modest merit of guarding against error.
At the same time, there must be some source of positive cogni
tions which belong to the domain of pure reason, and which be
come the causes of error only, from our mistaking their true
character, while they form the goal towards which reason con
tinually strives. How else can we account for the inextinguish
able desire in the human mind to find a firm footing in some
region beyond the limits of the world of experience ? — It hopes
to attain to the possession of a knowledge in which it has the
deepest interest. It enters upon the path of pure speculation;
but in vain. We have some reason, however, to expect that, in
the only other way that lies open to it — the path of practical rea
son — it may meet with better success.
I understand by a canon a list of the a priori principles of the
proper employment of certain faculties of cognition. Thus gen
eral logic, in its analytical department, is a formal canon for the
faculties of understanding and reason. In the same way, Trans
cendental Analytic was seen to be a canon of the pure under
standing; for it alone is competent to announce true a priori
synthetical cognitions. But, when no proper employment of a
faculty of cognition is possible, no canon can exist. But the
synthetical cognition of pure speculative reason is, as has been
shown, completely impossible. There cannot, therefore, exist
any canon for the speculative exercise of this faculty — for its
speculative exercise is entirely dialectical; and consequently,
transcendental logic, in this respect, is merely a discipline, and
not a canon. If, then, there is any proper mode of employing
the faculty of pure reason, — in which case there must be a canon
for this faculty, — this canon will relate, not to the speculative,
but to the practical use of reason. This canon we now proceed
to investigate.
Section I.— Of the Ultimate End of the Pure Use of Reason
There exists in the faculty of reason a natural desire to ven
ture beyond the field of experience, to attempt to reach the ut
most bounds of all cognition by the help of ideas alone, and not
to rest satisfied, until it has fulfilled its course and raised the
sum of its cognitions into a self-subsistent systematic whole.
Is the motive for this endeavor to be found in its speculative, or
in its practical interests alone?
448 KANT
Setting aside, at present, the results of the labors of pure
reason in its speculative exercise, I shall merely inquire re
garding the problems, the solution of which forms its ultimate
aim — whether reached or not, and in relation to which all other
aims are but partial and intermediate. These highest aims
must, from the nature of reason, possess complete unity ; other
wise the highest interest of humanity could not be successfully
promoted.
The transcendental speculation of reason relates to three
things : the freedom of the will, the immortality of the soul, and
the existence of God. The speculative interest which reason
has in those questions is very small ; and, for its sake alone, we
should not undertake the labor of transcendental investigation
— a labor full of toil and ceaseless struggle. We should be loth
to undertake this labor, because the discoveries we might make
would not be of the smallest use in the sphere of concrete or
physical investigation. We may find out that the will is free,
but this knowledge only relates to the intelligible cause of our
volition. As regards the phenomena or expressions of this will,
that is, our actions, we are bound, in obedience to an inviolable
maxim, without which reason cannot be employed in the sphere
of experience, to explain these in the same way as we explain all
the other phenomena of nature, that is to say, according to its
unchangeable laws. We may have discovered the spirituality
and immortality of the soul, but we cannot employ this knowl
edge to explain the phenomena of this life, nor the peculiar na
ture of the future; because our conception of an incorporeal
nature is purely negative and does not add anything to our
knowledge, and the only inferences to be drawn from it are
purely fictitious. If, again, we prove the existence of a supreme
intelligence, we should be able from it to make the conformity
to aims existing in the arrangement of the world comprehen
sible; but we should not be justified in deducing from it any
particular arrangement or disposition, or, inferring any, where
it is not perceived. For it is a necessary rule of the speculative
use of reason, that we must not overlook natural causes, or
refuse to listen to the teaching of experience, for the sake of
deducing what we know and perceive from something that
transcends all our knowledge. In one word, these three propo
sitions are, for the speculative reason, always transcendent, and
cannot be employed as immanent principles in relation to the
CRITIQUE OF PURE REASON 449
objects of experience ; they are, consequently, of no use to us
in this sphere, being but the valueless results of the severe but
unprofitable efforts of reason.
If, then, the actual cognition of these three cardinal proposi
tions is perfectly useless, while Reason uses her utmost en
deavors to induce us to admit them, it is plain that their real
value and importance relate to our practical, and not to our
speculative interest.
I term all that is possible through free-will, practical. But if
the conditions of the exercise of free volition are empirical, rea
son can have only a regulative, and not a constitutive, influence
upon it, and is serviceable merely for the introduction of unity
into its empirical laws. In the moral philosophy of prudence,
for example, the sole business of reason is to bring about a
union of all the ends, which are aimed at by our inclinations,
into one ultimate end — that of happiness, and to show the agree
ment which should exist among the means of attaining that end.
In this sphere, accordingly, reason cannot present to us any
other than pragmatical laws of free action, for our guidance
towards the aims set up by the senses, and is incompetent to
give us laws which are pure and determined completely a priori.
On the other hand, pure practical laws, the ends of which have
been given by reason entirely a priori, and which are not em
pirically conditioned, but are, on the contrary, absolutely im
perative in their nature, would be products of pure reason.
Such are the moral laws ; and these alone belong to the sphere
of the practical exercise of reason, and admit of a canon.
All the powers of reason, in the sphere of what may be termed
pure philosophy, are, in fact, directed to the three above-men
tioned problems alone. These again have a still higher end — the
answer to the question, ivhat ive ought to do, if the will is free, if
there is a God, and a future world. Now, as this problem relates
to our conduct, in reference to the highest aim of humanity, it is
evident that the ultimate intention of nature, in the constitu
tion of our reason, has been directed to the moral alone.
We must take care, however, in turning our attention to an
object which is foreign * to the sphere of transcendental philoso-
* All practical conceptions relate to of cognition, the elements of our judg-
objects of pleasure and pain, and con- ments, in so far as they relate to pleas-
sequently — in an indirect manner, at ure or pain, that is, the elements of our
least — to objects of feeling. But as feel- practical judgments, do not belong to
ing is not a faculty of representation, transcendental philosophy, which has to
but lies out of the sphere of our powers do with a priori cognitions alone.
29
45o KANT
phy, not to injure the unity of our system by digressions, nor,
on the other hand, to fail in clearness, by saying too little on the
new subject of discussion. I hope to avoid both extremes, by
keeping as close as possible to the transcendental, and exclud
ing all psychological, that is, empirical elements.
I have to remark, in the first place, that at present I treat of
the conception of freedom in the practical sense only, and set
aside the corresponding transcendental conception, which can
not be employed as a ground of explanation in the phenomenal
world, but is itself a problem for pure reason. A will is purely
animal (arbitrium brutum), when it is determined by sensu
ous impulses or instincts only, that is, when it is determined in a
pathological manner. A will, which can be determined inde
pendently of sensuous impulses, consequently by motives pre
sented by reason alone, is called a free will (arbitrium liberum) ;
and everything which is connected with this free will, either as
principle or consequence, is termed practical. The existence of
practical freedom can be proved from experience alone. For
the human will is not determined by that alone which immedi
ately affects the senses ; on the contrary, we have the power, by
calling up the notion of what is useful or hurtful in a more
distant relation, of overcoming the immediate impressions on
our sensuous faculty of desire. But these considerations of
what is desirable in relation to our whole state, that is, is in the
end good and useful, are based entirely upon reason. This
faculty, accordingly, announces laws, which are imperative or
objective laws of freedom, and which tell us what ought to take
place, thus distinguishing themselves from the laws of nature,
which relate to that which does take place. The laws of free
dom or of free will are hence termed practical laws.
Whether reason is not itself, in the actual delivery of these
laws, determined in its turn by other influences, and whether the
action which, in relation to sensuous impulses, we call free, may
not, in relation to higher and more remote operative causes,
really form a part of nature, — these are questions which do not
here concern us. They are purely speculative questions ; and all
we have to do, in the practical sphere, is to inquire into the rule
of conduct which reason has to present. Experience demon
strates to us the existence of practical freedom as one of the
causes which exist in nature, that is, it shows the causal power
of reason in the determination of the will. The idea of tran-
CRITIQUE OF PURE REASON 451
scendental freedom, on the contrary, requires that reason — in
relation to its causal power of commencing a series of phe
nomena — should be independent of all sensuous determining
causes; and thus it seems to be in opposition to the law of
nature and to all possible experience. It therefore remains a
problem for the human mind. But this problem does not con
cern reason in its practical use; and we have, therefore, in a
canon of pure reason, to do with only two questions, which relate
to the practical interest of pure reason — Is there a God ? and, Is
there a future life ? The question of transcendental freedom is
purely speculative, and we may therefore set it entirely aside
when we come to treat of practical reason. Besides, we have
already fully discussed this subject in the antinomy of pure
reason.
