Critique of Pure Reason


P 485
Section I
WE have seen above that no objects can be represented
through pure concepts of understanding, apart from the con-
ditions of sensibility. For the conditions of the objective
reality of the concepts are then absent, and nothing is to be
found in them save the mere form of thought. If, however,
they are applied to appearances, they can be exhibited in
concreto, because in the appearances they obtain the appro-
priate material for concepts of experience -- a concept of ex-
perience being nothing but a concept of understanding in
concreto. But ideas are even further removed from objective
reality than are categories, for no appearance can be found in
which they can be represented in concreto. They contain a
certain completeness to which no possible empirical know-
ledge ever attains. In them reason aims only at a systematic
unity, to which it seeks to approximate the unity that is em-
pirically possible, without ever completely reaching it. 
But what I entitle the ideal seems to be further removed
from objective reality even than the idea. By the ideal I under-
stand the idea, not merely in concreto, but in individuo, that is,
as an individual thing, determinable or even determined by
the idea alone. 
Humanity [as an idea] in its complete perfection contains
not only all the essential qualities which belong to human
nature and constitute our concept of it -- and these so extended
P 486
as to be in that complete conformity with their ends which
would be our idea of perfect humanity -- but also everything
which, in addition to this concept, is required for the complete
determination of the idea. For of all contradictory predicates
one only [of each pair] can apply to the idea of the perfect
man. What to us is an ideal was in Plato's view an idea of
the divine understanding, an individual object of its pure
intuition, the most perfect of every kind of possible being,
and the archetype of all copies in the [field of] appearance. 
 Without soaring so high, we are yet bound to confess that
human reason contains not only ideas, but ideals also, which
although they do not have, like the Platonic ideas, creative
power, yet have practical power (as regulative principles), and
form the basis of the possible perfection of certain actions. 
Moral concepts, as resting on something empirical (pleasure
or displeasure), are not completely pure concepts of reason. 
None the less, in respect of the principle whereby reason sets
bounds to a freedom which is in itself without law, these con-
cepts (when we attend merely to their form) may well serve as
examples of pure concepts of reason. Virtue, and therewith
human wisdom in its complete purity, are ideas. The wise
man (of the Stoics) is, however, an ideal, that is, a man exist-
ing in thought only, but in complete conformity with the idea
of wisdom. As the idea gives the rule, so the ideal in such a
case serves as the archetype for the complete determination
of the copy; and we have no other standard for our actions
than the conduct of this divine man within us, with which
we compare and judge ourselves, and so reform ourselves,
although we can never attain to the perfection thereby pre-
scribed. Although we cannot concede to these ideals objective
reality (existence), they are not therefore to be regarded as
figments of the brain; they supply reason with a standard
which is indispensable to it, providing it, as they do, with a
concept of that which is entirely complete in its kind, and
thereby enabling it to estimate and to measure the degree and
the defects of the incomplete. But to attempt to realise the
ideal in an example, that is, in the [field of] appearance, as, for
instance, to depict the [character of the perfectly] wise man in
a romance, is impracticable. There is indeed something absurd,
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and far from edifying, in such an attempt, inasmuch as the
natural limitations, which are constantly doing violence to the
completeness of the idea, make the illusion that is aimed at
altogether impossible, and so cast suspicion on the good itself
-- the good that has its source in the idea -- by giving it the air
of being a mere fiction. 
Such is the nature of the ideal of reason, which must
always rest on determinate concepts and serve as a rule and
archetype, alike in our actions and in our critical judgments. 
The products of the imagination are of an entirely different
nature; no one can explain or give an intelligible concept of
them; each is a kind of monogram, a mere set of particular
qualities, determined by no assignable rule, and forming
rather a blurred sketch drawn from diverse experiences than a
determinate image -- a representation such as painters and
physiognomists profess to carry in their heads, and which they
treat as being an incommunicable shadowy image of their
creations or even of their critical judgments. Such repre-
sentations may be entitled, though improperly, ideals of
sensibility, inasmuch as they are viewed as being models
(not indeed realisable) of possible empirical intuitions, and yet
furnish no rules that allow of being explained and examined. 
Reason, in its ideal, aims, on the contrary, at complete
determination in accordance with a priori rules. Accordingly
it thinks for itself an object which it regards as being com-
pletely determinable in accordance with principles. The
conditions that are required for such determination are not,
however, to be found in experience, and the concept itself is
therefore transcendent. 
Section 2
(Prototypon Transcendentale) 
Every concept is, in respect of what is not contained in it,
undetermined, and is subject to the principle of determin-
P 488
ability. According to this principle, of every two contradict-
orily opposed predicates only one can belong to a concept. 
This principle is based on the law of contradiction, and is
therefore a purely logical principle. As such, it abstracts from
the entire content of knowledge and is concerned solely with
its logical form. 
But every thing, as regards its possibility, is likewise sub-
ject to the principle of complete determination, according to
which if all the possible predicates of things be taken together
with their contradictory opposites, then one of each pair of
contradictory opposites must belong to it. This principle does
not rest merely on the law of contradiction; for, besides con-
sidering each thing in its relation to the two contradictory
predicates, it also considers it in its relation to the sum of
all possibilities, that is, to the sum-total of all predicates of
things. Presupposing this sum as being an a priori condition,
it proceeds to represent everything as deriving its own pos-
sibility from the share which it possesses in this sum of all
possibilities. The principle of complete determination con-
cerns, therefore, the content, and not merely the logical form. 
It is the principle of the synthesis of all predicates which are
intended to constitute the complete concept of a thing, and not
simply a principle of analytic representation in reference merely
to one of two contradictory predicates. It contains a transcend-
ental presupposition, namely, that of the material for all
possibility, which in turn is regarded as containing a priori
the data for the particular possibility of each and every thing. 
The proposition, everything which exists is completely de-
termined, does not mean only that one of every pair of given
contradictory predicates, but that one of every [pair of] possible
P 489
predicates, must always belong to it. 
P 488n
++ In accordance with this principle, each and every thing is there-
fore related to a common correlate, the sum of all possibilities. If this
correlate (that is, the material for all possible predicates) should be
found in the idea of some one thing, it would prove an affinity of all
possible things, through identity of the ground of their complete
determination. Whereas the determinability of every concept is sub-
ordinate to the universality (universalitas) of the principle of ex-
cluded middle, the determination of a thing is subordinate to the
totality (universitas) or sum of all possible predicates. 
P 489
In terms of this proposi-
tion the predicates are not merely compared with one another
logically, but the thing itself is compared, in transcendental
fashion, with the sum of all possible predicates. What the pro-
position therefore asserts is this: that to know a thing com-
pletely, we must know every possible [predicate], and must
determine it thereby, either affirmatively or negatively. The
complete determination is thus a concept, which, in its
totality, can never be exhibited in concreto. It is based upon
an idea, which has its seat solely in the faculty of reason --
the faculty which prescribes to the understanding the rule of
its complete employment. 
Although this idea of the sum of all possibility, in so far
as it serves as the condition of the complete determination of
each and every thing, is itself undetermined in respect of the
predicates which may constitute it, and is thought by us as
being nothing more than the sum of all possible predicates,
we yet find, on closer scrutiny, that this idea, as a primordial
concept, excludes a number of predicates which as derivative
are already given through other predicates or which are in-
compatible with others; and that it does, indeed, define itself
as a concept that is completely determinate a priori. It thus
becomes the concept of an individual object which is com-
pletely determined through the mere idea, and must there-
fore be entitled an ideal of pure reason. 
When we consider all possible predicates, not merely
logically, but transcendentally, that is, with reference to such
content as can be thought a priori as belonging to them, we
find that through some of them we represent a being, through
others a mere not-being. Logical negation, which is indi-
cated simply through the word not, does not properly refer
to a concept, but only to its relation to another concept in a
judgment, and is therefore quite insufficient to determine a
concept in respect of its content. The expression non-mortal
does not enable us to declare that we are thereby representing
in the object a mere not-being; the expression leaves all con-
tent unaffected. A transcendental negation, on the other hand,
signifies not-being in itself, and is opposed to transcendental
affirmation, which is a something the very concept of which
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in itself expresses a being. Transcendental affirmation is there-
fore entitled reality, because through it alone, and so far only
as it reaches, are objects something (things), whereas its
opposite, negation, signifies a mere want, and, so far as it
alone is thought, represents the abrogation of all thinghood. 
Now no one can think a negation determinately, save by
basing it upon the opposed affirmation. Those born blind can-
not have the least notion of darkness, since they have none of
light. The savage knows nothing of poverty, since he has no
acquaintance with wealth. The ignorant have no concept of
their ignorance, because they have none of knowledge etc. 
All concepts of negations are thus derivative; it is the realities
which contain the data, and, so to speak, the material or
transcendental content, for the possibility and complete
determination of all things. 
If, therefore, reason employs in the complete determina-
tion of things a transcendental substrate that contains, as
it were, the whole store of material from which all possible
predicates of things must be taken, this substrate cannot be
anything else than the idea of an omnitudo realitatis. All
true negations are nothing but limitations -- a title which
would be inapplicable, were they not thus based upon the
unlimited, that is, upon "the All. "
But the concept of what thus possesses all reality is just the
concept of a thing in itself as completely determined; and since
in all possible [pairs of] contradictory predicates one predi-
cate, namely, that which belongs to being absolutely, is to be
found in its determination, the concept of an ens realissimum
is the concept of an individual being. It is therefore a tran-
scendental ideal which serves as basis for the complete
P 491
determination that necessarily belongs to all that exists. 
P 490n
++ The observations and calculations of astronomers have taught
us much that is wonderful; but the most important lesson that they
have taught us has been by revealing the abyss of our ignorance,
which otherwise we could never have conceived to be so great. 
Reflection upon the ignorance thus disclosed must produce a great
change in our estimate of the purposes for which our reason should
be employed. 
P 491
This ideal
is the supreme and complete material condition of the possi-
bility of all that exists -- the condition to which all thought of
objects, so far as their content is concerned, has to be traced
back. It is also the only true ideal of which human reason is
capable. For only in this one case is a concept of a thing -- a con-
cept which is in itself universal -- completely determined in and
through itself, and known as the representation of an individual. 
The logical determination of a concept by reason is based
upon a disjunctive syllogism, in which the major premiss
contains a logical division (the division of the sphere of a
universal concept), the minor premiss limiting this sphere to
a certain part, and the conclusion determining the concept by
means of this part. The universal concept of a reality in general
cannot be divided a priori, because without experience we do
not know any determinate kinds of reality which would be con-
tained under that genus. The transcendental major premiss
which is presupposed in the complete determination of all
things is therefore no other than the representation of the sum
of all reality; it is not merely a concept which, as regards its
transcendental content, comprehends all predicates under
itself; it also contains them within itself; and the complete
determination of any and every thing rests on the limitation of
this total reality, inasmuch as part of it is ascribed to the thing,
and the rest is excluded -- a procedure which is in agreement
with the 'either-or' of the disjunctive major premiss and with
the determination of the object, in the minor premiss, through
one of the members of the division. Accordingly, reason, in em-
ploying the transcendental ideal as that by reference to which
it determines all possible things, is proceeding in a manner
analogous with its procedure in disjunctive syllogisms -- this,
indeed, is the principle upon which I have based the system-
atic division of all transcendental ideas, as parallel with, and
corresponding to, the three kinds of syllogism. 
It is obvious that reason, in achieving its purpose, that,
namely, of representing the necessary complete determination
of things, does not presuppose the existence of a being that
corresponds to this ideal, but only the idea of such a being, and
this only for the purpose of deriving from an unconditioned
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totality of complete determination the conditioned totality,
that is, the totality of the limited. The ideal is, therefore, the
archetype (prototypon) of all things, which one and all, as
imperfect copies (ectypa), derive from it the material of their
possibility, and while approximating to it in varying degrees,
yet always fall very far short of actually attaining it. 
All possibility of things (that is, of the synthesis of the mani-
fold, in respect of its content) must therefore be regarded as
derivative, with only one exception, namely, the possibility of
that which includes in itself all reality. This latter possibility
must be regarded as original. For all negations (which are the
only predicates through which anything can be distinguished
from the ens realissimum) are merely limitations of a greater,
and ultimately of the highest, reality; and they therefore pre-
suppose this reality, and are, as regards their content, derived
from it. All manifoldness of things is only a correspondingly
varied mode of limiting the concept of the highest reality which
forms their common substratum, just as all figures are only pos-
sible as so many different modes of limiting infinite space. The
object of the ideal of reason, an object which is present to us only
in and through reason, is therefore entitled the primordial being
(ens originarium). As it has nothing above it, it is also entitled
the highest being (ens summum); and as everything that is con-
ditioned is subject to it, the being of all beings (ens entium). 
These terms are not, however, to be taken as signifying the
objective relation of an actual object to other things, but of an
idea to concepts. We are left entirely without knowledge as to
the existence of a being of such outstanding pre-eminence. 
We cannot say that a primordial being consists of a number
of derivative beings, for since the latter presuppose the former
they cannot themselves constitute it. The idea of the prim-
ordial being must therefore be thought as simple. 
Consequently, the derivation of all other possibility from
this primordial being cannot, strictly speaking, be regarded as
a limitation of its supreme reality, and, as it were, a division
of it. For in that case the primordial being would be treated as a
mere aggregate of derivative beings; and this, as we have just
shown, is impossible, although in our first rough statements
we have used such language. On the contrary, the supreme
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reality must condition the possibility of all things as their
ground, not as their sum; and the manifoldness of things
must therefore rest, not on the limitation of the primordial
being itself, but on all that follows from it, including therein
all our sensibility, and all reality in the [field of] appearance
-- existences of a kind which cannot, as ingredients, belong
to the idea of the supreme being. 
If, in following up this idea of ours, we proceed to hypos-
tatise it, we shall be able to determine the primordial being
through the mere concept of the highest reality, as a being that
is one, simple, all-sufficient, eternal, etc. In short, we shall be
able to determine it, in its unconditioned completeness, through
all predicaments. The concept of such a being is the concept of
God, taken in the transcendental sense; and the ideal of pure
reason, as above defined, is thus the object of a transcendental
In any such use of the transcendental idea we should, how-
ever, be overstepping the limits of its purpose and validity. 
For reason, in employing it as a basis for the complete deter-
mination of things, has used it only as the concept of all reality,
without requiring that all this reality be objectively given and
be itself a thing. Such a thing is a mere fiction in which we
combine and realise the manifold of our idea in an ideal,
as an individual being. But we have no right to do this,
nor even to assume the possibility of such an hypothesis. Nor
do any of the consequences which flow from such an ideal have
any bearing upon the complete determination of things, or
exercise in that regard the least influence; and it is solely as
aiding in their determination that the idea has been shown to
be necessary. 
But merely to describe the procedure of our reason and its
dialectic does not suffice; we must also endeavour to discover
the sources of this dialectic, that we may be able to explain, as
a phenomenon of the understanding, the illusion to which it
has given rise. For the ideal, of which we are speaking, is
based on a natural, not on a merely arbitrary idea. The ques-
tion to be raised is therefore this: how does it happen that
reason regards all possibility of things as derived from one
single fundamental possibility, namely, that of the highest
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reality, and thereupon presupposes this to be contained in an
individual primordial being? 
The answer is obvious from the discussions in the Tran-
scendental Analytic. The possibility of the objects of the senses
is a relation of these objects to our thought, in which some-
thing (namely, the empirical form) can be thought a priori,
while that which constitutes the matter, reality in the [field of]
appearance (that which corresponds to sensation), must be
given, since otherwise it could not even be thought, nor its
possibility represented. Now an object of the senses can be
completely determined only when it is compared with all the
predicates that are possible in the [field of] appearance, and
by means of them is represented either affirmatively or nega-
tively. But since that which constitutes the thing itself, namely,
the real in the [field of] appearance, must be given -- other-
wise the thing could not be conceived at all -- and since that
)wherein the real of all appearances is given is experience,
considered as single and all-embracing, the material for the
possibility of all objects of the senses must be presupposed as
given in one whole; and it is upon the limitation of this whole
that all possibility of empirical objects, their distinction from
each other and their complete determination, can alone be
based. No other objects, besides those of the senses, can, as a
matter of fact, be given to us, and nowhere save in the con-
text of a possible experience; and consequently nothing is an
object for us, unless it presupposes the sum of all empirical
reality as the condition of its possibility. Now owing to a
natural illusion we regard this principle, which applies only
to those things which are given as objects of our senses, as
being a principle which must be valid of things in general. 
Accordingly, omitting this limitation, we treat the empirical
principle of our concepts of the possibility of things, viewed as
appearances, as being a transcendental principle of the pos-
sibility of things in general. 
If we thereupon proceed to hypostatise this idea of the sum
of all reality, that is because we substitute dialectically for
the distributive unity of the empirical employment of the
understanding, the collective unity of experience as a whole;
P 495
and then thinking this whole [realm] of appearance as one
single thing that contains all empirical reality in itself; and
then again, in turn, by means of the above-mentioned tran-
scendental subreption, substituting for it the concept of a thing
which stands at the source of the possibility of all things, and
supplies the real conditions for their complete determination. 
Section 3
Notwithstanding this pressing need of reason to presup-
pose something that may afford the understanding a sufficient
foundation for the complete determination of its concepts, it
is yet much too easily conscious of the ideal and merely fic-
titious character of such a presupposition to allow itself, on
this ground alone, to be persuaded that a mere creature of its
own thought is a real being -- were it not that it is impelled from
another direction to seek a resting-place in the regress from
the conditioned, which is given, to the unconditioned. This
unconditioned is not, indeed, given as being in itself real, nor
as having a reality that follows from its mere concept; it is,
however, what alone can complete the series of conditions
when we proceed to trace these conditions to their grounds. 
This is the course which our human reason, by its very nature,
leads all of us, even the least reflective, to adopt, though not
everyone continues to pursue it. 
++ This ideal of the ens realissimum, although it is indeed a mere
representation, is first realised, that is, made into an object, then
hypostatised, and finally, by the natural progress of reason towards
the completion of unity, is, as we shall presently show, personified. 
For the regulative unity of experience is not based on the appear-
ances themselves (on sensibility alone), but on the connection of the
manifold through the understanding (in an apperception); and con-
sequently the unity of the supreme reality and the complete deter-
minability (possibility) of all things seems to lie in a supreme
understanding, and therefore in an intelligence. 
P 495
It begins not with concepts,
but with common experience, and thus bases itself on something
P 496
actually existing. But if this ground does not rest upon
the immovable rock of the absolutely necessary, it yields be-
neath our feet. And this latter support is itself in turn without
support, if there be any empty space beyond and under it, and
if it does not itself so fill all things as to leave no room for any
further question -- unless, that is to say, it be infinite in its
If we admit something as existing, no matter what this
something may be, we must also admit that there is something
which exists necessarily. For the contingent exists only under
the condition of some other contingent existence as its cause,
and from this again we must infer yet another cause, until we
are brought to a cause which is not contingent, and which is
therefore unconditionally necessary. This is the argument upon
which reason bases its advance to the primordial being. 
