Critique of Pure Reason

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

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

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

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

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

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

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

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

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

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

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

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

We have shown that no transcendental use can be made either of the conceptions of reason or of understanding. We have shown, likewise, that the demand of absolute totality in the series of conditions in the world of sense arises from a transcendental employment of reason, resting on the opinion that phenomena are to be regarded as things in themselves. It follows that we are not required to answer the question respecting the absolute quantity of a series—whether it is in itself limited or unlimited. We are only called upon to determine how far we must proceed in the empirical regress from condition to condition, in order to discover, in conformity with the rule of reason, a full and correct answer to the questions proposed by reason itself.

This principle of reason is hence valid only as a rule for the extension of a possible experience—its invalidity as a principle constitutive of phenomena in themselves having been sufficiently demonstrated. And thus, too, the antinomial conflict of reason with itself is completely put an end to; inasmuch as we have not only presented a critical solution of the fallacy lurking in the opposite statements of reason, but have shown the true meaning of the ideas which gave rise to these statements. The dialectical principle of reason has, therefore, been changed into a doctrinal principle. But in fact, if this principle, in the subjective signification which we have shown to be its only true sense, may be guaranteed as a principle of the unceasing extension of the employment of our understanding, its influence and value are just as great as if it were an axiom for the à priori determination of objects. For such an axiom could not exert a stronger influence on the extension and rectification of our knowledge, otherwise than by procuring for the principles of the understanding the most widely expanded employment in the field of experience.

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

Here, as well as in the case of the other cosmological problems, the ground of the regulative principle of reason is the proposition that in our empirical regress no experience of an absolute limit, and consequently no experience of a condition, which is itself absolutely unconditioned, is discoverable. And the truth of this proposition itself rests upon the consideration that such an experience must represent to us phenomena as limited by nothing or the mere void, on which our continued regress by means of perception must abut—which is impossible.

Now this proposition, which declares that every condition attained in the empirical regress must itself be considered empirically conditioned, contains the rule in terminis, which requires me, to whatever extent I may have proceeded in the ascending series, always to look for some higher member in the series—whether this member is to become known to me through experience, or not.

Nothing further is necessary, then, for the solution of the first cosmological problem, than to decide, whether, in the regress to the unconditioned quantity of the universe (as regards space and time), this never limited ascent ought to be called a regressus in infinitum or indefinitum.

The general representation which we form in our minds of the series of all past states or conditions of the world, or of all the things which at present exist in it, is itself nothing more than a possible empirical regress, which is cogitated—although in an undetermined manner—in the mind, and which gives rise to the conception of a series of conditions for a given object.[60] Now I have a conception of the universe, but not an intuition—that is, not an intuition of it as a whole. Thus I cannot infer the magnitude of the regress from the quantity or magnitude of the world, and determine the former by means of the latter; on the contrary, I must first of all form a conception of the quantity or magnitude of the world from the magnitude of the empirical regress. But of this regress I know nothing more than that I ought to proceed from every given member of the series of conditions to one still higher. But the quantity of the universe is not thereby determined, and we cannot affirm that this regress proceeds in infinitum. Such an affirmation would anticipate the members of the series which have not yet been reached, and represent the number of them as beyond the grasp of any empirical synthesis; it would consequently determine the cosmical quantity prior to the regress (although only in a negative manner)—which is impossible. For the world is not given in its totality in any intuition: consequently, its quantity cannot be given prior to the regress. It follows that we are unable to make any declaration respecting the cosmical quantity in itself—not even that the regress in it is a regress in infinitum; we must only endeavour to attain to a conception of the quantity of the universe, in conformity with the rule which determines the empirical regress in it. But this rule merely requires us never to admit an absolute limit to our series—how far soever we may have proceeded in it, but always, on the contrary, to subordinate every phenomenon to some other as its condition, and consequently to proceed to this higher phenomenon. Such a regress is, therefore, the regressus in indefinitum, which, as not determining a quantity in the object, is clearly distinguishable from the regressus in infinitum.

[60] The cosmical series can neither be greater nor smaller than the possible empirical regress, upon which its conception is based. And as this regress cannot be a determinate infinite regress, still less a determinate finite (absolutely limited), it is evident that we cannot regard the world as either finite or infinite, because the regress, which gives us the representation of the world, is neither finite nor infinite.

