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The Critique of Pure Reason by Immanuel Kant

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This argument always deserves to be mentioned with respect. It is
the oldest, the clearest, and that most in conformity with the
common reason of humanity. It animates the study of nature, as it
itself derives its existence and draws ever new strength from that
source. It introduces aims and ends into a sphere in which our
observation could not of itself have discovered them, and extends
our knowledge of nature, by directing our attention to a unity, the
principle of which lies beyond nature. This knowledge of nature
again reacts upon this idea--its cause; and thus our belief in a
divine author of the universe rises to the power of an irresistible

For these reasons it would be utterly hopeless to attempt to rob
this argument of the authority it has always enjoyed. The mind,
unceasingly elevated by these considerations, which, although
empirical, are so remarkably powerful, and continually adding to their
force, will not suffer itself to be depressed by the doubts
suggested by subtle speculation; it tears itself out of this state
of uncertainty, the moment it casts a look upon the wondrous forms
of nature and the majesty of the universe, and rises from height to
height, from condition to condition, till it has elevated itself to
the supreme and unconditioned author of all.

But although we have nothing to object to the reasonableness and
utility of this procedure, but have rather to commend and encourage
it, we cannot approve of the claims which this argument advances to
demonstrative certainty and to a reception upon its own merits,
apart from favour or support by other arguments. Nor can it injure
the cause of morality to endeavour to lower the tone of the arrogant
sophist, and to teach him that modesty and moderation which are the
properties of a belief that brings calm and content into the mind,
without prescribing to it an unworthy subjection. I maintain, then,
that the physico-theological argument is insufficient of itself to
prove the existence of a Supreme Being, that it must entrust this to
the ontological argument--to which it serves merely as an
introduction, and that, consequently, this argument contains the
only possible ground of proof (possessed by speculative reason) for
the existence of this being.

The chief momenta in the physico-theological argument are as follow:
1. We observe in the world manifest signs of an arrangement full of
purpose, executed with great wisdom, and argument in whole of a
content indescribably various, and of an extent without limits. 2.
This arrangement of means and ends is entirely foreign to the things
existing in the world--it belongs to them merely as a contingent
attribute; in other words, the nature of different things could not
of itself, whatever means were employed, harmoniously tend towards
certain purposes, were they not chosen and directed for these purposes
by a rational and disposing principle, in accordance with certain
fundamental ideas. 3. There exists, therefore, a sublime and wise
cause (or several), which is not merely a blind, all-powerful
nature, producing the beings and events which fill the world in
unconscious fecundity, but a free and intelligent cause of the
world. 4. The unity of this cause may be inferred from the unity of
the reciprocal relation existing between the parts of the world, as
portions of an artistic edifice--an inference which all our
observation favours, and all principles of analogy support.

In the above argument, it is inferred from the analogy of certain
products of nature with those of human art, when it compels Nature
to bend herself to its purposes, as in the case of a house, a ship,
or a watch, that the same kind of causality--namely, understanding
and will--resides in nature. It is also declared that the internal
possibility of this freely-acting nature (which is the source of all
art, and perhaps also of human reason) is derivable from another and
superhuman art--a conclusion which would perhaps be found incapable
of standing the test of subtle transcendental criticism. But to neither
of these opinions shall we at present object. We shall only remark
that it must be confessed that, if we are to discuss the subject of
cause at all, we cannot proceed more securely than with the guidance
of the analogy subsisting between nature and such products of
design--these being the only products whose causes and modes of
organization are completely known to us. Reason would be unable to
satisfy her own requirements, if she passed from a causality which
she does know, to obscure and indemonstrable principles of explanation
which she does not know.

According to the physico-theological argument, the connection and
harmony existing in the world evidence the contingency of the form
merely, but not of the matter, that is, of the substance of the world.
To establish the truth of the latter opinion, it would be necessary
to prove that all things would be in themselves incapable of this harmony
and order, unless they were, even as regards their substance, the
product of a supreme wisdom. But this would require very different
grounds of proof from those presented by the analogy with human art.
This proof can at most, therefore, demonstrate the existence of an
architect of the world, whose efforts are limited by the
capabilities of the material with which he works, but not of a creator
of the world, to whom all things are subject. Thus this argument is
utterly insufficient for the task before us--a demonstration of the
existence of an all-sufficient being. If we wish to prove the
contingency of matter, we must have recourse to a transcendental
argument, which the physico-theological was constructed expressly to

We infer, from the order and design visible in the universe, as a
disposition of a thoroughly contingent character, the existence of
a cause proportionate thereto. The conception of this cause must contain
certain determinate qualities, and it must therefore be regarded as
the conception of a being which possesses all power, wisdom, and so
on, in one word, all perfection--the conception, that is, of an
all-sufficient being. For the predicates of very great, astonishing,
or immeasurable power and excellence, give us no determinate
conception of the thing, nor do they inform us what the thing may be
in itself. They merely indicate the relation existing between the
magnitude of the object and the observer, who compares it with himself
and with his own power of comprehension, and are mere expressions of
praise and reverence, by which the object is either magnified, or
the observing subject depreciated in relation to the object. Where
we have to do with the magnitude (of the perfection) of a thing, we
can discover no determinate conception, except that which
comprehends all possible perfection or completeness, and it is only
the total (omnitudo) of reality which is completely determined in
and through its conception alone.

Now it cannot be expected that any one will be bold enough to
declare that he has a perfect insight into the relation which the
magnitude of the world he contemplates bears (in its extent as well
as in its content) to omnipotence, into that of the order and design
in the world to the highest wisdom, and that of the unity of the world
to the absolute unity of a Supreme Being. Physico-theology is therefore
incapable of presenting a determinate conception of a supreme cause
of the world, and is therefore insufficient as a principle of theology--a
theology which is itself to be the basis of religion.

The attainment of absolute totality is completely impossible on
the path of empiricism. And yet this is the path pursued in the
physico-theological argument. What means shall we employ to bridge
the abyss?

After elevating ourselves to admiration of the magnitude of the
power, wisdom, and other attributes of the author of the world, and
finding we can advance no further, we leave the argument on
empirical grounds, and proceed to infer the contingency of the world
from the order and conformity to aims that are observable in it.
From this contingency we infer, by the help of transcendental
conceptions alone, the existence of something absolutely necessary;
and, still advancing, proceed from the conception of the absolute
necessity of the first cause to the completely determined or
determining conception thereof--the conception of an all-embracing
reality. Thus the physico-theological, failing in its undertaking,
recurs in its embarrassment to the cosmological argument; and, as this
is merely the ontological argument in disguise, it executes its design
solely by the aid of pure reason, although it at first professed to
have no connection with this faculty and to base its entire
procedure upon experience alone.

The physico-theologians have therefore no reason to regard with such
contempt the transcendental mode of argument, and to look down upon
it, with the conceit of clear-sighted observers of nature, as the
brain-cobweb of obscure speculatists. For, if they reflect upon and
examine their own arguments, they will find that, after following
for some time the path of nature and experience, and discovering
themselves no nearer their object, they suddenly leave this path and
pass into the region of pure possibility, where they hope to reach
upon the wings of ideas what had eluded all their empirical
investigations. Gaining, as they think, a firm footing after this
immense leap, they extend their determinate conception--into the
possession of which they have come, they know not how--over the
whole sphere of creation, and explain their ideal, which is entirely
a product of pure reason, by illustrations drawn from experience--though
in a degree miserably unworthy of the grandeur of the object, while
they refuse to acknowledge that they have arrived at this cognition
or hypothesis by a very different road from that of experience.

Thus the physico-theological is based upon the cosmological, and
this upon the ontological proof of the existence of a Supreme Being;
and as besides these three there is no other path open to
speculative reason, the ontological proof, on the ground of pure
conceptions of reason, is the only possible one, if any proof of a
proposition so far transcending the empirical exercise of the
understanding is possible at all.

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

If by the term theology I understand the cognition of a primal
being, that cognition is based either upon reason alone (theologia
rationalis) or upon revelation (theologia revelata). The former
cogitates its object either by means of pure transcendental
conceptions, as an ens originarium, realissimum, ens entium, and is
termed transcendental theology; or, by means of a conception derived
from the nature of our own mind, as a supreme intelligence, and must
then be entitled natural theology. The person who believes in a
transcendental theology alone, is termed a deist; he who
acknowledges the possibility of a natural theology also, a theist.
The former admits that we can cognize by pure reason alone the existence
of a Supreme Being, but at the same time maintains that our conception
of this being is purely transcendental, and that all we can say of
it is that it possesses all reality, without being able to define it
more closely. The second asserts that reason is capable of
presenting us, from the analogy with nature, with a more definite
conception of this being, and that its operations, as the cause of
all things, are the results of intelligence and free will. The former
regards the Supreme Being as the cause of the world--whether by the
necessity of his nature, or as a free agent, is left undetermined;
the latter considers this being as the author of the world.

Transcendental theology aims either at inferring the existence of
a Supreme Being from a general experience, without any closer
reference to the world to which this experience belongs, and in this
case it is called cosmotheology; or it endeavours to cognize the
existence of such a being, through mere conceptions, without the aid
of experience, and is then termed ontotheology.

Natural theology infers the attributes and the existence of an
author of the world, from the constitution of, the order and unity
observable in, the world, in which two modes of causality must be
admitted to exist--those of nature and freedom. Thus it rises from
this world to a supreme intelligence, either as the principle of all
natural, or of all moral order and perfection. In the former case it
is termed physico-theology, in the latter, ethical or moral-theology.*

[*Footnote: Not theological ethics; for this science contains ethical
laws, which presuppose the existence of a Supreme Governor of the world;
while moral-theology, on the contrary, is the expression of a
conviction of the existence of a Supreme Being, founded upon ethical

As we are wont to understand by the term God not merely an eternal
nature, the operations of which are insensate and blind, but a Supreme
Being, who is the free and intelligent author of all things, and as
it is this latter view alone that can be of interest to humanity, we
might, in strict rigour, deny to the deist any belief in God at all,
and regard him merely as a maintainer of the existence of a primal
being or thing--the supreme cause of all other things. But, as no
one ought to be blamed, merely because he does not feel himself
justified in maintaining a certain opinion, as if he altogether denied
its truth and asserted the opposite, it is more correct--as it is less
harsh--to say, the deist believes in a God, the theist in a living
God (summa intelligentia). We shall now proceed to investigate the
sources of all these attempts of reason to establish the existence
of a Supreme Being.

It may be sufficient in this place to define theoretical knowledge
or cognition as knowledge of that which is, and practical knowledge
as knowledge of that which ought to be. In this view, the theoretical
employment of reason is that by which I cognize a priori (as
necessary) that something is, while the practical is that by which
I cognize a priori what ought to happen. Now, if it is an indubitably
certain, though at the same time an entirely conditioned truth, that
something is, or ought to happen, either a certain determinate
condition of this truth is absolutely necessary, or such a condition
may be arbitrarily presupposed. In the former case the condition is
postulated (per thesin), in the latter supposed (per hypothesin).
There are certain practical laws--those of morality--which are
absolutely necessary. Now, if these laws necessarily presuppose the
existence of some being, as the condition of the possibility of
their obligatory power, this being must be postulated, because the
conditioned, from which we reason to this determinate condition, is
itself cognized a priori as absolutely necessary. We shall at some
future time show that the moral laws not merely presuppose the
existence of a Supreme Being, but also, as themselves absolutely
necessary in a different relation, demand or postulate it--although
only from a practical point of view. The discussion of this argument
we postpone for the present.