 Now reason looks around for a concept that squares with
so supreme a mode of existence as that of unconditioned ne-
cessity -- not for the purpose of inferring a priori from the con-
cept the existence of that for which it stands (for if that were
what it claimed to do, it ought to limit its enquiries to mere
concepts, and would not then require a given existence as its
basis), but solely in order to find among its various concepts
that concept which is in no respect incompatible with absolute
necessity. For that there must be something that exists with
absolute necessity, is regarded as having been established by
the first step in the argument. If, then, in removing every-
thing which is not compatible with this necessity, only one
existence remains, this existence must be the absolutely
necessary being, whether or not its necessity be comprehen-
sible, that is to say, deducible from its concept alone. 
Now that which in its concept contains a therefore for
every wherefore, that which is in no respect defective, that
which is in every way sufficient as a condition, seems to be
precisely the being to which absolute necessity can fittingly
be ascribed. For while it contains the conditions of all that
is possible, it itself does not require and indeed does not
allow of any condition, and therefore satisfies, at least in this
one feature, the concept of unconditioned necessity. In this
respect all other concepts must fall short of it; for since they
are deficient and in need of completion, they cannot have as
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their characteristic this independence of all further conditions. 
We are not indeed justified in arguing that what does not con-
tain the highest and in all respects complete condition is there-
fore itself conditioned in its existence. But we are justified in
saying that it does not possess that one feature through which
alone reason is in a position, by means of an a priori concept,
to know, in regard to any being, that it is unconditioned. 
The concept of an ens realissimum is therefore, of all con-
cepts of possible things, that which best squares with the con-
cept of an unconditionally necessary being; and though it may
not be completely adequate to it, we have no choice in the
matter, but find ourselves constrained to hold to it. For we
cannot afford to dispense with the existence of a necessary
being; and once its existence is granted, we cannot, in the
whole field of possibility, find anything that can make a
better grounded claim [than the ens realissimum] to such
pre-eminence in the mode of its existence. 
Such, then, is the natural procedure of human reason. It
begins by persuading itself of the existence of some necessary
being. This being it apprehends as having an existence that
is unconditioned. It then looks around for the concept of that
which is independent of any condition, and finds it in that
which is itself the sufficient condition of all else, that is, in that
which contains all reality. But that which is all-containing and
without limits is absolute unity, and involves the concept of a
single being that is likewise the supreme being. Accordingly,
we conclude that the supreme being, as primordial ground
of all things, must exist by absolute necessity. 
If what we have in view is the coming to a decision -- if, that
is to say, the existence of some sort of necessary being is taken
as granted, and if it be agreed further that we must come to
a decision as to what it is -- then the foregoing way of thinking
must be allowed to have a certain cogency. For in that case
no better choice can be made, or rather we have no choice
at all, but find ourselves compelled to decide in favour of the
absolute unity of complete reality, as the ultimate source of
possibility. If, however, we are not required to come to any
decision, and prefer to leave the issue open until the weight
of the evidence is such as to compel assent; if, in other words,
what we have to do is merely to estimate how much we really
P 498
know in the matter, and how much we merely flatter ourselves
that we know, then the foregoing argument is far from ap-
pearing in so advantageous a light, and special favour is
required to compensate for the defectiveness of its claims. 
For if we take the issue as being that which is here stated,
namely first, that from any given existence (it may be, merely
my own existence) we can correctly infer the existence of an
unconditionally necessary being; secondly, that we must regard
a being which contains all reality, and therefore every condi-
tion, as being absolutely unconditioned, and that in this con-
cept of an ens realissimum we have therefore found the concept
of a thing to which we can also ascribe absolute necessity --
granting all this, it by no means follows that the concept of a
limited being which does not have the highest reality is for
that reason incompatible with absolute reality. For although
I do not find in its concept that unconditioned which is in-
volved in the concept of the totality of conditions, we are not
justified in concluding that its existence must for this reason
be conditioned; just as I cannot say, in the case of a hypo-
thetical syllogism, that where a certain condition (in the case
under discussion, the condition of completeness in accordance
with [pure] concepts) does not hold, the conditioned also does
not hold. On the contrary, we are entirely free to hold that
any limited beings whatsoever, notwithstanding their being
limited, may also be unconditionally necessary, although we
cannot infer their necessity from the universal concepts which
we have of them. Thus the argument has failed to give us the
least concept of the properties of a necessary being, and indeed
is utterly ineffective. 
But this argument continues to have a certain importance
and to be endowed with an authority of which we cannot,
simply on the ground of this objective insufficiency, at once
proceed to divest it. For granting that there are in the idea of
reason obligations which are completely valid, but which in
their application to ourselves would be lacking in all reality --
that is, obligations to which there would be no motives -- save
on the assumption that there exists a supreme being to give
effect and confirmation to the practical laws, in such a situa-
tion we should be under an obligation to follow those concepts
which, though they may not be objectively sufficient, are yet,
P 499
according to the standard of our reason, preponderant, and in
comparison with which we know of nothing that is better and
more convincing. The duty of deciding would thus, by a practi-
cal addition, incline the balance so delicately preserved by the
indecisiveness of speculation. Reason would indeed stand con-
demned in its own judgment -- and there is none more circum-
spect -- if, when impelled by such urgent motives, it should
fail, however incomplete its insight, to conform its judgment
to those pleas which are at least of greater weight than any
others known to us. 
Though this argument, as resting on the inner insuffi-
ciency of the contingent, is in actual fact transcendental, it is
yet so simple and natural that, immediately it is propounded,
it commends itself to the commonest understanding. We see
things alter, come into being, and pass away; and these, or
at least their state, must therefore have a cause. But the same
question can be raised in regard to every cause that can be
given in experience. Where, therefore, can we more suitably
locate the ultimate causality than where there also exists the
highest causality, that is, in that being which contains prim-
ordially in itself the sufficient ground of every possible
effect, and the concept of which we can also very easily enter-
tain by means of the one attribute of an all-embracing per-
fection. This supreme cause we then proceed to regard as
absolutely necessary, inasmuch as we find it absolutely
necessary that we should ascend to it, and find no ground for
passing beyond it. And thus, in all peoples, there shine amidst
the most benighted polytheism some gleams of monotheism,
to which they have been led, not by reflection and profound
speculation, but simply by the natural bent of the common
understanding, as step by step it has come to apprehend its
own requirements. 
There are only three possible ways of proving the existence
of God by means of speculative reason. 
All the paths leading to this goal begin either from deter-
minate experience and the specific constitution of the world of
sense as thereby known, and ascend from it, in accordance
with laws of causality, to the supreme cause outside the
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world; or they start from experience which is purely indeter-
minate, that is, from experience of existence in general; or
finally they abstract from all experience, and argue completely
a priori, from mere concepts, to the existence of a supreme
cause. The first proof is the physico-theological, the second the
cosmological, the third the ontological. There are, and there
can be, no others. 
I propose to show that reason is as little able to make pro-
gress on the one path, the empirical, as on the other path, the
transcendental, and that it stretches its wings in vain in thus
attempting to soar above the world of sense by the mere power
of speculation. As regards the order in which these arguments
should be dealt with, it will be exactly the reverse of that
which reason takes in the progress of its own development, and
therefore of that which we have ourselves followed in the above
account. For it will be shown that, although experience is what
first gives occasion to this enquiry, it is the transcendental
concept which in all such endeavours marks out the goal that
reason has set itself to attain, and which is indeed its sole
guide in its efforts to achieve that goal. I shall therefore
begin with the examination of the transcendental proof, and
afterwards enquire what effect the addition of the empirical
factor can have in enhancing the force of the argument;
Section 4
It is evident, from what has been said, that the concept of
an absolutely necessary being is a concept of pure reason, that
is, a mere idea the objective reality of which is very far from
being proved by the fact that reason requires it. For the idea
instructs us only in regard to a certain unattainable complete-
ness, and so serves rather to limit the understanding than to
extend it to new objects. But we are here faced by what is
indeed strange and perplexing, namely, that while the infer-
P 501
ence from a given existence in general to some absolutely
necessary being seems to be both imperative and legitimate,
all those conditions under which alone the understanding can
form a concept of such a necessity are so many obstacles in
the way of our doing so. 
In all ages men have spoken of an absolutely necessary
being, and in so doing have endeavoured, not so much to
understand whether and how a thing of this kind allows even
of being thought, but rather to prove its existence. There is,
of course, no difficulty in giving a verbal definition of the con-
cept, namely, that it is something the non-existence of which
is impossible. But this yields no insight into the conditions
which make it necessary to regard the non-existence of a
thing as absolutely unthinkable. It is precisely these condi-
tions that we desire to know, in order that we may determine
whether or not, in resorting to this concept, we are thinking
anything at all. The expedient of removing all those condi-
tions which the understanding indispensably requires in order
to regard something as necessary, simply through the intro-
duction of the word unconditioned, is very far from sufficing
to show whether I am still thinking anything in the concept
of the unconditionally necessary, or perhaps rather nothing
at all. 
Nay more, this concept, at first ventured upon blindly,
and now become so completely familiar, has been supposed
to have its meaning exhibited in a number of examples; and
on this account all further enquiry into its intelligibility has
seemed to be quite needless. Thus the fact that every geo-
metrical proposition, as, for instance, that a triangle has three
angles, is absolutely necessary, has been taken as justifying us
in speaking of an object which lies entirely outside the sphere
of our understanding as if we understood perfectly what it is
that we intend to convey by the concept of that object. 
All the alleged examples are, without exception, taken
from judgments, not from things and their existence. But the
unconditioned necessity of judgments is not the same as an
absolute necessity of things. The absolute necessity of the
judgment is only a conditioned necessity of the thing, or of the
predicate in the judgment. The above proposition does not
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declare that three angles are absolutely necessary, but that,
under the condition that there is a triangle (that is, that a tri-
angle is given), three angles will necessarily be found in it. So
great, indeed, is the deluding influence exercised by this logi-
cal necessity that, by the simple device of forming an a priori
concept of a thing in such a manner as to include existence
within the scope of its meaning, we have supposed ourselves
to have justified the conclusion that because existence neces-
sarily belongs to the object of this concept -- always under the
condition that we posit the thing as given (as existing) -- we are
also of necessity, in accordance with the law of identity, re-
quired to posit the existence of its object, and that this being
is therefore itself absolutely necessary -- and this, to repeat, for
the reason that the existence of this being has already been
thought in a concept which is assumed arbitrarily and on con-
dition that we posit its object. 
If, in an identical proposition, I reject the predicate while
retaining the subject, contradiction results; and I therefore say
that the former belongs necessarily to the latter. But if we
reject subject and predicate alike, there is no contradiction;
for nothing is then left that can be contradicted. To posit a
triangle, and yet to reject its three angles, is self-contradictory;
but there is no contradiction in rejecting the triangle together
with its three angles. The same holds true of the concept of an
absolutely necessary being. If its existence is rejected, we re-
ject the thing itself with all its predicates; and no question of
contradiction can then arise. There is nothing outside it that
would then be contradicted, since the necessity of the thing
is not supposed to be derived from anything external; nor is
there anything internal that would be contradicted, since in
rejecting the thing itself we have at the same time rejected all
its internal properties. 'God is omnipotent' is a necessary
judgment. The omnipotence cannot be rejected if we posit a
Deity, that is, an infinite being; for the two concepts are
identical. But if we say, 'There is no God', neither the omni-
potence nor any other of its predicates is given; they are one
and all rejected together with the subject, and there is there-
fore not the least contradiction in such a judgment. 
We have thus seen that if the predicate of a judgment is
rejected together with the subject, no internal contradiction
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can result and that this holds no matter what the predicate
may be. The only way of evading this conclusion is to argue
that there are subjects which cannot be removed, and must
always remain. That, however, would only be another way of
saying that there are absolutely necessary subjects; and that is
the very assumption which I have called in question, and the
possibility of which the above argument professes to establish. 
For I cannot form the least concept of a thing which, should
it be rejected with all its predicates, leaves behind a contra-
diction; and in the absence of contradiction I have, through
pure a priori concepts alone, no criterion of impossibility. 
Notwithstanding all these general considerations, in which
every one must concur, we may be challenged with a case
which is brought forward as proof that in actual fact the
contrary holds, namely, that there is one concept, and indeed
only one, in reference to which the not-being or rejection of its
object is in itself contradictory, namely, the concept of the ens
realissimum. It is declared that it possesses all reality, and
that we are justified in assuming that such a being is possible
(the fact that a concept does not contradict itself by no means
proves the possibility of its object: but the contrary assertion
I am for the moment willing to allow). Now [the argument
proceeds] 'all reality' includes existence; existence is therefore
contained in the concept of a thing that is possible. If, then,
this thing is rejected, the internal possibility of the thing is
rejected -- which is self-contradictory. 
My answer is as follows. There is already a contradiction
in introducing the concept of existence -- no matter under what
title it may be disguised -- into the concept of a thing which
we profess to be thinking solely in reference to its possibility. 
If that be allowed as legitimate, a seeming victory has been won; 
++ A concept is always possible if it is not self-contradictory. 
This is the logical criterion of possibility, and by it the object of the
concept is distinguishable from the nihil negativum. But it may
none the less be an empty concept, unless the objective reality of the
synthesis through which the concept is generated has been specific-
ally proved; and such proof, as we have shown above, rests on prin-
ciples of possible experience, and not on the principle of analysis
(the law of contradiction). This is a warning against arguing
directly from the logical possibility of concepts to the real possibility
of things. 
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but in actual fact nothing at all is said: the assertion
is a mere tautology. We must ask: Is the proposition that
this or that thing (which, whatever it may be, is allowed
as possible) exists, an analytic or a synthetic proposition? If
it is analytic, the assertion of the existence of the thing adds
nothing to the thought of the thing; but in that case either
the thought, which is in us, is the thing itself, or we have pre-
supposed an existence as belonging to the realm of the possible,
and have then, on that pretext, inferred its existence from its
internal possibility -- which is nothing but a miserable tauto-
logy. The word 'reality', which in the concept of the thing
sounds other than the word 'existence' in the concept of the
predicate, is of no avail in meeting this objection. For if all
positing (no matter what it may be that is posited) is entitled
reality, the thing with all its predicates is already posited in
the concept of the subject, and is assumed as actual; and in the
predicate this is merely repeated. But if, on the other hand,
we admit, as every reasonable person must, that all existential
propositions are synthetic, how can we profess to maintain
that the predicate of existence cannot be rejected without con-
tradiction? This is a feature which is found only in analytic
propositions, and is indeed precisely what constitutes their
analytic character. 
I should have hoped to put an end to these idle and fruit-
less disputations in a direct manner, by an accurate deter-
mination of the concept of existence, had I not found that
the illusion which is caused by the confusion of a logical with
a real predicate (that is, with a predicate which determines a
thing) is almost beyond correction. Anything we please can
be made to serve as a logical predicate; the subject can even be
predicated of itself; for logic abstracts from all content. But a
determining predicate is a predicate which is added to the con-
cept of the subject and enlarges it. Consequently, it must not
be already contained in the concept. 
'Being' is obviously not a real predicate; that is, it is not a
concept of something which could be added to the concept of
a thing. It is merely the positing of a thing, or of certain deter-
minations, as existing in themselves. Logically, it is merely the
copula of a judgment. The proposition, 'God is omnipotent',
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contains two concepts, each of which has its object -- God and
omnipotence. The small word 'is' adds no new predicate, but
only serves to posit the predicate in its relation to the subject. If,
now, we take the subject (God) with all its predicates (among
which is omnipotence), and say 'God is', or 'There is a God', we
attach no new predicate to the concept of God, but only posit the
subject in itself with all its predicates, and indeed posit it as being
an object that stands in relation to my concept. The content of
both must be one and the same; nothing can have been added
to the concept, which expresses merely what is possible, by
my thinking its object (through the expression 'it is') as given
absolutely. Otherwise stated, the real contains no more than
the merely possible. A hundred real thalers do not contain
the least coin more than a hundred possible thalers. For as the
latter signify the concept, and the former the object and the
positing of the object, should the former contain more than the
latter, my concept would not, in that case, express the whole
object, and would not therefore be an adequate concept of it. 
My financial position is, however, affected very differently by
a hundred real thalers than it is by the mere concept of them
(that is, of their possibility). For the object, as it actually exists,
is not analytically contained in my concept, but is added to my
concept (which is a determination of my state) synthetically;
and yet the conceived hundred thalers are not themselves in
the least increased through thus acquiring existence outside
my concept. 
By whatever and by however many predicates we may
think a thing -- even if we completely determine it -- we do not
make the least addition to the thing when we further declare
that this thing is. Otherwise, it would not be exactly the same
thing that exists, but something more than we had thought in
the concept; and we could not, therefore, say that the exact
object of my concept exists. If we think in a thing every feature
of reality except one, the missing reality is not added by my
saying that this defective thing exists. On the contrary, it
exists with the same defect with which I have thought it, since
otherwise what exists would be something different from what
I thought. When, therefore, I think a being as the supreme
reality, without any defect, the question still remains whether
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it exists or not. For though, in my concept, nothing may be
lacking of the possible real content of a thing in general, some-
thing is still lacking in its relation to my whole state of thought,
namely, [in so far as I am unable to assert] that knowledge of
this object is also possible a posteriori. And here we find the
source of our present difficulty. Were we dealing with an ob-
ject of the senses, we could not confound the existence of the
thing with the mere concept of it. For through the concept the
object is thought only as conforming to the universal condi-
tions of possible empirical knowledge in general, whereas
through its existence it is thought as belonging to the context
of experience as a whole. In being thus connected with the
content of experience as a whole, the concept of the object is
not, however, in the least enlarged; all that has happened is
that our thought has thereby obtained an additional possible
perception. It is not, therefore, surprising that, if we attempt
to think existence through the pure category alone, we cannot
specify a single mark distinguishing it from mere possibility. 
Whatever, therefore, and however much, our concept of an
object may contain, we must go outside it, if we are to ascribe
existence to the object. In the case of objects of the senses, this
takes place through their connection with some one of our per-
ceptions, in accordance with empirical laws. But in dealing
with objects of pure thought, we have no means whatsoever
of knowing their existence, since it would have to be known
in a completely a priori manner. Our consciousness of all
existence (whether immediately through perception, or medi-
ately through inferences which connect something with per-
ception) belongs exclusively to the unity of experience; any
[alleged] existence outside this field, while not indeed such
as we can declare to be absolutely impossible, is of the
nature of an assumption which we can never be in a position
to justify. 