It follows from what we have said that we are not justified in declaring the world to be infinite in space, or as regards past time. For this conception of an infinite given quantity is empirical; but we cannot apply the conception of an infinite quantity to the world as an object of the senses. I cannot say, “The regress from a given perception to everything limited either in space or time, proceeds in infinitum,” for this presupposes an infinite cosmical quantity; neither can I say, “It is finite,” for an absolute limit is likewise impossible in experience. It follows that I am not entitled to make any assertion at all respecting the whole object of experience—the world of sense; I must limit my declarations to the rule according to which experience or empirical knowledge is to be attained.

To the question, therefore, respecting the cosmical quantity, the first and negative answer is: “The world has no beginning in time, and no absolute limit in space.”

For, in the contrary case, it would be limited by a void time on the one hand, and by a void space on the other. Now, since the world, as a phenomenon, cannot be thus limited in itself for a phenomenon is not a thing in itself; it must be possible for us to have a perception of this limitation by a void time and a void space. But such a perception—such an experience is impossible; because it has no content. Consequently, an absolute cosmical limit is empirically, and therefore absolutely, impossible.[61]

[61] The reader will remark that the proof presented above is very different from the dogmatical demonstration given in the antithesis of the first antinomy. In that demonstration, it was taken for granted that the world is a thing in itself—given in its totality prior to all regress, and a determined position in space and time was denied to it—if it was not considered as occupying all time and all space. Hence our conclusion differed from that given above; for we inferred in the antithesis the actual infinity of the world.

From this follows the affirmative answer: “The regress in the series of phenomena—as a determination of the cosmical quantity, proceeds in indefinitum.” This is equivalent to saying: “The world of sense has no absolute quantity, but the empirical regress (through which alone the world of sense is presented to us on the side of its conditions) rests upon a rule, which requires it to proceed from every member of the series, as conditioned, to one still more remote (whether through personal experience, or by means of history, or the chain of cause and effect), and not to cease at any point in this extension of the possible empirical employment of the understanding.” And this is the proper and only use which reason can make of its principles.

The above rule does not prescribe an unceasing regress in one kind of phenomena. It does not, for example, forbid us, in our ascent from an individual human being through the line of his ancestors, to expect that we shall discover at some point of the regress a primeval pair, or to admit, in the series of heavenly bodies, a sun at the farthest possible distance from some centre. All that it demands is a perpetual progress from phenomena to phenomena, even although an actual perception is not presented by them (as in the case of our perceptions being so weak as that we are unable to become conscious of them), since they, nevertheless, belong to possible experience.

Every beginning is in time, and all limits to extension are in space. But space and time are in the world of sense. Consequently phenomena in the world are conditionally limited, but the world itself is not limited, either conditionally or unconditionally.

For this reason, and because neither the world nor the cosmical series of conditions to a given conditioned can be completely given, our conception of the cosmical quantity is given only in and through the regress and not prior to it—in a collective intuition. But the regress itself is really nothing more than the determining of the cosmical quantity, and cannot therefore give us any determined conception of it—still less a conception of a quantity which is, in relation to a certain standard, infinite. The regress does not, therefore, proceed to infinity (an infinity given), but only to an indefinite extent, for or the of presenting to us a quantity—realized only in and through the regress itself.

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

When I divide a whole which is given in intuition, I proceed from a conditioned to its conditions. The division of the parts of the whole (subdivisio or decompositio) is a regress in the series of these conditions. The absolute totality of this series would be actually attained and given to the mind, if the regress could arrive at simple parts. But if all the parts in a continuous decomposition are themselves divisible, the division, that is to say, the regress, proceeds from the conditioned to its conditions in infinitum; because the conditions (the parts) are themselves contained in the conditioned, and, as the latter is given in a limited intuition, the former are all given along with it. This regress cannot, therefore, be called a regressus in indefinitum, as happened in the case of the preceding cosmological idea, the regress in which proceeded from the conditioned to the conditions not given contemporaneously and along with it, but discoverable only through the empirical regress. We are not, however, entitled to affirm of a whole of this kind, which is divisible in infinitum, that it consists of an infinite number of parts. For, although all the parts are contained in the intuition of the whole, the whole division is not contained therein. The division is contained only in the progressing decomposition—in the regress itself, which is the condition of the possibility and actuality of the series. Now, as this regress is infinite, all the members (parts) to which it attains must be contained in the given whole as an aggregate. But the complete series of division is not contained therein. For this series, being infinite in succession and always incomplete, cannot represent an infinite number of members, and still less a composition of these members into a whole.