Section II. — Of the Ideal of the Summum Bonum as a Deter
mining Ground of the Ultimate End of Pure Reason
Reason conducted us, in its speculative use, through the field
of experience, and, as it can never find complete satisfaction in
that sphere, from thence to speculative ideas, — which, however,
in the end brought us back again to experience, and thus ful
filled the purpose of reason, in a manner which, though useful,
was not at all in accordance with our expectations. It now
remains for us to consider whether pure reason can be employed
in a practical sphere, and whether it will here conduct us to
those ideas which attain the highest ends of pure reason, as we
have just stated them. We shall thus ascertain whether, from
the point of view of its practical interest, reason may not be
able to supply us with that which, on the speculative side, it
wholly denies us.
The whole interest of reason, speculative as well as practical,
is centred in the three following questions:
1. What can I know?
2. What ought I to do?
3. What may I hope?
The first question is purely speculative. We have, as I flatter
myself, exhausted all the replies of which it is susceptible, and
have at last found the reply with which reason must content
itself, and with which it ought to be content, so long as it pays
no regard to the practical. But from the two great ends to the
452 KANT
attainment of which all these efforts of pure reason were in fact
directed, we remain just as far removed as if we had consulted
our ease, and declined the task at the outset. So far, then, as
knowledge is concerned, thus much, at least, is established, that,
in regard to those two problems, it lies beyond our reach.
The second question is purely practical. As such it may in
deed fall within the province of pure reason, but still it is not
transcendental, but moral, and consequently cannot in itself
form the subject of our criticism.
The third question, If I act as I ought to do, what may I then
hope ? — is at once practical and theoretical. The practical forms
a clue to the answer of the theoretical, and — in its highest form
— speculative question. For all hoping has happiness for its
object, and stands in precisely the same relation to the practical
and the law of morality, as knowing to the theoretical cognition
of things and the law of nature. The former arrives finally at
the conclusion thai something is (which determines the ultimate
end), because something ought to take place; the latter, that
something is (which operates as the highest cause), because
something does take place.
Happiness is the satisfaction of all our desires ; extensive in
regard to their multiplicity; intensive, in regard to their de
gree; and protensive, in regard to their duration. The prac
tical law based on the motive of happiness, I term a pragmatical
law (or prudential rule) ; but that law, assuming such to exist,
which has no other motive than the worthiness of being happy,
I term a moral or ethical law. The first tells us what we have
to do, if we wish to become possessed of happiness ; the second
dictates how we ought to act, in order to deserve happiness.
The first is based upon empirical principles; for it is only by
experience that I can learn either what inclinations exist which
desire satisfaction, or what are the natural means of satisfying
them. The second takes no account of our desires or the means
of satisfying them, and regards only the freedom of a rational
being, and the necessary conditions under which alone this
freedom can harmonize with the distribution of happiness ac
cording to principles. This second law may therefore rest upon
mere ideas of pure reason, and may be cognized a priori.
I assume that there are pure moral laws which determine, en
tirely a priori (without regard to empirical motives, that is, to
happiness), the conduct of a rational being, or in other words,
CRITIQUE OF PURE REASON 453
the use which it makes of its freedom, and that these laws are
absolutely imperative (not merely hypothetically, on the sup
position of other empirical ends), and therefore in all respects
necessary. I am warranted in assuming this, not only by the
arguments of the most enlightened moralists, but by the moral
judgment of every man who will make the attempt to form a dis
tinct conception of such a law.
Pure reason, then, contains, not indeed in its speculative, but
in its practical, or, more strictly, its moral use, principles of the
possibility of experience, of such actions, namely, as, in ac
cordance with ethical precepts, might be met with in the history
of man. For since reason commands that such actions should
take place, it must be possible for them to take place ; and hence
a particular kind of systematic unity — the moral, must be pos
sible. We have found, it is true, that the systematic unity of
nature could not be established according to speculative prin
ciples of reason, because, while reason possesses a causal power
in relation to freedom, it has none in relation to the whole sphere
of nature ; and, while moral principles of reason can produce
free actions, they cannot produce natural laws. It is, then, in its
practical, but especially in its moral use, that the principles of
pure reason possess objective reality.
I call the world a moral world, in so far as it may be in ac
cordance with all the ethical laws — which, by virtue of the free
dom of reasonable beings, it can be, and according to the neces
sary laws of morality it ought to be. But this world must be
conceived only as an intelligible world, inasmuch as abstraction
is therein made of all conditions (ends), and even of all im
pediments to morality (the weakness or pravity of human na
ture). So far, then, it is a mere idea — though still a practical
idea — which may have, and ought to have, an influence on the
world of sense, so as to bring it as far as possible into conformity
with itself. The idea of a moral world has, therefore, objective
reality, not as referring to an object of intelligible intuition —
for of such an object we can form no conception whatever — but
to the world of sense — conceived, however, as an object of pure
reason in its practical use — and to a corpus mysticitm of rational
beings in it, in so far as the liberum arbitrium of the individual
is placed, under and by virtue of moral laws, in complete sys
tematic unity both with itself, and with the freedom of all others.
That is the answer to the first of the two questions of pure
454 KANT
reason which relate to its practical interest : — Do that which will
render thee worthy of happiness. The second question is this :
If I conduct myself so as not to be unworthy of happiness, may
I hope thereby to obtain happiness? In order to arrive at the
solution of this question, we must inquire whether the principles
of pure reason, which prescribe a priori the law, necessarily also
connect this hope with it.
I say, then, that just as the moral principles are necessary
according to reason in its practical use, so it is equally necessary
according to reason in its theoretical use, to assume that every
one has ground to hope for happiness in the measure in which
• he has made himself worthy of it in his conduct, and that there
fore the system of morality is inseparably (though only in the
idea of pure reason) connected with that of happiness.
Now in an intelligible, that is, in the moral world, in the con
ception of which we make abstraction of all the impediments to
morality (sensuous desires), such a system of happiness, con
nected with and proportioned to morality, may be conceived as
necessary, because freedom of volition — partly incited, and
partly restrained by moral laws — would be itself the cause of
general happiness ; and thus rational beings, under the guidance
of such principles, would be themselves the authors both of
their own enduring welfare and that of others. But such a sys
tem of self-rewarding morality is only an idea, the carrying out
of which depends upon the condition that every one acts as he
ought ; in other words, that all actions of reasonable beings be
such as they would be if they sprung from a Supreme Will,
comprehending in, or under, itself all particular wills. But
since the moral law is binding on each individual in the use of
his freedom of volition, even if others should not act in con
formity with this law, neither the nature of things, nor the
causality of actions and their relation to morality, determine
how the consequences of these actions will be related to happi
ness; and the necessary connection of the hope of happiness
with the unceasing endeavor to become worthy of happiness,
cannot be cognized by reason, if we take nature alone for our
guide. This connection can be hoped for only on the assump
tion that the cause of nature is a supreme reason, which gov
erns according to moral laws.
I term the idea of an intelligence in which the morally most
perfect will, united with supreme blessedness, is the cause of all
CRITIQUE OF PURE REASON 455
happiness in the world, so far as happiness stands in strict rela
tion to morality (as the worthiness of being happy), the Ideal
of the Supreme Good. It is only, then, in the' ideal of the su
preme original good, that pure reason can find the ground of the
practically necessary connection of both elements of the highest
derivative good, and accordingly of an intelligible, that is, moral
world. Now since we are necessitated by reason to conceive our
selves as belonging to such a world, while the senses present to
us nothing but a world of phenomena, we must assume the
former as a consequence of our conduct in the world of sense
(since the world of sense gives us no hint of it), and therefore
as future in relation to us. Thus God and a future life are two
hypotheses which, according to the principles of pure reason, are
inseparable from the obligation which this reason imposes upon
us.