The concept of a supreme being is in many respects a very
useful idea; but just because it is a mere idea, it is altogether
incapable, by itself alone, of enlarging our knowledge in re-
gard to what exists. It is not even competent to enlighten us
as to the possibility of any existence beyond that which is
known in and through experience. The analytic criterion of
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possibility, as consisting in the principle that bare positives
(realities) give rise to no contradiction, cannot be denied to it. 
But since the realities are not given to us in their specific char-
acters; since even if they were, we should still not be in a posi-
tion to pass judgment; since the criterion of the possibility of
synthetic knowledge is never to be looked for save in ex-
perience, to which the object of an idea cannot belong, the
connection of all real properties in a thing is a synthesis, the
possibility of which we are unable to determine a priori. And
thus the celebrated Leibniz is far from having succeeded in
what he plumed himself on achieving -- the comprehension
a priori of the possibility of this sublime ideal being. 
The attempt to establish the existence of a supreme being
by means of the famous ontological argument of Descartes is
therefore merely so much labour and effort lost; we can no
more extend our stock of [theoretical] insight by mere ideas,
than a merchant can better his position by adding a few
noughts to his cash account. 
Section 5
To attempt to extract from a purely arbitrary idea the
existence of an object corresponding to it is a quite unnatural
procedure and a mere innovation of scholastic subtlety. Such
an attempt would never have been made if there had not been
antecedently, on the part of our reason,the need to assume as
a basis of existence in general something necessary (in which
our regress may terminate); and if, since this necessity must
be unconditioned and certain a priori, reason had not, in con-
sequence, been forced to seek a concept which would satisfy, if
possible, such a demand, and enable us to know an existence
in a completely a priori manner. Such a concept was supposed
to have been found in the idea of an ens realissimum; and that
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idea was therefore used only for the more definite knowledge
of that necessary being, of the necessary existence of which
we were already convinced, or persuaded, on other grounds. 
This natural procedure of reason was, however, concealed
from view, and instead of ending with this concept, the attempt
was made to begin with it, and so to deduce from it that
necessity of existence which it was only fitted to supplement. 
Thus arose the unfortunate ontological proof, which yields
satisfaction neither to the natural and healthy understanding
nor to the more academic demands of strict proof. 
The cosmological proof, which we are now about to ex-
amine, retains the connection of absolute necessity with the
highest reality, but instead of reasoning, like the former proof,
from the highest reality to necessity of existence, it reasons
from the previously given unconditioned necessity of some
being to the unlimited reality of that being. It thus enters upon
a course of reasoning which, whether rational or only pseudo-
rational, is at any rate natural, and the most convincing not
only for common sense but even for speculative understand-
ing. It also sketches the first outline of all the proofs in natural
theology, an outline which has always been and always will
be followed, however much embellished and disguised by
superfluous additions. This proof, termed by Leibniz the proof
a contingentia mundi, we shall now proceed to expound and
It runs thus: If anything exists, an absolutely necessary
being must also exist. Now I, at least, exist. Therefore an
absolutely necessary being exists. The minor premiss contains
an experience, the major premiss the inference from there
being any experience at all to the existence of the necessary. 
The proof therefore really begins with experience, and is not
wholly a priori or ontological. For this reason, and because
the object of all possible experience is called the world, it is en-
titled the cosmological proof. 
++ This inference is too well known to require detailed state-
ment. It depends on the supposedly transcendental law of natural
causality: that everything contingent has a cause, which, if itself
contingent, must likewise have a cause, till the series of subordinate
causes ends with an absolutely necessary cause, without which it
would have no completeness. 
P 508
Since, in dealing with the objects
P 509
of experience, the proof abstracts from all special properties
through which this world may differ from any other possible
world, the title also serves to distinguish it from the physico-
theological proof, which is based upon observations of the par-
ticular properties of the world disclosed to us by our senses. 
The proof then proceeds as follows: The necessary being
can be determined in one way only, that is, by one out of each
possible pair of opposed predicates. It must therefore be com-
pletely determined through its own concept. Now there is only
one possible concept which determines a thing completely
a priori, namely, the concept of the ens realissimum. The
concept of the ens realissimum is therefore the only concept
through which a necessary being can be thought. In other
words, a supreme being necessarily exists. 
In this cosmological argument there are combined so many
pseudo-rational principles that speculative reason seems in
this case to have brought to bear all the resources of its dia-
lectical skill to produce the greatest possible transcendental
illusion. The testing of the argument may meantime be post-
poned while we detail in order the various devices whereby
an old argument is disguised as a new one, and by which
appeal is made to the agreement of two witnesses, the one with
credentials of pure reason and the other with those of experi-
ence. In reality the only witness is that which speaks in the
name of pure reason; in the endeavour to pass as a second
witness it merely changes its dress and voice. In order to lay
a secure foundation for itself, this proof takes its stand on
experience, and thereby makes profession of being distinct
from the ontological proof, which puts its entire trust in pure
a priori concepts. But the cosmological proof uses this experi-
ence only for a single step in the argument, namely, to con-
clude the existence of a necessary being. What properties this
being may have, the empirical premiss cannot tell us. Reason
therefore abandons experience altogether, and endeavours to
discover from mere concepts what properties an absolutely
necessary being must have, that is, which among all possible
things contains in itself the conditions (requisita) essential to
absolute necessity. Now these, it is supposed, are nowhere to
be found save in the concept of an ens realissimum; and the
conclusion is therefore drawn, that the ens realissimum is the
P 510
absolutely necessary being. But it is evident that we are here
presupposing that the concept of the highest reality is com-
pletely adequate to the concept of absolute necessity of existence;
that is, that the latter can be inferred from the former. Now
this is the proposition maintained by the ontological proof; it
is here being assumed in the cosmological proof, and indeed
made the basis of the proof; and yet it is an assumption with
which this latter proof has professed to dispense. For ab-
solute necessity is an existence determined from mere con-
cepts. If I say, the concept of the ens realissimum is a con-
cept, and indeed the only concept, which is appropriate and
adequate to necessary existence, I must also admit that neces-
sary existence can be inferred from this concept. Thus the so-
called cosmological proof really owes any cogency which it
may have to the ontological proof from mere concepts. The
appeal to experience is quite superfluous; experience may per-
haps lead us to the concept of absolute necessity, but is unable
to demonstrate this necessity as belonging to any determinate
thing. For immediately we endeavour to do so, we must
abandon all experience and search among pure concepts
to discover whether any one of them contains the condi-
tions of the possibility of an absolutely necessary being. If
in this way we can determine the possibility of a necessary
being, we likewise establish its existence. For what we are
then saying is this: that of all possible beings there is one
which carries with it absolute necessity, that is, that this being
exists with absolute necessity. 
Fallacious and misleading arguments are most easily
detected if set out in correct syllogistic form. This we now
proceed to do in the instance under discussion. 
If the proposition, that every absolutely necessary being is
likewise the most real of all beings, is correct (and this is the
nervus probandi of the cosmological proof), it must, like all
affirmative judgments, be convertible, at least per accidens. 
It therefore follows that some entia realissima are likewise
absolutely necessary beings. But one ens realissimum is in no
respect different from another, and what is true of some under
this concept is true also of all. In this case, therefore, I can
convert the proposition simpliciter, not only per accidens,
and say that every ens realissimum is a necessary being. But
P 511
since this proposition is determined from its a priori concepts
alone, the mere concept of the ens realissimum must carry
with it the absolute necessity of that being; and this is precisely
what the ontological proof has asserted and what the cosmo-
logical proof has refused to admit, although the conclusions
of the latter are indeed covertly based on it. 
Thus the second path upon which speculative reason enters
in its attempt to prove the existence of a supreme being is not
only as deceptive as the first, but has this additional defect,
that it is guilty of an ignoratio elenchi. It professes to lead
us by a new path, but after a short circuit brings us back to
the very path which we had deserted at its bidding. 
I have stated that in this cosmological argument there lies
hidden a whole nest of dialectical assumptions, which the
transcendental critique can easily detect and destroy. These
deceptive principles I shall merely enumerate, leaving to the
reader, who by this time will be sufficiently expert in these
matters, the task of investigating them further, and of re-
futing them. 
We find, for instance, (1) the transcendental principle
whereby from the contingent we infer a cause. This principle
is applicable only in the sensible world; outside that world it
has no meaning whatsoever. For the mere intellectual concept
of the contingent cannot give rise to any synthetic proposition,
such as that of causality. The principle of causality has no
meaning and no criterion for its application save only in the
sensible world. But in the cosmological proof it is precisely in
order to enable us to advance beyond the sensible world that
it is employed. (2) The inference to a first cause, from the im-
possibility of an infinite series of causes, given one after the
other, in the sensible world. The principles of the employment
of reason do not justify this conclusion even within the world
of experience; still less beyond this world in a realm into
which this series can never be extended. (3) The unjustified
self-satisfaction of reason in respect of the completion of this
series. The removal of all the conditions without which no
concept of necessity is possible is taken by reason to be a com-
pletion of the concept of the series, on the ground that we can
then conceive nothing further. (4) The confusion between the
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logical possibility of a concept of all reality united into one
(without inner contradiction) and the transcendental possi-
bility of such a reality. In the case of the latter there is
needed a principle to establish the practicability of such a
synthesis, a principle which itself, however, can apply only
to the field of possible experiences -- etc. 
The procedure of the cosmological proof is artfully designed
to enable us to escape having to prove the existence of a neces-
sary being a priori through mere concepts. Such proof would
require to be carried out in the ontological manner, and that
is an enterprise for which we feel ourselves to be altogether in-
competent. Accordingly, we take as the starting-point of our
inference an actual existence (an experience in general), and ad-
vance, in such manner as we can, to some absolutely necessary
condition of this existence. We have then no need to show the
possibility of this condition. For if it has been proved to exist,
the question as to its possibility is entirely superfluous. If now
we want to determine more fully the nature of this necessary
being, we do not endeavour to do so in the manner that would
be really adequate, namely, by discovering from its concept the
necessity of its existence. For could we do that, we should be
in no need of an empirical starting-point. No, all we seek is
the negative condition (conditio sine qua non), without which a
being would not be absolutely necessary. And in all other kinds
of reasoning from a given consequence to its ground this would
be legitimate; but in the present case it unfortunately happens
that the condition which is needed for absolute necessity is only
to be found in one single being. This being must therefore
contain in its concept all that is required for absolute necessity,
and consequently it enables me to infer this absolute necessity
a priori. I must therefore be able also to reverse the inference,
and to say: Anything to which this concept (of supreme reality)
applies is absolutely necessary. If I cannot make this inference
(as I must concede, if I am to avoid admitting the ontological
proof), I have come to grief in the new way that I have been
following, and am back again at my starting-point. The con-
cept of the supreme being satisfies all questions a priori which
can be raised regarding the inner determinations of a thing,
and is therefore an ideal that is quite unique, in that the con-
cept, while universal, also at the same time designates an
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individual as being among the things that are possible. But it
does not give satisfaction concerning the question of its own
existence -- though this is the real purpose of our enquiries --
and if anyone admitted the existence of a necessary being but
wanted to know which among all [existing] things is to be
identified with that being, we could not answer: "This, not
that. is the necessary being. "
We may indeed be allowed to postulate the existence of an
all-sufficient being, as the cause of all possible effects, with a
view to lightening the task of reason in its search for the unity
of the grounds of explanation. But in presuming so far as to
say that such a being necessarily exists, we are no longer
giving modest expression to an admissible hypothesis, but
are confidently laying claim to apodeictic certainty. For the
knowledge of what we profess to know as absolutely necessary
must itself carry with it absolute necessity. 
The whole problem of the transcendental ideal amounts to
this: either, given absolute necessity, to find a concept which
possesses it, or, given the concept of something, to find that
something to be absolutely necessary. If either task be possible,
so must the other; for reason recognises that only as absolutely
necessary which follows of necessity from its concept. But both
tasks are quite beyond our utmost efforts to satisfy our under-
standing in this matter; and equally unavailing are all attempts
to induce it to acquiesce in its incapacity. 
Unconditioned necessity, which we so indispensably re-
quire as the last bearer of all things, is for human reason the
veritable abyss. Eternity itself, in all its terrible sublimity, as
depicted by a Haller, is far from making the same overwhelm-
ing impression on the mind; for it only measures the duration
of things, it does not support them. We cannot put aside, and
yet also cannot endure the thought, that a being, which we
represent to ourselves as supreme amongst all possible beings,
should, as it were, say to itself: 'I am from eternity to eternity,
and outside me there is nothing save what is through my will,
but whence then am I? ' All support here fails us; and the
greatest perfection, no less than the least perfection, is unsub-
stantial and baseless for the merely speculative reason, which
P 514
makes not the least effort to retain either the one or the other,
and feels indeed no loss in allowing them to vanish entirely. 
Many forces in nature, which manifest their existence
through certain effects, remain for us inscrutable; for we cannot
track them sufficiently far by observation. Also, the transcend-
ental object lying at the basis of appearances (and with it the
reason why our sensibility is subject to certain supreme con-
ditions rather than to others) is and remains for us inscrutable. 
The thing itself is indeed given, but we can have no insight
into its nature. But it is quite otherwise with an ideal of pure
reason; it can never be said to be inscrutable. For since it is
not required to give any credentials of its reality save only
the need on the part of reason to complete all synthetic unity
by means of it; and since, therefore, it is in no wise given as
thinkable object, it cannot be inscrutable in the manner in
which an object is. On the contrary it must, as a mere idea,
find its place and its solution in the nature of reason, and
must therefore allow of investigation. For it is of the very
essence of reason that we should be able to give an account
of all our concepts, opinions, and assertions, either upon
objective or, in the case of mere illusion, upon subjective
of the Dialectical Illusion in all Transcendental Proofs of the Existence of
a Necessary Being 
Both the above proofs were transcendental, that is, were
attempted independently of empirical principles. For although
the cosmological proof presupposes an experience in general,
it is not based on any particular property of this experience
but on pure principles of reason, as applied to an existence
given through empirical consciousness in general. Further, it
soon abandons this guidance and relies on pure concepts alone. 
What, then, in these transcendental proofs is the cause of the
dialectical but natural illusion which connects the concepts of
necessity and supreme reality, and which realises and hypos-
tatises what can be an idea only? Why are we constrained
to assume that some one among existing things is in itself
P 515
necessary, and yet at the same time to shrink back from the
existence of such a being as from an abyss? And how are
we to secure that reason may come to an agreement with
itself in this matter, and that from the wavering condition of
a diffident approval, ever again withdrawn, it may arrive at
settled insight? 
There is something very strange in the fact, that once we
assume something to exist we cannot avoid inferring that
something exists necessarily. The cosmological argument rests
on this quite natural (although not therefore certain) infer-
ence. On the other hand, if I take the concept of anything, no
matter what, I find that the existence of this thing can never
be represented by me as absolutely necessary, and that, what-
ever it may be that exists, nothing prevents me from think-
ing its non-existence. Thus while I may indeed be obliged to
assume something necessary as a condition of the existent in
general, I cannot think any particular thing as in itself neces-
sary. In other words, I can never complete the regress to the
conditions of existence save by assuming a necessary being
and yet am never in a position to begin with such a being. 
If I am constrained to think something necessary as a
condition of existing things, but am unable to think any
particular thing as in itself necessary, it inevitably follows that
necessity and contingency do not concern the things them-
selves; otherwise there would be a contradiction. Conse-
quently, neither of these two principles can be objective. They
may, however, be regarded as subjective principles of reason. 
The one calls upon us to seek something necessary as a con-
dition of all that is given as existent, that is, to stop nowhere
until we have arrived at an explanation which is complete
a priori; the other forbids us ever to hope for this completion,
that is, forbids us to treat anything empirical as uncondi-
tioned and to exempt ourselves thereby from the toil of its
further derivation. Viewed in this manner, the two principles,
as merely heuristic and regulative, and as concerning only the
formal interest of reason, can very well stand side by side. The
one prescribes that we are to philosophise about nature as if
there were a necessary first ground for all that belongs to
existence -- solely, however, for the purpose of bringing sys-
tematic unity into our knowledge, by always pursuing such
P 516
an idea, as an imagined ultimate ground. The other warns us
not to regard any determination whatsoever of existing things
as such an ultimate ground, that is, as absolutely necessary,
but to keep the way always open for further derivation, and
so to treat each and every determination as always condi-
tioned by something else. But if everything which is perceived
in things must necessarily be treated by us as conditioned,
nothing that allows of being empirically given can be re-
garded as absolutely necessary. 
Since, therefore, the absolutely necessary is only intended
to serve as a principle for obtaining the greatest possible
unity among appearances, as being their ultimate ground;
and since -- inasmuch as the second rule commands us al-
ways to regard all empirical causes of unity as themselves
derived -- we can never reach this unity within the world, it
follows that we must regard the absolutely necessary as being
outside the world. 
While the philosophers of antiquity regard all form in
nature as contingent, they follow the judgment of the common
man in their view of matter as original and necessary. But if,
instead of regarding matter relatively, as substratum of ap-
pearances, they had considered it in itself, and as regards its
existence, the idea of absolute necessity would at once have
disappeared. For there is nothing which absolutely binds
reason to accept such an existence; on the contrary it can al-
ways annihilate it in thought, without contradiction; absolute
necessity is a necessity that is to be found in thought alone. 
This belief must therefore have been due to a certain regu-
lative principle. In fact extension and impenetrability (which
between them make up the concept of matter) constitute the
supreme empirical principle of the unity of appearances;
and this principle, so far as it is empirically unconditioned,
has the character of a regulative principle. Nevertheless,
since every determination of the matter which constitutes what
is real in appearances, including impenetrability, is an effect
(action) which must have its cause and which is therefore
always derivative in character, matter is not compatible with
the idea of a necessary being as a principle of all derived unity. 
(For its real properties, being derivative, are one and all only
P 517
conditionally necessary, and so allow of being removed --
wherewith the whole existence of matter would be removed. )
If this were not the case, we should have reached the ulti-
mate ground of unity by empirical means -- which is for-
bidden by the second regulative principle. It therefore follows
that matter, and in general whatever belongs to the world,
is not compatible with the idea of a necessary original being,
even when the latter is regarded simply as a principle of the
greatest empirical unity. That being or principle must be set
outside the world, leaving us free to derive the appearances
of the world and their existence from other appearances, with
unfailing confidence, just as if there were no necessary being,
while yet we are also free to strive unceasingly towards the
completeness of that derivation, just as if such a being were
presupposed as an ultimate ground. 
As follows from these considerations, the ideal of the
supreme being is nothing but a regulative principle of reason,
which directs us to look upon all connection in the world as if
it originated from an all-sufficient necessary cause. We can
base upon the ideal the rule of a systematic and, in accord-
ance with universal laws, necessary unity in the explanation
of that connection; but the ideal is not an assertion of an
existence necessary in itself. At the same time we cannot avoid
the transcendental subreption, by which this formal principle
is represented as constitutive, and by which this unity is hypos-
tatised. We proceed here just as we do in the case of space. 