To apply this remark to space. Every limited part of space presented to intuition is a whole, the parts of which are always spaces—to whatever extent subdivided. Every limited space is hence divisible to infinity.

Let us again apply the remark to an external phenomenon enclosed in limits, that is, a body. The divisibility of a body rests upon the divisibility of space, which is the condition of the possibility of the body as an extended whole. A body is consequently divisible to infinity, though it does not, for that reason, consist of an infinite number of parts.

It certainly seems that, as a body must be cogitated as substance in space, the law of divisibility would not be applicable to it as substance. For we may and ought to grant, in the case of space, that division or decomposition, to any extent, never can utterly annihilate composition (that is to say, the smallest part of space must still consist of spaces); otherwise space would entirely cease to exist—which is impossible. But, the assertion on the other hand that when all composition in matter is annihilated in thought, nothing remains, does not seem to harmonize with the conception of substance, which must be properly the subject of all composition and must remain, even after the conjunction of its attributes in space—which constituted a body—is annihilated in thought. But this is not the case with substance in the phenomenal world, which is not a thing in itself cogitated by the pure category. Phenomenal substance is not an absolute subject; it is merely a permanent sensuous image, and nothing more than an intuition, in which the unconditioned is not to be found.

But, although this rule of progress to infinity is legitimate and applicable to the subdivision of a phenomenon, as a mere occupation or filling of space, it is not applicable to a whole consisting of a number of distinct parts and constituting a quantum discretum—that is to say, an organized body. It cannot be admitted that every part in an organized whole is itself organized, and that, in analysing it to infinity, we must always meet with organized parts; although we may allow that the parts of the matter which we decompose in infinitum, may be organized. For the infinity of the division of a phenomenon in space rests altogether on the fact that the divisibility of a phenomenon is given only in and through this infinity, that is, an undetermined number of parts is given, while the parts themselves are given and determined only in and through the subdivision; in a word, the infinity of the division necessarily presupposes that the whole is not already divided in se. Hence our division determines a number of parts in the whole—a number which extends just as far as the actual regress in the division; while, on the other hand, the very notion of a body organized to infinity represents the whole as already and in itself divided. We expect, therefore, to find in it a determinate, but at the same time, infinite, number of parts—which is self-contradictory. For we should thus have a whole containing a series of members which could not be completed in any regress—which is infinite, and at the same time complete in an organized composite. Infinite divisibility is applicable only to a quantum continuum, and is based entirely on the infinite divisibility of space, But in a quantum discretum the multitude of parts or units is always determined, and hence always equal to some number. To what extent a body may be organized, experience alone can inform us; and although, so far as our experience of this or that body has extended, we may not have discovered any inorganic part, such parts must exist in possible experience. But how far the transcendental division of a phenomenon must extend, we cannot know from experience—it is a question which experience cannot answer; it is answered only by the principle of reason which forbids us to consider the empirical regress, in the analysis of extended body, as ever absolutely complete.

Concluding Remark on the Solution of the Transcendental Mathematical Ideas—and Introductory to the Solution of the Dynamical Ideas.

We presented the antinomy of pure reason in a tabular form, and we endeavoured to show the ground of this self-contradiction on the part of reason, and the only means of bringing it to a conclusion—namely, by declaring both contradictory statements to be false. We represented in these antinomies the conditions of phenomena as belonging to the conditioned according to relations of space and time—which is the usual supposition of the common understanding. In this respect, all dialectical representations of totality, in the series of conditions to a given conditioned, were perfectly homogeneous. The condition was always a member of the series along with the conditioned, and thus the homogeneity of the whole series was assured. In this case the regress could never be cogitated as complete; or, if this was the case, a member really conditioned was falsely regarded as a primal member, consequently as unconditioned. In such an antinomy, therefore, we did not consider the object, that is, the conditioned, but the series of conditions belonging to the object, and the magnitude of that series. And thus arose the difficulty—a difficulty not to be settled by any decision regarding the claims of the two parties, but simply by cutting the knot—by declaring the series proposed by reason to be either too long or too short for the understanding, which could in neither case make its conceptions adequate with the ideas.