Morality per se constitutes a system. But we can form no
system of happiness, except in so far as it is dispensed in strict
proportion to morality. But this is only possible in the intel
ligible world, under a wise author and ruler. Such a ruler, to
gether with life in such a world, which we must look upon as
future, reason finds itself compelled to assume ; or it must re
gard the moral laws as idle dreams, since the necessary con
sequence which this same reason connects with them, must,
without this hypothesis, fall to the ground. Hence also the
moral laws are universally regarded as commands, which they
could not be, did they not connect a priori adequate conse
quences with their dictates, and thus carry with them promises
and threats. But this, again, they could not do, did they not
reside in a necessary being, as the Supreme Good, which alone
can render such a teleological unity possible.
Leibnitz termed the world, when viewed in relation to the
rational beings which it contains, and the moral relations in
which they stand to each other, under the government of the
Supreme Good, the kingdom of Grace, and distinguished it from
the kingdom of Nature, in which these rational beings live, un
der moral laws, indeed, but expect no other consequences from
their actions than such as follow according to the course of
nature in the world of sense. To view ourselves, therefore, as in
the kingdom of grace, in which all happiness awaits us, except
in so far as we ourselves limit our participation in it by actions
which render us unworthy of happiness, is a practically neces
sary idea of reason.
456
KANT
Practical laws, in so far as they are subjective grounds of
actions, that is, subjective principles, are termed maxims. The
judgments of morality, in its purity and ultimate results, are
framed according to ideas; the observance of its laws, accord
ing to maxims.
The whole course of our life must be subject to moral
maxims; but this is impossible, unless with the moral law,
which is a mere idea, reason connects an efficient cause which
ordains to all conduct which is in conformity with the moral
law an issue either in this or in another life, which is in exact
conformity with our highest aims. Thus, without a God and
without a world, invisible to us now, but hoped for, the glorious
ideas of morality are, indeed, objects of approbation and of ad
miration, but cannot be the springs of purpose and action. For
they do not satisfy all the aims which are natural to every
rational being, and which are determined a priori by pure rea
son itself, and necessary.
Happiness alone is, in the view of reason, far from being the
complete good. Reason does not approve of it (however much
inclination may desire it), except as united with desert. On the
other hand, morality alone, and with it, mere desert, is likewise
far from being the complete good. To make it complete, he who
conducts himself in a manner not unworthy of happiness, must
be able to hope for the possession of happiness. Even reason,
unbiassed by private ends, or interested considerations, cannot
judge otherwise, if it puts itself in the place of a being whose
business it is to dispense all happiness to others. For in the
practical idea both points are essentially combined, though in
such a way that participation in happiness is rendered possible
by the moral disposition, as its condition, and not conversely, the
moral disposition by the prospect of happiness. For a disposi
tion which should require the prospect of happiness as its neces
sary condition, would not be moral, and hence also would not be
worthy of complete happiness — a happiness which, in the view
of reason, recognizes no limitation but such as arises from our
own immoral conduct.
Happiness, therefore, in exact proportion with the morality
of rational beings (whereby they are made worthy of happi
ness), constitutes alone the supreme good of a world into which
we absolutely must transport ourselves according to the com
mands of pure but practical reason. This world is, it is true,
CRITIQUE OF PURE REASON 457
only an intelligible world ; for of such a systematic unity of ends
as it requires, the world of sense gives us no hint. Its reality
can be based on nothing else but the hypothesis of a supreme
original good. In it independent reason, equipped with all the
sufficiency of a supreme cause, founds, maintains, and fulfils
the uniyersal order of things, with the most perfect teleological
harmony, however much this order may be hidden from us in
the world of sense.
This moral theology has the peculiar advantage, in contrast
with speculative theology, of leading inevitably to the concep
tion of a sole, perfect, and rational First Cause, whereof specu
lative theology does not give us any indication on objective
grounds, far less any convincing evidence. For we find neither
in transcendental nor in natural theology, however far reason
may lead us in these, any ground to warrant us in assuming the
existence of one only Being, which stands at the head of all
natural causes, and on which these are entirely dependent. On
the other hand, if we take our stand on moral unity as a neces
sary law of the universe, and from this point of view consider
what is necessary to give this law adequate efficiency and, for us,
obligatory force, we must come to the conclusion that there is
one only supreme will, which comprehends all these laws in
itself. For how, under different wills, should we find complete
unity of ends? This will must be omnipotent, that all nature
and its relation to morality in the world may be subject to it ;
omniscient, that it may have knowledge of the most secret feel
ings and their moral worth ; omnipresent, that it may be at hand
to supply every necessity to which the highest weal of the world
may give rise ; eternal, that this harmony of nature and liberty
may never fail ; and so on.
But this systematic unity of ends in this world of intelligences
— which, as mere nature, is only a world of sense, but as a sys
tem of freedom of volition, may be termed an intelligible, that is,
moral world (regnum gratia) — leads inevitably also to the tele
ological unity of all things which constitute this great whole,
according to universal natural laws— just as the unity of the
former is according to universal and necessary moral laws—
and unites the practical with the speculative reason. The world
must be represented as having originated from an idea, if it is to
harmonize with that use of reason without which we cannot
even consider ourselves as worthy of reason— namely, the moral
KANT
use, which rests entirely on the idea of the supreme good.
Hence the investigation of nature receives a teleological direc
tion, and becomes, in its widest extension, physico-theology.
But this, taking its rise in moral order as a unity founded on the
essence of freedom, and not accidentally instituted by external
commands, establishes the teleological view of nature on
grounds which must be inseparably connected with the internal
possibility of things. This gives rise to a transcendental theol
ogy, which takes the ideal of the highest ontological perfection
as a principle of systematic unity; and this principle connects
all things according to universal and necessary natural laws,
because all things have their origin in the absolute necessity of
the one only Primal Being.
What use can we make of our understanding, even in respect
of experience, if we do not propose ends to ourselves? But
the highest ends are those of morality, and it is only pure reason
that can give us the knowledge of these. Though supplied with
these, and putting ourselves under their guidance, we can make
no teleological use of the knowledge of nature, as regards cog
nition, unless nature itself has established teleological unity.
For without this unity we should not even possess reason, be
cause we should have no school for reason, and no cultivation
through objects which afford the materials for its conceptions.
But teleological unity is a necessary unity, and founded on the
essence of the individual will itself. Hence this will, which is
the condition of the application of this unity in concrete, must
be so likewise. In this way the transcendental enlargement of
our rational cognition would be, not the cause, but merely the
effect of the practical teleology, which pure reason imposes
upon us.
Hence, also, we find in the history of human reason that,
before the moral conceptions were sufficiently purified and de
termined, and before men had attained to a perception of the
systematic unity of ends according to these conceptions and
from necessary principles, the knowledge of nature, and even
a considerable amount of intellectual culture in many other
sciences, could produce only rude and vague conceptions of the
Deity, sometimes even admitting of an astonishing indifference
with regard to this question altogether. But the more enlarged
treatment of moral ideas, which was rendered necessary by the
extremely pure moral law of our religion, awakened the interest,
CRITIQUE OF PURE REASON 459
and thereby quickened the perceptions of reason in relation to
this object. In this way, and without the help either of an
extended acquaintance with nature, or of a reliable transcen
dental insight (for these have been wanting in all ages), a con
ception of the Divine Being was arrived at, which we now hold
to be the correct one, not because speculative reason convinces
us of its correctness, but because it accords with the moral
principles of reason. Thus it is to pure reason, but only in its
practical use, that we must ascribe the merit of having con
nected with our highest interest a cognition, of which mere
speculation was able only to form a conjecture, but the validity
of which it was unable to establish — and of having thereby
rendered it, not indeed a demonstrated dogma, but a hypothesis
absolutely necessary to the essential ends of reason.