Space is only a principle of sensibility, but since it is the
primary source and condition of all shapes, which are only so
many limitations of itself, it is taken as something absolutely
necessary, existing in its own right, and as an object given a -
priori in itself. In the same way, since the systematic unity of
nature cannot be prescribed as a principle for the empirical
employment of our reason, except in so far as we presuppose
the idea of an ens realissimum as the supreme cause, it is
quite natural that this latter idea should be represented as an
actual object, which, in its character of supreme condition, is
also necessary -- thus changing a regulative into a constitutive
principle. That such a substitution has been made becomes
evident, when we consider this supreme being, which relatively
P 518
to the world is absolutely (unconditionally) necessary, as a
thing in and by itself. For we are then unable to conceive
what can be meant by its necessity. The concept of necessity
is only to be found in our reason, as a formal condition of
thought; it does not allow of being hypostatised as a material
condition of existence. 
Section 6
If, then, neither the concept of things in general nor the
experience of any existence in general can supply what is re-
quired, it remains only to try whether a determinate experience,
the experience of the things of the present world, and the con-
stitution and order of these, does not provide the basis of a
proof which may help us to attain to an assured conviction of a
supreme being. Such proof we propose to entitle the physico-
theological. Should this attempt also fail, it must follow that
no satisfactory proof of the existence of a being corresponding
to our transcendental idea can be possible by pure speculative
 In view of what has already been said, it is evident that we
can count upon a quite easy and conclusive answer to this
enquiry. For how can any experience ever be adequate to an
idea? The peculiar nature of the latter consists just in the fact
that no experience can ever be equal to it. The transcendental
idea of a necessary and all-sufficient original being is so
overwhelmingly great, so high above everything empirical,
the latter being always conditioned, that it leaves us at a
loss, partly because we can never find in experience material
sufficient to satisfy such a concept, and partly because it is
always in the sphere of the conditioned that we carry out our
search, seeking there ever vainly for the unconditioned -- no
law of any empirical synthesis giving us an example of any
such unconditioned or providing the least guidance in its
If the supreme being should itself stand in this chain of
P 519
conditions, it would be a member of the series, and like the
lower members which it precedes, would call for further en-
quiry as to the still higher ground from which it follows. If, on
the other hand, we propose to separate it from the chain, and
to conceive it as a purely intelligible being, existing apart from
the series of natural causes, by what bridge can reason contrive
to pass over to it? For all laws governing the transition from
effects to causes, all synthesis and extension of our knowledge,
refer to nothing but possible experience, and therefore solely
to objects of the sensible world, and apart from them can have
no meaning whatsoever. 
This world presents to us so immeasurable a stage of
variety, order, purposiveness, and beauty, as displayed alike in
its infinite extent and in the unlimited divisibility of its parts,
that even with such knowledge as our weak understanding
can acquire of it, we are brought face to face with so many
marvels immeasurably great, that all speech loses its force, all
numbers their power to measure, our thoughts themselves all
definiteness, and that our judgment of the whole resolves itself
into an amazement which is speechless, and only the more elo-
quent on that account. Everywhere we see a chain of effects
and causes, of ends and means, a regularity in origination and
dissolution. Nothing has of itself come into the condition in
which we find it to exist, but always points to something
else as its cause, while this in turn commits us to repetition
of the same enquiry. The whole universe must thus sink into
the abyss of nothingness, unless, over and above this infinite
chain of contingencies, we assume something to support it --
something which is original and independently self-subsistent,
and which as the cause of the origin of the universe secures
also at the same time its continuance. What magnitude are we
to ascribe to this supreme cause -- admitting that it is supreme
in respect of all things in the world? We are not acquainted
with the whole content of the world, still less do we know
how to estimate its magnitude by comparison with all that is
possible. But since we cannot, as regards causality, dispense
with an ultimate and supreme being, what is there to pre-
vent us ascribing to it a degree of perfection that sets it above
everything else that is possible?  This we can easily do -- though
P 520
only through the slender outline of an abstract concept -- by
representing this being to ourselves as combining in itself all
possible perfection, as in a single substance. This concept is
in conformity with the demand of our reason for parsimony
of principles; it is free from self-contradiction, and is never
decisively contradicted by any experience; and it is likewise
of such a character that it contributes to the extension of
the employment of reason within experience, through the
guidance which it yields in the discovery of order and
This proof always deserves to be mentioned with respect. 
It is the oldest, the clearest, and the most accordant with the
common reason of mankind. It enlivens the study of nature,
just as it itself derives its existence and gains ever new vigour
from that source. It suggests ends and purposes, where our
observation would not have detected them by itself, and extends
our knowledge of nature by means of the guiding-concept of a
special unity, the principle of which is outside nature. This
knowledge again reacts on its cause, namely, upon the idea
which has led to it, and so strengthens the belief in a supreme
Author [of nature] that the belief acquires the force of an irre-
sistible conviction. 
It would therefore not only be uncomforting but utterly
vain to attempt to diminish in any way the authority of this
argument. Reason, constantly upheld by this ever-increasing
evidence, which, though empirical, is yet so powerful, can-
not be so depressed through doubts suggested by subtle and
abstruse speculation, that it is not at once aroused from the
indecision of all melancholy reflection, as from a dream, by
one glance at the wonders of nature and the majesty of the
universe -- ascending from height to height up to the all-
highest, from the conditioned to its conditions, up to the
supreme and unconditioned Author [of all conditioned
But although we have nothing to bring against the ration-
ality and utility of this procedure, but have rather to commend
and to further it, we still cannot approve the claims, which this
mode of argument would fain advance, to apodeictic certainty
and to an assent founded on no special favour or support from
other quarters. It cannot hurt the good cause, if the dogmatic
P 521
language of the overweening sophist be toned down to the
more moderate and humble requirements of a belief adequate
to quieten our doubts, though not to command unconditional
submission. I therefore maintain that the physico-theological
proof can never by itself establish the existence of a supreme
being, but must always fall back upon the ontological argu-
ment to make good its deficiency. It only serves as an intro-
duction to the ontological argument; and the latter therefore
contains (in so far as a speculative proof is possible at all) the
one possible ground of proof with which human reason can
never dispense. 
The chief points of the physico-theological proof are as
follows: (1) In the world we everywhere find clear signs of an
order in accordance with a determinate purpose, carried out
with great wisdom; and this in a universe which is indescrib-
ably varied in content and unlimited in extent. (2) This pur-
posive order is quite alien to the things of the world, and only
belongs to them contingently; that is to say, the diverse things
could not of themselves have co-operated, by so great a com-
bination of diverse means, to the fulfilment of determinate
final purposes, had they not been chosen and designed for
these purposes by an ordering rational principle in conformity
with underlying ideas. (3) There exists, therefore, a sublime
and wise cause (or more than one), which must be the cause
of the world not merely as a blindly working all-powerful
nature, by fecundity, but as intelligence, through freedom. 
(4) The unity of this cause may be inferred from the unity of
the reciprocal relations existing between the parts of the world,
as members of an artfully arranged structure -- inferred with
certainty in so far as our observation suffices for its verification
and beyond these limits with probability, in accordance with
the principles of analogy. 
We need not here criticise natural reason too strictly in
regard to its conclusion from the analogy between certain
natural products and what our human art produces when we
do violence to nature, and constrain it to proceed not according
to its own ends but in conformity with ours -- appealing to the
similarity of these particular natural products with houses,
ships, watches. Nor need we here question its conclusion that
P 522
there lies at the basis of nature a causality similar to that
responsible for artificial products, namely, an understand-
ing and a will; and that the inner possibility of a self-acting
nature (which is what makes all art, and even, it may be,
reason itself, possible) is therefore derived from another,
though superhuman, art -- a mode of reasoning which could
not perhaps withstand a searching transcendental criticism. 
But at any rate we must admit that, if we are to specify a
cause at all, we cannot here proceed more securely than by
analogy with those purposive productions of which alone the
cause and mode of action are fully known to us. Reason could
never be justified in abandoning the causality which it knows
for grounds of explanation which are obscure, of which it
does not have any knowledge, and which are incapable of
On this method of argument, the purposiveness and har-
monious adaptation of so much in nature can suffice to prove
the contingency of the form merely, not of the matter, that is,
not of the substance in the world. To prove the latter we should
have to demonstrate that the things in the world would not
of themselves be capable of such order and harmony, in
accordance with universal laws, if they were not in their
substance the product of supreme wisdom. But to prove this
we should require quite other grounds of proof than those
which are derived from the analogy with human art. The
utmost, therefore, that the argument can prove is an architect
of the world who is always very much hampered by the
adaptability of the material in which he works, not a creator
of the world to whose idea everything is subject. This, how-
ever, is altogether inadequate to the lofty purpose which we
have before our eyes, namely, the proof of an all-sufficient
primordial being. To prove the contingency of matter itself,
we should have to resort to a transcendental argument, and
this is precisely what we have here set out to avoid. 
The inference, therefore, is that the order and purposive-
ness everywhere observable throughout the world may be
regarded as a completely contingent arrangement, and that
we may argue to the existence of a cause proportioned to it. 
But the concept of this cause must enable us to know some-
P 523
thing quite determinate about it, and can therefore be no
other than the concept of a being who possesses all might,
wisdom, etc. , in a word, all the perfection which is proper to
an all-sufficient being. For the predicates -- 'very great', 'as-
tounding', 'immeasurable' in power and excellence -- give no
determinate concept at all, and do not really tell us what the
thing is in itself. They are only relative representations of the
magnitude of the object, which the observer, in contemplat-
ing the world, compares with himself and with his capacity
of comprehension, and which are equally terms of eulogy
whether we be magnifying the object or be depreciating the
observing subject in relation to that object. Where we are
concerned with the magnitude (of the perfection) of a thing,
there is no determinate concept except that which compre-
hends all possible perfection; and in that concept only the
allness (omnitudo) of the reality is completely determined. 
Now no one, I trust, will be so bold as to profess that he
comprehends the relation of the magnitude of the world as he
has observed it (alike as regards both extent and content) to
omnipotence, of the world order to supreme wisdom, of the
world unity to the absolute unity of its Author, etc. Physico-
theology is therefore unable to give any determinate concept
of the supreme cause of the world, and cannot therefore serve
as the foundation of a theology which is itself in turn to
form the basis of religion. 
To advance to absolute totality by the empirical road is
utterly impossible. None the less this is what is attempted in
the physico-theological proof. What, then, are the means
which have been adopted to bridge this wide abyss? 
The physico-theological argument can indeed lead us to
the point of admiring the greatness, wisdom, power, etc. , of
the Author of the world, but can take us no further. Accord-
ingly, we then abandon the argument from empirical grounds
of proof, and fall back upon the contingency which, in the
first steps of the argument, we had inferred from the order and
purposiveness of the world. With this contingency as our sole
premiss, we then advance, by means of transcendental con-
cepts alone, to the existence of an absolutely necessary being,
and [as a final step] from the concept of the absolute necessity
of the first cause to the completely determinate or determin-
P 524
able concept of that necessary being, namely, to the concept of
an all-embracing reality. Thus the physico-theological proof,
failing in its undertaking, has in face of this difficulty suddenly
fallen back upon the cosmological proof; and since the latter
is only a disguised ontological proof, it has really achieved
its purpose by pure reason alone -- although at the start it
disclaimed all kinship with pure reason and professed to
establish its conclusions on convincing evidence derived from
Those who propound the physico-theological argument
have therefore no ground for being so contemptuous in their
attitude to the transcendental mode of proof, posing as clear-
sighted students of nature, and complacently looking down
upon that proof as the artificial product of obscure speculative
refinements. For were they willing to scrutinise their own pro-
cedure, they would find that, after advancing some considerable
way on the solid ground of nature and experience, and finding
themselves just as far distant as ever from the object which dis-
closes itself to their reason, they suddenly leave this ground, and
pass over into the realm of mere possibilities, where they hope
upon the wings of ideas to draw near to the object -- the object
that has refused itself to all their empirical enquiries. For after
this tremendous leap, when they have, as they think, found firm
ground, they extend their concept -- the determinate concept,
into the possession of which they have now come, they know not
how -- over the whole sphere of creation. And the ideal, [which
this reasoning thus involves, and] which is entirely a product
of pure reason, they then elucidate by reference to experience,
though inadequately enough, and in a manner far below the
dignity of its object; and throughout they persist in refusing
to admit that they have arrived at this knowledge or hypo-
thesis by a road quite other than that of experience. 
Thus the physico-theological proof of the existence of an
original or supreme being rests upon the cosmological proof,
and the cosmological upon the ontological. And since, besides
these three, there is no other path open to speculative reason,
the ontological proof from pure concepts of reason is the only
possible one, if indeed any proof of a proposition so far exalted
above all empirical employment of the understanding is pos-
sible at all. 
P 525
Section 7
If I understand by theology knowledge of the original
being, it is based either solely upon reason (theologia rationa-
lis) or upon revelation (revelata). The former thinks its object
either through pure reason, solely by means of transcendental
concepts (ens originarium, realissimum, ens entium), in which
case it is entitled transcendental theology, or through a con-
cept borrowed from nature (from the nature of our soul) -- a
concept of the original being as a supreme intelligence -- and
it would then have to be called natural theology. Those who
accept only a transcendental theology are called deists; those
who also admit a natural theology are called theists. The
former grant that we can know the existence of an original
being solely through reason, but maintain that our concept
of it is transcendental only, namely, the concept of a being
which possesses all reality, but which we are unable to de-
termine in any more specific fashion. The latter assert that
reason is capable of determining its object more precisely
through analogy with nature, namely, as a being which,
through understanding and freedom, contains in itself the
ultimate ground of everything else. Thus the deist repre-
sents this being merely as a cause of the world (whether by
the necessity of its nature or through freedom, remains un-
decided), the theist as the Author of the world. 
Transcendental theology, again, either proposes to deduce
the existence of the original being from an experience in
general (without determining in any more specific fashion the
nature of the world to which the experience belongs), and is
then entitled cosmo-theology; or it believes that it can know the
existence of such a being through mere concepts, without the
help of any experience whatsoever, and is then entitled onto-
Natural theology infers the properties and the existence of
P 526
an Author of the world from the constitution, the order and
unity, exhibited in the world -- a world in which we have to
recognise two kinds of causality with their rules, namely,
nature and freedom. From this world natural theology ascends
to a supreme intelligence, as the principle either of all natural
or of all moral order and perfection. In the former case it is
entitled physico-theology, in the latter moral theology. 
Since we are wont to understand by the concept of God not
merely an eternal nature that works blindly, as the root-source
of all things, but a supreme being who through understanding
and freedom is the Author of all things; and since it is in this
sense only that the concept interests us, we could, strictly
speaking, deny to the deist any belief in God, allowing him
only the assertion of an original being or supreme cause. How-
ever, since no one ought to be accused of denying what he only
does not venture to assert, it is less harsh and more just to
say that the deist believes in a God, the theist in a living God
(summa intelligentia). We shall now proceed to enquire what
are the possible sources of all these endeavours of reason. 
For the purposes of this enquiry, theoretical knowledge
may be defined as knowledge of what is, practical knowledge
as the representation of what ought to be. On this definition, the
theoretical employment of reason is that by which I know a -
priori (as necessary) that something is, and the practical that
by which it is known a priori what ought to happen. Now if it
is indubitably certain that something is or that something
ought to happen, but this certainty is at the same time only
conditional, then a certain determinate condition of it can be
absolutely necessary, or can be an optional and contingent
presupposition. In the former case the condition is postulated
(per thesin); in the latter case it is assumed (per hypothesin). 
++ Not theological ethics: for this contains moral laws, which pre-
suppose the existence of a supreme ruler of the world. Moral theology,
on the other hand, is a conviction of the existence of a supreme being
-- a conviction which bases itself on moral laws. 
P 526
Now since there are practical laws which are absolutely neces-
sary, that is, moral laws, it must follow that if these neces-
sarily presuppose the existence of any being as the condition of
P 527
the possibility of their obligatory power, this existence must
be postulated; and this for the sufficient reason that the condi-
tioned, from which the inference is drawn to this determinate
condition, is itself known a priori to be absolutely necessary. 
At some future time we shall show that the moral laws do
not merely presuppose the existence of a supreme being, but
also, as themselves in a different connection absolutely neces-
sary, justify us in postulating it, though, indeed, only from
a practical point of view. For the present, however, we are
leaving this mode of argument aside. 
Where we are dealing merely with what is (not with what
ought to be), the conditioned, which is given to us in experi-
ence, is always thought as being likewise contingent. That
which conditions it is not, therefore, known as absolutely
necessary, but serves only as something relatively necessary
or rather as needful; in itself and a priori it is an arbitrary
presupposition, assumed by us in our attempt to know the
conditioned by means of reason. If, therefore in the field of
theoretical knowledge, the absolute necessity of a thing were
to be known, this could only be from a priori concepts, and
never by positing it as a cause relative to an existence given
in experience. 
Theoretical knowledge is speculative if it concerns an ob-
ject, or those concepts of an object, which cannot be reached
in any experience. It is so named to distinguish it from the
knowledge of nature, which concerns only those objects or pre-
dicates of objects which can be given in a possible experience. 
The principle by which, from that which happens (the em-
pirically contingent) [viewed] as [an] effect, we infer a cause,
is a principle of the knowledge of nature, but not of specula-
tive knowledge. For, if we abstract from what it is as a principle
that contains the condition of all possible experience, and leav-
ing aside all that is empirical attempt to assert it of the con-
tingent in general, there remains not the least justification for
any synthetic proposition such as might show us how to pass
from that which is before us to something quite different
(called its cause). In this merely speculative employment any
meaning whose objective reality admits of being made intelli-
gible in concreto, is taken away not only from the concept of
the contingent but from the concept of a cause. 
P 528
If we infer from the existence of things in the world the
existence of their cause, we are employing reason, not in the
knowledge of nature, but in speculation. For the former type
of knowledge treats as empirically contingent, and refers to a
cause, not the things themselves (substances), but only that
which happens, that is, their states. That substance (matter) is
itself contingent in its existence would have to be known in a
purely speculative manner. Again, even if we were speaking
only of the form of the world, the way in which things are con-
nected and change, and sought to infer from this a cause
entirely distinct from the world, this would again be a judg-
ment of purely speculative reason, since the object which we
are inferring is not an object of a possible experience. So em-
ployed, the principle of causality, which is only valid within
the field of experience, and outside this field has no applica-
tion, nay, is indeed meaningless, would be altogether diverted
from its proper use. 