When the question relates merely to that which is, not to that which
ought to be, the conditioned which is presented in experience is
always cogitated as contingent. For this reason its condition cannot
be regarded as absolutely necessary, but merely as relatively
necessary, or rather as needful; the condition is in itself and a
priori a mere arbitrary presupposition in aid of the cognition, by
reason, of the conditioned. If, then, we are to possess a
theoretical cognition of the absolute necessity of a thing, we
cannot attain to this cognition otherwise than a priori by means of
conceptions; while it is impossible in this way to cognize the
existence of a cause which bears any relation to an existence given
in experience.

Theoretical cognition is speculative when it relates to an object or
certain conceptions of an object which is not given and cannot be
discovered by means of experience. It is opposed to the cognition of
nature, which concerns only those objects or predicates which can be
presented in a possible experience.

The principle that everything which happens (the empirically
contingent) must have a cause, is a principle of the cognition of
nature, but not of speculative cognition. For, if we change it into
an abstract principle, and deprive it of its reference to experience
and the empirical, we shall find that it cannot with justice be
regarded any longer as a synthetical proposition, and that it is
impossible to discover any mode of transition from that which exists
to something entirely different--termed cause. Nay, more, the
conception of a cause likewise that of the contingent--loses, in
this speculative mode of employing it, all significance, for its
objective reality and meaning are comprehensible from experience

When from the existence of the universe and the things in it the
existence of a cause of the universe is inferred, reason is proceeding
not in the natural, but in the speculative method. For the principle
of the former enounces, not that things themselves or substances,
but only that which happens or their states--as empirically
contingent, have a cause: the assertion that the existence of
substance itself is contingent is not justified by experience, it is
the assertion of a reason employing its principles in a speculative
manner. If, again, I infer from the form of the universe, from the
way in which all things are connected and act and react upon each other,
the existence of a cause entirely distinct from the universe--this
would again be a judgement of purely speculative reason; because the
object in this case--the cause--can never be an object of possible
experience. In both these cases the principle of causality, which is
valid only in the field of experience--useless and even meaningless
beyond this region, would be diverted from its proper destination.

Now I maintain that all attempts of reason to establish a theology
by the aid of speculation alone are fruitless, that the principles
of reason as applied to nature do not conduct us to any theological
truths, and, consequently, that a rational theology can have no
existence, unless it is founded upon the laws of morality. For all
synthetical principles of the understanding are valid only as immanent
in experience; while the cognition of a Supreme Being necessitates
their being employed transcendentally, and of this the understanding
is quite incapable. If the empirical law of causality is to conduct
us to a Supreme Being, this being must belong to the chain of empirical
objects--in which case it would be, like all phenomena, itself
conditioned. If the possibility of passing the limits of experience
be admitted, by means of the dynamical law of the relation of an effect
to its cause, what kind of conception shall we obtain by this
procedure? Certainly not the conception of a Supreme Being, because
experience never presents us with the greatest of all possible
effects, and it is only an effect of this character that could witness
to the existence of a corresponding cause. If, for the purpose of
fully satisfying the requirements of Reason, we recognize her right
to assert the existence of a perfect and absolutely necessary being,
this can be admitted only from favour, and cannot be regarded as the
result or irresistible demonstration. The physico-theological proof
may add weight to others--if other proofs there are--by connecting
speculation with experience; but in itself it rather prepares the mind
for theological cognition, and gives it a right and natural direction,
than establishes a sure foundation for theology.

It is now perfectly evident that transcendental questions admit only
of transcendental answers--those presented a priori by pure
conceptions without the least empirical admixture. But the question
in the present case is evidently synthetical--it aims at the extension
of our cognition beyond the bounds of experience--it requires an
assurance respecting the existence of a being corresponding with the
idea in our minds, to which no experience can ever be adequate. Now
it has been abundantly proved that all a priori synthetical cognition
is possible only as the expression of the formal conditions of a
possible experience; and that the validity of all principles depends
upon their immanence in the field of experience, that is, their
relation to objects of empirical cognition or phenomena. Thus all
transcendental procedure in reference to speculative theology is
without result.

If any one prefers doubting the conclusiveness of the proofs of
our analytic to losing the persuasion of the validity of these old
and time honoured arguments, he at least cannot decline answering the
question--how he can pass the limits of all possible experience by
the help of mere ideas. If he talks of new arguments, or of improvements
upon old arguments, I request him to spare me. There is certainly no
great choice in this sphere of discussion, as all speculative
arguments must at last look for support to the ontological, and I
have, therefore, very little to fear from the argumentative
fecundity of the dogmatical defenders of a non-sensuous reason.
Without looking upon myself as a remarkably combative person, I
shall not decline the challenge to detect the fallacy and destroy
the pretensions of every attempt of speculative theology. And yet
the hope of better fortune never deserts those who are accustomed to
the dogmatical mode of procedure. I shall, therefore, restrict
myself to the simple and equitable demand that such reasoners will
demonstrate, from the nature of the human mind as well as from that
of the other sources of knowledge, how we are to proceed to extend
our cognition completely a priori, and to carry it to that point where
experience abandons us, and no means exist of guaranteeing the
objective reality of our conceptions. In whatever way the
understanding may have attained to a conception, the existence of
the object of the conception cannot be discovered in it by analysis,
because the cognition of the existence of the object depends upon
the object's being posited and given in itself apart from the
conception. But it is utterly impossible to go beyond our
conception, without the aid of experience--which presents to the
mind nothing but phenomena, or to attain by the help of mere
conceptions to a conviction of the existence of new kinds of objects
or supernatural beings.

But although pure speculative reason is far from sufficient to
demonstrate the existence of a Supreme Being, it is of the highest
utility in correcting our conception of this being--on the supposition
that we can attain to the cognition of it by some other means--in
making it consistent with itself and with all other conceptions of
intelligible objects, clearing it from all that is incompatible with
the conception of an ens summun, and eliminating from it all
limitations or admixtures of empirical elements.

Transcendental theology is still therefore, notwithstanding its
objective insufficiency, of importance in a negative respect; it is
useful as a test of the procedure of reason when engaged with pure
ideas, no other than a transcendental standard being in this case
admissible. For if, from a practical point of view, the hypothesis
of a Supreme and All-sufficient Being is to maintain its validity
without opposition, it must be of the highest importance to define
this conception in a correct and rigorous manner--as the
transcendental conception of a necessary being, to eliminate all
phenomenal elements (anthropomorphism in its most extended
signification), and at the same time to overflow all contradictory
assertions--be they atheistic, deistic, or anthropomorphic. This is
of course very easy; as the same arguments which demonstrated the
inability of human reason to affirm the existence of a Supreme Being
must be alike sufficient to prove the invalidity of its denial. For
it is impossible to gain from the pure speculation of reason
demonstration that there exists no Supreme Being, as the ground of
all that exists, or that this being possesses none of those properties
which we regard as analogical with the dynamical qualities of a
thinking being, or that, as the anthropomorphists would have us
believe, it is subject to all the limitations which sensibility
imposes upon those intelligences which exist in the world of

A Supreme Being is, therefore, for the speculative reason, a mere
ideal, though a faultless one--a conception which perfects and
crowns the system of human cognition, but the objective reality of
which can neither be proved nor disproved by pure reason. If this
defect is ever supplied by a moral theology, the problematic
transcendental theology which has preceded, will have been at least
serviceable as demonstrating the mental necessity existing for the
conception, by the complete determination of it which it has
furnished, and the ceaseless testing of the conclusions of a reason
often deceived by sense, and not always in harmony with its own ideas.
The attributes of necessity, infinitude, unity, existence apart from
the world (and not as a world soul), eternity (free from conditions
of time), omnipresence (free from conditions of space), omnipotence,
and others, are pure transcendental predicates; and thus the
accurate conception of a Supreme Being, which every theology requires,
is furnished by transcendental theology alone.


Of the Regulative Employment of the Ideas of Pure Reason.

The result of all the dialectical attempts of pure reason not only
confirms the truth of what we have already proved in our
Transcendental Analytic, namely, that all inferences which would
lead us beyond the limits of experience are fallacious and groundless,
but it at the same time teaches us this important lesson, that human
reason has a natural inclination to overstep these limits, and that
transcendental ideas are as much the natural property of the reason
as categories are of the understanding. There exists this difference,
however, that while the categories never mislead us, outward objects
being always in perfect harmony therewith, ideas are the parents of
irresistible illusions, the severest and most subtle criticism being
required to save us from the fallacies which they induce.

Whatever is grounded in the nature of our powers will be found to be
in harmony with the final purpose and proper employment of these
powers, when once we have discovered their true direction and aim.
We are entitled to suppose, therefore, that there exists a mode of
employing transcendental ideas which is proper and immanent; although,
when we mistake their meaning, and regard them as conceptions of
actual things, their mode of application is transcendent and delusive.
For it is not the idea itself, but only the employment of the idea
in relation to possible experience, that is transcendent or
immanent. An idea is employed transcendently, when it is applied to
an object falsely believed to be adequate with and to correspond to
it; imminently, when it is applied solely to the employment of the
understanding in the sphere of experience. Thus all errors of
subreptio--of misapplication, are to be ascribed to defects of
judgement, and not to understanding or reason.

Reason never has an immediate relation to an object; it relates
immediately to the understanding alone. It is only through the
understanding that it can be employed in the field of experience. It
does not form conceptions of objects, it merely arranges them and
gives to them that unity which they are capable of possessing when
the sphere of their application has been extended as widely as possible.
Reason avails itself of the conception of the understanding for the
sole purpose of producing totality in the different series. This
totality the understanding does not concern itself with; its only
occupation is the connection of experiences, by which series of
conditions in accordance with conceptions are established. The
object of reason is, therefore, the understanding and its proper
destination. As the latter brings unity into the diversity of
objects by means of its conceptions, so the former brings unity into
the diversity of conceptions by means of ideas; as it sets the final
aim of a collective unity to the operations of the understanding,
which without this occupies itself with a distributive unity alone.

I accordingly maintain that transcendental ideas can never be
employed as constitutive ideas, that they cannot be conceptions of
objects, and that, when thus considered, they assume a fallacious
and dialectical character. But, on the other hand, they are capable
of an admirable and indispensably necessary application to objects--as
regulative ideas, directing the understanding to a certain aim, the
guiding lines towards which all its laws follow, and in which they
all meet in one point. This point--though a mere idea (focus imaginarius),
that is, not a point from which the conceptions of the understanding
do really proceed, for it lies beyond the sphere of possible
experience--serves, notwithstanding, to give to these conceptions
the greatest possible unity combined with the greatest possible
extension. Hence arises the natural illusion which induces us to
believe that these lines proceed from an object which lies out of
the sphere of empirical cognition, just as objects reflected in a
mirror appear to be behind it. But this illusion--which we may
hinder from imposing upon us--is necessary and unavoidable, if we
desire to see, not only those objects which lie before us, but those
which are at a great distance behind us; that is to say, when, in
the present case, we direct the aims of the understanding, beyond
every given experience, towards an extension as great as can
possibly be attained.