But if practical reason has reached this elevation, and has
attained to the conception of a sole Primal Being, as the su
preme good, it must not, therefore, imagine that it has trans
cended the empirical conditions of its application, and risen
to the immediate cognition of new objects ; it must not presume
to start from the conception which it has gained, and to deduce
from it the moral laws themselves. For it was these very laws,
the internal practical necessity of which led us to the hypothesis
of an independent cause, or of a wise ruler of the universe, who
should give them effect. Hence we are not entitled to regard
them as accidental and derived from the mere will of the ruler,
especially as we have no conception of such a will, except as
formed in accordance with these laws. So far, then, as practical
reason has the right to conduct us, we shall not look upon ac
tions as binding on us, because they are the commands of God,
but we shall regard them as divine commands, because we are
internally bound by them. We shall study freedom under the
teleological unity which accords with principles of reason ; we
shall look upon ourselves as acting in conformity with the divine
will only in so far as we hold sacred the moral law which reason
teaches us from the nature of actions themselves, and we shall
believe that we can obey that will only by promoting the weal
of the universe in ourselves and in others. Moral theology is,
therefore, only of immanent use. It teaches us to fulfil our
destiny here in the world, by placing ourselves in harmony with
the general system of ends, and warns us against the fanaticism,
nay, the crime of depriving reason of its legislative authority
460
KANT
in the moral conduct of life, for the purpose of directly con
necting this authority with the idea of the Supreme Being. For
this would be, not an immanent, but a transcendent use of moral
theology, and, like the transcendent use of mere speculation,
would inevitably pervert and frustrate the ultimate ends of
reason.
Section III. — Of Opinion, Knowledge, and Belief
The holding of a thing to be true, is a phenomenon in our
understanding which may rest on objective grounds, but re
quires, also, subjective causes in the mind of the person judging.
If a judgment is valid for every rational being, then its ground
is objectively sufficient, and it is termed a conviction. If, on the
other hand, it has its ground in the particular character of the
subject, it is termed a persuasion.
Persuasion is a mere illusion, the ground of the judgment,
which lies solely in the subject, being regarded as objective.
Hence a judgment of this kind has only private validity — is
only valid for the individual who judges, and the holding of
a thing to be true in this way cannot be communicated. But
truth depends upon agreement with the object, and consequently
the judgments of all understandings, if true, must be in agree
ment with each other (consentientia uni tertio consent'mnt inter
se). Conviction may, therefore, be distinguished, from an ex
ternal point of view, from persuasion, by the possibility of
communicating it, and by showing its validity for the reason
of every man ; for in this case the presumption, at least, arises,
that the agreement of all judgments with each other, in spite
of the different characters of individuals, rests upon the com
mon ground of the agreement of each with the object, and thus
the correctness of the judgment is established.
Persuasion, accordingly, cannot be subjectively distinguished
from conviction, that is, so long as the subject views its judg
ment simply as a phenomenon of its own mind. But if we
inquire whether the grounds of our judgment, which are valid
for us, produce the same effect on the reason of others as on
our own, we have then the means, though only subjective means,
not, indeed, of producing conviction, but of detecting the merely
private validity of the judgment; in other words, of discover
ing that there is in it the element of mere persuasion.
If we can, in addition to this, develop the subjective causes
CRITIQUE OF PURE REASON 461
of the judgment, which we have taken for its objective grounds,
and thus explain the deceptive judgment as a phenomenon in
our mind, apart altogether from the objective character of the
object, we can then expose the illusion and need be no longer
deceived by it, although, if its subjective cause lies in our nat
ure, we cannot hope altogether to escape its influence.
I can only maintain, that is, affirm as necessarily valid for
everyone, that which produces conviction. Persuasion I may
keep for myself, if it is agreeable to me; but I cannot, and
ought not, to attempt to impose it as binding upon others.
Holding for trite, or the subjective validity of a judgment
in relation to conviction (which is, at the same time, objectively
valid), has the three following degrees: Opinion, Belief, and
Knowledge. Opinion is a consciously insufficient judgment,
subjectively as well as objectively. Belief is subjectively suffi
cient, but is recognized as being objectively insufficient. Knowl
edge is both subjectively and objectively sufficient. Subjective
sufficiency is termed conviction (for myself) ; objective suffi
ciency is termed certainty (for all). I need not dwell longer
on the explanation of such simple conceptions.
I must never venture to be of opinion, without knowing
something, at least, by which my judgment, in itself merely
problematical, is brought into connection with the truth — which
connection, although not perfect, is still something more than
an arbitrary fiction. Moreover, the law of such a connection
must be certain. For if, in relation to this law, I have nothing
more than opinion, my judgment is but a play of the imagina
tion, without the least relation to truth.— In the judgments of
pure reason, opinion has no place. For as they do not rest on
empirical grounds, and as the sphere of pure reason is that
of necessary truth and a priori cognition, the principle of con
nection in it requires universality and necessity, and conse
quently perfect certainty — otherwise we should have no guide
to the truth at all. Hence it is absurd to have an opinion in
pure mathematics; we must know, or abstain from forming
a judgment altogether. The case is the same with the maxims
of morality. For we must not hazard an action on the mere
opinion that it is allowed, but we must know it to be so.
In the transcendental sphere of reason, on the other hand,
the term opinion is too weak, while the word knowledge is too
strong. From the merely speculative point of view, therefore,
462
KANT
we cannot form a judgment at all. For the subjective grounds
of a judgment, such as produce belief, cannot be admitted in
speculative inquiries, inasmuch as they cannot stand without
empirical support, and are incapable of being communicated
to others in equal measure.
But it is only from the practical point of view that a theoreti
cally insufficient judgment can be termed belief. Now the
practical reference is either to skill or to morality; to the
former, when the end proposed is arbitrary and accidental, to
the latter, when it is absolutely necessary.
If we propose to ourselves any end whatever, the conditions
of its attainment are hypothetically necessary. The necessity
is subjectively, but still only comparatively, sufficient, if I am
acquainted with no other conditions under which the end can
be attained. On the other hand, it is sufficient, absolutely, and
for everyone, if I know for certain that no one can be acquainted
with any other conditions, under which the attainment of the
proposed end would be possible. In the former case my sup
position — my judgment with regard to certain conditions, is
a merely accidental belief ; in the latter it is a necessary belief.
The physician must pursue some course in the case of a patient
who is in danger, but is ignorant of the nature of the disease.
He observes the symptoms, and concludes, according to the
best of his judgment, that it is a case of phthisis. His belief
is, even in his own judgment, only contingent: another man
might, perhaps, come nearer the truth. Such a belief, contin
gent indeed, but still forming the ground of the actual use of
means for the attainment of certain ends, I term pragmatical
belief.
The usual test, whether that which anyone maintains is
merely his persuasion, or his subjective conviction at least, that
is, his firm belief, is a bet. It frequently happens that a man
delivers his opinions with so much boldness and assurance, that
he appears to be under no apprehension as to the possibility of
his being in error. The offer of a bet startles him, and makes
him pause. Sometimes it turns out that his persuasion may
be valued at a ducat, but not at ten. For he does not hesitate,
perhaps, to venture a ducat, but if it is proposed to stake ten,
he immediately becomes aware of the possibility of his being
mistaken — a possibility which has hitherto escaped his observa
tion. If we imagine to ourselves that we have to stake the
QRITIQUE OF PURE REASON 463
happiness of our whole life on the truth of any proposition,
our judgment drops its air of triumph, we take the alarm, and
discover the actual strength of our belief. Thus pragmatical
belief has degrees, varying in proportion to the interests at stake.
Now, in cases where we cannot enter upon any course of
action in reference to some object, and where, accordingly, our
judgment is purely theoretical, we can still represent to our
selves, in thought, the possibility of a course of action, for
which we suppose that we have sufficient grounds, if any means
existed of ascertaining the truth of the matter. Thus we find
in purely theoretical judgments an analogon of practical judg
ments, to which the word belief may properly be applied, and
which we may term doctrinal belief. I should not hesitate to
stake my all on the truth of the proposition — if there were any
possibility of bringing it to the test of experience — that, at
least, some one of the planets, which we see, is inhabited. Hence
I say that I have not merely the opinion, but the strong belief,
on the correctness of which I would stake even many of the
advantages of life, that there are inhabitants in other worlds.