Now I maintain that all attempts to employ reason in theo-
logy in any merely speculative manner are altogether fruit-
less and by their very nature null and void, and that the prin-
ciples of its employment in the study of nature do not lead to
any theology whatsoever. Consequently, the only theology of
reason which is possible is that which is based upon moral laws
or seeks guidance from them. All synthetic principles of reason
allow only of an immanent employment; and in order to have
knowledge of a supreme being we should have to put them to
a transcendent use, for which our understanding is in no way
fitted. If the empirically valid law of causality is to lead to the
original being, the latter must belong to the chain of objects of
experience, and in that case it would, like all appearances, be
itself again conditioned. But even if the leap beyond the limits
of experience, by means of the dynamical law of the relation of
effects to their causes, be regarded as permissible, what sort of
a concept could we obtain by this procedure? It is far from pro-
viding the concept of a supreme being, since experience never
gives us the greatest of all possible effects, such as would be re-
quired to provide the evidence for a cause of that kind. Should
we seek to make good this lack of determination in our concept,
by means of a mere idea of [a being that possesses] the highest
perfection and original necessity, this may indeed be granted
P 529
as a favour; it cannot be demanded as a right on the strength
of an incontrovertible proof. The physico-theological proof, as
combining speculation and intuition, might therefore perhaps
give additional weight to other proofs (if such there be); but
taken alone, it serves only to prepare the understanding for
theological knowledge, and to give it a natural leaning in this
direction, not to complete the work in and by itself. 
All this clearly points to the conclusion that transcendental
questions allow only of transcendental answers, that is, an-
swers exclusively based on concepts that are a priori, without
the least empirical admixture. But the question under con-
sideration is obviously synthetic, calling for an extension of our
knowledge beyond all limits of experience, namely, to the
existence of a being that is to correspond to a mere idea
of ours, an idea that cannot be paralleled in any experience. 
Now as we have already proved, synthetic a priori knowledge
is possible only in so far as it expresses the formal conditions
of a possible experience; and all principles are therefore only
of immanent validity, that is, they are applicable only to ob-
jects of empirical knowledge, to appearances. Thus all attempts
to construct a theology through purely speculative reason, by
means of a transcendental procedure, are without result. 
But even if anyone prefers to call in question all those
proofs which have been given in the Analytic, rather than
allow himself to be robbed of his conviction of the conclusive-
ness of the arguments upon which he has so long relied, he
still cannot refuse to meet my demand that he should at least
give a satisfactory account how, and by what kind of inner
illumination, he believes himself capable of soaring so far
above all possible experience, on the wings of mere ideas. 
New proofs, or attempts to improve upon the old ones, I
would ask to be spared. There is not indeed, in this field, much
room for choice, since all merely speculative proofs in the
end bring us always back to one and the same proof, namely,
the ontological; and I have therefore no real ground to fear
the fertile ingenuity of the dogmatic champions of super-
sensible reason. I shall not, however, decline the challenge
to discover the fallacy in any attempt of this kind, and
so to nullify its claims; and this I can indeed do without
P 530
considering myself a particularly combative person. But by
such means I should never succeed in eradicating the hope
of better fortune in those who have once become accustomed
to dogmatic modes of persuasion; and I therefore confine
myself to the moderate demand, that they give, in terms
which are universal and which are based on the nature of the
human understanding and of all our other sources of know-
ledge, a satisfactory answer to this one question: how we can
so much as make a beginning in the proposed task of ex-
tending our knowledge entirely a priori, and of carrying it
into a realm where no experience is possible to us, and in
which there is therefore no means of establishing the object-
ive reality of any concept that we have ourselves invented. 
In whatever manner the understanding may have arrived at
a concept, the existence of its object is never, by any process
of analysis, discoverable within it; for the knowledge of the
existence of the object consists precisely in the fact that the
object is posited in itself, beyond the [mere] thought of it. 
Through concepts alone, it is quite impossible to advance to
the discovery of new objects and supernatural beings; and it
is useless to appeal to experience, which in all cases yields only
But although reason, in its merely speculative employ-
ment, is very far from being equal to so great an undertak-
ing, namely, to demonstrate the existence of a supreme being,
it is yet of very great utility in correcting any knowledge of this
being which may be derived from other sources, in making it
consistent with itself and with every point of view from which
intelligible objects may be regarded, and in freeing it from
everything incompatible with the concept of an original
being and from all admixture of empirical limitations. 
Transcendental theology is still, therefore, in spite of all
its disabilities, of great importance in its negative employ-
ment, and serves as a permanent censor of our reason, in so
far as the latter deals merely with pure ideas which, as such,
allow of no criterion that is not transcendental. For if, in some
other relation, perhaps on practical grounds, the presupposi-
tion of a supreme and all-sufficient being, as highest intelli-
P 531
gence, established its validity beyond all question, it would be
of the greatest importance accurately to determine this con-
cept on its transcendental side, as the concept of a necessary
and supremely real being, to free it from whatever, as be-
longing to mere appearance (anthropomorphism in its wider
sense), is out of keeping with the supreme reality, and at
the same time to dispose of all counter-assertions, whether
atheistic, deistic, or anthropomorphic. Such critical treatment
is, indeed, far from being difficult, inasmuch as the same
grounds which have enabled us to demonstrate the inability of
human reason to maintain the existence of such a being must
also suffice to prove the invalidity of all counter-assertions. 
For from what source could we, through a purely speculative
employment of reason, derive the knowledge that there is no
supreme being as ultimate ground of all things, or that it has
none of the attributes which, arguing from their consequences,
we represent to ourselves as analogical with the dynamical
realities of a thinking being, or (as the anthropomorphists
contend) that it must be subject to all the limitations which
sensibility inevitably imposes on those intelligences which are
known to us through experience. 
Thus, while for the merely speculative employment of
reason the supreme being remains a mere ideal, it is yet an
ideal without a flaw, a concept which completes and crowns
the whole of human knowledge. Its objective reality cannot
indeed be proved, but also cannot be disproved, by merely
speculative reason. If, then, there should be a moral theology
that can make good this deficiency, transcendental theology,
which before was problematic only, will prove itself indis-
pensable in determining the concept of this supreme being
and in constantly testing reason, which is so often deceived by
sensibility, and which is frequently out of harmony with its
own ideas. Necessity, infinity, unity, existence outside the
world (and not as world-soul), eternity as free from conditions
of time, omnipresence as free from conditions of space, omni-
potence, etc. are purely transcendental predicates, and for
this reason the purified concepts of them, which every theology
finds so indispensable, are only to be obtained from tran-
scendental theology. 
P 532
The outcome of all dialectical attempts of pure reason
does not merely confirm what we have already proved in the
Transcendental Analytic, namely, that all those conclusions of
ours which profess to lead us beyond the field of possible ex-
perience are deceptive and without foundation; it likewise
teaches us this further lesson, that human reason has a natural
tendency to transgress these limits, and that transcendental
ideas are just as natural to it as the categories are to under-
standing -- though with this difference, that while the categories
lead to truth, that is, to the conformity of our concepts with
the object, the ideas produce what, though a mere illusion,
is none the less irresistible, and the harmful influence of
which we can barely succeed in neutralising even by means
of the severest criticism. 
Everything that has its basis in the nature of our powers
must be appropriate to, and consistent with, their right em-
ployment -- if only we can guard against a certain misunder-
standing and so can discover the proper direction of these
powers. We are entitled, therefore, to suppose that tran-
scendental ideas have their own good, proper, and therefore
immanent use, although, when their meaning is misunder-
stood, and they are taken for concepts of real things, they
become transcendent in their application and for that very
reason can be delusive. For it is not the idea in itself, but its
use only, that can be either transcendent or immanent (that
is, either range beyond all possible experience or find em-
ployment within its limits), according as it is applied to an
object which is supposed to correspond to it, or is directed
solely to the use of understanding in general, in respect of
those objects that fall to be dealt with by the understand-
ing. All errors of subreption are to be ascribed to a defect
of judgment, never to understanding or to reason. 
Reason is never in immediate relation to an object, but
P 533
only to the understanding; and it is only through the under-
standing that it has its own [specific] empirical employment. 
It does not, therefore, create concepts (of objects) but only
orders them, and gives them that unity which they can have
only if they be employed in their widest possible application,
that is, with a view to obtaining totality in the various series. 
The understanding does not concern itself with this totality,
but only with that connection through which, in accordance
with concepts, such series of conditions come into being. 
Reason has, therefore, as its sole object, the understanding
and its effective application. Just as the understanding unifies
the manifold in the object by means of concepts, so reason
unifies the manifold of concepts by means of ideas, positing
a certain collective unity as the goal of the activities of the
understanding, which otherwise are concerned solely with
distributive unity. 
I accordingly maintain that transcendental ideas never
allow of any constitutive employment. When regarded in
that mistaken manner, and therefore as supplying concepts
of certain objects, they are but pseudo-rational, merely dia-
lectical concepts. On the other hand, they have an excellent,
and indeed indispensably necessary, regulative employment,
namely, that of directing the understanding towards a certain
goal upon which the routes marked out by all its rules con-
verge, as upon their point of intersection. This point is indeed
a mere idea, a focus imaginarius, from which, since it lies
quite outside the bounds of possible experience, the concepts
of the understanding do not in reality proceed; none the less
it serves to give to these concepts the greatest [possible] unity
combined with the greatest [possible] extension. Hence arises
the illusion that the lines have their source in a real object
lying outside the field of empirically possible knowledge -- just
as objects reflected in a mirror are seen as behind it. Never-
theless this illusion (which need not, however, be allowed
to deceive us) is indispensably necessary if we are to direct
the understanding beyond every given experience (as part of
the sum of possible experience), and thereby to secure its
greatest possible extension, just as, in the case of mirror-
vision, the illusion involved is indispensably necessary if,
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besides the objects which lie before our eyes, we are also to
see those which lie at a distance behind our back. 
If we consider in its whole range the knowledge obtained
for us by the understanding, we find that what is peculiarly
distinctive of reason in its attitude to this body of knowledge,
is that it prescribes and seeks to achieve its systematisation,
that is, to exhibit the connection of its parts in conformity
with a single principle. This unity of reason always presup-
poses an idea, namely, that of the form of a whole of know-
ledge -- a whole which is prior to the determinate knowledge
of the parts and which contains the conditions that deter-
mine a priori for every part its position and relation to
the other parts. This idea accordingly postulates a complete
unity in the knowledge obtained by the understanding, by
which this knowledge is to be not a mere contingent aggregate,
but a system connected according to necessary laws. We may
not say that this idea is a concept of the object, but only of the
thoroughgoing unity of such concepts, in so far as that unity
serves as a rule for the understanding. These concepts of
reason are not derived from nature; on the contrary, we in-
terrogate nature in accordance with these ideas, and consider
our knowledge as defective so long as it is not adequate to
them. By general admission, pure earth, pure water, pure air,
etc. , are not to be found. We require, however, the concepts of
them (though, in so far as their complete purity is concerned,
they have their origin solely in reason) in order properly to
determine the share which each of these natural causes has in
producing appearances. Thus in order to explain the chemical
interactions of bodies in accordance with the idea of a mechan-
ism, every kind of matter is reduced to earths (qua mere
weight), to salts and inflammable substances (qua force), and
to water and air as vehicles (machines, as it were, by which
the first two produce their effects). The modes of expression
usually employed are, indeed, somewhat different; but the
influence of reason on the classifications of the natural
scientist is still easily detected. 
If reason is a faculty of deducing the particular from the
universal, and if the universal is already certain in itself and
given, only judgment is required to execute the process of
P 535
subsumption, and the particular is thereby determined in a
necessary manner. This I shall entitle the apodeictic use of
reason. If, however, the universal is admitted as problem-
atic only, and is a mere idea, the particular is certain, but
the universality of the rule of which it is a consequence
is still a problem. Several particular instances, which are
one and all certain, are scrutinised in view of the rule, to
see whether they follow from it. If it then appears that all
particular instances which can be cited follow from the rule,
we argue to its universality, and from this again to all particu-
lar instances, even to those which are not themselves given. 
This I shall entitle the hypothetical employment of reason. 
The hypothetical employment of reason, based upon ideas
viewed as problematic concepts, is not, properly speaking,
constitutive, that is, it is not of such a character that, judging
in all strictness, we can regard it as proving the truth of the
universal rule which we have adopted as hypothesis. For how
are we to know all the possible consequences which, as actually
following from the adopted principle, prove its universality? 
The hypothetical employment of reason is regulative only; its
sole aim is, so far as may be possible, to bring unity into the
body of our detailed knowledge, and thereby to approximate
the rule to universality. 
 The hypothetical employment of reason has, therefore, as
its aim the systematic unity of the knowledge of understand-
ing, and this unity is the criterion of the truth of its rules. The
systematic unity (as a mere idea) is, however, only a projected
unity, to be regarded not as given in itself, but as a problem
only. This unity aids us in discovering a principle for the
understanding in its manifold and special modes of employ-
ment, directing its attention to cases which are not given, and
thus rendering it more coherent. 
But the only conclusion which we are justified in drawing
from these considerations is that the systematic unity of the
manifold knowledge of understanding, as prescribed by reason,
is a logical principle. Its function is to assist the understanding
by means of ideas, in those cases in which the understanding
cannot by itself establish rules, and at the same time to give
P 536
to the numerous and diverse rules of the understanding unity
or system under a single principle, and thus to secure co-
herence in every possible way. But to say that the constitu-
tion of the objects or the nature of the understanding which
knows them as such, is in itself determined to systematic
unity, and that we can in a certain measure postulate this
unity a priori, without reference to any such special interest
of reason, and that we are therefore in a position to maintain
that knowledge of the understanding in all its possible modes
(including empirical knowledge) has the unity required by
reason, and stands under common principles from which all
its various modes can, in spite of their diversity, be deduced
-- that would be to assert a transcendental principle of reason,
and would make the systematic unity necessary, not only
subjectively and logically, as method, but objectively also. 
We may illustrate this by an instance of the employment
of reason. Among the various kinds of unity which conform
to the concepts of the understanding, is that of the causality
of a substance, which is called power. The various appear-
ances of one and the same substance show at first sight so
great a diversity, that at the start we have to assume just as
many different powers as there are different effects. For in-
stance in the human mind we have sensation, conscious-
ness, imagination, memory, wit, power of discrimination,
pleasure, desire, etc. Now there is a logical maxim which
requires that we should reduce, so far as may be possible, this
seeming diversity, by comparing these with one another and
detecting their hidden identity. We have to enquire whether
imagination combined with consciousness may not be the same
thing as memory, wit, power of discrimination, and perhaps
even identical with understanding and reason. Though logic
is not capable of deciding whether a fundamental power
actually exists, the idea of such a power is the problem in-
volved in a systematic representation of the multiplicity of
powers. The logical principle of reason calls upon us to bring
about such unity as completely as possible; and the more the
appearances of this and that power are found to be identical
with one another, the more probable it becomes that they are
simply different manifestations of one and the same power,
P 537
which may be entitled, relatively to the more specific powers,
the fundamental power. The same is done with the other
The relatively fundamental powers must in turn be com-
pared with one another, with a view to discovering their har-
mony, and so to bring them nearer to a single radical, that
is, absolutely fundamental, power. But this unity of reason is
purely hypothetical. We do not assert that such a power must
necessarily be met with, but that we must seek it in the
interests of reason, that is, of establishing certain principles
for the manifold rules which experience may supply to us. 
We must endeavour, wherever possible, to bring in this way
systematic unity into our knowledge. 
On passing, however, to the transcendental employment
of understanding, we find that this idea of a fundamental
power is not treated merely as a problem for the hypothetical
use of reason, but claims to have objective reality, as postulat-
ing the systematic unity of the various powers of a substance,
and as giving expression to an apodeictic principle of reason. 
For without having made any attempt to show the harmony
of these various powers, nay, even after all attempts to do so
have failed, we yet presuppose that such a unity does actually
exist, and this not only, as in the case cited, on account of the
unity of the substance, but also in those cases in which, as with
matter in general, we encounter powers which, though to a
certain extent homogeneous, are likewise diverse. In all such
cases reason presupposes the systematic unity of the various
powers, on the ground that special natural laws fall under more
general laws, and that parsimony in principles is not only an
economical requirement of reason, but is one of nature's own
It is, indeed, difficult to understand how there can be a
logical principle by which reason prescribes the unity of rules,
unless we also presuppose a transcendental principle whereby
such a systematic unity is a priori assumed to be necessarily
inherent in the objects. For with what right can reason, in its
logical employment, call upon us to treat the multiplicity of
powers exhibited in nature as simply a disguised unity and
to derive this unity, so far as may be possible, from a funda-
mental power -- how can reason do this, if it be free to admit
P 538
as likewise possible that all powers may be heterogeneous, and
that such systematic unity of derivation may not be in con-
formity with nature? Reason would then run counter to its own
vocation, proposing as its aim an idea quite inconsistent with
the constitution of nature. Nor can we say that reason, while
proceeding in accordance with its own principles, has arrived at
knowledge of this unity through observation of the accidental
constitution of nature. The law of reason which requires us to
seek for this unity, is a necessary law, since without it we should
have no reason at all, and without reason no coherent em-
ployment of the understanding, and in the absence of this no
sufficient criterion of empirical truth. In order, therefore, to
secure an empirical criterion we have no option save to pre-
suppose the systematic unity of nature as objectively valid and
Although philosophers have not always acknowledged this
transcendental principle, even to themselves, or indeed been
conscious of employing it, we none the less find it covertly im-
plied, in remarkable fashion, in the principles upon which they
proceed. That the manifold respects in which individual things
differ do not exclude identity of species, that the various species
must be regarded merely as different determinations of a few
genera, and these, in turn, of still higher genera, and so on; in
short, that we must seek for a certain systematic unity of all
possible empirical concepts, in so far as they can be deduced
from higher and more general concepts -- this is a logical
principle, a rule of the Schools, without which there could
be no employment of reason. For we can conclude from the
universal to the particular, only in so far as universal pro-
perties are ascribed to things as being the foundation upon
which the particular properties rest. 
That such unity is to be found in nature, is presupposed by
philosophers in the well-known scholastic maxim, that rudi-
ments or principles must not be unnecessarily multiplied (entia
praeter necessitatem non esse multiplicanda). This maxim de-
clares that things by their very nature supply material for the
unity of reason, and that the seemingly infinite variety need
not hinder us from assuming that behind this variety there is
a unity of fundamental properties -- properties from which the
P 539
diversity can be derived through repeated determination. This
unity, although it is a mere idea, has been at all times so eagerly
sought, that there has been need to moderate the desire for it,
not to encourage it. A great advance was made when chemists
succeeded in reducing all salts to two main genera, acids and
alkalies; and they endeavour to show that even this difference
is merely a variety, or diverse manifestation, of one and the
same fundamental material. Chemists have sought, step by
step, to reduce the different kinds of earths (the material of
stones and even of metals) to three, and at last to two; but, not
content with this, they are unable to banish the thought that
behind these varieties there is but one genus, nay, that there
may even be a common principle for the earths and the salts. 