But we have overlooked, up to this point, an essential difference existing between the conceptions of the understanding which reason endeavours to raise to the rank of ideas—two of these indicating a mathematical, and two a dynamical synthesis of phenomena. Hitherto, it was necessary to signalize this distinction; for, just as in our general representation of all transcendental ideas, we considered them under phenomenal conditions, so, in the two mathematical ideas, our discussion is concerned solely with an object in the world of phenomena. But as we are now about to proceed to the consideration of the dynamical conceptions of the understanding, and their adequateness with ideas, we must not lose sight of this distinction. We shall find that it opens up to us an entirely new view of the conflict in which reason is involved. For, while in the first two antinomies, both parties were dismissed, on the ground of having advanced statements based upon false hypothesis; in the present case the hope appears of discovering a hypothesis which may be consistent with the demands of reason, and, the judge completing the statement of the grounds of claim, which both parties had left in an unsatisfactory state, the question may be settled on its own merits, not by dismissing the claimants, but by a comparison of the arguments on both sides. If we consider merely their extension, and whether they are adequate with ideas, the series of conditions may be regarded as all homogeneous. But the conception of the understanding which lies at the basis of these ideas, contains either a synthesis of the homogeneous (presupposed in every quantity—in its composition as well as in its division) or of the heterogeneous, which is the case in the dynamical synthesis of cause and effect, as well as of the necessary and the contingent.

Thus it happens that in the mathematical series of phenomena no other than a sensuous condition is admissible—a condition which is itself a member of the series; while the dynamical series of sensuous conditions admits a heterogeneous condition, which is not a member of the series, but, as purely intelligible, lies out of and beyond it. And thus reason is satisfied, and an unconditioned placed at the head of the series of phenomena, without introducing confusion into or discontinuing it, contrary to the principles of the understanding.

Now, from the fact that the dynamical ideas admit a condition of phenomena which does not form a part of the series of phenomena, arises a result which we should not have expected from an antinomy. In former cases, the result was that both contradictory dialectical statements were declared to be false. In the present case, we find the conditioned in the dynamical series connected with an empirically unconditioned, but non-sensuous condition; and thus satisfaction is done to the understanding on the one hand and to the reason on the other.[62] While, moreover, the dialectical arguments for unconditioned totality in mere phenomena fall to the ground, both propositions of reason may be shown to be true in their proper signification. This could not happen in the case of the cosmological ideas which demanded a mathematically unconditioned unity; for no condition could be placed at the head of the series of phenomena, except one which was itself a phenomenon and consequently a member of the series.

[62] For the understanding cannot admit among phenomena a condition which is itself empirically unconditioned. But if it is possible to cogitate an intelligible condition—one which is not a member of the series of phenomena—for a conditioned phenomenon, without breaking the series of empirical conditions, such a condition may be admissible as empirically unconditioned, and the empirical regress continue regular, unceasing, and intact.

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

There are only two modes of causality cogitable—the causality of nature or of freedom. The first is the conjunction of a particular state with another preceding it in the world of sense, the former following the latter by virtue of a law. Now, as the causality of phenomena is subject to conditions of time, and the preceding state, if it had always existed, could not have produced an effect which would make its first appearance at a particular time, the causality of a cause must itself be an effect—must itself have begun to be, and therefore, according to the principle of the understanding, itself requires a cause.

We must understand, on the contrary, by the term freedom, in the cosmological sense, a faculty of the spontaneous origination of a state; the causality of which, therefore, is not subordinated to another cause determining it in time. Freedom is in this sense a pure transcendental idea, which, in the first place, contains no empirical element; the object of which, in the second place, cannot be given or determined in any experience, because it is a universal law of the very possibility of experience, that everything which happens must have a cause, that consequently the causality of a cause, being itself something that has happened, must also have a cause. In this view of the case, the whole field of experience, how far soever it may extend, contains nothing that is not subject to the laws of nature. But, as we cannot by this means attain to an absolute totality of conditions in reference to the series of causes and effects, reason creates the idea of a spontaneity, which can begin to act of itself, and without any external cause determining it to action, according to the natural law of causality.

It is especially remarkable that the practical conception of freedom is based upon the transcendental idea, and that the question of the possibility of the former is difficult only as it involves the consideration of the truth of the latter. Freedom, in the practical sense, is the independence of the will of coercion by sensuous impulses. A will is sensuous, in so far as it is pathologically affected (by sensuous impulses); it is termed animal (arbitrium brutum), when it is pathologically necessitated. The human will is certainly an arbitrium sensitivum, not brutum, but liberum; because sensuousness does not necessitate its action, a faculty existing in man of self-determination, independently of all sensuous coercion.