Now we must admit that the doctrine of the existence of
God belongs to doctrinal belief. For, although in respect to
the theoretical cognition of the universe I do not require to
form any theory which necessarily involves this idea, as the
condition of my explanation of the phenomena which the uni
verse presents, but, on the contrary, am rather bound so to use
my reason as if everything were mere nature, still teleological
unity is so important a condition of the application of my
reason to nature, that it is impossible for me to ignore it —
especially since, in addition to these considerations, abundant
examples of it are supplied by experience. But the sole condi
tion, so far as my knowledge extends, under which this unity
can be my guide in the investigation of nature, is the assump
tion that a supreme intelligence has ordered all things according
to the wisest ends. Consequently the hypothesis of a wise au
thor of the universe is necessary for my guidance in the investi
gation of nature — is the condition under which alone I can fulfil
an end which is contingent indeed, but by no means unimpor
tant. Moreover, since the result of my attempts so frequently
confirms the utility of this assumption, and since nothing de
cisive can be adduced against it, it follows that it would be say
ing far too little to term my judgment, in this case, a mere
464 KANT
opinion, and that, even in this theoretical connection, I may
assert that I firmly believe in God. Still, if we use words
strictly, this must not be called a practical, but a doctrinal be
lief, which the theology of nature (physico-theology) must also
produce in my mind. In the wisdom of a Supreme Being, and
in the shortness of life, so inadequate to the development of the
glorious powers of human nature, we may find equally sufficient
grounds for a doctrinal belief in the future life of the human
soul.
The expression of belief is, in such cases, an expression of
modesty from the objective point of view, but, at the same
time, of firm confidence, from the subjective. If I should vent
ure to term this merely theoretical judgment even so much as
a hypothesis which I am entitled to assume ; a more complete
conception, with regard to another world and to the cause of
the world, might then be justly required of me than I am, in
reality, able to give. For, if I assume anything, even as a mere
hypothesis, I must, at least, know so much of the properties
of such a being as will enable me, not to form the conception,
but to imagine the existence of it. But the word belief refers
only to the guidance which an idea gives me, and to its subjec
tive influence on the conduct of my reason, which forces me
to hold it fast, though I may not be in a position to give a
speculative account of it.
But mere doctrinal belief is, to some extent, wanting in sta
bility. We often quit our hold of it, in consequence of the
difficulties which occur in speculation, though in the end we
inevitably return to it again.
It is quite otherwise with moral belief. For in this sphere
action is absolutely necessary, that is, I must act in obedience
to the moral law in all points. The end is here incontrovertibly
established, and there is only one condition possible, according
to the best of my perception, under which this end can har
monize with all other ends, and so have practical validity —
namely, the existence of a God and of a future world. I know
also, to a certainty, that no one can be acquainted with any
other conditions which conduct to the same unity of ends under
the moral law. But since the moral precept is, at the same time,
my maxim (as reason requires that it should be), I am irre
sistibly constrained to believe in the existence of God and in
a future life ; and I am sure that nothing can make me waver
CRITIQUE OF PURE REASON
465
in this belief, since I should thereby overthrow my moral max
ims, the renunciation of which would render me hateful in my
own eyes.
Thus, while all the ambitious attempts of reason to pene
trate beyond the limits of experience end in disappointment,
there is still enough left to satisfy us in a practical point of
view. No one, it is true, will be able to boast that he knows
that there is a God and a future life ; for, if he knows this, he
is just the man whom I have long wished to find. All knowl
edge, regarding an object of mere reason, can be communi
cated; and I should thus be enabled to hope that my own
knowledge would receive this wonderful extension, through
the instrumentality of his instruction. No, my conviction is
not logical, but moral certainty ; and since it rests on subjective
grounds (of the moral sentiment), I must not even say: It is
morally certain that there is a God, etc., but: / am morally
certain, that is, my belief in God and in another world is so
interwoven with my moral nature, that I am under as little
apprehension of having the former torn from me as of losing
the latter.
The only point in this argument that may appear open to
suspicion, is that this rational belief presupposes the existence
of moral sentiments. If we give up this assumption, and take
a man who is entirely indifferent with regard to moral laws,
the question which reason proposes, becomes then merely a
problem for speculation, and may, indeed, be supported by
strong grounds from analogy, but not by such as will compel
the most obstinate scepticism to give way.* But in these ques
tions no man is free from all interest. For though the want of
good sentiments may place him beyond the influence of moral
: interests, still even in this case enough may be left to make him
« fear the existence of God and a future life. For he cannot
pretend to any certainty of the non-existence of God and of
a future life, unless — since it could only be proved by mere
reason, and therefore apodictically — he is prepared to establish
the impossibility of both, which certainly no reasonable man
would undertake to do. This would be a negative belief, which
* The human mind (as, I believe, docile, more enlightened, and more
every rational being must of necessity capable of uniting the speculative in-
do) takes a natural interest in morality, terest with the practical. But if you do
although this interest is not undivided, not take care at the outset, or at least
and may not be practically in prepon- mid-way, to make men good, you will
derance. If you strengthen and increase never force them into an honest belief,
it, you will find the reason become
30
466
KANT
could not, indeed, produce morality and good sentiments, but
still could produce an analogon of these, by operating as a pow
erful restraint on the outbreak of evil dispositions.
But, it will be said, is this all that pure reason can effect,
in opening up prospects beyond the limits of experience ? Noth
ing more than two articles of belief ? Common sense could have
done as much as this, without taking the philosophers to counsel
in the matter.
I shall not here eulogize philosophy for the benefits which
the laborious efforts of its criticism have conferred on human
reason — even granting that its merit should turn out in the
end to be only negative — for on this point something more
will be said in the next section. But I ask, do you require that
that knowledge which concerns all men, should transcend the
common understanding, and should only be revealed to you
by philosophers ? The very circumstance which has called forth
your censure, is the best confirmation of the correctness of our
previous assertions, since it discloses, what could not have been
foreseen, that Nature is not chargeable with any partial dis
tribution of her gifts in those matters which concern all men
without distinction, and that in respect to the essential ends of
human nature, we cannot advance further with the help of the
highest philosophy, than under the guidance which nature has
vouchsafed to the meanest understanding.
CHAPTER III
The 'Architectonic of Pure Reason
By the term Architectonic I mean the art of constructing a
system. Without systematic unity, our knowledge cannot be
come science ; it will be an aggregate, and not a system. Thus
Architectonic is the doctrine of the scientific in cognition, and
therefore necessarily forms part of our Methodology.
Reason cannot permit our knowledge to remain in an un
connected and rhapsodistic state, but requires that the sum of
our cognitions should constitute a system. It is thus alone
that they can advance the ends of reason. By a system I
mean the unity of various cognitions under one idea. This
idea is the conception — given by reason — of the form of a
CRITIQUE OF PURE REASON 467
whole, in so far as the conception determines a priori not only
the limits of its content, but the place which each of its parts
is to occupy. The scientific idea contains, therefore, the end,
and the form of the whole which is in accordance with that end!
The unity of the end, to which all the parts of the system relate,"
and through which all have a relation to each other, communi
cates unity to the whole system, so that the absence of any
part can be immediately detected from our knowledge of the
rest ; and it determines a priori the limits of the system, thus
excluding all contingent or arbitrary additions. The whole
is thus an organism (articulatio) , and not an aggregate (coa-
cervatio} ; it may grow from within (per intussusceptionem),
but it cannot increase by external additions (per appositionem}.
It is thus like an animal body, the growth of which does not
add any limb, but, without changing their proportions, makes
each in its sphere stronger and more active.
We require, for the execution of the idea of a system, a
schema, that is, a content and an arrangement of parts deter
mined a priori by the principle which the aim of the system
prescribes. A schema which is not projected in accordance
with an idea, that is, from the standpoint of the highest aim
of reason, but merely empirically, in accordance with accidental
aims and purposes (the number of which cannot be predeter
mined), can give us nothing more than technical unity. But the
schema which is originated from an idea (in which case reason
presents us with aims a priori, and does not look for them to
experience), forms the basis of architectonical unity. A sci
ence, in the proper acceptation of that term, cannot be formed
technically, that is, from observation of the similarity existing
between different objects, and the purely contingent use we
make of our knowledge in concrete with reference to all kinds
of arbitrary external aims ; its constitution must be framed
on architectonical principles, that is, its parts must be shown
to possess an essential affinity, and be capable of being deduced
from one supreme and internal aim or end, which forms the
condition of the possibility of the scientific whole. The schema
of a science must give a priori the plan of it (mono gramma},
and the division of the whole into parts, in conformity with
the idea of the science ; and it must also distinguish this whole
from all others, according to certain understood principles.