It might be supposed that this is merely an economical con-
trivance whereby reason seeks to save itself all possible trouble,
a hypothetical attempt, which, if it succeeds, will, through the
unity thus attained, impart probability to the presumed prin-
ciple of explanation. But such a selfish purpose can very easily
be distinguished from the idea. For in conformity with the
idea everyone presupposes that this unity of reason accords
with nature itself, and that reason -- although indeed unable
to determine the limits of this unity -- does not here beg but
If among the appearances which present themselves to us,
there were so great a variety -- I do not say in form, for in that
respect the appearances might resemble one another; but in
content, that is, in the manifoldness of the existing entities --
that even the acutest human understanding could never by
comparison of them detect the slightest similarity (a possi-
bility which is quite conceivable), the logical law of genera
would have no sort of standing; we should not even have the
concept of a genus, or indeed any other universal concept; and
the understanding itself, which has to do solely with such con-
cepts, would be non-existent. If, therefore, the logical prin-
ciple of genera is to be applied to nature (by which I here under-
stand those objects only which are given to us), it presupposes
a transcendental principle. And in accordance with this latter
principle, homogeneity is necessarily presupposed in the mani-
fold of possible experience (although we are not in a position
to determine in a priori fashion its degree); for in the absence
P 540
of homogeneity, no empirical concepts, and therefore no ex-
perience, would be possible. 
The logical principle of genera, which postulates identity,
is balanced by another principle, namely, that of species,
which calls for manifoldness and diversity in things, notwith-
standing their agreement as coming under the same genus,
and which prescribes to the understanding that it attend to the
diversity no less than to the identity. This principle (of discrimi-
native observation, that is, of the faculty of distinction) sets
a limit to possible indiscretion in the former principle (of the
faculty of wit); and reason thus exhibits a twofold, self-con-
flicting interest, on the one hand interest in extent (universal-
ity) in respect of genera, and on the other hand in content (de-
terminateness) in respect of the multiplicity of the species. In
the one case the understanding thinks more under its concepts,
in the other more in them. This twofold interest manifests it-
self also among students of nature in the diversity of their ways
of thinking. Those who are more especially speculative are,
we may almost say, hostile to heterogeneity, and are always on
the watch for the unity of the genus; those, on the other hand,
who are more especially empirical, are constantly endeavour-
ing to differentiate nature in such manifold fashion as almost
to extinguish the hope of ever being able to determine its ap-
pearances in accordance with universal principles. 
This latter mode of thought is evidently based upon a logi-
cal principle which aims at the systematic completeness of all
knowledge -- prescribing that, in beginning with the genus, we
descend to the manifold which may be contained thereunder,
in such fashion as to secure extension for the system, just as in
the alternative procedure, that of ascending to the genus, we
endeavour to secure the unity of the system. For if we limit
our attention to the sphere of the concept which marks out a
genus, we can no more determine how far it is possible to pro-
ceed in the [logical] division of it, than we can judge merely
from the space which a body occupies how far it is possible to
proceed in the [physical] division of its parts. Consequently,
P 541
every genus requires diversity of species, and these in turn
diversity of subspecies; and since no one of these subspecies is
ever itself without a sphere (extent as conceptus communis),
reason, in being carried to completion, demands that no
species be regarded as being in itself the lowest. For since the
species is always a concept, containing only what is common
to different things, it is not completely determined. It cannot,
therefore, be directly related to an individual, and other con-
cepts, that is, subspecies, must always be contained under it. 
This law of specification can be formulated as being the prin-
ciple: entium varietates non temere esse minuendas. 
But it is easily seen that this logical law would be without
meaning and application if it did not rest upon a transcendental
law of specification, which does not indeed demand an actual
infinity of differences in the things which can be objects to us
-- the logical principle, as affirming only the indeterminateness
of the logical sphere in respect of possible division, gives no
occasion for any such assertion -- but which none the less im-
poses upon the understanding the obligation of seeking under
every discoverable species for subspecies, and under every dif-
ference for yet smaller differences. For if there were no lower
concepts, there could not be higher concepts. Now the under-
standing can have knowledge only through concepts, and
therefore, however far it carries the process of division, never
through mere intuition, but always again through lower
concepts. The knowledge of appearances in their complete
determination, which is possible only through the under-
standing, demands an endless progress in the specification of
our concepts, and an advance to yet other remaining differ-
ences, from which we have made abstraction in the concept of
the species, and still more so in that of the genus. 
This law of specification cannot be derived from experi-
ence, which can never open to our view any such extensive
prospects. Empirical specification soon comes to a stop in the
distinction of the manifold, if it be not guided by the ante-
cedent transcendental law of specification, which, as a prin-
ciple of reason, leads us to seek always for further differences,
and to suspect their existence even when the senses are unable
to disclose them. That absorbent earths are of different kinds
(chalk and muriatic earths), is a discovery that was possible
P 542
only under the guidance of an antecedent rule of reason -- reason
proceeding on the assumption that nature is so richly diversi-
fied that we may presume the presence of such differences,
and therefore prescribing to the understanding the task of
searching for them. Indeed it is only on the assumption of
differences in nature, just as it is also only under the condition
that its objects exhibit homogeneity, that we can have any
faculty of understanding whatsoever. For the diversity of that
which is comprehended under a concept is precisely what gives
occasion for the employment of the concept and the exercise
of the understanding. 
Reason thus prepares the field for the understanding: (1)
through a principle of the homogeneity of the manifold under
higher genera; (2) through a principle of the variety of the
homogeneous under lower species; and (3) in order to complete
the systematic unity, a further law, that of the affinity of all
concepts -- a law which prescribes that we proceed from each
species to every other by gradual increase of the diversity. 
These we may entitle the principles of homogeneity, specifica-
tion, and continuity of forms. The last named arises from
union of the other two, inasmuch as only through the pro-
cesses of ascending to the higher genera and of descending to
the lower species do we obtain the idea of systematic connec-
tion in its completeness. For all the manifold differences are
then related to one another, inasmuch as they one and all
spring from one highest genus, through all degrees of a more
and more widely extended determination. 
The systematic unity, prescribed by the three logical
principles, can be illustrated in the following manner. Every
concept may be regarded as a point which, as the station for
an observer, has its own horizon, that is, a variety of things
which can be represented, and, as it were, surveyed from that
standpoint. This horizon must be capable of containing an
infinite number of points, each of which has its own narrower
horizon; that is, every species contains subspecies, according
to the principle of specification, and the logical horizon con-
sists exclusively of smaller horizons (subspecies), never of
points which possess no extent (individuals). But for different
horizons, that is, genera, each of which is determined by its
own concept, there can be a common horizon, in reference to
P 543
which, as from a common centre, they can all be surveyed; and
from this higher genus we can proceed until we arrive at the
highest of all genera, and so at the universal and true horizon,
which is determined from the standpoint of the highest con-
cept, and which comprehends under itself all manifoldness --
genera, species, and subspecies. 
We are carried to this highest standpoint by the law of
homogeneity, and to all lower standpoints, and their greatest
possible variety, by the law of specification. And since there
is thus no void in the whole sphere of all possible concepts,
and since nothing can be met with outside this sphere,
there arises from the presupposition of this universal horizon
and of its complete division, the principle: non datur vacuum
formarum, that is, that there are not different, original, first
genera, which are isolated from one another, separated, as it
were, by an empty intervening space; but that all the manifold
genera are simply divisions of one single highest and universal
genus. From this principle there follows, as its immediate con-
sequence: datur continuum formarum, that is, that all differ-
ences of species border upon one another, admitting of no
transition from one to another per saltum, but only through
all the smaller degrees of difference that mediate between
them. In short, there are no species or subspecies which (in
the view of reason) are the nearest possible to each other; still
other intermediate species are always possible, the difference
of which from each of the former is always smaller than the
difference between these. 
The first law thus keeps us from resting satisfied with an
excessive number of different original genera, and bids us pay
due regard to homogeneity; the second, in turn, imposes a
check upon this tendency towards unity, and insists that be-
fore we proceed to apply a universal concept to individuals we
distinguish subspecies within it. The third law combines these
two laws by prescribing that even amidst the utmost mani-
foldness we observe homogeneity in the gradual transition
from one species to another, and thus recognise a relationship
of the different branches, as all springing from the same stem. 
This logical law of the continuum specierum (formarum
logicarum) presupposes, however, a transcendental law (lex
P 544
continui in natura), without which the former law would only
lead the understanding astray, causing it to follow a path
which is perhaps quite contrary to that prescribed by nature
itself. This law must therefore rest upon pure transcendental,
not on empirical, grounds. For if it rested on empirical
grounds, it would come later than the systems, whereas in
actual fact it has itself given rise to all that is systematic in
our knowledge of nature. The formulation of these laws is
not due to any secret design of making an experiment, by
putting them forward as merely tentative suggestions. Such
anticipations, when confirmed, yield strong evidence in sup-
port of the view that the hypothetically conceived unity is
well-grounded; and such evidence has therefore in this re-
spect a certain utility. But it is evident that the laws contem-
plate the parsimony of fundamental causes, the manifoldness
of effects, and the consequent affinity of the parts of nature
as being in themselves in accordance both with reason and
with nature. Hence these principles carry their recommend-
ation directly in themselves, and not merely as methodo-
logical devices. 
But it is easily seen that this continuity of forms is a mere
idea, to which no congruent object can be discovered in ex-
perience. For in the first place, the species in nature are actually
divided, and must therefore constitute a quantum discretum. 
Were the advance in the tracing of their affinity continuous,
there would be a true infinity of intermediate members be-
tween any two given species, which is impossible. And further,
in the second place, we could not make any determinate em-
pirical use of this law, since it instructs us only in quite general
terms that we are to seek for grades of affinity, and yields no
criterion whatsoever as to how far, and in what manner, we
are to prosecute the search for them. 
 If we place these principles of systematic unity in the order
appropriate to their empirical employment, they will stand
thus: manifoldness, affinity, unity, each being taken, as an
idea, in the highest degree of its completeness. Reason pre-
supposes the knowledge which is obtained by the understand-
ing and which stands in immediate relation to experience, and
P 545
seeks for the unity of this knowledge in accordance with ideas
which go far beyond all possible experience. The affinity of
the manifold (as, notwithstanding its diversity, coming under
a principle of unity) refers indeed to things, but still more to
their properties and powers. Thus, for instance, if at first our im-
perfect experience leads us to regard the orbits of the planets
as circular, and if we subsequently detect deviations therefrom,
we trace the deviations to that which can change the circle,
in accordance with a fixed law, through all the infinite inter-
mediate degrees, into one of these divergent orbits. That is to
say, we assume that the movements of the planets which are
not circular will more or less approximate to the properties of a
circle; and thus we come upon the idea of an ellipse. Since the
comets do not, so far as observation reaches, return in any such
courses, their paths exhibit still greater deviations. What we
then do is to suppose that they proceed in a parabolic course,
which is akin to the ellipse, and which in all our observation
is indistinguishable from an ellipse that has its major axis in-
definitely extended. Thus, under the guidance of these prin-
ciples, we discover a unity in the generic forms of the orbits,
and thereby a unity in the cause of all the laws of planetary
motion, namely, gravitation. And we then extend our con-
quests still further, endeavouring to explain by the same prin-
ciple all variations and seeming departures from these rules;
finally, we even go on to make additions such as experience
can never confirm, namely, to conceive, in accordance with
the rules of affinity, hyperbolic paths of comets, in the course
of which these bodies entirely leave our solar system, and
passing from sun to sun, unite the most distant parts of the
universe -- a universe which, though for us unlimited, is
throughout held together by one and the same moving force. 
The remarkable feature of these principles, and what in
them alone concerns us, is that they seem to be transcendental,
and that although they contain mere ideas for the guidance of
the empirical employment of reason -- ideas which reason
follows only as it were asymptotically, i.e. ever more closely
without ever reaching them -- they yet possess, as synthetic
a priori propositions, objective but indeterminate validity, and
serve as rules for possible experience. They can also be em-
ployed with great advantage in the elaboration of experience,
P 546
as heuristic principles. A transcendental deduction of them
cannot, however, be effected; in the case of ideas, as we have
shown above, such a deduction is never possible. 
In the Transcendental Analytic we have distinguished the
dynamical principles of the understanding, as merely regula-
tive principles of intuition, from the mathematical, which, as
regards intuition, are constitutive. None the less these dyna-
mical laws are constitutive in respect of experience, since they
render the concepts, without which there can be no experi-
ence, possible a priori. But principles of pure reason can
never be constitutive in respect of empirical concepts; for since
no schema of sensibility corresponding to them can ever be
given, they can never have an object in concreto. If, then, we
disallow such empirical employment of them, as constitutive
principles, how are we to secure for them a regulative em-
ployment, and therewith some sort of objective validity, and
what can we mean by such regulative employment? 
The understanding is an object for reason, just as sensi-
bility is for the understanding. It is the business of reason to
render the unity of all possible empirical acts of the under-
standing systematic; just as it is of the understanding to con-
nect the manifold of the appearances by means of concepts,
and to bring it under empirical laws. But the acts of the under-
standing are, without the schemata of sensibility, undeter-
mined; just as the unity of reason is in itself undetermined, as
regards the conditions under which, and the extent to which,
the understanding ought to combine its concepts in systematic
fashion. But although we are unable to find in intuition a
schema for the complete systematic unity of all concepts of the
understanding, an analogon of such a schema must necessarily
allow of being given. This analogon is the idea of the maxi-
mum in the division and unification of the knowledge of the
understanding under one principle. For what is greatest and
absolutely complete can be determinately thought, all re-
stricting conditions, which give rise to an indeterminate
manifoldness, being left aside. Thus the idea of reason is
an analogon of a schema of sensibility; but with this differ-
ence, that the application of the concepts of the understanding
to the schema of reason does not yield knowledge of the object
itself (as is the case in the application of categories to their
P 547
sensible schemata) but only a rule or principle for the system-
atic unity of all employment of the understanding. Now
since every principle which prescribes a priori to the under-
standing thoroughgoing unity in its employment, also holds,
although only indirectly, of the object of experience, the
principles of pure reason must also have objective reality
in respect of that object, not, however, in order to determine
anything in it, but only in order to indicate the procedure
whereby the empirical and determinate employment of the
understanding can be brought into complete harmony with
itself. This is acheived by bringing its employment, so far as
may be possible, into connection with the principle of thorough-
going unity, and by determining its procedure in the light of
this principle. 
I entitle all subjective principles which are derived, not
from the constitution of an object but from the interest of
reason in respect of a certain possible perfection of the
knowledge of the object, maxims of reason. There are there-
fore maxims of speculative reason, which rest entirely on its
speculative interest, although they may seem to be objective
When merely regulative principles are treated as constitu-
tive, and are therefore employed as objective principles, they
may come into conflict with one another. But when they
are treated merely as maxims, there is no real conflict, but
merely those differences in the interest of reason that give rise
to differing modes of thought. In actual fact, reason has only
one single interest, and the conflict of its maxims is only a
difference in, and a mutual limitation of, the methods where-
by this interest endeavours to obtain satisfaction. 
Thus one thinker may be more particularly interested in
manifoldness (in accordance with the principle of specifica-
tion), another thinker in unity (in accordance with the prin-
ciple of aggregation). Each believes that his judgment has
been arrived at through insight into the object, whereas it really
rests entirely on the greater or lesser attachment to one of the
two principles. And since neither of these principles is based
on objective grounds, but solely on the interest of reason, the
P 548
title 'principles' is not strictly applicable; they may more fit-
tingly be entitled 'maxims'. When we observe intelligent people
disputing in regard to the characteristic properties of men,
animals, or plants -- even of bodies in the mineral realm -- some
assuming, for instance, that there are certain special heredit-
ary characteristics in each nation, certain well-defined inherited
differences in families, races, etc. , whereas others are bent upon
maintaining that in all such cases nature has made precisely
the same provision for all, and that it is solely to external
accidental conditions that the differences are due, we have
only to consider what sort of an object it is about which they
are making these assertions, to realise that it lies too deeply
hidden to allow of their speaking from insight into its nature. 
The dispute is due simply to the twofold interest of reason,
the one party setting its heart upon, or at least adopting, the
one interest, and the other party the other. The differences
between the maxims of manifoldness and of unity in nature
thus easily allow of reconciliation. So long, however, as the
maxims are taken as yielding objective insight, and until a
way has been discovered of adjusting their conflicting claims,
and of satisfying reason in that regard, they will not only
give rise to disputes but will be a positive hindrance, and
cause long delays in the discovery of truth. 
Similar observations are relevant in regard to the assertion
or denial of the widely discussed law of the continuous grada-
tion of created beings, which was propounded by Leibniz, and
admirably supported by Bonnet. It is simply the following
out of that principle of affinity which rests on the interest of
reason. For observation and insight into the constitution of
nature could never justify us in the objective assertion of the
law. The steps of this ladder, as they are presented to us in
experience, stand much too far apart; and what may seem to
us small differences are usually in nature itself such wide gaps,
that from any such observations we can come to no decision
in regard to nature's ultimate design -- especially if we bear in
mind that in so great a multiplicity of things there can never
be much difficulty in finding similarities and approximations. 
On the other hand, the method of looking for order in nature
P 549
in accordance with such a principle, and the maxim which
prescribes that we regard such order -- leaving, however, un-
determined where and how far -- as grounded in nature as
such, is certainly a legitimate and excellent regulative prin-
ciple of reason. In this regulative capacity it goes far beyond
what experience or observation can verify; and though not
itself determining anything, yet serves to mark out the path
towards systematic unity. 
The ideas of pure reason can never be dialectical in them-
selves; any deceptive illusion to which they give occasion
must be due solely to their misemployment. For they arise
from the very nature of our reason; and it is impossible that
this highest tribunal of all the rights and claims of speculation
should itself be the source of deceptions and illusions. Pre-
sumably, therefore, the ideas have their own good and ap-
propriate vocation as determined by the natural disposition of
our reason. The mob of sophists, however, raise against reason
the usual cry of absurdities and contradictions, and though
unable to penetrate to its innermost designs, they none the less
inveigh against its prescriptions. Yet it is to the beneficent in-
fluences exercised by reason that they owe the possibility of
their own self-assertiveness, and indeed that very culture
which enables them to blame and to condemn what reason
requires of them. 
We cannot employ an a priori concept with any certainty
without having first given a transcendental deduction of it. 
The ideas of pure reason do not, indeed, admit of the kind of
deduction that is possible in the case of the categories. But if
they are to have the least objective validity, no matter how
indeterminate that validity may be, and are not to be mere
empty thought-entities (entia rationis ratiocinantis), a deduc-
tion of them must be possible, however greatly (as we admit)
it may differ from that which we have been able to give of the
categories. This will complete the critical work of pure reason,
and is what we now propose to undertake. 