If we review our cognitions in their entire extent, we shall find
that the peculiar business of reason is to arrange them into a system,
that is to say, to give them connection according to a principle. This
unity presupposes an idea--the idea of the form of a whole (of
cognition), preceding the determinate cognition of the parts, and
containing the conditions which determine a priori to every part its
place and relation to the other parts of the whole system. This
idea, accordingly, demands complete unity in the cognition of the
understanding--not the unity of a contingent aggregate, but that of
a system connected according to necessary laws. It cannot be
affirmed with propriety that this idea is a conception of an object;
it is merely a conception of the complete unity of the conceptions
of objects, in so far as this unity is available to the
understanding as a rule. Such conceptions of reason are not derived
from nature; on the contrary, we employ them for the interrogation
and investigation of nature, and regard our cognition as defective
so long as it is not adequate to them. We admit that such a thing as
pure earth, pure water, or pure air, is not to be discovered. And yet
we require these conceptions (which have their origin in the reason,
so far as regards their absolute purity and completeness) for the purpose
of determining the share which each of these natural causes has in
every phenomenon. Thus the different kinds of matter are all referred
to earths, as mere weight; to salts and inflammable bodies, as pure
force; and finally, to water and air, as the vehicula of the former,
or the machines employed by them in their operations--for the
purpose of explaining the chemical action and reaction of bodies in
accordance with the idea of a mechanism. For, although not actually
so expressed, the influence of such ideas of reason is very observable
in the procedure of natural philosophers.

If reason is the faculty of deducing the particular from the
general, and if the general be certain in se and given, it is only
necessary that the judgement should subsume the particular under the
general, the particular being thus necessarily determined. I shall
term this the demonstrative or apodeictic employment of reason. If,
however, the general is admitted as problematical only, and is a
mere idea, the particular case is certain, but the universality of
the rule which applies to this particular case remains a problem.
Several particular cases, the certainty of which is beyond doubt,
are then taken and examined, for the purpose of discovering whether
the rule is applicable to them; and if it appears that all the
particular cases which can be collected follow from the rule, its
universality is inferred, and at the same time, all the causes which
have not, or cannot be presented to our observation, are concluded
to be of the same character with those which we have observed. This
I shall term the hypothetical employment of the reason.

The hypothetical exercise of reason by the aid of ideas employed
as problematical conceptions is properly not constitutive. That is
to say, if we consider the subject strictly, the truth of the rule,
which has been employed as an hypothesis, does not follow from the
use that is made of it by reason. For how can we know all the possible
cases that may arise? some of which may, however, prove exceptions
to the universality of the rule. This employment of reason is merely
regulative, and its sole aim is the introduction of unity into the
aggregate of our particular cognitions, and thereby the
approximating of the rule to universality.

The object of the hypothetical employment of reason is therefore the
systematic unity of cognitions; and this unity is the criterion of
the truth of a rule. On the other hand, this systematic unity--as a
mere idea--is in fact merely a unity projected, not to be regarded
as given, but only in the light of a problem--a problem which serves,
however, as a principle for the various and particular exercise of
the understanding in experience, directs it with regard to those cases
which are not presented to our observation, and introduces harmony
and consistency into all its operations.

All that we can be certain of from the above considerations is
that this systematic unity is a logical principle, whose aim is to
assist the understanding, where it cannot of itself attain to rules,
by means of ideas, to bring all these various rules under one
principle, and thus to ensure the most complete consistency and
connection that can be attained. But the assertion that objects and
the understanding by which they are cognized are so constituted as
to be determined to systematic unity, that this may be postulated a
priori, without any reference to the interest of reason, and that we
are justified in declaring all possible cognitions--empirical and
others--to possess systematic unity, and to be subject to general
principles from which, notwithstanding their various character, they
are all derivable such an assertion can be founded only upon a
transcendental principle of reason, which would render this systematic
unity not subjectively and logically--in its character of a method,
but objectively necessary.

We shall illustrate this by an example. The conceptions of the
understanding make us acquainted, among many other kinds of unity,
with that of the causality of a substance, which is termed power.
The different phenomenal manifestations of the same substance appear
at first view to be so very dissimilar that we are inclined to
assume the existence of just as many different powers as there are
different effects--as, in the case of the human mind, we have feeling,
consciousness, imagination, memory, wit, analysis, pleasure, desire
and so on. Now we are required by a logical maxim to reduce these
differences to as small a number as possible, by comparing them and
discovering the hidden identity which exists. We must inquire, for
example, whether or not imagination (connected with consciousness),
memory, wit, and analysis are not merely different forms of
understanding and reason. The idea of a fundamental power, the
existence of which no effort of logic can assure us of, is the problem
to be solved, for the systematic representation of the existing
variety of powers. The logical principle of reason requires us to
produce as great a unity as is possible in the system of our
cognitions; and the more the phenomena of this and the other power
are found to be identical, the more probable does it become, that they
are nothing but different manifestations of one and the same power,
which may be called, relatively speaking, a fundamental power. And
so with other cases.

These relatively fundamental powers must again be compared with each
other, to discover, if possible, the one radical and absolutely
fundamental power of which they are but the manifestations. But this
unity is purely hypothetical. It is not maintained, that this unity
does really exist, but that we must, in the interest of reason, that
is, for the establishment of principles for the various rules
presented by experience, try to discover and introduce it, so far as
is practicable, into the sphere of our cognitions.

But the transcendental employment of the understanding would lead us
to believe that this idea of a fundamental power is not problematical,
but that it possesses objective reality, and thus the systematic unity
of the various powers or forces in a substance is demanded by the
understanding and erected into an apodeictic or necessary principle.
For, without having attempted to discover the unity of the various
powers existing in nature, nay, even after all our attempts have
failed, we notwithstanding presuppose that it does exist, and may
be, sooner or later, discovered. And this reason does, not only, as
in the case above adduced, with regard to the unity of substance, but
where many substances, although all to a certain extent homogeneous,
are discoverable, as in the case of matter in general. Here also
does reason presuppose the existence of the systematic unity of
various powers--inasmuch as particular laws of nature are
subordinate to general laws; and parsimony in principles is not merely
an economical principle of reason, but an essential law of nature.

We cannot understand, in fact, how a logical principle of unity
can of right exist, unless we presuppose a transcendental principle,
by which such a systematic unit--as a property of objects
themselves--is regarded as necessary a priori. For with what right
can reason, in its logical exercise, require us to regard the variety
of forces which nature displays, as in effect a disguised unity, and
to deduce them from one fundamental force or power, when she is free
to admit that it is just as possible that all forces should be
different in kind, and that a systematic unity is not conformable to
the design of nature? In this view of the case, reason would be
proceeding in direct opposition to her own destination, by setting
as an aim an idea which entirely conflicts with the procedure and
arrangement of nature. Neither can we assert that reason has
previously inferred this unity from the contingent nature of
phenomena. For the law of reason which requires us to seek for this
unity is a necessary law, inasmuch as without it we should not possess
a faculty of reason, nor without reason a consistent and
self-accordant mode of employing the understanding, nor, in the
absence of this, any proper and sufficient criterion of empirical
truth. In relation to this criterion, therefore, we must suppose the
idea of the systematic unity of nature to possess objective validity
and necessity.

We find this transcendental presupposition lurking in different
forms in the principles of philosophers, although they have neither
recognized it nor confessed to themselves its presence. That the
diversities of individual things do not exclude identity of species,
that the various species must be considered as merely different
determinations of a few genera, and these again as divisions of
still higher races, and so on--that, accordingly, a certain systematic
unity of all possible empirical conceptions, in so far as they can
be deduced from higher and more general conceptions, must be sought
for, is a scholastic maxim or logical principle, without which
reason could not be employed by us. For we can infer the particular
from the general, only in so far as general properties of things
constitute the foundation upon which the particular rest.

That the same unity exists in nature is presupposed by
philosophers in the well-known scholastic maxim, which forbids us
unnecessarily to augment the number of entities or principles (entia
praeter necessitatem non esse multiplicanda). This maxim asserts
that nature herself assists in the establishment of this unity of
reason, and that the seemingly infinite diversity of phenomena
should not deter us from the expectation of discovering beneath this
diversity a unity of fundamental properties, of which the aforesaid
variety is but a more or less determined form. This unity, although
a mere idea, thinkers have found it necessary rather to moderate the
desire than to encourage it. It was considered a great step when
chemists were able to reduce all salts to two main genera--acids and
alkalis; and they regard this difference as itself a mere variety,
or different manifestation of one and the same fundamental material.
The different kinds of earths (stones and even metals) chemists have
endeavoured to reduce to three, and afterwards to two; but still,
not content with this advance, they cannot but think that behind these
diversities there lurks but one genus--nay, that even salts and earths
have a common principle. It might be conjectured that this is merely
an economical plan of reason, for the purpose of sparing itself
trouble, and an attempt of a purely hypothetical character, which,
when successful, gives an appearance of probability to the principle
of explanation employed by the reason. But a selfish purpose of this
kind is easily to be distinguished from the idea, according to which
every one presupposes that this unity is in accordance with the laws
of nature, and that reason does not in this case request, but
requires, although we are quite unable to determine the proper
limits of this unity.

If the diversity existing in phenomena--a diversity not of form (for
in this they may be similar) but of content--were so great that the
subtlest human reason could never by comparison discover in them the
least similarity (which is not impossible), in this case the logical
law of genera would be without foundation, the conception of a
genus, nay, all general conceptions would be impossible, and the
faculty of the understanding, the exercise of which is restricted to
the world of conceptions, could not exist. The logical principle of
genera, accordingly, if it is to be applied to nature (by which I mean
objects presented to our senses), presupposes a transcendental
principle. In accordance with this principle, homogeneity is
necessarily presupposed in the variety of phenomena (although we are
unable to determine a priori the degree of this homogeneity),
because without it no empirical conceptions, and consequently no
experience, would be possible.

The logical principle of genera, which demands identity in
phenomena, is balanced by another principle--that of species, which
requires variety and diversity in things, notwithstanding their
accordance in the same genus, and directs the understanding to
attend to the one no less than to the other. This principle (of the
faculty of distinction) acts as a check upon the reason and reason
exhibits in this respect a double and conflicting interest--on the
one hand, the interest in the extent (the interest of generality) in
relation to genera; on the other, that of the content (the interest
of individuality) in relation to the variety of species. In the former
case, the understanding cogitates more under its conceptions, in the
latter it cogitates more in them. This distinction manifests itself
likewise in the habits of thought peculiar to natural philosophers,
some of whom--the remarkably speculative heads--may be said to be
hostile to heterogeneity in phenomena, and have their eyes always
fixed on the unity of genera, while others--with a strong empirical
tendency--aim unceasingly at the analysis of phenomena, and almost
destroy in us the hope of ever being able to estimate the character
of these according to general principles.

The latter mode of thought is evidently based upon a logical
principle, the aim of which is the systematic completeness of all
cognitions. This principle authorizes me, beginning at the genus, to
descend to the various and diverse contained under it; and in this
way extension, as in the former case unity, is assured to the system.
For if we merely examine the sphere of the conception which
indicates a genus, we cannot discover how far it is possible to
proceed in the division of that sphere; just as it is impossible, from
the consideration of the space occupied by matter, to determine how
far we can proceed in the division of it. Hence every genus must
contain different species, and these again different subspecies; and
as each of the latter must itself contain a sphere (must be of a
certain extent, as a conceptus communis), reason demands that no
species or sub-species is to be considered as the lowest possible.
For a species or sub-species, being always a conception, which contains
only what is common to a number of different things, does not
completely determine any individual thing, or relate immediately to
it, and must consequently contain other conceptions, that is, other
sub-species under it. This law of specification may be thus expressed:
entium varietates non temere sunt minuendae.