It is plain that, if all causality in the world of sense were natural—and natural only—every event would be determined by another according to necessary laws, and that, consequently, phenomena, in so far as they determine the will, must necessitate every action as a natural effect from themselves; and thus all practical freedom would fall to the ground with the transcendental idea. For the latter presupposes that although a certain thing has not happened, it ought to have happened, and that, consequently, its phenomenal cause was not so powerful and determinative as to exclude the causality of our will—a causality capable of producing effects independently of and even in opposition to the power of natural causes, and capable, consequently, of spontaneously originating a series of events.

Here, too, we find it to be the case, as we generally found in the self-contradictions and perplexities of a reason which strives to pass the bounds of possible experience, that the problem is properly not physiological, but transcendental. The question of the possibility of freedom does indeed concern psychology; but, as it rests upon dialectical arguments of pure reason, its solution must engage the attention of transcendental philosophy. Before attempting this solution, a task which transcendental philosophy cannot decline, it will be advisable to make a remark with regard to its procedure in the settlement of the question.

If phenomena were things in themselves, and time and space forms of the existence of things, condition and conditioned would always be members of the same series; and thus would arise in the present case the antinomy common to all transcendental ideas—that their series is either too great or too small for the understanding. The dynamical ideas, which we are about to discuss in this and the following section, possess the peculiarity of relating to an object, not considered as a quantity, but as an existence; and thus, in the discussion of the present question, we may make abstraction of the quantity of the series of conditions, and consider merely the dynamical relation of the condition to the conditioned. The question, then, suggests itself, whether freedom is possible; and, if it is, whether it can consist with the universality of the natural law of causality; and, consequently, whether we enounce a proper disjunctive proposition when we say: “Every effect must have its origin either in nature or in freedom,” or whether both cannot exist together in the same event in different relations. The principle of an unbroken connection between all events in the phenomenal world, in accordance with the unchangeable laws of nature, is a well-established principle of transcendental analytic which admits of no exception. The question, therefore, is: “Whether an effect, determined according to the laws of nature, can at the same time be produced by a free agent, or whether freedom and nature mutually exclude each other?” And here, the common but fallacious hypothesis of the absolute reality of phenomena manifests its injurious influence in embarrassing the procedure of reason. For if phenomena are things in themselves, freedom is impossible. In this case, nature is the complete and all-sufficient cause of every event; and condition and conditioned, cause and effect are contained in the same series, and necessitated by the same law. If, on the contrary, phenomena are held to be, as they are in fact, nothing more than mere representations, connected with each other in accordance with empirical laws, they must have a ground which is not phenomenal. But the causality of such an intelligible cause is not determined or determinable by phenomena; although its effects, as phenomena, must be determined by other phenomenal existences. This cause and its causality exist therefore out of and apart from the series of phenomena; while its effects do exist and are discoverable in the series of empirical conditions. Such an effect may therefore be considered to be free in relation to its intelligible cause, and necessary in relation to the phenomena from which it is a necessary consequence—a distinction which, stated in this perfectly general and abstract manner, must appear in the highest degree subtle and obscure. The sequel will explain. It is sufficient, at present, to remark that, as the complete and unbroken connection of phenomena is an unalterable law of nature, freedom is impossible—on the supposition that phenomena are absolutely real. Hence those philosophers who adhere to the common opinion on this subject can never succeed in reconciling the ideas of nature and freedom.

_Possibility of Freedom in Harmony with the Universal Law of Natural Necessity._

That element in a sensuous object which is not itself sensuous, I may be allowed to term intelligible. If, accordingly, an object which must be regarded as a sensuous phenomenon possesses a faculty which is not an object of sensuous intuition, but by means of which it is capable of being the cause of phenomena, the causality of an object or existence of this kind may be regarded from two different points of view. It may be considered to be intelligible, as regards its action—the action of a thing which is a thing in itself, and sensuous, as regards its effects—the effects of a phenomenon belonging to the sensuous world. We should accordingly, have to form both an empirical and an intellectual conception of the causality of such a faculty or power—both, however, having reference to the same effect. This twofold manner of cogitating a power residing in a sensuous object does not run counter to any of the conceptions which we ought to form of the world of phenomena or of a possible experience. Phenomena—not being things in themselves—must have a transcendental object as a foundation, which determines them as mere representations; and there seems to be no reason why we should not ascribe to this transcendental object, in addition to the property of self-phenomenization, a causality whose effects are to be met with in the world of phenomena, although it is not itself a phenomenon. But every effective cause must possess a character, that is to say, a law of its causality, without which it would cease to be a cause. In the above case, then, every sensuous object would possess an empirical character, which guaranteed that its actions, as phenomena, stand in complete and harmonious connection, conformably to unvarying natural laws, with all other phenomena, and can be deduced from these, as conditions, and that they do thus, in connection with these, constitute a series in the order of nature. This sensuous object must, in the second place, possess an intelligible character, which guarantees it to be the cause of those actions, as phenomena, although it is not itself a phenomenon nor subordinate to the conditions of the world of sense. The former may be termed the character of the thing as a phenomenon, the latter the character of the thing as a thing in itself.