P 550
There is a great difference between something being given
to my reason as an object absolutely, or merely as an object in
the idea. In the former case our concepts are employed to deter-
mine the object; in the latter case there is in fact only a schema
which no object, not even a hypothetical one, is directly
given, and which only enables us to represent to ourselves
other objects in an indirect manner, namely in their systematic
unity, by means of their relation to this idea. Thus I say that
the concept of a highest intelligence is a mere idea, that is
to say, its objective reality is not to be taken as consisting in
its referring directly to an object (for in that sense we should
not be able to justify its objective validity). It is only a schema
constructed in accordance with the conditions of the greatest
possible unity of reason -- the schema of the concept of a thing
in general, which serves only to secure the greatest possible sys-
tematic unity in the empirical employment of our reason. We
then, as it were, derive the object of experience from the sup-
posed object of this idea, viewed as the ground or cause of the
object of experience. We declare, for instance, that the things
of the world must be viewed as if they received their existence
from a highest intelligence. The idea is thus really only a heur-
istic, not an ostensive concept. It does not show us how an
object is constituted, but how, under its guidance, we should
seek to determine the constitution and connection of the objects
of experience. If, then, it can be shown that the three transcen-
dental ideas (the psychological, the cosmological, and the theo-
logical), although they do not directly relate to, or determine,
any object corresponding to them, none the less, as rules of the
empirical employment of reason, lead us to systematic unity,
under the presupposition of such an object in the idea; and
that they thus contribute to the extension of empirical know-
ledge, without ever being in a position to run counter to it,
we may conclude that it is a necessary maxim of reason to
proceed always in accordance with such ideas. This, indeed,
is the transcendental deduction of all ideas of speculative
reason, not as constitutive principles for the extension of our
knowledge to more objects than experience can give, but as
regulative principles of the systematic unity of the manifold
of empirical knowledge in general, whereby this empirical
P 551
knowledge is more adequately secured within its own Limits
and more effectively improved than would be possible, in the
absence of such ideas, through the employment merely of the
principles of the understanding. 
I shall endeavour to make this clearer. In conformity with
these ideas as principles we shall, first, in psychology, under
the guidance of inner experience, connect all the appearances,
all the actions and receptivity of our mind, as if the mind were
a simple substance which persists with personal identity (in
this life at least), while its states, to which those of the body
belong only as outer conditions, are in continual change. 
Secondly, in cosmology, we must follow up the conditions of
both inner and outer natural appearances, in an enquiry which
is to be regarded as never allowing of completion, just as if
the series of appearances were in itself endless, without any
first or supreme member. We need not, in so doing, deny that,
outside all appearances, there are purely intelligible grounds
of the appearances; but as we have no knowledge of these
whatsoever, we must never attempt to make use of them in our
explanations of nature. Thirdly, and finally, in the domain
of theology, we must view everything that can belong to the
context of possible experience as if this experience formed
an absolute but at the same time completely dependent and
sensibly conditioned unity, and yet also at the same time as if
the sum of all appearances (the sensible world itself) had a
single, highest and all-sufficient ground beyond itself, namely,
a self-subsistent, original, creative reason. For it is in the light
of this idea of a creative reason that we so guide the empirical
employment of our reason as to secure its greatest possible
extension -- that is, by viewing all objects as if they drew their
origin from such an archetype. In other words, we ought not
to derive the inner appearances of the soul from a simple
thinking substance but from one another, in accordance with
the idea of a simple being; we ought not to derive the order
and systematic unity of the world from a supreme intelligence,
but to obtain from the idea of a supremely wise cause the rule
according to which reason in connecting empirical causes and
effects in the world may be employed to best advantage, and in
such manner as to secure satisfaction of its own demands. 
Now there is nothing whatsoever to hinder us from as-
P 552
suming these ideas to be also objective, that is, from hyposta-
tising them -- except in the case of the cosmological ideas,
where reason, in so proceeding, falls into antinomy. The
psychological and theological ideas contain no antinomy,
and involve no contradiction. How, then, can anyone dispute
their [possible] objective reality? He who denies their possi-
bility must do so with just as little knowledge [of this possi-
bility] as we can have in affirming it. It is not, however, a
sufficient ground for assuming anything, that there is no
positive hindrance to our so doing; we are not justified in
introducing thought-entities which transcend all our con-
cepts, though without contradicting them, as being real and
determinate objects, merely on the authority of a speculative
reason that is bent upon completing the tasks which it has
set itself. They ought not to be assumed as existing in
themselves, but only as having the reality of a schema -- the
schema of the regulative principle of the systematic unity of
all knowledge of nature. They should be regarded only as
analoga of real things, not as in themselves real things. We
remove from the object of the idea the conditions which limit
the concept provided by our understanding, but which also
alone make it possible for us to have a determinate con-
cept of anything. What we then think is a something of
which, as it is in itself, we have no concept whatsoever, but
which we none the less represent to ourselves as standing to
the sum of appearances in a relation analogous to that in
which appearances stand to one another. 
If, in this manner, we assume such ideal beings, we do not
really extend our knowledge beyond the objects of possible
experience; we extend only the empirical unity of such experi-
ence, by means of the systematic unity for which the schema
is provided by the idea -- an idea which has therefore no claim
to be a constitutive, but only a regulative principle. For
to allow that we posit a thing, a something, a real being,
corresponding to the idea, is not to say that we profess
to extend our knowledge of things by means of transcen-
dental concepts. For this being is posited only in the idea and
not in itself; and therefore only as expressing the systematic
P 553
unity which is to serve as a rule for the empirical employ-
ment of reason. It decides nothing in regard to the ground of
this unity or as to what may be the inner character of the being
on which as cause the unity depends. 
Thus the transcendental, and the only determinate, con-
cept which the purely speculative reason gives us of God is, in
the strictest sense, deistic; that is, reason does not determine
the objective validity of such a concept, but yields only the
idea of something which is the ground of the highest and
necessary unity of all empirical reality. This something we
cannot think otherwise than on the analogy of a real sub-
stance that, in conformity with laws of reason, is the cause
of all things. This, indeed, is how we must think it, in
so far as we venture to think it as a special object, and do
not rather remain satisfied with the mere idea of the regu-
lative principle of reason, leaving aside the completion of
all conditions of thought as being too surpassingly great
for the human understanding. The latter procedure is, how-
ever, inconsistent with the pursuit of that complete system-
atic unity in our knowledge to which reason at least sets
no limits. 
This, then, is how matters stand: if we assume a divine
being, we have indeed no concept whatsoever either of the
inner possibility of its supreme perfection or of the necessity
of its existence; but, on the other hand, we are in a position
to give a satisfactory answer to all those questions which
relate to the contingent, and to afford reason the most com-
plete satisfaction in respect to that highest unity after which
it is seeking in its empirical employment. The fact, however,
that we are unable to satisfy reason in respect to the assump-
tion itself, shows that it is the speculative interest of reason,
not any insight, which justifies it in thus starting from a point
that lies so far above its sphere; and in endeavouring, by this
device, to survey its objects as constituting a complete whole. 
We here come upon a distinction bearing on the procedure
of thought in dealing with one and the same assumption, a
distinction which is somewhat subtle, but of great importance
in transcendental philosophy. I may have sufficient ground to
assume something, in a relative sense (suppositio relativa), and
yet have no right to assume it absolutely (suppositio absoluta). 
P 554
This distinction has to be reckoned with in the case of a
merely regulative principle. We recognise the necessity of the
principle, but have no knowledge of the source of its neces-
sity; and in assuming that it has a supreme ground, we do so
solely in order to think its universality more determinately. 
Thus, for instance, when I think as existing a being that
corresponds to a mere idea, indeed to a transcendental idea,
I have no right to assume any such thing as in itself exist-
ing, since no concepts through which I am able to think any
object as determined suffice for such a purpose -- the condi-
tions which are required for the objective validity of my con-
cepts being excluded by the idea itself. The concepts of reality,
substance, causality, even that of necessity in existence, apart
from their use in making possible the empirical knowledge of
an object, have no meaning whatsoever, such as might serve
to determine any object. They can be employed, therefore, to
explain the possibility of things in the world of sense, but not
to explain the possibility of the universe itself. Such a ground
of explanation would have to be outside the world, and could
not therefore be an object of a possible experience. None the
less, though I cannot assume such an inconceivable being [as
existing] in itself, I may yet assume it as the object of a mere
idea, relatively to the world of sense. For if the greatest
possible empirical employment of my reason rests upon an
idea (that of systematically complete unity, which I shall
presently be defining more precisely), an idea which, al-
though it can never itself be adequately exhibited in experi-
ence, is yet indispensably necessary in order that we may
approximate to the highest possible degree of empirical unity,
I shall not only be entitled, but shall also be constrained, to
realise this idea, that is, to posit for it a real object. But I may
posit it only as a something which I do not at all know in
itself, and to which, as a ground of that systematic unity, I
ascribe, in relation to this unity, such properties as are ana-
logous to the concepts employed by the understanding in the
empirical sphere. Accordingly, in analogy with realities in
the world, that is, with substances, with causality and with
necessity, I think a being which possesses all this in the
highest perfection; and since this idea depends merely on
my reason, I can think this being as self-subsistent reason,
P 555
which through ideas of the greatest harmony and unity is
the cause of the universe. I thus omit all conditions which
might limit the idea, solely in order, under countenance of
such an original ground, to make possible systematic unity
of the manifold in the universe, and thereby the greatest
possible empirical employment of reason. This I do by repre-
senting all connections as if they were the ordinances of a
supreme reason, of which our reason is but a faint copy. I then
proceed to think this supreme being exclusively through con-
cepts which, properly, are applicable only in the world of
sense. But since I make none but a relative use of the trans-
cendental assumption, namely, as giving the substratum of
the greatest possible unity of experience, I am quite in order in
thinking a being which I distinguish from the world of sense,
through properties which belong solely to that world. For I
do not seek, nor am I justified in seeking, to know this object
of my idea according to what it may be in itself. There are no
concepts available for any such purpose; even the concepts of
reality, substance, causality, nay, even that of necessity in
existence, lose all meaning, and are empty titles for [possible]
concepts, themselves entirely without content, when we thus
venture with them outside the field of the senses. I think to
myself merely the relation of a being, in itself completely un-
known to me, to the greatest possible systematic unity of the
universe, solely for the purpose of using it as a schema of the
regulative principle of the greatest possible empirical employ-
ment of my reason. 
If it be the transcendental object of our idea that we have
in view, it is obvious that we cannot thus, in terms of the
concepts of reality, substance, causality, etc. , presuppose its
reality in itself, since these concepts have not the least applica-
tion to anything that is entirely distinct from the world of sense. 
The supposition which reason makes of a supreme being, as
the highest cause, is, therefore relative only; it is devised solely
for the sake of systematic unity in the world of sense, and is a
mere something in idea, of which, as it may be in itself, we
have no concept. This explains why, in relation to what is
given to the senses as existing, we require the idea of a prim-
ordial being necessary in itself, and yet can never form the
slightest concept of it or of its absolute necessity. 
P 556
We are now in a position to have a clear view of the outcome
of the whole Transcendental Dialectic, and accurately to define
the final purpose of the ideas of pure reason, which become
dialectical only through heedlessness and misapprehension. 
Pure reason is in fact occupied with nothing but itself. It can
have no other vocation. For what is given to it does not consist
in objects that have to be brought to the unity of the empirical
concept, but in those modes of knowledge supplied by the
understanding that require to be brought to the unity of the
concept of reason -- that is, to unity of connection in conform-
ity with a principle. The unity of reason is the unity of system;
and this systematic unity does not serve objectively as a prin-
ciple that extends the application of reason to objects, but sub-
jectively as a maxim that extends its application to all possible
empirical knowledge of objects. Nevertheless, since the system-
atic connection which reason can give to the empirical em-
ployment of the understanding not only furthers its extension,
but also guarantees its correctness, the principle of such system-
atic unity is so far also objective, but in an indeterminate
manner (principium vagum). It is not a constitutive principle
that enables us to determine anything in respect of its direct
object, but only a merely regulative principle and maxim, to
further and strengthen in infinitum (indeterminately) the
empirical employment of reason -- never in any way proceed-
ing counter to the laws of its empirical employment, and yet
at the same time opening out new paths which are not within
the cognisance of the understanding. 
 But reason cannot think this systematic unity otherwise
than by giving to the idea of this unity an object; and since
experience can never give an example of complete systematic
unity, the object which we have to assign to the idea is not
such as experience can ever supply. This object, as thus enter-
tained by reason (ens rationis ratiocinatae), is a mere idea;
it is not assumed as a something that is real absolutely and
in itself, but is postulated only problematically (since we
cannot reach it through any of the concepts of the under-
standing) in order that we may view all connection of the
things of the world of sense as if they had their ground in such
a being. In thus proceeding, our sole purpose is to secure
that systematic unity which is indispensable to reason, and
P 557
which while furthering in every way the empirical knowledge
obtainable by the understanding can never interfere to hinder
or obstruct it. 
We misapprehend the meaning of this idea if we regard
it as the assertion or even as the assumption of a real thing,
to which we may proceed to ascribe the ground of the sys-
tematic order of the world. On the contrary, what this ground
which eludes our concepts may be in its own inherent con-
stitution is left entirely undetermined; the idea is posited only
as being the point of view from which alone that unity, which
is so essential to reason and so beneficial to the understand-
ing, can be further extended. In short, this transcendental
thing is only the schema of the regulative principle by which
reason, so far as lies in its power, extends systematic unity
over the whole field of experience. 
The first object of such an idea is the 'I' itself, viewed
simply as thinking nature or soul. If I am to investigate the
properties with which a thinking being is in itself endowed, I
must interrogate experience. For I cannot even apply any one
of the categories to this object, except in so far as the schema
of the category is given in sensible intuition. But I never there-
by attain to a systematic unity of all appearances of inner sense. 
Instead, then, of the empirical concept (of that which the soul
actually is), which cannot carry us far, reason takes the concept
of the empirical unity of all thought; and by thinking this unity
as unconditioned and original, it forms from it a concept of
reason, that is, the idea of a simple substance, which, unchange-
able in itself (personally identical), stands in association with
other real things outside it; in a word, the idea of a simple self-
subsisting intelligence. Yet in so doing it has nothing in view
save principles of systematic unity in the explanation of the
appearances of the soul. It is endeavouring to represent all
determinations as existing in a single subject, all powers, so
far as possible, as derived from a single fundamental power, all
change as belonging to the states of one and the same per-
manent being, and all appearances in space as completely dif-
ferent from the actions of thought. The simplicity and other
properties of substance are intended to be only the schema of
this regulative principle, and are not presupposed as being the
actual ground of the properties of the soul. For these may rest
P 558
on altogether different grounds, of which we can know nothing. 
The soul in itself could not be known through these assumed
predicates, not even if we regarded them as absolutely valid
in respect of it. For they constitute a mere idea which cannot
be represented in concreto. Nothing but advantage can result
from the psychological idea thus conceived, if only we take
heed that it is not viewed as more than a mere idea, and that
it is therefore taken as valid only relatively to the systematic
employment of reason in determining the appearances of our
soul. For no empirical laws of bodily appearance, which are
of a totally different kind, will then intervene in the explana-
tion of what belongs exclusively to inner sense. No windy
hypotheses of generation, extinction, and palingenesis of souls
will be permitted. The consideration of this object of inner
sense will thus be kept completely pure and will not be con-
fused by the introduction of heterogeneous properties. Also,
reason's investigations will be directed to reducing the grounds
of explanation in this field, so far as may be possible, to a
single principle. All this will be best attained through such a
schema, viewed as if it were a real being; indeed it is attain-
able in no other way. The psychological idea can signify
nothing but the schema of a regulative concept. For were
I to enquire whether the soul in itself is of spiritual nature,
the question would have no meaning. In employing such a
concept I not only abstract from corporeal nature, but from
nature in general, that is, from all predicates of any possible
experience, and therefore from all conditions requisite for
thinking an object for such a concept; yet only as related to
an object can the concept be said to have a meaning. 
The second regulative idea of merely speculative reason
is the concept of the world in general. For nature is properly
the only given object in regard to which reason requires regu-
lative principles. This nature is twofold, either thinking or
corporeal. To think the latter, so far as regards its inner
possibility, that is, to determine the application of the cate-
gories to it, we need no idea, that is, no representation which
transcends experience. Nor, indeed, is any idea possible in this
connection, since in dealing with corporeal nature we are
guided solely by sensible intuition. The case is different from
that of the fundamental psychological concept ('I'), which
P 559
contains a priori a certain form of thought, namely, the unity
of thought. There therefore remains for pure reason nothing
but nature in general, and the completeness of the conditions
in nature in accordance with some principle. The absolute
totality of the series of these conditions, in the derivation of
their members, is an idea which can never be completely
realised in the empirical employment of reason, but which
yet serves as a rule that prescribes how we ought to proceed
in dealing with such series, namely, that in explaining appear-
ances, whether in their regressive or in their ascending order,
we ought to treat the series as if it were in itself infinite, that
is, as if it proceeded in indefinitum. When, on the other hand,
reason is itself regarded as the determining cause, as in [the
sphere of] freedom, that is to say, in the case of practical prin-
ciples, we have to proceed as if we had before us an object, not
of the senses, but of the pure understanding. In this practical
sphere the conditions are no longer in the series of appear-
ances; they can be posited outside the series, and the series of
states can therefore be regarded as if it had an absolute be-
ginning, through an intelligible cause. All this shows that the
cosmological ideas are nothing but simply regulative prin-
ciples, and are very far from positing, in the manner of con-
stitutive principles, an actual totality of such series. The fuller
treatment of this subject will be found in the chapter on the
antinomy of pure reason. 
The third idea of pure reason, which contains a merely
relative supposition of a being that is the sole and sufficient
cause of all cosmological series, is the idea of God. We have
not the slightest ground to assume in an absolute manner (to
suppose in itself) the object of this idea; for what can enable
us to believe in or assert a being of the highest perfection and
one absolutely necessary by its very nature, merely on the basis
of its concept, or if we did how could we justify our procedure? 
It is only by way of its relation to the world that we can attempt
to establish the necessity of this supposition; and it then becomes
evident that the idea of such a being, like all speculative ideas,
seeks only to formulate the command of reason, that all con-
nection in the world be viewed in accordance with the prin-
ciples of a systematic unity -- as if all such connection had its
source in one single all-embracing being, as the supreme and
P 560
all-sufficient cause. It is thus evident that reason has here no
other purpose than to prescribe its own formal rule for the
extension of its empirical employment, and not any extension
beyond all limits of empirical employment. Consequently it is
evident that this idea does not, in any concealed fashion, in-
volve any principle that claims, in its application to possible
experience, to be constitutive in character. 