But it is easy to see that this logical law would likewise be
without sense or application, were it not based upon a
transcendental law of specification, which certainly does not
require that the differences existing phenomena should be infinite
in number, for the logical principle, which merely maintains the
indeterminateness of the logical sphere of a conception, in relation
to its possible division, does not authorize this statement; while
it does impose upon the understanding the duty of searching for
subspecies to every species, and minor differences in every
difference. For, were there no lower conceptions, neither could
there be any higher. Now the understanding cognizes only by means of
conceptions; consequently, how far soever it may proceed in
division, never by mere intuition, but always by lower and lower
conceptions. The cognition of phenomena in their complete
determination (which is possible only by means of the understanding)
requires an unceasingly continued specification of conceptions, and
a progression to ever smaller differences, of which abstraction bad
been made in the conception of the species, and still more in that
of the genus.

This law of specification cannot be deduced from experience; it
can never present us with a principle of so universal an
application. Empirical specification very soon stops in its
distinction of diversities, and requires the guidance of the
transcendental law, as a principle of the reason--a law which
imposes on us the necessity of never ceasing in our search for
differences, even although these may not present themselves to the
senses. That absorbent earths are of different kinds could only be
discovered by obeying the anticipatory law of reason, which imposes
upon the understanding the task of discovering the differences
existing between these earths, and supposes that nature is richer in
substances than our senses would indicate. The faculty of the
understanding belongs to us just as much under the presupposition of
differences in the objects of nature, as under the condition that
these objects are homogeneous, because we could not possess
conceptions, nor make any use of our understanding, were not the
phenomena included under these conceptions in some respects
dissimilar, as well as similar, in their character.

Reason thus prepares the sphere of the understanding for the
operations of this faculty: 1. By the principle of the homogeneity
of the diverse in higher genera; 2. By the principle of the variety
of the homogeneous in lower species; and, to complete the systematic
unity, it adds, 3. A law of the affinity of all conceptions which
prescribes a continuous transition from one species to every other
by the gradual increase of diversity. We may term these the principles
of the homogeneity, the specification, and the continuity of forms.
The latter results from the union of the two former, inasmuch as we
regard the systematic connection as complete in thought, in the ascent
to higher genera, as well as in the descent to lower species. For
all diversities must be related to each other, as they all spring from
one highest genus, descending through the different gradations of a
more and more extended determination.

We may illustrate the systematic unity produced by the three logical
principles in the following manner. Every conception may be regarded
as a point, which, as the standpoint of a spectator, has a certain
horizon, which may be said to enclose a number of things that may be
viewed, so to speak, from that centre. Within this horizon there
must be an infinite number of other points, each of which has its
own horizon, smaller and more circumscribed; in other words, every
species contains sub-species, according to the principle of
specification, and the logical horizon consists of smaller horizons
(subspecies), but not of points (individuals), which possess no
extent. But different horizons or genera, which include under them
so many conceptions, may have one common horizon, from which, as
from a mid-point, they may be surveyed; and we may proceed thus,
till we arrive at the highest genus, or universal and true horizon,
which is determined by the highest conception, and which contains
under itself all differences and varieties, as genera, species, and

To this highest standpoint I am conducted by the law of homogeneity,
as to all lower and more variously-determined conceptions by the law
of specification. Now as in this way there exists no void in the whole
extent of all possible conceptions, and as out of the sphere of
these the mind can discover nothing, there arises from the
presupposition of the universal horizon above mentioned, and its
complete division, the principle: Non datur vacuum formarum. This
principle asserts that there are not different primitive and highest
genera, which stand isolated, so to speak, from each other, but all
the various genera are mere divisions and limitations of one highest
and universal genus; and hence follows immediately the principle:
Datur continuum formarum. This principle indicates that all
differences of species limit each other, and do not admit of
transition from one to another by a saltus, but only through smaller
degrees of the difference between the one species and the other. In
one word, there are no species or sub-species which (in the view of
reason) are the nearest possible to each other; intermediate species
or sub-species being always possible, the difference of which from
each of the former is always smaller than the difference existing
between these.

The first law, therefore, directs us to avoid the notion that
there exist different primal genera, and enounces the fact of
perfect homogeneity; the second imposes a check upon this tendency
to unity and prescribes the distinction of sub-species, before
proceeding to apply our general conceptions to individuals. The
third unites both the former, by enouncing the fact of homogeneity
as existing even in the most various diversity, by means of the
gradual transition from one species to another. Thus it indicates a
relationship between the different branches or species, in so far as
they all spring from the same stem.

But this logical law of the continuum specierum (formarum logicarum)
presupposes a transcendental principle (lex continui in natura),
without which the understanding might be led into error, by
following the guidance of the former, and thus perhaps pursuing a path
contrary to that prescribed by nature. This law must, consequently,
be based upon pure transcendental, and not upon empirical,
considerations. For, in the latter case, it would come later than
the system; whereas it is really itself the parent of all that is
systematic in our cognition of nature. These principles are not mere
hypotheses employed for the purpose of experimenting upon nature;
although when any such connection is discovered, it forms a solid
ground for regarding the hypothetical unity as valid in the sphere
of nature--and thus they are in this respect not without their use.
But we go farther, and maintain that it is manifest that these
principles of parsimony in fundamental causes, variety in effects,
and affinity in phenomena, are in accordance both with reason and
nature, and that they are not mere methods or plans devised for the
purpose of assisting us in our observation of the external world.

But it is plain that this continuity of forms is a mere idea, to
which no adequate object can be discovered in experience. And this
for two reasons. First, because the species in nature are really
divided, and hence form quanta discreta; and, if the gradual
progression through their affinity were continuous, the intermediate
members lying between two given species must be infinite in number,
which is impossible. Secondly, because we cannot make any
determinate empirical use of this law, inasmuch as it does not present
us with any criterion of affinity which could aid us in determining
how far we ought to pursue the graduation of differences: it merely
contains a general indication that it is our duty to seek for and,
if possible, to discover them.

When we arrange these principles of systematic unity in the order
conformable to their employment in experience, they will stand thus:
Variety, Affinity, Unity, each of them, as ideas, being taken in the
highest degree of their completeness. Reason presupposes the existence
of cognitions of the understanding, which have a direct relation to
experience, and aims at the ideal unity of these cognitions--a unity
which far transcends all experience or empirical notions. The affinity
of the diverse, notwithstanding the differences existing between its
parts, has a relation to things, but a still closer one to the mere
properties and powers of things. For example, imperfect experience
may represent the orbits of the planets as circular. But we discover
variations from this course, and we proceed to suppose that the
planets revolve in a path which, if not a circle, is of a character
very similar to it. That is to say, the movements of those planets
which do not form a circle will approximate more or less to the
properties of a circle, and probably form an ellipse. The paths of
comets exhibit still greater variations, for, so far as our
observation extends, they do not return upon their own course in a
circle or ellipse. But we proceed to the conjecture that comets
describe a parabola, a figure which is closely allied to the
ellipse. In fact, a parabola is merely an ellipse, with its longer
axis produced to an indefinite extent. Thus these principles conduct
us to a unity in the genera of the forms of these orbits, and,
proceeding farther, to a unity as regards the cause of the motions
of the heavenly bodies--that is, gravitation. But we go on extending
our conquests over nature, and endeavour to explain all seeming
deviations from these rules, and even make additions to our system
which no experience can ever substantiate--for example, the theory,
in affinity with that of ellipses, of hyperbolic paths of comets,
pursuing which, these bodies leave our solar system and, passing
from sun to sun, unite the most distant parts of the infinite
universe, which is held together by the same moving power.

The most remarkable circumstance connected with these principles
is that they seem to be transcendental, and, although only
containing ideas for the guidance of the empirical exercise of reason,
and although this empirical employment stands to these ideas in an
asymptotic relation alone (to use a mathematical term), that is,
continually approximate, without ever being able to attain to them,
they possess, notwithstanding, as a priori synthetical propositions,
objective though undetermined validity, and are available as rules
for possible experience. In the elaboration of our experience, they
may also be employed with great advantage, as heuristic [Footnote:
From the Greek, eurhioko.] principles. A transcendental deduction of
them cannot be made; such a deduction being always impossible in the
case of ideas, as has been already shown.

We distinguished, in the Transcendental Analytic, the dynamical
principles of the understanding, which are regulative principles of
intuition, from the mathematical, which are constitutive principles
of intuition. These dynamical laws are, however, constitutive in relation
to experience, inasmuch as they render the conceptions without which
experience could not exist possible a priori. But the principles of
pure reason cannot be constitutive even in regard to empirical
conceptions, because no sensuous schema corresponding to them can be
discovered, and they cannot therefore have an object in concreto. Now,
if I grant that they cannot be employed in the sphere of experience,
as constitutive principles, how shall I secure for them employment
and objective validity as regulative principles, and in what way can
they be so employed?

The understanding is the object of reason, as sensibility is the
object of the understanding. The production of systematic unity in
all the empirical operations of the understanding is the proper occupation
of reason; just as it is the business of the understanding to
connect the various content of phenomena by means of conceptions,
and subject them to empirical laws. But the operations of the
understanding are, without the schemata of sensibility,
undetermined; and, in the same manner, the unity of reason is
perfectly undetermined as regards the conditions under which, and
the extent to which, the understanding ought to carry the systematic
connection of its conceptions. But, although it is impossible to
discover in intuition a schema for the complete systematic unity of
all the conceptions of the understanding, there must be some
analogon of this schema. This analogon is the idea of the maximum of
the division and the connection of our cognition in one principle.
For we may have a determinate notion of a maximum and an absolutely
perfect, all the restrictive conditions which are connected with an
indeterminate and various content having been abstracted. Thus the
idea of reason is analogous with a sensuous schema, with this
difference, that the application of the categories to the schema of
reason does not present a cognition of any object (as is the case with
the application of the categories to sensuous schemata), but merely
provides us with a rule or principle for the systematic unity of the
exercise of the understanding. Now, as every principle which imposes
upon the exercise of the understanding a priori compliance with the
rule of systematic unity also relates, although only in an indirect
manner, to an object of experience, the principles of pure reason will
also possess objective reality and validity in relation to experience.
But they will not aim at determining our knowledge in regard to any
empirical object; they will merely indicate the procedure, following
which the empirical and determinate exercise of the understanding
may be in complete harmony and connection with itself--a result
which is produced by its being brought into harmony with the principle
of systematic unity, so far as that is possible, and deduced from it.

I term all subjective principles, which are not derived from
observation of the constitution of an object, but from the interest
which Reason has in producing a certain completeness in her
cognition of that object, maxims of reason. Thus there are maxims of
speculative reason, which are based solely upon its speculative
interest, although they appear to be objective principles.

When principles which are really regulative are regarded as
constitutive, and employed as objective principles, contradictions
must arise; but if they are considered as mere maxims, there is no
room for contradictions of any kind, as they then merely indicate
the different interests of reason, which occasion differences in the
mode of thought. In effect, Reason has only one single interest, and
the seeming contradiction existing between her maxims merely indicates
a difference in, and a reciprocal limitation of, the methods by
which this interest is satisfied.