No one will attempt to construct a science, unless he have
468
KANT
some idea to rest on as a proper basis. But, in the elaboration
of the science he finds that the schema, nay, even the definition
which he at first gave of the science, rarely corresponds with
his idea ; for this idea lies, like a germ, in our reason, its parts
undeveloped and hid even from microscopical observation. For
this reason, we ought to explain and define sciences, not accord
ing to the description which the originator gives of them, but
according to the idea which we find based in reason itself, and
which is suggested by the natural unity of the parts of the
science already accumulated. For it will often be found, that
the originator of a science, and even his latest successors, re
main attached to an erroneous idea, which they cannot render
clear to themselves, and that they thus fail in determining the
true content, the articulation or systematic unity, and the limits
of their science.
It is unfortunate that, only after having occupied ourselves
for a long time in the collection of materials, under the guidance
of an idea which lies undeveloped in the mind, but not accord
ing to any definite plan of arrangement — nay, only after we
have spent much time and labor in the technical disposition
of our materials, does it become possible to view the idea of
a science in a clear light, and to project, according to architec-
tonical principles, a plan of the whole, in accordance with the
aims of reason. Systems seem, like certain worms, to be formed
by a kind of generatio cuquivoca — by the mere confluence of
conceptions, and to gain completeness only with the progress
of time. But the schema or germ of all lies in reason; and
thus is not only every system organized according to its own
idea, but all are united into one grand system of human knowl
edge, of which they form members. For this reason, it is pos
sible to frame an architectonic of all human cognition, the for
mation of which, at the present time, considering the immense
materials collected or to be found in the ruins of old systems,
would not indeed be very difficult. Our purpose at present is
merely to sketch the plan of the Architectonic of all cognition
given by pure reason; and we begin from the point where the
main root of human knowledge divides into two, one of which
is reason. By reason I understand here the whole higher fac
ulty of cognition, the rational being placed in contradistinction
to the empirical.
If I make complete abstraction of the content of cognition,
CRITIQUE OF PURE REASON 469
objectively considered, all cognition is, from a subjective point
of view, either historical or rational. Historical cognition is
cognitio ex datis, rational, cognitio ex principiis. Whatever
may be the original source of a cognition, it is, in relation to
the person who possesses it, merely historical, if he knows only
what has been given him from another quarter, whether that
knowledge was communicated by direct experience or by in
struction. Thus the person who has learned a system of philos
ophy — say the Wolfian — although he has a perfect knowledge
of all the principles, definitions and arguments in that philos
ophy, as well as of the divisions that have been made of the
system, he possesses really no more than a historical knowledge
of the Wolfian system ; he knows only what has been told him,
his judgments are only those which he has received from his
teachers. Dispute the validity of a definition, and he is at
completely a loss to find another. He has formed his mind
on another's; but the imitative faculty is not the productive.
His knowledge has not been drawn from reason ; and, although,
objectively considered, it is rational knowledge, subjectively,
it is merely historical. He has learned this or that philosophy,
and is merely a plaster-cast of a living man. Rational cogni
tions which are objective, that is, which have their source in
reason, can be so termed from a subjective point of view, only
when they have been drawn by the individual himself from the
sources of reason, that is, from principles ; and it is in this way
alone that criticism, or even the rejection of what has been al
ready learned, can spring up in the mind.
All rational cognition is, again, based either on conceptions,
or on the construction of conceptions. The former is termed
philosophical, the latter mathematical. I have already shown
the essential difference of these two methods of cognition in
the first chapter. A cognition may be objectively philosophical
and subjectively historical — as is the case with the majority of
scholars and those who cannot look beyond the limits of their
system, and who remain in a state of pupilage all their lives.
But it is remarkable that mathematical knowledge, when com
mitted to memory, is valid, from the subjective point of view,
as rational knowledge also, and that the same distinction cannot
be drawn here as in the case of philosophical cognition. The
reason is, that the only way of arriving at this knowledge is
through the essential principles of reason, and thus it is always
470
KANT
certain and indisputable; because reason is employed in con
crete — but at the same time a priori — that is, in pure, and there
fore, infallible intuition; and thus all causes of illusion and
error are excluded. Of all the a priori sciences of reason, there
fore, mathematics alone can be learned. Philosophy — unless it
be in an historical manner — cannot be learned ; we can at most
learn to philosophise.
Philosophy is the system of all philosophical cognition. We
must use this term in an objective sense, if we understand by
it the archetype of all attempts at philosophizing, and the stand
ard by which all subjective philosophies are to be judged. In
this sense, philosophy is merely the idea of a possible science,
which does not exist in concreto, but to which we endeavor in
various ways to approximate, until we have discovered the right
path to pursue — a path overgrown by the errors and illusions
of sense — and the image we have hitherto tried to shape in vain,
has become a perfect copy of the great prototype. Until that
time, we cannot learn philosophy — it does not exist ; if it does,
where is it, who possesses it, and how shall we know it? We
can only learn to philosophize ; in other words, we can only
exercise our powers of reasoning in accordance with general
principles, retaining at the same time, the right of investigating
the sources of these principles, of testing, and even of rejecting
them.
Until then, our conception of philosophy is only a scholastic
conception — a conception, that is, of a system of cognition
which we are trying to elaborate into a science ; all that we at
present know, being the systematic unity of this cognition, and
consequently the logical completeness of the cognition for the
desired end. But there is also a cosmical conception (conceptus
cosmicus) of philosophy, which has always formed the true
basis of this term, especially when philosophy was personified
and presented to us in the ideal of a philosopher. In this view,
philosophy is the science of the relation of all cognition to the
ultimate and essential aims of human reason (teleologia rationis
humane?), and the philosopher is not merely an artist — who
occupies himself with conceptions, but a law-giver — legislating
for human reason. In this sense of the word, it would be in
the highest degree arrogant to assume the title of philosopher,
and to pretend that we had reached the perfection of the proto
type which lies in the idea alone.
CRITIQUE OF PURE REASON 4?1
The mathematician, the natural philosopher, and the logician
—how far soever the first may have advanced in rational, and
the two latter in philosophical knowledge — are merely artists,
engaged in the arrangement and formation of conceptions;
they cannot be termed philosophers. Above them all, there is
the ideal teacher, who employs them as instruments for the
advancement of the essential aims of human reason. Him alone
can we call philosopher ; but he nowhere exists. But the idea
of his legislative power resides in the mind of every man, and
it alone teaches us what kind of systematic unity philosophy
demands in view of the ultimate aims of reason. This idea is,
therefore, a cosmical conception.*
In view of the complete systematic unity of reason, there
can only be one ultimate end of all the operations of the mind.
To this all other aims are subordinate, and nothing more than
means for its attainment. This ultimate end is the destination
of man, and the philosophy which relates to it is termed Moral
Philosophy. The superior position occupied by moral philos
ophy, above all other spheres for the operations of reason, suffi
ciently indicates the reason why the ancients always included
the idea — and in an especial manner — of Moralist in that of
Philosopher. Even at the present day, we call a man who ap
pears to have the power of self-government, even although his
knowledge may be very limited, by the name of philosopher.
The legislation of human reason, or philosophy, has two
objects — Nature and Freedom, and thus contains not only the
laws of nature, but also those of ethics, at first in two separate
systems, which, finally, merge into one grand philosophical
system of cognition. The philosophy of Nature relates to that
which is, that of Ethics to that which ought to be.
But all philosophy is either cognition on the basis of pure
reason, or the cognition of reason on the basis of empirical
principles. The former is termed pure, the latter empirical
philosophy.
The philosophy of pure reason is either propcedeutic, that is,
an inquiry into the powers of reason in regard to pure a priori
cognition, and is termed Critical Philosophy ; or it is, secondly,
the system of pure reason — a science containing the systematic
* By a cosmical conception, I mean one scholastic [or partial] conceptions, if it is
in which all men necessarily take an regarded merely as a means to certain
interest; the aim of a science must ac- arbitrarily proposed ends,
cordingly be determined according to
472 KANT
presentation of the whole body of philosophical knowledge, true
as well as illusory, given by pure reason, and is called Meta-
physic. This name may, however, be also given to the whole
system of pure philosophy, critical philosophy included, and
may designate the investigation into the sources or possibility
of a priori cognition, as well as the presentation of the a priori
cognitions which form a system of pure philosophy — excluding,
at the same time, all empirical and mathematical elements.