Now this active subject would, in its character of intelligible subject, be subordinate to no conditions of time, for time is only a condition of phenomena, and not of things in themselves. No action would begin or cease to be in this subject; it would consequently be free from the law of all determination of time—the law of change, namely, that everything which happens must have a cause in the phenomena of a preceding state. In one word, the causality of the subject, in so far as it is intelligible, would not form part of the series of empirical conditions which determine and necessitate an event in the world of sense. Again, this intelligible character of a thing cannot be immediately cognized, because we can perceive nothing but phenomena, but it must be capable of being cogitated in harmony with the empirical character; for we always find ourselves compelled to place, in thought, a transcendental object at the basis of phenomena although we can never know what this object is in itself.

In virtue of its empirical character, this subject would at the same time be subordinate to all the empirical laws of causality, and, as a phenomenon and member of the sensuous world, its effects would have to be accounted for by a reference to preceding phenomena. Eternal phenomena must be capable of influencing it; and its actions, in accordance with natural laws, must explain to us how its empirical character, that is, the law of its causality, is to be cognized in and by means of experience. In a word, all requisites for a complete and necessary determination of these actions must be presented to us by experience.

In virtue of its intelligible character, on the other hand (although we possess only a general conception of this character), the subject must be regarded as free from all sensuous influences, and from all phenomenal determination. Moreover, as nothing happens in this subject—for it is a noumenon, and there does not consequently exist in it any change, demanding the dynamical determination of time, and for the same reason no connection with phenomena as causes—this active existence must in its actions be free from and independent of natural necessity, for this necessity exists only in the world of phenomena. It would be quite correct to say that it originates or begins its effects in the world of sense from itself, although the action productive of these effects does not begin in itself. We should not be in this case affirming that these sensuous effects began to exist of themselves, because they are always determined by prior empirical conditions—by virtue of the empirical character, which is the phenomenon of the intelligible character—and are possible only as constituting a continuation of the series of natural causes. And thus nature and freedom, each in the complete and absolute signification of these terms, can exist, without contradiction or disagreement, in the same action.

_Exposition of the Cosmological Idea of Freedom in Harmony with the Universal Law of Natural Necessity._

I have thought it advisable to lay before the reader at first merely a sketch of the solution of this transcendental problem, in order to enable him to form with greater ease a clear conception of the course which reason must adopt in the solution. I shall now proceed to exhibit the several momenta of this solution, and to consider them in their order.

The natural law that everything which happens must have a cause, that the causality of this cause, that is, the action of the cause (which cannot always have existed, but must be itself an event, for it precedes in time some effect which it has originated), must have itself a phenomenal cause, by which it is determined and, and, consequently, all events are empirically determined in an order of nature—this law, I say, which lies at the foundation of the possibility of experience, and of a connected system of phenomena or nature is a law of the understanding, from which no departure, and to which no exception, can be admitted. For to except even a single phenomenon from its operation is to exclude it from the sphere of possible experience and thus to admit it to be a mere fiction of thought or phantom of the brain.

Thus we are obliged to acknowledge the existence of a chain of causes, in which, however, absolute totality cannot be found. But we need not detain ourselves with this question, for it has already been sufficiently answered in our discussion of the antinomies into which reason falls, when it attempts to reach the unconditioned in the series of phenomena. If we permit ourselves to be deceived by the illusion of transcendental idealism, we shall find that neither nature nor freedom exists. Now the question is: “Whether, admitting the existence of natural necessity in the world of phenomena, it is possible to consider an effect as at the same time an effect of nature and an effect of freedom—or, whether these two modes of causality are contradictory and incompatible?”