This reasoner has at heart the interest of diversity--in
accordance with the principle of specification; another, the
interest of unity--in accordance with the principle of aggregation.
Each believes that his judgement rests upon a thorough insight into
the subject he is examining, and yet it has been influenced solely
by a greater or less degree of adherence to some one of the two
principles, neither of which are objective, but originate solely
from the interest of reason, and on this account to be termed maxims
rather than principles. When I observe intelligent men disputing about
the distinctive characteristics of men, animals, or plants, and even
of minerals, those on the one side assuming the existence of certain
national characteristics, certain well-defined and hereditary
distinctions of family, race, and so on, while the other side maintain
that nature has endowed all races of men with the same faculties and
dispositions, and that all differences are but the result of
external and accidental circumstances--I have only to consider for
a moment the real nature of the subject of discussion, to arrive at
the conclusion that it is a subject far too deep for us to judge of,
and that there is little probability of either party being able to
speak from a perfect insight into and understanding of the nature of
the subject itself. Both have, in reality, been struggling for the
twofold interest of reason; the one maintaining the one interest,
the other the other. But this difference between the maxims of
diversity and unity may easily be reconciled and adjusted; although,
so long as they are regarded as objective principles, they must
occasion not only contradictions and polemic, but place hinderances
in the way of the advancement of truth, until some means is discovered
of reconciling these conflicting interests, and bringing reason into
union and harmony with itself.

The same is the case with the so-called law discovered by Leibnitz, and
supported with remarkable ability by Bonnet--the law of the continuous
gradation of created beings, which is nothing more than an inference
from the principle of affinity; for observation and study of the order
of nature could never present it to the mind as an objective truth. The
steps of this ladder, as they appear in experience, are too far apart
from each other, and the so-called petty differences between different
kinds of animals are in nature commonly so wide separations that no
confidence can be placed in such views (particularly when we reflect on
the great variety of things, and the ease with which we can discover
resemblances), and no faith in the laws which are said to express the
aims and purposes of nature. On the other hand, the method of
investigating the order of nature in the light of this principle, and
the maxim which requires us to regard this order--it being still
undetermined how far it extends--as really existing in nature, is
beyond doubt a legitimate and excellent principle of reason--a
principle which extends farther than any experience or observation of
ours and which, without giving us any positive knowledge of anything in
the region of experience, guides us to the goal of systematic unity.

Of the Ultimate End of the Natural Dialectic of Human Reason.

The ideas of pure reason cannot be, of themselves and in their own
nature, dialectical; it is from their misemployment alone that
fallacies and illusions arise. For they originate in the nature of
reason itself, and it is impossible that this supreme tribunal for
all the rights and claims of speculation should be itself undeserving
of confidence and promotive of error. It is to be expected, therefore,
that these ideas have a genuine and legitimate aim. It is true, the
mob of sophists raise against reason the cry of inconsistency and
contradiction, and affect to despise the government of that faculty,
because they cannot understand its constitution, while it is to its
beneficial influences alone that they owe the position and the
intelligence which enable them to criticize and to blame its

We cannot employ an a priori conception with certainty, until we
have made a transcendental deduction therefore. The ideas of pure
reason do not admit of the same kind of deduction as the categories.
But if they are to possess the least objective validity, and to
represent anything but mere creations of thought (entia rationis
ratiocinantis), a deduction of them must be possible. This deduction
will complete the critical task imposed upon pure reason; and it is
to this part Of our labours that we now proceed.

There is a great difference between a thing's being presented to the
mind as an object in an absolute sense, or merely as an ideal
object. In the former case I employ my conceptions to determine the
object; in the latter case nothing is present to the mind but a mere
schema, which does not relate directly to an object, not even in a
hypothetical sense, but which is useful only for the purpose of
representing other objects to the mind, in a mediate and indirect
manner, by means of their relation to the idea in the intellect.
Thus I say the conception of a supreme intelligence is a mere idea;
that is to say, its objective reality does not consist in the fact
that it has an immediate relation to an object (for in this sense we
have no means of establishing its objective validity), it is merely
a schema constructed according to the necessary conditions of the
unity of reason--the schema of a thing in general, which is useful
towards the production of the highest degree of systematic unity in
the empirical exercise of reason, in which we deduce this or that
object of experience from the imaginary object of this idea, as the
ground or cause of the said object of experience. In this way, the
idea is properly a heuristic, and not an ostensive, conception; it
does not give us any information respecting the constitution of an
object, it merely indicates how, under the guidance of the idea, we
ought to investigate the constitution and the relations of objects
in the world of experience. Now, if it can be shown that the three
kinds of transcendental ideas (psychological, cosmological, and
theological), although not relating directly to any object nor
determining it, do nevertheless, on the supposition of the existence
of an ideal object, produce systematic unity in the laws of the
empirical employment of the reason, and extend our empirical
cognition, without ever being inconsistent or in opposition with it-
it must be a necessary maxim of reason to regulate its procedure
according to these ideas. And this forms the transcendental
deduction of all speculative ideas, not as constitutive principles
of the extension of our cognition beyond the limits of our experience,
but as regulative principles of the systematic unity of empirical
cognition, which is by the aid of these ideas arranged and emended
within its own proper limits, to an extent unattainable by the
operation of the principles of the understanding alone.

I shall make this plainer. Guided by the principles involved in
these ideas, we must, in the first place, so connect all the
phenomena, actions, and feelings of the mind, as if it were a simple
substance, which, endowed with personal identity, possesses a
permanent existence (in this life at least), while its states, among
which those of the body are to be included as external conditions,
are in continual change. Secondly, in cosmology, we must investigate
the conditions of all natural phenomena, internal as well as external,
as if they belonged to a chain infinite and without any prime or
supreme member, while we do not, on this account, deny the existence
of intelligible grounds of these phenomena, although we never employ
them to explain phenomena, for the simple reason that they are not
objects of our cognition. Thirdly, in the sphere of theology, we
must regard the whole system of possible experience as forming an
absolute, but dependent and sensuously-conditioned unity, and at the
same time as based upon a sole, supreme, and all-sufficient ground
existing apart from the world itself--a ground which is a
self-subsistent, primeval and creative reason, in relation to which
we so employ our reason in the field of experience, as if all objects
drew their origin from that archetype of all reason. In other words,
we ought not to deduce the internal phenomena of the mind from a
simple thinking substance, but deduce them from each other under the
guidance of the regulative idea of a simple being; we ought not to
deduce the phenomena, order, and unity of the universe from a
supreme intelligence, but merely draw from this idea of a supremely
wise cause the rules which must guide reason in its connection of
causes and effects.

Now there is nothing to hinder us from admitting these ideas to
possess an objective and hyperbolic existence, except the cosmological
ideas, which lead reason into an antinomy: the psychological and
theological ideas are not antinomial. They contain no contradiction;
and how, then, can any one dispute their objective reality, since he
who denies it knows as little about their possibility as we who
affirm? And yet, when we wish to admit the existence of a thing, it
is not sufficient to convince ourselves that there is no positive
obstacle in the way; for it cannot be allowable to regard mere
creations of thought, which transcend, though they do not
contradict, all our conceptions, as real and determinate objects,
solely upon the authority of a speculative reason striving to
compass its own aims. They cannot, therefore, be admitted to be real
in themselves; they can only possess a comparative reality--that of
a schema of the regulative principle of the systematic unity of all
cognition. They are to be regarded not as actual things, but as in
some measure analogous to them. We abstract from the object of the
idea all the conditions which limit the exercise of our understanding,
but which, on the other hand, are the sole conditions of our
possessing a determinate conception of any given thing. And thus we
cogitate a something, of the real nature of which we have not the
least conception, but which we represent to ourselves as standing in
a relation to the whole system of phenomena, analogous to that in
which phenomena stand to each other.

By admitting these ideal beings, we do not really extend our
cognitions beyond the objects of possible experience; we extend merely
the empirical unity of our experience, by the aid of systematic unity,
the schema of which is furnished by the idea, which is therefore
valid--not as a constitutive, but as a regulative principle. For
although we posit a thing corresponding to the idea--a something, an
actual existence--we do not on that account aim at the extension of
our cognition by means of transcendent conceptions. This existence
is purely ideal, and not objective; it is the mere expression of the
systematic unity which is to be the guide of reason in the field of
experience. There are no attempts made at deciding what the ground
of this unity may be, or what the real nature of this imaginary being.

Thus the transcendental and only determinate conception of God,
which is presented to us by speculative reason, is in the strictest
sense deistic. In other words, reason does not assure us of the
objective validity of the conception; it merely gives us the idea of
something, on which the supreme and necessary unity of all
experience is based. This something we cannot, following the analogy
of a real substance, cogitate otherwise than as the cause of all
things operating in accordance with rational laws, if we regard it
as an individual object; although we should rest contented with the
idea alone as a regulative principle of reason, and make no attempt
at completing the sum of the conditions imposed by thought. This
attempt is, indeed, inconsistent with the grand aim of complete
systematic unity in the sphere of cognition--a unity to which no
bounds are set by reason.

Hence it happens that, admitting a divine being, I can have no
conception of the internal possibility of its perfection, or of the
necessity of its existence. The only advantage of this admission is
that it enables me to answer all other questions relating to the
contingent, and to give reason the most complete satisfaction as
regards the unity which it aims at attaining in the world of
experience. But I cannot satisfy reason with regard to this hypothesis
itself; and this proves that it is not its intelligence and insight
into the subject, but its speculative interest alone which induces
it to proceed from a point lying far beyond the sphere of our
cognition, for the purpose of being able to consider all objects as
parts of a systematic whole.

Here a distinction presents itself, in regard to the way in which we
may cogitate a presupposition--a distinction which is somewhat subtle,
but of great importance in transcendental philosophy. I may have
sufficient grounds to admit something, or the existence of
something, in a relative point of view (suppositio relativa),
without being justified in admitting it in an absolute sense
(suppositio absoluta). This distinction is undoubtedly requisite, in
the case of a regulative principle, the necessity of which we
recognize, though we are ignorant of the source and cause of that
necessity, and which we assume to be based upon some ultimate
ground, for the purpose of being able to cogitate the universality
of the principle in a more determinate way. For example, I cogitate
the existence of a being corresponding to a pure transcendental
idea. But I cannot admit that this being exists absolutely and in
itself, because all of the conceptions by which I can cogitate an
object in a determinate manner fall short of assuring me of its
existence; nay, the conditions of the objective validity of my
conceptions are excluded by the idea--by the very fact of its being
an idea. The conceptions of reality, substance, causality, nay, even
that of necessity in existence, have no significance out of the sphere
of empirical cognition, and cannot, beyond that sphere, determine any
object. They may, accordingly, be employed to explain the
possibility of things in the world of sense, but they are utterly
inadequate to explain the possibility of the universe itself
considered as a whole; because in this case the ground of
explanation must lie out of and beyond the world, and cannot,
therefore, be an object of possible experience. Now, I may admit the
existence of an incomprehensible being of this nature--the object of
a mere idea, relatively to the world of sense; although I have no ground
to admit its existence absolutely and in itself. For if an idea
(that of a systematic and complete unity, of which I shall presently
speak more particularly) lies at the foundation of the most extended
empirical employment of reason, and if this idea cannot be
adequately represented in concreto, although it is indispensably
necessary for the approximation of empirical unity to the highest
possible degree--I am not only authorized, but compelled, to realize
this idea, that is, to posit a real object corresponding thereto.
But I cannot profess to know this object; it is to me merely a
something, to which, as the ground of systematic unity in cognition,
I attribute such properties as are analogous to the conceptions employed
by the understanding in the sphere of experience. Following the
analogy of the notions of reality, substance, causality, and
necessity, I cogitate a being, which possesses all these attributes
in the highest degree; and, as this idea is the offspring of my reason
alone, I cogitate this being as self-subsistent reason, and as the
cause of the universe operating by means of ideas of the greatest
possible harmony and unity. Thus I abstract all conditions that
would limit my idea, solely for the purpose of rendering systematic
unity possible in the world of empirical diversity, and thus
securing the widest possible extension for the exercise of reason in
that sphere. This I am enabled to do, by regarding all connections
and relations in the world of sense, as if they were the dispositions
of a supreme reason, of which our reason is but a faint image. I then
proceed to cogitate this Supreme Being by conceptions which have,
properly, no meaning or application, except in the world of sense.
But as I am authorized to employ the transcendental hypothesis of such
a being in a relative respect alone, that is, as the substratum of
the greatest possible unity in experience--I may attribute to a being
which I regard as distinct from the world, such properties as belong
solely to the sphere of sense and experience. For I do not desire,
and am not justified in desiring, to cognize this object of my idea,
as it exists in itself; for I possess no conceptions sufficient for
or task, those of reality, substance, causality, nay, even that of
necessity in existence, losing all significance, and becoming merely
the signs of conceptions, without content and without applicability,
when I attempt to carry them beyond the limits of the world of sense.
I cogitate merely the relation of a perfectly unknown being to the
greatest possible systematic unity of experience, solely for the purpose
of employing it as the schema of the regulative principle which directs
reason in its empirical exercise.