Metaphysic is divided into that of the speculative and that
of the practical use of pure reason, and is, accordingly, either
the Metaphysic of Nature, or the Metaphysic of Ethics. The
former contains all the pure rational principles — based upon
conceptions alone (and thus excluding mathematics) — of all
theoretical cognition ; the latter, the principles which determine
and necessitate a priori all action. Now moral philosophy alone
contains a code of laws — for the regulation of our actions —
which are deduced from principles entirely a priori. Hence
the Metaphysics of Ethics is the only pure and moral philos
ophy, as it is not based upon anthropological or other empirical
considerations. The metaphysic of speculative reason is what
is commonly called Metaphysic in the more limited sense. But
as pure Moral Philosophy properly forms a part of this system
of cognition, we must allow it to retain the name of Metaphysic,
although it is not requisite that we should insist on so terming
it in our present discussion.
It is of the highest importance to separate those cognitions
which differ from others both in kind and in origin, and to
take great care that they are not confounded with those with
which they are generally found connected. What the chemist
does in the analysis of substances, what the mathematician in
pure mathematics, is, in a still higher degree, the duty of the
philosopher, that the value of each different kind of cognition,
and the part it takes in the operations of the mind, may be
clearly defined. Human reason has never wanted a Metaphysic
of some kind, since it attained the power of thought, or rather
of reflection; but it has never been able to keep this sphere
of thought and cognition pure from all admixture of foreign
elements. The idea of a science of this kind is as old as specu
lation itself; and what mind does not speculate — either in the
scholastic or in the popular fashion ? At the same time, it must
be admitted that even thinkers by profession have been unable
CRITIQUE OF PURE REASON 473
clearly to explain the distinction between the two elements of
our cognition— the one completely a priori, the other a pos
teriori; and hence the proper definition of a peculiar kind of
cognition, and with it the just idea of a science which has so
long and so deeply engaged the attention of the human mind,
has never been established. When it was said— Metaphysic is
the science of the first principles of human cognition, this defini
tion did not signalize a peculiarity in kind, but only a difference
in degree ; these first principles were thus declared to be more
general than others, but no criterion of distinction from em
pirical principles was given. Of these some are more general,
and therefore higher, than others; and — as we cannot distin
guish what is completely a priori, from that which is known
to be a posteriori — where shall we draw the line which is to
separate the higher and so-called first principles, from the lower
and subordinate principles of cognition ? What would be said
if we were asked to be satisfied with a division of the epochs
of the world into the earlier centuries and those following them ?
Does the fifth, or the tenth century belong to the earlier cen
turies? it would be asked. In the same way I ask: Does the
conception of extension belong to metaphysics? You answer,
yes. Well, that of body too ? Yes. And that of a fluid body ?
You stop, you are unprepared to admit this; for if you do,
everything will belong to metaphysics. From this it is evident
that the mere degree of subordination — of the particular to the
general — cannot determine the limits of a science; and that,
in the present case, we must expect to find a difference in the
conceptions of metaphysics both in kind and in origin. The
fundamental idea of metaphysics was obscured on another side,
by the fact that this kind of a priori cognition showed a certain
similarity in character with the science of mathematics. Both
have the property in common of possessing an a priori origin ;
but, in the one, our knowledge is based upon conceptions, in
the other, on the construction of conceptions. Thus a decided
dissimilarity between philosophical and mathematical cognition
comes out — a dissimilarity which was always felt, but which
could not be made distinct for want of an insight into the criteria
of the difference. And thus it happened that, as philosophers
themselves failed in the proper development of the idea of their
science, the elaboration of the science could not proceed with
a definite aim, or under trustworthy guidance. Thus, too, phi-
474 KANT
losophers, ignorant of the path they ought to pursue, and always
disputing with each other regarding the discoveries which each
asserted he had made, brought their science in disrepute with
the rest of the world, and finally, even among themselves.
All pure a priori cognition forms, therefore, in view of the
peculiar faculty which originates it, a peculiar and distinct
unity; and metaphysic is the term applied to the philosophy
which attempts to represent that cognition in this systematic
unity. The speculative part of metaphysic, which has especially
appropriated this appellation — that, which we have called the
Metaphysic of Nature — and which considers everything, as it
is (not as it ought to be), by means of a priori conceptions,
is divided in the following manner.
Metaphysic, in the more limited acceptation of the term, con
sists of two parts — Transcendental Philosophy and the Physiol
ogy of pure reason. The former presents the system of all the
conceptions and principles belonging to the understanding and
the reason, and which relate to objects in general, but not to
any particular given objects (Ontologia) ; the latter has nature
for its subject-matter, that is, the sum of given objects —
whether given to the senses, or, if we will, to some other kind
of intuition — and is accordingly Physiology, although only ra-
tionalis. But the use of the faculty of reason in this rational
mode of regarding nature is either physical or hyperphysical,
or, more properly speaking, immanent or transcendent. The
former relates to nature, in so far as our knowledge regarding
it may be applied in experience (in concreto} ; the latter to that
connection of the objects of experience, which transcends all
experience. Transcendent Physiology has, again, an internal
and an external connection with its object, both, however, trans
cending possible experience; the former is the Physiology of
nature as a whole, or transcendental cognition of the world, the
latter of the connection of the whole of nature with a being
above nature, or transcendental cognition of God.
Immanent physiology, on the contrary, considers nature as
the sum of all sensuous objects, consequently, as it is presented
to us — but still according to a priori conditions, for it is under
these alone that nature can be presented to our minds at all.
The objects of immanent physiology are of two kinds : i. those
of the external senses, or corporeal nature; 2. the object of
the internal sense, the soul, or, in accordance with our funda-
CRITIQUE OF PURE REASON 475
mental conceptions of it, thinking nature. The metaphysics of
corporeal nature is called Physics, but, as it must contain only
the principles of an d priori cognition of nature, we must term
it rational physics. The metaphysics of thinking nature is called
Psychology, and for the same reason is to be regarded as merely
the rational cognition of the soul.
Thus the whole system of metaphysics consists of four prin
cipal parts : i. Ontology; 2. Rational Physiology; 3. Rational
Cosmology; and 4. Rational Theology. The second part-
that of the rational doctrine of nature — may be subdivided into
two, physica rationalis * and psychologia rationalis.
The fundamental idea of a philosophy of pure reason of ne
cessity dictates this division; it is, therefore, architectonical —
in accordance with the highest aims of reason, and not merely
technical, or according to certain accidentally observed similar
ities existing between the different parts of the whole science.
For this reason, also, is the division immutable and of legislative
authority. But the reader may observe in it a few points to
which he ought to demur, and which may weaken his conviction
of its truth and legitimacy.
In the first place, how can I desire an a priori cognition or
metaphysic of objects, in so far as they are given d posteriori?
and how is it possible to cognize the nature of things accord
ing to a priori principles, and to attain to a rational physiology?
The answer is this. We take from experience nothing more
than is requisite to present us with an object (in general) of
the external, or of the internal sense ; in the former case, by
the mere conception of matter (impenetrable and inanimate ex
tension), in the latter, by the conception of a thinking being —
given in the internal empirical representation, / think. As to
the rest, we must not employ in our metaphysic of these objects
any empirical principles (which add to the content of our con
ceptions by means of experience), for the purpose of forming
by their help any judgments respecting these objects.
Secondly, what place shall we assign to empirical psychology,
* It must not be supposed that I mean want of its guidance, even mathema-
by this appellation what is generally ticians, adopting certain common no-
called physica generalis, and which is tions — which are, in fact, metaphysical
rather mathematics than a philosophy — have unconsciously crowded their
of nature. For the metaphysic of nature theories of nature with hypotheses, the
is completely different from mathe- fallacy of which becomes evident upon
matics, nor is it so rich in results, al- the application of the principles of this
though it is of great importance as a metaphysic, without detriment, how-
critical test of the application of pure ever, to the employment of mathematics
understanding-cognition to nature. For in this sphere of cognition.