This highest formal unity, which rests solely on concepts
of reason, is the purposive unity of things. The speculative
interest of reason makes it necessary to regard all order in the
world as if it had originated in the purpose of a supreme
reason. Such a principle opens out to our reason, as applied
in the field of experience, altogether new views as to how the
things of the world may be connected according to teleological
laws, and so enables it to arrive at their greatest systematic
unity. The assumption of a supreme intelligence, as the one
and only cause of the universe, though in the idea alone, can
therefore always benefit reason and can never injure it. Thus
if, in studying the shape of the earth (which is round, but some-
what flattened), of the mountains, seas, etc. , we assume it to be
the outcome of wise purposes on the part of an Author of the
world, we are enabled to make in this way a number of dis-
coveries. And provided we restrict ourselves to a merely regu-
lative use of this principle, even error cannot do us any serious
harm. For the worst that can happen would be that where we
expected a teleological connection (nexus finalis), we find only
a mechanical or physical connection (nexus effectivus). In such
a case, we merely fail to find the additional unity; we do not
destroy the unity upon which reason insists in its empirical employment. 
++ The advantage arising from the spherical shape of the earth
is well known. But few are aware that its spheroidal flattening alone
prevents the continental elevations, or even the smaller hills, thrown
up perhaps by earthquakes, from continuously, and indeed quite
appreciably in a comparatively short time, altering the position of
the axis of the earth. The protuberance of the earth at the equator
forms so vast a mountain that the impetus of all the other moun-
tains can never produce any observable effect in changing the posi-
tion of the earth's axis. And yet, wise as this arrangement is, we feel
no scruples in explaining it from the equilibrium of the formerly
fluid mass of the earth. 
P 561
But even a disappointment of this sort cannot
affect the teleological law itself, in its general bearing. For
although an anatomist can be convicted of error when he
assigns to some member of an animal body an end which
it can be clearly shown not to subserve, it is yet quite im-
possible to prove in any given case that an arrangement
of nature, be it what it may, subserves no end whatsoever. 
Accordingly, medical physiology extends its very limited em-
pirical knowledge of the ends served by the articulation of an
organic body, by resorting to a principle for which pure reason
has alone been responsible; and it carries this principle so far as
to assume confidently, and with general approval, that every-
thing in an animal has its use, and subserves some good pur-
pose. If this assumption be treated as constitutive it goes much
further than observation has thus far been able to justify; and
we must therefore conclude that it is nothing more than a
regulative principle of reason, to aid us in securing the highest
possible systematic unity, by means of the idea of the pur-
posive causality of the supreme cause of the world -- as if this
being, as supreme intelligence, acting in accordance with a
supremely wise purpose, were the cause of all things. 
If, however, we overlook this restriction of the idea to a
merely regulative use, reason is led away into mistaken paths. 
For it then leaves the ground of experience, which alone can
contain the signs that mark out its proper course, and ventures
out beyond it to the incomprehensible and unsearchable,
rising to dizzy heights where it finds itself entirely cut off
from all possible action in conformity with experience. 
The first error which arises from our using the idea of a
supreme being in a manner contrary to the nature of an idea,
that is, constitutively, and not regulatively only, is the error of
ignava ratio. 
++ This was the title given by the ancient dialecticians to a
sophistical argument, which ran thus: If it is your fate to recover
from this illness, you will recover, whether you employ a physician
or not. Cicero states that this mode of argument has been so named,
because, if we conformed to it, reason would be left without any use
in life. On the same ground I apply the name also to the sophistical
argument of pure reason. 
P 561
We may so entitle every principle which makes
P 562
us regard our investigation into nature, on any subject, as
absolutely complete, disposing reason to cease from further
enquiry, as if it had entirely succeeded in the task which it had
set itself. Thus the psychological idea, when it is employed as
a constitutive principle to explain the appearances of our soul,
and thereby to extend our knowledge of the self beyond the
limits of experience (its state after death), does indeed simplify
the task of reason; but it interferes with, and entirely ruins,
our use of reason in dealing with nature under the guidance
of our experiences. The dogmatic spiritualist explains the
abiding and unchanging unity of a person throughout all
change of state, by the unity of the thinking substance, of
which, as he believes, he has immediate perception in the 'I';
or he explains the interest which we take in what can happen
only after our death, by means of our consciousness of the im-
material nature of the thinking subject; and so forth. He thus
dispenses with all empirical investigation of the cause of these
inner appearances, so far as that cause is to be found in physi-
cal grounds of explanation; and to his own great convenience,
though at the sacrifice of all real insight, he professes, in re-
liance upon the assumed authority of a transcendent reason, to
have the right to ignore those sources of knowledge which are
immanent in experience. These detrimental consequences are
even more obvious in the dogmatic treatment of our idea of a
supreme intelligence, and in the theological system of nature
(physico-theology) which is falsely based upon it. For in
this field of enquiry, if instead of looking for causes in the
universal laws of material mechanism, we appeal directly to
the unsearchable decree of supreme wisdom, all those ends
which are exhibited in nature, together with the many ends
which are only ascribed by us to nature, make our investi-
gation of the causes a very easy task, and so enable us to
regard the labour of reason as completed, when, as a matter
of fact, we have merely dispensed with its employment -- an
employment which is wholly dependent for guidance upon the
order of nature and the series of its alterations, in accordance
with the universal laws which they are found to exhibit. This
error can be avoided, if we consider from the teleological point
of view not merely certain parts of nature, such as the distribu-
P 563
tion of land, its structure, the constitution and location of
the mountains, or only the organisation of the vegetable and
animal kingdoms, but make this systematic unity of nature
completely universal, in relation to the idea of a supreme in-
telligence. For we then treat nature as resting upon a purpos-
iveness, in accordance with universal laws, from which no
special arrangement is exempt, however difficult it may be to
establish this in any given case. We then have a regulative
principle of the systematic unity of teleological connection --
a connection which we do not, however, predetermine. What
we may presume to do is to follow out the physico-mechanical
connection in accordance with universal laws in the hope of
discovering what the teleological connection actually is. In this
way alone can the principle of purposive unity aid always in
extending the employment of reason in reference to experience
without being in any instance prejudicial to it. 
The second error arising from the misapprehension of the
above principle of systematic unity is that of perversa ratio
(husteron proteron). The idea of systematic unity should be
used only as a regulative principle to guide us in seeking for
such unity in the connection of things, according to universal
laws of nature; and we ought, therefore, to believe that we
have approximated to completeness in the employment of the
principle only in proportion as we are in a position to verify
such unity in empirical fashion -- a completeness which is
never, of course, attainable. Instead of this the reverse pro-
cedure is adopted. The reality of a principle of purposive
unity is not only presupposed but hypostatised; and since the
concept of a supreme intelligence is in itself completely be-
yond our powers of comprehension, we proceed to determine
it in an anthropomorphic manner, and so to impose ends
upon nature, forcibly and dictatorially, instead of pursuing
the more reasonable course of searching for them by the path
of physical investigation. And thus teleology, which is in-
tended to aid us merely in completing the unity of nature in
accordance with universal laws, not only tends to abrogate
such unity, but also prevents reason from carrying out its own
professed purpose, that of proving from nature, in conformity
with these laws, the existence of a supreme intelligent cause. 
P 564
For if the most complete purposiveness cannot be presupposed
a priori in nature, that is, as belonging to its essence, how can
we be required to search for it, and through all its gradations
to approximate to the supreme perfection of an Author of all
things, a perfection that, as absolutely necessary, must be
knowable a priori?  The regulative principle prescribes that
systematic unity as a unity in nature, which is not known
merely empirically but is presupposed a priori (although in
an indeterminate manner), be presupposed absolutely, and
consequently as following from the essence of things. If,
however, I begin with a supreme purposive being as the
ground of all things, the unity of nature is really surrendered,
as being quite foreign and accidental to the nature of things,
and as not capable of being known from its own universal laws. 
There then arises a vicious circle; we are assuming just that
very point which is mainly in dispute. 
To take the regulative principle of the systematic unity of
nature as being a constitutive principle, and to hypostatise, and
presuppose as a cause, that which serves, merely in idea, as the
ground of the consistent employment of reason, is simply to
confound reason. The investigation of nature takes its own
independent course, keeping to the chain of natural causes
in conformity with their universal laws. It does indeed, in so
doing, proceed in accordance with the idea of an Author of the
universe, but not in order to deduce therefrom the purposive-
ness for which it is ever on the watch, but in order to obtain
knowledge of the existence of such an Author from this pur-
posiveness. And by seeking this purposiveness in the essence
of the things of nature, and so far as may be possible in the
essence of things in general, it seeks to know the existence of
this supreme being as absolutely necessary. Whether this latter
enterprise succeed or not, the idea remains always true in itself,
and justified in its use, provided it be restricted to the condi-
tions of a merely regulative principle. 
Complete purposive unity constitutes what is, in the ab-
solute sense, perfection. If we do not find this unity in the
essence of the things which go to constitute the entire object of
experience, that is, of all our objectively valid knowledge, and
therefore do not find it in the universal and necessary laws of
nature, how can we profess to infer directly from this unity the
P 565
idea of a supreme and absolutely necessary perfection of an
original being, as the source of all causality? The greatest pos-
sible systematic unity, and consequently also purposive unity, is
the training school for the use of reason, and is indeed the very
foundation of the possibility of its greatest possible employ-
ment. The idea of such unity is, therefore, inseparably bound
up with the very nature of our reason. This same idea is on
that account legislative for us; and it is therefore very natural
that we should assume a corresponding legislative reason
(intellectus archetypus), from which, as the object of our reason,
all systematic unity of nature is to be derived. 
In discussing the antinomy of pure reason we have stated
that the questions propounded by pure reason must in every
case admit of an answer, and that in their regard it is not per-
missible to plead the limits of our knowledge (a plea which
in many questions that concern nature is as unavoidable as
it is relevant). For we are not here asking questions in regard
to the nature of things, but only such questions as arise from
the very nature of reason, and which concern solely its own
inner constitution. We are now in a position to confirm this
assertion -- which at first sight may have appeared rash -- so
far as regards the two questions in which pure reason is most
of all interested; and thus finally to complete our discussion of
the dialectic of pure reason. 
If, in connection with a transcendental theology, we ask,
first, whether there is anything distinct from the world, which
contains the ground of the order of the world and of its con-
nection in accordance with universal laws, the answer is that
there undoubtedly is. For the world is a sum of appearances;
and there must therefore be some transcendental ground of
the appearances, that is, a ground which is thinkable only by
the pure understanding. If, secondly, the question be, whether
this being is substance, of the greatest reality, necessary, etc. ,
++ After what I have already said regarding the psychological
idea and its proper vocation, as a principle for the merely regulative
employment of reason, I need not dwell at any length upon the
transcendental illusion by which the systematic unity of all the mani-
foldness of inner sense is hypostatised. The procedure is very similar
to that which is under discussion in our criticism of the theological
P 566
we reply that this question is entirely without meaning. For
all categories through which we can attempt to form a concept
of such an object allow only of empirical employment, and
have no meaning whatsoever when not applied to objects of
possible experience, that is, to the world of sense. Outside this
field they are merely titles of concepts, which we may admit,
but through which [in and by themselves] we can understand
nothing. If, thirdly, the question be, whether we may not at
least think this being, which is distinct from the world, in
analogy with the objects of experience, the answer is: cer-
tainly, but only as object in idea and not in reality, namely,
only as being a substratum, to us unknown, of the systematic
unity, order, and purposiveness of the arrangement of the
world -- an idea which reason is constrained to form as the
regulative principle of its investigation of nature. Nay, more,
we may freely, without laying ourselves open to censure, admit
into this idea certain anthropomorphisms which are helpful
to the principle in its regulative capacity. For it is always an
idea only, which does not relate directly to a being distinct
from the world, but to the regulative principle of the systematic
unity of the world, and only by means of a schema of this
unity, namely, through the schema of a supreme intelligence
which, in originating the world, acts in accordance with wise
purposes. What this primordial ground of the unity of the
world may be in itself, we should not profess to have thereby
decided, but only how we should use it, or rather its idea, in
relation to the systematic employment of reason in respect of
the things of the world. 
But the question may still be pressed: Can we, on such
grounds, assume a wise and omnipotent Author of the world? 
Undoubtedly we may; and we not only may, but must, do so. 
But do we then extend our knowledge beyond the field of pos-
sible experience? By no means. All that we have done is merely
to presuppose a something, a merely transcendental object, of
which, as it is in itself, we have no concept whatsoever. It is
only in relation to the systematic and purposive ordering of
the world, which, if we are to study nature, we are constrained
to presuppose, that we have thought this unknown being
by analogy with an intelligence (an empirical concept); that
is, have endowed it, in respect of the ends and perfection
P 567
which are to be grounded upon it, with just those properties
which, in conformity with the conditions of our reason, can
be regarded as containing the ground of such systematic unity. 
This idea is thus valid only in respect of the employment of our
reason in reference to the world. If we ascribed to it a validity
that is absolute and objective, we should be forgetting that
what we are thinking is a being in idea only; and in thus taking
our start from a ground which is not determinable through
observation of the world, we should no longer be in a position
to apply the principle in a manner suited to the empirical
employment of reason. 
But, it will still be asked, can I make any such use of the
concept and of the presupposition of a supreme being in the
rational consideration of the world? Yes, it is precisely for
this purpose that reason has resorted to this idea. But may I
then proceed to regard seemingly purposive arrangements as
purposes, and so derive them from the divine will, though,
of course, mediately through certain special natural means,
themselves established in furtherance of that divine will? Yes,
we can indeed do so; but only on condition that we regard
it as a matter of indifference whether it be asserted that
divine wisdom has disposed all things in accordance with its
supreme ends, or that the idea of supreme wisdom is a regu-
lative principle in the investigation of nature and a principle
of its systematic and purposive unity, in accordance with
universal laws, even in those cases in which we are unable
to detect that unity. In other words, it must be a matter of
complete indifference to us, when we perceive such unity,
whether we say that God in his wisdom has willed it to be
so, or that nature has wisely arranged it thus. For what has
justified us in adopting the idea of a supreme intelligence as
a schema of the regulative principle is precisely this greatest
possible systematic and purposive unity -- a unity which our
reason has required as a regulative principle that must under-
lie all investigation of nature. The more, therefore, we dis-
cover purposiveness in the world, the more fully is the legiti-
macy of our idea confirmed. But since the sole aim of that
principle was to guide us in seeking a necessary unity of nature,
and that in the greatest possible degree, while we do indeed,
P 568
in so far as we attain that unity, owe it to the idea of a supreme
being, we cannot, without contradicting ourselves, ignore the
universal laws of nature -- with a view to discovering which the
idea was alone adopted -- and look upon this purposiveness
of nature as contingent and hyperphysical in its origin. For we
were not justified in assuming above nature a being with those
qualities, but only in adopting the idea of such a being in order
to view the appearances as systematically connected with one
another in accordance with the principle of a causal deter-
For the same reasons, in thinking the cause of the world,
we are justified in representing it in our idea not only in
terms of a certain subtle anthropomorphism (without which
we could not think anything whatsoever in regard to it),
namely, as a being that has understanding, feelings of pleasure
and displeasure, and desires and volitions corresponding to
these, but also in ascribing to it a perfection which, as infinite,
far transcends any perfection that our empirical knowledge of
the order of the world can justify us in attributing to it. For
the regulative law of systematic unity prescribes that we should
study nature as if systematic and purposive unity, combined
with the greatest possible manifoldness, were everywhere to be
met with, in infinitum. For although we may succeed in dis-
covering but little of this perfection of the world, it is never-
theless required by the legislation of our reason that we must
always search for and surmise it; and it must always be bene-
ficial, and can never be harmful, to direct our investigations
into nature in accordance with this principle. But it is evident
that in this way of representing the principle as involving the
idea of a supreme Author, I do not base the principle upon the
existence and upon the knowledge of such a being, but upon
its idea only, and that I do not really derive anything from this
being, but only from the idea of it -- that is, from the nature of
the things of the world, in accordance with such an idea. A
certain, unformulated consciousness of the true use of this
concept of reason seems indeed to have inspired the modest
and reasonable language of the philosophers of all times,
since they speak of the wisdom and providence of nature and
of divine wisdom, just as if nature and divine wisdom were
P 569
equivalent expressions -- indeed, so long as they are dealing
solely with speculative reason, giving preference to the former
mode of expression, on the ground that it enables us to avoid
making profession of more than we are justified in asserting,
and that it likewise directs reason to its own proper field,
namely, nature. 
Thus pure reason, which at first seemed to promise nothing
less than the extension of knowledge beyond all limits of ex-
perience, contains, if properly understood, nothing but regu-
lative principles, which, while indeed prescribing greater unity
than the empirical employment of understanding can achieve,
yet still, by the very fact that they place the goal of its
endeavours at so great a distance, carry its agreement with
itself, by means of systematic unity, to the highest possible
degree. But if, on the other hand, they be misunderstood,
and be treated as constitutive principles of transcendent
knowledge, they give rise, by a dazzling and deceptive
illusion, to persuasion and a merely fictitious knowledge,
and therewith to contradictions and eternal disputes. 
Thus all human knowledge begins with intuitions, pro-
ceeds from thence to concepts, and ends with ideas. Although
in respect of all three elements it possesses a priori sources of
knowledge, which on first consideration seem to scorn the
limits of all experience, a thoroughgoing critique convinces us
that reason, in its speculative employment, can never with
these elements transcend the field of possible experience, and
that the proper vocation of this supreme faculty of knowledge
is to use all methods, and the principles of these methods,
solely for the purpose of penetrating to the innermost secrets
of nature, in accordance with every possible principle of unity
-- that of ends being the most important -- but never to soar
beyond its limits, outside which there is for us nothing but
empty space. The critical examination, as carried out in the
Transcendental Analytic, of all propositions which may seem
to extend our knowledge beyond actual experience, has doubt-
less sufficed to convince us that they can never lead to any-
thing more than a possible experience. Were it not that we are
suspicious of abstract and general doctrines, however clear,
P 570
and were it not that specious and alluring prospects tempt us
to escape from the compulsion which these doctrines impose,
we might have been able to spare ourselves the laborious in-
terrogation of all those dialectical witnesses that a transcen-
dent reason brings forward in support of its pretensions. For
we should from the start have known with complete certainty
that all such pretensions, while perhaps honestly meant, must
be absolutely groundless, inasmuch as they relate to a kind
of knowledge to which man can never attain. But there is no
end to such discussions, unless we can penetrate to the true
cause of the illusion by which even the wisest are deceived. 
Moreover, the resolution of all our transcendent knowledge
into its elements (as a study of our inner nature) is in itself
of no slight value, and to the philosopher is indeed a matter
of duty. Accordingly, fruitless as are all these endeavours of
speculative reason, we have none the less found it necessary
to follow them up to their primary sources. And since the
dialectical illusion does not merely deceive us in our judg-
ments, but also, because of the interest which we take in these
judgments, has a certain natural attraction which it will always
continue to possess, we have thought it advisable, with a view
to the prevention of such errors in the future, to draw up in
full detail what we may describe as being the records of this
lawsuit, and to deposit them in the archives of human reason.