It is evident, at the first view, that we cannot presuppose the
reality of this transcendental object, by means of the conceptions
of reality, substance, causality, and so on, because these conceptions
cannot be applied to anything that is distinct from the world of
sense. Thus the supposition of a Supreme Being or cause is purely
relative; it is cogitated only in behalf of the systematic unity of
experience; such a being is but a something, of whose existence in
itself we have not the least conception. Thus, too, it becomes
sufficiently manifest why we required the idea of a necessary being
in relation to objects given by sense, although we can never have the
least conception of this being, or of its absolute necessity.

And now we can clearly perceive the result of our transcendental
dialectic, and the proper aim of the ideas of pure reason--which
become dialectical solely from misunderstanding and inconsiderateness.
Pure reason is, in fact, occupied with itself, and not with any
object. Objects are not presented to it to be embraced in the unity
of an empirical conception; it is only the cognitions of the
understanding that are presented to it, for the purpose of receiving
the unity of a rational conception, that is, of being connected
according to a principle. The unity of reason is the unity of
system; and this systematic unity is not an objective principle,
extending its dominion over objects, but a subjective maxim, extending
its authority over the empirical cognition of objects. The
systematic connection which reason gives to the empirical employment
of the understanding not only advances the extension of that
employment, but ensures its correctness, and thus the principle of
a systematic unity of this nature is also objective, although only
in an indefinite respect (principium vagum). It is not, however, a
constitutive principle, determining an object to which it directly
relates; it is merely a regulative principle or maxim, advancing and
strengthening the empirical exercise of reason, by the opening up of
new paths of which the understanding is ignorant, while it never
conflicts with the laws of its exercise in the sphere of experience.

But reason cannot cogitate this systematic unity, without at the
same time cogitating an object of the idea--an object that cannot be
presented in any experience, which contains no concrete example of
a complete systematic unity. This being (ens rationis ratiocinatae)
is therefore a mere idea and is not assumed to be a thing which is
real absolutely and in itself. On the contrary, it forms merely the
problematical foundation of the connection which the mind introduces
among the phenomena of the sensuous world. We look upon this
connection, in the light of the above-mentioned idea, as if it drew
its origin from the supposed being which corresponds to the idea.
And yet all we aim at is the possession of this idea as a secure
foundation for the systematic unity of experience--a unity
indispensable to reason, advantageous to the understanding, and
promotive of the interests of empirical cognition.

We mistake the true meaning of this idea when we regard it as an
enouncement, or even as a hypothetical declaration of the existence
of a real thing, which we are to regard as the origin or ground of
a systematic constitution of the universe. On the contrary, it is left
completely undetermined what the nature or properties of this
so-called ground may be. The idea is merely to be adopted as a point
of view, from which this unity, so essential to reason and so
beneficial to the understanding, may be regarded as radiating. In
one word, this transcendental thing is merely the schema of a
regulative principle, by means of which Reason, so far as in her lies,
extends the dominion of systematic unity over the whole sphere of

The first object of an idea of this kind is the ego, considered
merely as a thinking nature or soul. If I wish to investigate the
properties of a thinking being, I must interrogate experience. But
I find that I can apply none of the categories to this object, the
schema of these categories, which is the condition of their
application, being given only in sensuous intuition. But I cannot thus
attain to the cognition of a systematic unity of all the phenomena
of the internal sense. Instead, therefore, of an empirical
conception of what the soul really is, reason takes the conception
of the empirical unity of all thought, and, by cogitating this unity
as unconditioned and primitive, constructs the rational conception
or idea of a simple substance which is in itself unchangeable,
possessing personal identity, and in connection with other real things
external to it; in one word, it constructs the idea of a simple
self-subsistent intelligence. But the real aim of reason in this
procedure is the attainment of principles of systematic unity for
the explanation of the phenomena of the soul. That is, reason
desires to be able to represent all the determinations of the internal
sense as existing in one subject, all powers as deduced from one
fundamental power, all changes as mere varieties in the condition of
a being which is permanent and always the same, and all phenomena in
space as entirely different in their nature from the procedure of
thought. Essential simplicity (with the other attributes predicated
of the ego) is regarded as the mere schema of this regulative
principle; it is not assumed that it is the actual ground of the
properties of the soul. For these properties may rest upon quite
different grounds, of which we are completely ignorant; just as the
above predicates could not give us any knowledge of the soul as it
is in itself, even if we regarded them as valid in respect of it,
inasmuch as they constitute a mere idea, which cannot be represented
in concreto. Nothing but good can result from a psychological idea
of this kind, if we only take proper care not to consider it as more
than an idea; that is, if we regard it as valid merely in relation
to the employment of reason, in the sphere of the phenomena of the
soul. Under the guidance of this idea, or principle, no empirical laws
of corporeal phenomena are called in to explain that which is a
phenomenon of the internal sense alone; no windy hypotheses of the
generation, annihilation, and palingenesis of souls are admitted. Thus
the consideration of this object of the internal sense is kept pure,
and unmixed with heterogeneous elements; while the investigation of
reason aims at reducing all the grounds of explanation employed in
this sphere of knowledge to a single principle. All this is best
effected, nay, cannot be effected otherwise than by means of such a
schema, which requires us to regard this ideal thing as an actual
existence. The psychological idea is, therefore, meaningless and
inapplicable, except as the schema of a regulative conception. For,
if I ask whether the soul is not really of a spiritual nature--it is
a question which has no meaning. From such a conception has been
abstracted, not merely all corporeal nature, but all nature, that
is, all the predicates of a possible experience; and consequently,
all the conditions which enable us to cogitate an object to this
conception have disappeared. But, if these conditions are absent, it
is evident that the conception is meaningless.

The second regulative idea of speculative reason is the conception
of the universe. For nature is properly the only object presented to
us, in regard to which reason requires regulative principles. Nature
is twofold--thinking and corporeal nature. To cogitate the latter in
regard to its internal possibility, that is, to determine the
application of the categories to it, no idea is required--no
representation which transcends experience. In this sphere, therefore,
an idea is impossible, sensuous intuition being our only guide; while,
in the sphere of psychology, we require the fundamental idea (I),
which contains a priori a certain form of thought namely, the unity
of the ego. Pure reason has, therefore, nothing left but nature in
general, and the completeness of conditions in nature in accordance
with some principle. The absolute totality of the series of these
conditions is an idea, which can never be fully realized in the
empirical exercise of reason, while it is serviceable as a rule for
the procedure of reason in relation to that totality. It requires
us, in the explanation of given phenomena (in the regress or ascent
in the series), to proceed as if the series were infinite in itself,
that is, were prolonged in indefinitum,; while on the other hand, where
reason is regarded as itself the determining cause (in the region of
freedom), we are required to proceed as if we had not before us an
object of sense, but of the pure understanding. In this latter case,
the conditions do not exist in the series of phenomena, but may be
placed quite out of and beyond it, and the series of conditions may
be regarded as if it had an absolute beginning from an intelligible
cause. All this proves that the cosmological ideas are nothing but
regulative principles, and not constitutive; and that their aim is
not to realize an actual totality in such series. The full discussion
of this subject will be found in its proper place in the chapter on
the antinomy of pure reason.

The third idea of pure reason, containing the hypothesis of a
being which is valid merely as a relative hypothesis, is that of the
one and all-sufficient cause of all cosmological series, in other
words, the idea of God. We have not the slightest ground absolutely
to admit the existence of an object corresponding to this idea; for
what can empower or authorize us to affirm the existence of a being
of the highest perfection--a being whose existence is absolutely
necessary--merely because we possess the conception of such a being?
The answer is: It is the existence of the world which renders this
hypothesis necessary. But this answer makes it perfectly evident
that the idea of this being, like all other speculative ideas, is
essentially nothing more than a demand upon reason that it shall
regulate the connection which it and its subordinate faculties
introduce into the phenomena of the world by principles of
systematic unity and, consequently, that it shall regard all phenomena
as originating from one all-embracing being, as the supreme and
all-sufficient cause. From this it is plain that the only aim of
reason in this procedure is the establishment of its own formal rule
for the extension of its dominion in the world of experience; that
it does not aim at an extension of its cognition beyond the limits
of experience; and that, consequently, this idea does not contain
any constitutive principle.

The highest formal unity, which is based upon ideas alone, is the
unity of all things--a unity in accordance with an aim or purpose;
and the speculative interest of reason renders it necessary to regard
all order in the world as if it originated from the intention and
design of a supreme reason. This principle unfolds to the view of
reason in the sphere of experience new and enlarged prospects, and
invites it to connect the phenomena of the world according to
teleological laws, and in this way to attain to the highest possible
degree of systematic unity. The hypothesis of a supreme
intelligence, as the sole cause of the universe--an intelligence which
has for us no more than an ideal existence--is accordingly always of
the greatest service to reason. Thus, if we presuppose, in relation
to the figure of the earth (which is round, but somewhat flattened
at the poles),* or that of mountains or seas, wise designs on the part
of an author of the universe, we cannot fail to make, by the light
of this supposition, a great number of interesting discoveries. If
we keep to this hypothesis, as a principle which is purely regulative,
even error cannot be very detrimental. For, in this case, error can
have no more serious consequences than that, where we expected to
discover a teleological connection (nexus finalis), only a
mechanical or physical connection appears. In such a case, we merely
fail to find the additional form of unity we expected, but we do not
lose the rational unity which the mind requires in its procedure in
experience. But even a miscarriage of this sort cannot affect the
law in its general and teleological relations. For although we may
convict an anatomist of an error, when he connects the limb of some
animal with a certain purpose, it is quite impossible to prove in a
single case that any arrangement of nature, be it what it may, is
entirely without aim or design. And thus medical physiology, by the
aid of a principle presented to it by pure reason, extends its very
limited empirical knowledge of the purposes of the different parts
of an organized body so far that it may be asserted with the utmost
confidence, and with the approbation of all reflecting men, that every
organ or bodily part of an animal has its use and answers a certain
design. Now, this is a supposition which, if regarded as of a
constitutive character, goes much farther than any experience or
observation of ours can justify. Hence it is evident that it is
nothing more than a regulative principle of reason, which aims at
the highest degree of systematic unity, by the aid of the idea of a
causality according to design in a supreme cause--a cause which it
regards as the highest intelligence.