No phenomenal cause can absolutely and of itself begin a series. Every action, in so far as it is productive of an event, is itself an event or occurrence, and presupposes another preceding state, in which its cause existed. Thus everything that happens is but a continuation of a series, and an absolute beginning is impossible in the sensuous world. The actions of natural causes are, accordingly, themselves effects, and presuppose causes preceding them in time. A primal action which forms an absolute beginning, is beyond the causal power of phenomena.

Now, is it absolutely necessary that, granting that all effects are phenomena, the causality of the cause of these effects must also be a phenomenon and belong to the empirical world? Is it not rather possible that, although every effect in the phenomenal world must be connected with an empirical cause, according to the universal law of nature, this empirical causality may be itself the effect of a non-empirical and intelligible causality—its connection with natural causes remaining nevertheless intact? Such a causality would be considered, in reference to phenomena, as the primal action of a cause, which is in so far, therefore, not phenomenal, but, by reason of this faculty or power, intelligible; although it must, at the same time, as a link in the chain of nature, be regarded as belonging to the sensuous world.

A belief in the reciprocal causality of phenomena is necessary, if we are required to look for and to present the natural conditions of natural events, that is to say, their causes. This being admitted as unexceptionably valid, the requirements of the understanding, which recognizes nothing but nature in the region of phenomena, are satisfied, and our physical explanations of physical phenomena may proceed in their regular course, without hindrance and without opposition. But it is no stumbling-block in the way, even assuming the idea to be a pure fiction, to admit that there are some natural causes in the possession of a faculty which is not empirical, but intelligible, inasmuch as it is not determined to action by empirical conditions, but purely and solely upon grounds brought forward by the understanding—this action being still, when the cause is phenomenized, in perfect accordance with the laws of empirical causality. Thus the acting subject, as a causal phenomenon, would continue to preserve a complete connection with nature and natural conditions; and the phenomenon only of the subject (with all its phenomenal causality) would contain certain conditions, which, if we ascend from the empirical to the transcendental object, must necessarily be regarded as intelligible. For, if we attend, in our inquiries with regard to causes in the world of phenomena, to the directions of nature alone, we need not trouble ourselves about the relation in which the transcendental subject, which is completely unknown to us, stands to these phenomena and their connection in nature. The intelligible ground of phenomena in this subject does not concern empirical questions. It has to do only with pure thought; and, although the effects of this thought and action of the pure understanding are discoverable in phenomena, these phenomena must nevertheless be capable of a full and complete explanation, upon purely physical grounds and in accordance with natural laws. And in this case we attend solely to their empirical and omit all consideration of their intelligible character (which is the transcendental cause of the former) as completely unknown, except in so far as it is exhibited by the latter as its empirical symbol. Now let us apply this to experience. Man is a phenomenon of the sensuous world and, at the same time, therefore, a natural cause, the causality of which must be regulated by empirical laws. As such, he must possess an empirical character, like all other natural phenomena. We remark this empirical character in his actions, which reveal the presence of certain powers and faculties. If we consider inanimate or merely animal nature, we can discover no reason for ascribing to ourselves any other than a faculty which is determined in a purely sensuous manner. But man, to whom nature reveals herself only through sense, cognizes himself not only by his senses, but also through pure apperception; and this in actions and internal determinations, which he cannot regard as sensuous impressions. He is thus to himself, on the one hand, a phenomenon, but on the other hand, in respect of certain faculties, a purely intelligible object—intelligible, because its action cannot be ascribed to sensuous receptivity. These faculties are understanding and reason. The latter, especially, is in a peculiar manner distinct from all empirically-conditioned faculties, for it employs ideas alone in the consideration of its objects, and by means of these determines the understanding, which then proceeds to make an empirical use of its own conceptions, which, like the ideas of reason, are pure and non-empirical.

That reason possesses the faculty of causality, or that at least we are compelled so to represent it, is evident from the imperatives, which in the sphere of the practical we impose on many of our executive powers. The words I ought express a species of necessity, and imply a connection with grounds which nature does not and cannot present to the mind of man. Understanding knows nothing in nature but that which is, or has been, or will be. It would be absurd to say that anything in nature ought to be other than it is in the relations of time in which it stands; indeed, the ought, when we consider merely the course of nature, has neither application nor meaning. The question, “What ought to happen in the sphere of nature?” is just as absurd as the question, “What ought to be the properties of a circle?” All that we are entitled to ask is, “What takes place in nature?” or, in the latter case, “What are the properties of a circle?”