KANT
which has always been considered a part of Metaphysics, and
from which in our time such important philosophical results
have been expected, after the hope of constructing an a priori
system of knowledge had been abandoned ? I answer : It must
be placed by the side of empirical physics or physics proper;
that it, must be regarded as forming a part of applied philoso
phy, the a priori principles of which are contained in pure
philosophy, which is therefore connected, although it must not
be confounded, with psychology. Empirical psychology must
therefore be banished from the sphere of Metaphysics, and is
indeed excluded by the very idea of that science. In conform
ity, however, with scholastic usage, we must permit it to oc
cupy a place in metaphysics — but only as an appendix to it.
We adopt this course from motives of economy ; as psychology
is not as yet full enough to occupy our attention as an inde
pendent study, while it is, at the same time, of too great impor
tance, to be entirely excluded or placed where it has still less
affinity than it has with the subject of metaphysics. It is a
stranger who has been long a guest ; and we make it welcome
to stay, until it can take up a more suitable abode in a com
plete system of Anthropology — the pendant to empirical
physics.
The above is the general idea of Metaphysics, which, as more
was expected from it than could be looked for with justice,
and as these pleasant expectations were unfortunately never
realized, fell into general disrepute. Our Critique must have
fully convinced the reader, that, although metaphysics cannot
form the foundation of religion, it must always be one of its
most important bulwarks, and that human reason, which natur
ally pursues a dialectical course, cannot do without this science,
which checks its tendencies towards dialectic, and, by elevating
reason to a scientific and clear self-knowledge, prevents the
ravages which a lawless speculative reason would infallibly com
mit in the sphere of morals as well as in that of religion. We
may be sure, therefore, whatever contempt may be thrown
upon metaphysics by those who judge a science not by its
own nature, but according to the accidental effects it may have
produced, that it can never be completely abandoned, that we
must always return to it as to a beloved one who has been for
a time estranged, because the questions with which it is en
gaged relate to the highest aims of humanity, and reason must
CRITIQUE OF PURE REASON 477
always labor either to attain to settled views in regard to these,
or to destroy those which others have already established.
Metaphysic, therefore— that of nature, as well as that of
ethics, but in an especial manner the criticism which forms the
propaedeutic to all the operations of reason — forms properly
that department of knowledge which may be termed, in the tru
est sense of the word, philosophy. The path which it pursues is
that of science, which, when it has once been discovered, is never
lost, and never misleads. Mathematics, natural science, the
common experience of men, have a high value as means, for the
most part, to accidental ends — but at last also, to those which
are necessary and essential to the existence of humanity. But
to guide them to this high goal, they require the aid of rational
cognition on the basis of pure conceptions, which, be it termed
as it may, is properly nothing but metaphysics.
For the same reason, metaphysics forms likewise the com
pletion of the culture of human reason. In this respect, it is
indispensable, setting aside altogether the influence which it
exerts as a science. For its subject-matter is the elements and
highest maxims of reason, which form the basis of the possibility
of some sciences and of the use of all. That, as a purely specula
tive science, it is more useful in preventing error, than in the
extension of knowledge, does not detract from its value; on
the contrary, the supreme office of censor which it occupies,
assures to it the highest authority and importance. This office
it administers for the purpose of securing order, harmony, and
well-being to science, and of directing its noble and fruitful la
bors to the highest possible aim — the happiness of all mankind.
CHAPTER IV
The History of Pure Reason
This title is placed here merely for the purpose of "designat
ing a division of the system of pure reason, of which I do not in
tend to treat at present. I shall content myself with casting a
cursory glance, from a purely transcendental point of view —
that of the nature of pure reason, on the labors of philosophers
up to the present time. They have aimed at erecting an edifice
of philosophy ; but to my eye this edifice appears to be in a very
ruinous condition.
KANT
It is very remarkable, although naturally it could not have
been otherwise, that, in the infancy of philosophy, the study of
the nature of God, and the constitution of a future world,
formed the commencement, rather than the conclusion, as we
should have it, of the speculative efforts of the human mind.
However rude the religious conceptions generated by the re
mains of the old manners and customs of a less cultivated time,
the intelligent classes were not thereby prevented from devoting
themselves to free inquiry into the existence and nature of God ;
and they easily saw that there could be no surer way of pleasing
the invisible ruler of the world, and of attaining to happiness
in another world at least, than a good and honest course of life
in this. Thus theology and morals formed the two chief mo
tives, or rather the points of attraction in all abstract inquiries.
But it was the former that especially occupied the attention of
speculative reason, and which afterwards became so celebrated
under the name of metaphysics.
I shall not at present indicate the periods of time at which the
greatest changes in metaphysics took place, but shall merely
give a hasty sketch of the different ideas which occasioned the
most important revolutions in this sphere of thought. There
are three different ends, in relation to which these revolutions
have taken place.
1. In relation to the object of the cognition of reason, philoso
phers may be divided into Sensualists and Intellectualists. Epi
curus may be regarded as the head of the former, Plato of the
latter. The distinction here signalized, subtle as it is, dates from
the earliest times, and was long maintained. The former as
serted, that reality resides in sensuous objects alone, and that
everything else is merely imaginary ; the latter, that the senses
are the parents of illusion, and that truth is to be found in the
understanding alone. The former did not deny to the concep
tions of the understanding a certain kind of reality ; but with
them it was merely logical, with the others it was mystical. The
former admitted intellectual conceptions, but declared that sen
suous objects alone possessed real existence. The latter main
tained that all real objects were intelligible, and believed that the
pure understanding possessed a faculty of intuition apart form
sense, which, in their opinion, served only to confuse the ideas
of the understanding.
2. In relation to the origin of the pure cognitions of reason.
CRITIQUE OF PURE REASON 479
we find one school maintaining that they are derived entirely
from experience, and another, that they have their origin in
reason alone. Aristotle may be regarded as the head of the
Empiricists, and Plato, of the Noologists. Locke, the follower
of Aristotle in modern times, and Leibnitz of Plato (although
he cannot be said to have imitated him in his mysticism), have
not been able to bring this question to a settled conclusion. The
procedure of Epicurus in his sensual system, in which he al
ways restricted his conclusions to the sphere of experience, was
much more consequent than that of Aristotle and Locke. The
latter especially, after having derived all the conceptions and
principles of the mind from experience, goes so far, in the em
ployment of these conceptions and principles, as to maintain that
we can prove the existence of God and the immortality of the
soul — both of them objects lying beyond the limits of possible
experience — with the same force of demonstration, as any
mathematical proposition.
3. In relation to method. Method is procedure according to
principles. We may divide the methods at present employed in
the field of inquiry into the naturalistic and the scientific. The
naturalist of pure reason lays it down as his principles, that
common reason, without the aid of science — which he calls sound
reason, or common sense — can give a more satisfactory answer
to the most important questions of metaphysics than specula
tion is able to do. He must maintain, therefore, that we can
determine the content and circumference of the moon more cer
tainly by the naked eye, than by the aid of mathematical rea
soning. But this system is mere misology reduced to principles ;
and, what is the most absurd thing in this doctrine, the neglect
of all scientific means is paraded as a peculiar method of extend
ing our cognition. As regards those who are naturalists because
they know no better, they are certainly not to be blamed. They
follow common sense, without parading their ignorance as a
method which is to teach us the wonderful secret, how we are
to find the truth which lies at the bottom of the well of Demo-
critus.
" Quod sapio satis est mihi, non ego euro
Esse quod Arcesilas serumnosique Solones." — PERSIUS.
is their motto, under which they may lead a pleasant and praise
worthy life, without troubling themselves with science, or troub
ling science with them.
480 KANT
As regards those who wish to pursue a scientific method, they
have now the choice of following either the dogmatical or the
sceptical, while they are bound never to desert the systematic
mode of procedure. When I mention, in relation to the former,
the celebrated Wolf, and as regards the latter, David Hume, I
may leave, in accordance with my present intention, all others
unnamed. The critical path alone is still open. If my reader
has been kind and patient enough to accompany me on this
hitherto untravelled route, he can now judge whether, if he
and others will contribute their exertions towards making this
narrow foot-path a high-road of thought, that, which many cen
turies have failed to accomplish, may not be executed before
the close of the present — namely, to bring Reason to perfect
contentment in regard to that which has always, but without
permanent results, occupied her powers and engaged her ardent
desire for knowledge.
Kant, I. B
2773
Critique of pure reason. •^"
•53
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