[*Footnote: The advantages which a circular form, in the case of the
earth, has over every other, are well known. But few are aware that
the slight flattening at the poles, which gives it the figure of a
spheroid, is the only cause which prevents the elevations of continents
or even of mountains, perhaps thrown up by some internal convulsion,
from continually altering the position of the axis of the earth--and
that to some considerable degree in a short time. The great protuberance
of the earth under the Equator serves to overbalance the impetus of
all other masses of earth, and thus to preserve the axis of the earth,
so far as we can observe, in its present position. And yet this wise
arrangement has been unthinkingly explained from the equilibrium of
the formerly fluid mass.]

If, however, we neglect this restriction of the idea to a purely
regulative influence, reason is betrayed into numerous errors. For
it has then left the ground of experience, in which alone are to be
found the criteria of truth, and has ventured into the region of the
incomprehensible and unsearchable, on the heights of which it loses
its power and collectedness, because it has completely severed its
connection with experience.

The first error which arises from our employing the idea of a
Supreme Being as a constitutive (in repugnance to the very nature of
an idea), and not as a regulative principle, is the error of
inactive reason (ignava ratio).* We may so term every principle
which requires us to regard our investigations of nature as absolutely
complete, and allows reason to cease its inquiries, as if it had fully
executed its task. Thus the psychological idea of the ego, when
employed as a constitutive principle for the explanation of the
phenomena of the soul, and for the extension of our knowledge
regarding this subject beyond the limits of experience--even to the
condition of the soul after death--is convenient enough for the
purposes of pure reason, but detrimental and even ruinous to its
interests in the sphere of nature and experience. The dogmatizing
spiritualist explains the unchanging unity of our personality
through all changes of condition from the unity of a thinking
substance, the interest which we take in things and events that can
happen only after our death, from a consciousness of the immaterial
nature of our thinking subject, and so on. Thus he dispenses with
all empirical investigations into the cause of these internal
phenomena, and with all possible explanations of them upon purely
natural grounds; while, at the dictation of a transcendent reason,
he passes by the immanent sources of cognition in experience,
greatly to his own ease and convenience, but to the sacrifice of
all, genuine insight and intelligence. These prejudicial
consequences become still more evident, in the case of the
dogmatical treatment of our idea of a Supreme Intelligence, and the
theological system of nature (physico-theology) which is falsely based
upon it. For, in this case, the aims which we observe in nature, and
often those which we merely fancy to exist, make the investigation
of causes a very easy task, by directing us to refer such and such
phenomena immediately to the unsearchable will and counsel of the
Supreme Wisdom, while we ought to investigate their causes in the
general laws of the mechanism of matter. We are thus recommended to
consider the labour of reason as ended, when we have merely
dispensed with its employment, which is guided surely and safely
only by the order of nature and the series of changes in the world-
which are arranged according to immanent and general laws. This
error may be avoided, if we do not merely consider from the view-point
of final aims certain parts of nature, such as the division and
structure of a continent, the constitution and direction of certain
mountain-chains, or even the organization existing in the vegetable
and animal kingdoms, but look upon this systematic unity of nature
in a perfectly general way, in relation to the idea of a Supreme
Intelligence. If we pursue this advice, we lay as a foundation for
all investigation the conformity to aims of all phenomena of nature
in accordance with universal laws, for which no particular arrangement
of nature is exempt, but only cognized by us with more or less
difficulty; and we possess a regulative principle of the systematic
unity of a teleological connection, which we do not attempt to
anticipate or predetermine. All that we do, and ought to do, is to
follow out the physico-mechanical connection in nature according to
general laws, with the hope of discovering, sooner or later, the
teleological connection also. Thus, and thus only, can the principle
of final unity aid in the extension of the employment of reason in
the sphere of experience, without being in any case detrimental to
its interests.

[*Footnote: This was the term applied by the old dialecticians to a
sophistical argument, which ran thus: If it is your fate to die of
this disease, you will die, whether you employ a physician or not.
Cicero says that this mode of reasoning has received this appellation,
because, if followed, it puts an end to the employment of reason in
the affairs of life. For a similar reason, I have applied this designation
to the sophistical argument of pure reason.]

The second error which arises from the misconception of the
principle of systematic unity is that of perverted reason (perversa
ratio, usteron roteron rationis). The idea of systematic unity is
available as a regulative principle in the connection of phenomena
according to general natural laws; and, how far soever we have to
travel upon the path of experience to discover some fact or event,
this idea requires us to believe that we have approached all the
more nearly to the completion of its use in the sphere of nature,
although that completion can never be attained. But this error
reverses the procedure of reason. We begin by hypostatizing the
principle of systematic unity, and by giving an anthropomorphic
determination to the conception of a Supreme Intelligence, and then
proceed forcibly to impose aims upon nature. Thus not only does
teleology, which ought to aid in the completion of unity in accordance
with general laws, operate to the destruction of its influence, but
it hinders reason from attaining its proper aim, that is, the proof,
upon natural grounds, of the existence of a supreme intelligent cause.
For, if we cannot presuppose supreme finality in nature a priori, that
is, as essentially belonging to nature, how can we be directed to
endeavour to discover this unity and, rising gradually through its
different degrees, to approach the supreme perfection of an author
of all--a perfection which is absolutely necessary, and therefore
cognizable a priori? The regulative principle directs us to presuppose
systematic unity absolutely and, consequently, as following from the
essential nature of things--but only as a unity of nature, not
merely cognized empirically, but presupposed a priori, although only
in an indeterminate manner. But if I insist on basing nature upon
the foundation of a supreme ordaining Being, the unity of nature is
in effect lost. For, in this case, it is quite foreign and unessential
to the nature of things, and cannot be cognized from the general laws
of nature. And thus arises a vicious circular argument, what ought
to have been proved having been presupposed.

To take the regulative principle of systematic unity in nature for
a constitutive principle, and to hypostatize and make a cause out of
that which is properly the ideal ground of the consistent and
harmonious exercise of reason, involves reason in inextricable
embarrassments. The investigation of nature pursues its own path under
the guidance of the chain of natural causes, in accordance with the
general laws of nature, and ever follows the light of the idea of an
author of the universe--not for the purpose of deducing the
finality, which it constantly pursues, from this Supreme Being, but
to attain to the cognition of his existence from the finality which
it seeks in the existence of the phenomena of nature, and, if possible,
in that of all things to cognize this being, consequently, as
absolutely necessary. Whether this latter purpose succeed or not,
the idea is and must always be a true one, and its employment, when
merely regulative, must always be accompanied by truthful and
beneficial results.

Complete unity, in conformity with aims, constitutes absolute
perfection. But if we do not find this unity in the nature of the
things which go to constitute the world of experience, that is, of
objective cognition, consequently in the universal and necessary
laws of nature, how can we infer from this unity the idea of the
supreme and absolutely necessary perfection of a primal being, which
is the origin of all causality? The greatest systematic unity, and
consequently teleological unity, constitutes the very foundation of
the possibility of the most extended employment of human reason. The
idea of unity is therefore essentially and indissolubly connected with
the nature of our reason. This idea is a legislative one; and hence
it is very natural that we should assume the existence of a legislative
reason corresponding to it, from which the systematic unity of nature-
the object of the operations of reason--must be derived.

In the course of our discussion of the antinomies, we stated that it
is always possible to answer all the questions which pure reason may
raise; and that the plea of the limited nature of our cognition, which
is unavoidable and proper in many questions regarding natural
phenomena, cannot in this case be admitted, because the questions
raised do not relate to the nature of things, but are necessarily
originated by the nature of reason itself, and relate to its own
internal constitution. We can now establish this assertion, which at
first sight appeared so rash, in relation to the two questions in
which reason takes the greatest interest, and thus complete our
discussion of the dialectic of pure reason.

If, then, the question is asked, in relation to transcendental
theology,* first, whether there is anything distinct from the world,
which contains the ground of cosmical order and connection according
to general laws? The answer is: Certainly. For the world is a sum of
phenomena; there must, therefore, be some transcendental basis of
these phenomena, that is, a basis cogitable by the pure
understanding alone. If, secondly, the question is asked whether
this being is substance, whether it is of the greatest reality,
whether it is necessary, and so forth? I answer that this question
is utterly without meaning. For all the categories which aid me in
forming a conception of an object cannot be employed except in the
world of sense, and are without meaning when not applied to objects
of actual or possible experience. Out of this sphere, they are not
properly conceptions, but the mere marks or indices of conceptions,
which we may admit, although they cannot, without the help of
experience, help us to understand any subject or thing. If, thirdly,
the question is whether we may not cogitate this being, which is
distinct from the world, in analogy with the objects of experience?
The answer is: Undoubtedly, but only as an ideal, and not as a real
object. That is, we must cogitate it only as an unknown substratum
of the systematic unity, order, and finality of the world--a unity
which reason must employ as the regulative principle of its
investigation of nature. Nay, more, we may admit into the idea certain
anthropomorphic elements, which are promotive of the interests of this
regulative principle. For it is no more than an idea, which does not
relate directly to a being distinct from the world, but to the
regulative principle of the systematic unity of the world, by means,
however, of a schema of this unity--the schema of a Supreme
Intelligence, who is the wisely-designing author of the universe. What
this basis of cosmical unity may be in itself, we know not--we
cannot discover from the idea; we merely know how we ought to employ
the idea of this unity, in relation to the systematic operation of
reason in the sphere of experience.

[*Footnote: After what has been said of the psychological idea of the
ego and its proper employment as a regulative principle of the operations
of reason, I need not enter into details regarding the transcendental
illusion by which the systematic unity of all the various phenomena
of the internal sense is hypostatized. The procedure is in this case
very similar to that which has been discussed in our remarks on the
theological ideal.]

But, it will be asked again, can we on these grounds, admit the
existence of a wise and omnipotent author of the world? Without doubt;
and not only so, but we must assume the existence of such a being.
But do we thus extend the limits of our knowledge beyond the field
of possible experience? By no means. For we have merely presupposed
a something, of which we have no conception, which we do not know as
it is in itself; but, in relation to the systematic disposition of
the universe, which we must presuppose in all our observation of nature,
we have cogitated this unknown being in analogy with an intelligent
existence (an empirical conception), that is to say, we have endowed
it with those attributes, which, judging from the nature of our own
reason, may contain the ground of such a systematic unity. This idea
is therefore valid only relatively to the employment in experience
of our reason. But if we attribute to it absolute and objective
validity, we overlook the fact that it is merely an ideal being that
we cogitate; and, by setting out from a basis which is not
determinable by considerations drawn from experience, we place
ourselves in a position which incapacitates us from applying this
principle to the empirical employment of reason.