But the idea of an ought or of duty indicates a possible action, the ground of which is a pure conception; while the ground of a merely natural action is, on the contrary, always a phenomenon. This action must certainly be possible under physical conditions, if it is prescribed by the moral imperative ought; but these physical or natural conditions do not concern the determination of the will itself, they relate to its effects alone, and the consequences of the effect in the world of phenomena. Whatever number of motives nature may present to my will, whatever sensuous impulses—the moral ought it is beyond their power to produce. They may produce a volition, which, so far from being necessary, is always conditioned—a volition to which the ought enunciated by reason, sets an aim and a standard, gives permission or prohibition. Be the object what it may, purely sensuous—as pleasure, or presented by pure reason—as good, reason will not yield to grounds which have an empirical origin. Reason will not follow the order of things presented by experience, but, with perfect spontaneity, rearranges them according to ideas, with which it compels empirical conditions to agree. It declares, in the name of these ideas, certain actions to be necessary which nevertheless have not taken place and which perhaps never will take place; and yet presupposes that it possesses the faculty of causality in relation to these actions. For, in the absence of this supposition, it could not expect its ideas to produce certain effects in the world of experience.

Now, let us stop here and admit it to be at least possible that reason does stand in a really causal relation to phenomena. In this case it must—pure reason as it is—exhibit an empirical character. For every cause supposes a rule, according to which certain phenomena follow as effects from the cause, and every rule requires uniformity in these effects; and this is the proper ground of the conception of a cause—as a faculty or power. Now this conception (of a cause) may be termed the empirical character of reason; and this character is a permanent one, while the effects produced appear, in conformity with the various conditions which accompany and partly limit them, in various forms.

Thus the volition of every man has an empirical character, which is nothing more than the causality of his reason, in so far as its effects in the phenomenal world manifest the presence of a rule, according to which we are enabled to examine, in their several kinds and degrees, the actions of this causality and the rational grounds for these actions, and in this way to decide upon the subjective principles of the volition. Now we learn what this empirical character is only from phenomenal effects, and from the rule of these which is presented by experience; and for this reason all the actions of man in the world of phenomena are determined by his empirical character, and the co-operative causes of nature. If, then, we could investigate all the phenomena of human volition to their lowest foundation in the mind, there would be no action which we could not anticipate with certainty, and recognize to be absolutely necessary from its preceding conditions. So far as relates to this empirical character, therefore, there can be no freedom; and it is only in the light of this character that we can consider the human will, when we confine ourselves to simple observation and, as is the case in anthropology, institute a physiological investigation of the motive causes of human actions.

But when we consider the same actions in relation to reason—not for the purpose of explaining their origin, that is, in relation to speculative reason, but to practical reason, as the producing cause of these actions—we shall discover a rule and an order very different from those of nature and experience. For the declaration of this mental faculty may be that what has and could not but take place in the course of nature, ought not to have taken place. Sometimes, too, we discover, or believe that we discover, that the ideas of reason did actually stand in a causal relation to certain actions of man; and that these actions have taken place because they were determined, not by empirical causes, but by the act of the will upon grounds of reason.

Now, granting that reason stands in a causal relation to phenomena; can an action of reason be called free, when we know that, sensuously, in its empirical character, it is completely determined and absolutely necessary? But this empirical character is itself determined by the intelligible character. The latter we cannot cognize; we can only indicate it by means of phenomena, which enable us to have an immediate cognition only of the empirical character.[63] An action, then, in so far as it is to be ascribed to an intelligible cause, does not result from it in accordance with empirical laws. That is to say, not the conditions of pure reason, but only their effects in the internal sense, precede the act. Pure reason, as a purely intelligible faculty, is not subject to the conditions of time. The causality of reason in its intelligible character does not begin to be; it does not make its appearance at a certain time, for the purpose of producing an effect. If this were not the case, the causality of reason would be subservient to the natural law of phenomena, which determines them according to time, and as a series of causes and effects in time; it would consequently cease to be freedom and become a part of nature. We are therefore justified in saying: “If reason stands in a causal relation to phenomena, it is a faculty which originates the sensuous condition of an empirical series of effects.” For the condition, which resides in the reason, is non-sensuous, and therefore cannot be originated, or begin to be. And thus we find—what we could not discover in any empirical series—a condition of a successive series of events itself empirically unconditioned. For, in the present case, the condition stands out of and beyond the series of phenomena—it is intelligible, and it consequently cannot be subjected to any sensuous condition, or to any time-determination by a preceding cause.