But, it will be asked further, can I make any use of this conception
and hypothesis in my investigations into the world and nature? Yes,
for this very purpose was the idea established by reason as a
fundamental basis. But may I regard certain arrangements, which seemed
to have been made in conformity with some fixed aim, as the
arrangements of design, and look upon them as proceeding from the
divine will, with the intervention, however, of certain other
particular arrangements disposed to that end? Yes, you may do so;
but at the same time you must regard it as indifferent, whether it
is asserted that divine wisdom has disposed all things in conformity
with his highest aims, or that the idea of supreme wisdom is a
regulative principle in the investigation of nature, and at the same
time a principle of the systematic unity of nature according to
general laws, even in those cases where we are unable to discover that
unity. In other words, it must be perfectly indifferent to you whether
you say, when you have discovered this unity: God has wisely willed
it so; or: Nature has wisely arranged this. For it was nothing but
the systematic unity, which reason requires as a basis for the
investigation of nature, that justified you in accepting the idea of
a supreme intelligence as a schema for a regulative principle; and,
the farther you advance in the discovery of design and finality, the
more certain the validity of your idea. But, as the whole aim of
this regulative principle was the discovery of a necessary and
systematic unity in nature, we have, in so far as we attain this, to
attribute our success to the idea of a Supreme Being; while, at the
same time, we cannot, without involving ourselves in contradictions,
overlook the general laws of nature, as it was in reference to them
alone that this idea was employed. We cannot, I say, overlook the
general laws of nature, and regard this conformity to aims
observable in nature as contingent or hyperphysical in its origin;
inasmuch as there is no ground which can justify us in the admission
of a being with such properties distinct from and above nature. All
that we are authorized to assert is that this idea may be employed
as a principle, and that the properties of the being which is
assumed to correspond to it may be regarded as systematically
connected in analogy with the causal determination of phenomena.

For the same reasons we are justified in introducing into the idea
of the supreme cause other anthropomorphic elements (for without these
we could not predicate anything of it); we may regard it as
allowable to cogitate this cause as a being with understanding, the
feelings of pleasure and displeasure, and faculties of desire and will
corresponding to these. At the same time, we may attribute to this
being infinite perfection--a perfection which necessarily transcends
that which our knowledge of the order and design in the world
authorize us to predicate of it. For the regulative law of
systematic unity requires us to study nature on the supposition that
systematic and final unity in infinitum is everywhere discoverable,
even in the highest diversity. For, although we may discover little
of this cosmical perfection, it belongs to the legislative prerogative
of reason to require us always to seek for and to expect it; while
it must always be beneficial to institute all inquiries into nature
in accordance with this principle. But it is evident that, by this
idea of a supreme author of all, which I place as the foundation of
all inquiries into nature, I do not mean to assert the existence of
such a being, or that I have any knowledge of its existence; and,
consequently, I do not really deduce anything from the existence of
this being, but merely from its idea, that is to say, from the
nature of things in this world, in accordance with this idea. A
certain dim consciousness of the true use of this idea seems to have
dictated to the philosophers of all times the moderate language used
by them regarding the cause of the world. We find them employing the
expressions wisdom and care of nature, and divine wisdom, as
synonymous--nay, in purely speculative discussions, preferring the
former, because it does not carry the appearance of greater
pretensions than such as we are entitled to make, and at the same time
directs reason to its proper field of action--nature and her

Thus, pure reason, which at first seemed to promise us nothing
less than the extension of our cognition beyond the limits of
experience, is found, when thoroughly examined, to contain nothing
but regulative principles, the virtue and function of which is to
introduce into our cognition a higher degree of unity than the
understanding could of itself. These principles, by placing the goal
of all our struggles at so great a distance, realize for us the most
thorough connection between the different parts of our cognition,
and the highest degree of systematic unity. But, on the other hand,
if misunderstood and employed as constitutive principles of
transcendent cognition, they become the parents of illusions and
contradictions, while pretending to introduce us to new regions of

Thus all human cognition begins with intuitions, proceeds from
thence to conceptions, and ends with ideas. Although it possesses,
in relation to all three elements, a priori sources of cognition,
which seemed to transcend the limits of all experience, a
thoroughgoing criticism demonstrates that speculative reason can
never, by the aid of these elements, pass the bounds of possible
experience, and that the proper destination of this highest faculty
of cognition is to employ all methods, and all the principles of these
methods, for the purpose of penetrating into the innermost secrets
of nature, by the aid of the principles of unity (among all kinds of
which teleological unity is the highest), while it ought not to
attempt to soar above the sphere of experience, beyond which there
lies nought for us but the void inane. The critical examination, in
our Transcendental Analytic, of all the propositions which professed
to extend cognition beyond the sphere of experience, completely
demonstrated that they can only conduct us to a possible experience.
If we were not distrustful even of the clearest abstract theorems,
if we were not allured by specious and inviting prospects to escape
from the constraining power of their evidence, we might spare
ourselves the laborious examination of all the dialectical arguments
which a transcendent reason adduces in support of its pretensions;
for we should know with the most complete certainty that, however honest
such professions might be, they are null and valueless, because they
relate to a kind of knowledge to which no man can by any possibility
attain. But, as there is no end to discussion, if we cannot discover
the true cause of the illusions by which even the wisest are deceived,
and as the analysis of all our transcendent cognition into its
elements is of itself of no slight value as a psychological study,
while it is a duty incumbent on every philosopher--it was found
necessary to investigate the dialectical procedure of reason in its
primary sources. And as the inferences of which this dialectic is
the parent are not only deceitful, but naturally possess a profound
interest for humanity, it was advisable at the same time, to give a
full account of the momenta of this dialectical procedure, and to
deposit it in the archives of human reason, as a warning to all future
metaphysicians to avoid these causes of speculative error.



If we regard the sum of the cognition of pure speculative reason
as an edifice, the idea of which, at least, exists in the human
mind, it may be said that we have in the Transcendental Doctrine of
Elements examined the materials and determined to what edifice these
belong, and what its height and stability. We have found, indeed,
that, although we had purposed to build for ourselves a tower which
should reach to Heaven, the supply of materials sufficed merely for
a habitation, which was spacious enough for all terrestrial
purposes, and high enough to enable us to survey the level plain of
experience, but that the bold undertaking designed necessarily
failed for want of materials--not to mention the confusion of tongues,
which gave rise to endless disputes among the labourers on the plan
of the edifice, and at last scattered them over all the world, each
to erect a separate building for himself, according to his own plans
and his own inclinations. Our present task relates not to the
materials, but to the plan of an edifice; and, as we have had
sufficient warning not to venture blindly upon a design which may be
found to transcend our natural powers, while, at the same time, we
cannot give up the intention of erecting a secure abode for the
mind, we must proportion our design to the material which is presented
to us, and which is, at the same time, sufficient for all our wants.

I understand, then, by the transcendental doctrine of method, the
determination of the formal conditions of a complete system of pure
reason. We shall accordingly have to treat of the discipline, the
canon, the architectonic, and, finally, the history of pure reason.
This part of our Critique will accomplish, from the transcendental
point of view, what has been usually attempted, but miserably
executed, under the name of practical logic. It has been badly
executed, I say, because general logic, not being limited to any
particular kind of cognition (not even to the pure cognition of the
understanding) nor to any particular objects, it cannot, without
borrowing from other sciences, do more than present merely the
titles or signs of possible methods and the technical expressions,
which are employed in the systematic parts of all sciences; and thus
the pupil is made acquainted with names, the meaning and application
of which he is to learn only at some future time.

CHAPTER I. The Discipline of Pure Reason.

Negative judgements--those which are so not merely as regards
their logical form, but in respect of their content--are not
commonly held in especial respect. They are, on the contrary, regarded
as jealous enemies of our insatiable desire for knowledge; and it
almost requires an apology to induce us to tolerate, much less to
prize and to respect them.

All propositions, indeed, may be logically expressed in a negative
form; but, in relation to the content of our cognition, the peculiar
province of negative judgements is solely to prevent error. For this
reason, too, negative propositions, which are framed for the purpose
of correcting false cognitions where error is absolutely impossible,
are undoubtedly true, but inane and senseless; that is, they are in
reality purposeless and, for this reason, often very ridiculous.
Such is the proposition of the schoolman that Alexander could not have
subdued any countries without an army.

But where the limits of our possible cognition are very much
contracted, the attraction to new fields of knowledge great, the
illusions to which the mind is subject of the most deceptive
character, and the evil consequences of error of no inconsiderable
magnitude--the negative element in knowledge, which is useful only
to guard us against error, is of far more importance than much of that
positive instruction which makes additions to the sum of our
knowledge. The restraint which is employed to repress, and finally
to extirpate the constant inclination to depart from certain rules,
is termed discipline. It is distinguished from culture, which aims
at the formation of a certain degree of skill, without attempting to
repress or to destroy any other mental power, already existing. In
the cultivation of a talent, which has given evidence of an impulse
towards self-development, discipline takes a negative,* culture and
doctrine a positive, part.

[*Footnote: I am well aware that, in the language of the schools, the
term discipline is usually employed as synonymous with instruction.
But there are so many cases in which it is necessary to distinguish
the notion of the former, as a course of corrective training, from
that of the latter, as the communication of knowledge, and the nature
of things itself demands the appropriation of the most suitable
expressions for this distinction, that it is my desire that the former
terms should never be employed in any other than a negative

That natural dispositions and talents (such as imagination and wit),
which ask a free and unlimited development, require in many respects
the corrective influence of discipline, every one will readily
grant. But it may well appear strange that reason, whose proper duty
it is to prescribe rules of discipline to all the other powers of
the mind, should itself require this corrective. It has, in fact,
hitherto escaped this humiliation, only because, in presence of its
magnificent pretensions and high position, no one could readily
suspect it to be capable of substituting fancies for conceptions,
and words for things.

Reason, when employed in the field of experience, does not stand
in need of criticism, because its principles are subjected to the
continual test of empirical observations. Nor is criticism requisite
in the sphere of mathematics, where the conceptions of reason must
always be presented in concreto in pure intuition, and baseless or
arbitrary assertions are discovered without difficulty. But where
reason is not held in a plain track by the influence of empirical or
of pure intuition, that is, when it is employed in the
transcendental sphere of pure conceptions, it stands in great need
of discipline, to restrain its propensity to overstep the limits of
possible experience and to keep it from wandering into error. In fact,
the utility of the philosophy of pure reason is entirely of this
negative character. Particular errors may be corrected by particular
animadversions, and the causes of these errors may be eradicated by
criticism. But where we find, as in the case of pure reason, a
complete system of illusions and fallacies, closely connected with
each other and depending upon grand general principles, there seems
to be required a peculiar and negative code of mental legislation,
which, under the denomination of a discipline, and founded upon the
nature of reason and the objects of its exercise, shall constitute
a system of thorough examination and testing, which no fallacy will
be able to withstand or escape from, under whatever disguise or
concealment it may lurk.

But the reader must remark that, in this the second division of
our transcendental Critique the discipline of pure reason is not
directed to the content, but to the method of the cognition of pure
reason. The former task has been completed in the doctrine of
elements. But there is so much similarity in the mode of employing
the faculty of reason, whatever be the object to which it is applied,
while, at the same time, its employment in the transcendental sphere
is so essentially different in kind from every other, that, without
the warning negative influence of a discipline specially directed to
that end, the errors are unavoidable which spring from the
unskillful employment of the methods which are originated by reason
but which are out of place in this sphere.

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

The science of mathematics presents the most brilliant example of
the extension of the sphere of pure reason without the aid of

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