A Commentary to Kant's 'Critique of Pure Reason'

by Norman Kemp Smith

“...the ultimate intention of Nature in her wise provision for us has indeed, in the constitution of our Reason, been directed to our moral interests alone.”[1714]

This is the position which Kant endeavours to establish in his Foundations of the Metaphysics of Morals, and in the Critique of Practical Reason. The very brief outline which he here gives of his argument is necessarily incomplete; and is in consequence somewhat misleading. He first disposes of the problem of freedom; and does so in a manner which shows that he had not, when this section was composed, developed his Critical views on the nature of moral freedom. He is for the present content to draw a quite un-Critical distinction between transcendental and practical freedom.[1715] The latter belongs to the will in so far as it is determined by Reason alone, independently of sensuous impulses. Reason prescribes objective laws of freedom, and the will under the influence of these laws overcomes the affections of sense. Such practical freedom can, Kant asserts, be proved by experience to be a natural cause. Transcendental freedom,[1716] on the other hand, i.e. the power of making a new beginning in the series of phenomena, is a problem which can never be empirically solved. It is a purely speculative question with which Reason in its practical employment is not in the least concerned. The canon of pure Reason has therefore to deal only with the two remaining problems, God and immortality. Comment upon these assertions can best be made in connection with the argument of the next section.[1717]

SECTION II
THE IDEAL OF THE HIGHEST GOOD, AS A DETERMINING GROUND OF THE ULTIMATE END OF PURE REASON[1718]

Reason in its speculative employment transcends experience, but solely for the sake of experience. In other words, speculative Reason has a purely empirical function. (This is the explanation of the somewhat paradoxical contention, to which Kant has already committed himself, that the problems of God and immortality, though seemingly speculative in character, really originate in our practical interests.) But pure Reason has also a practical use; and it is in this latter employment that it first discloses the genuinely metaphysical character of its present constitution and ultimate aims. The moral consciousness, in revealing to us an Ideal of absolute value, places in our hands the only available key to the mysteries of existence. As this moral consciousness represents the deepest reality of human life, it may be expected to have greater metaphysical significance than anything else in human experience; and since the ends which it reveals also present themselves as absolute in value, and are indeed the only absolute values of which we can form any conception, this conclusion would seem to be confirmed.

Happiness has natural value; morality, i.e. the being worthy to be happy, has absolute value. The means of attaining the former obtain expression in prudential or pragmatic laws that are empirically grounded. The conditions of the latter are embodied in a categorical imperative of an a priori character. The former advise us how best to satisfy our natural desire for happiness; the latter dictates to us how we must behave in order to deserve happiness.

Kant’s further argument is too condensed to be really clear, and if adequately discussed would carry us quite beyond the legitimate limits of this Commentary. I shall therefore confine myself to a brief and free restatement of his general position. The Critical teaching can be described as resulting in a new interpretation of the function of philosophy.[1719] The task of the philosopher, properly viewed, does not consist in the solution of speculative problems; such problems transcend our human powers. All that philosophy can reasonably attempt is to analyse and define the situations, cognitive and practical, in which, owing to the specific conditions of human existence, we find ourselves to be placed. Upon analysis of the cognitive situation Kant discovers that while all possibilities are open, the theoretical data are never such as to justify ontological assertions.[1720] When, however, he passes to the practical situation, wider horizons, definitely outlined, at once present themselves. The moral consciousness is the key to the meaning of the entire universe as well as of human life. Its values are the sole ultimate values, and enable us to interpret in moral terms (even though we cannot comprehend in any genuinely theoretical fashion) the meaning of the dispensation under which we live. The moral consciousness, like sense-experience, discloses upon examination a systematic unity of presupposed conditions. In the theoretical sphere this unity cannot be proved to be more than a postulated Ideal of empirical experience; and it is an Ideal which, even if granted to have absolute validity, is too indefinite to enable us to assert that ultimate reality is spiritual in character, or is teleologically ordered. The underlying conditions, on the other hand, of practical experience have from the start a purely noumenal reference. They have no other function than to define, in terms of the moral consciousness, the ultimate meaning of reality as a whole. They postulate[1721] a universe in which the values of spiritual experience are supported and conserved.

But the main difference in Kant’s treatment of the two situations, cognitive and practical, only emerges into view when we recognise the differing modes in which the transcendental method of proof is applied in the two cases. The a priori forms of sensibility, understanding, and Reason are proved by reference to possible experience, as being its indispensable conditions. In moral matters, however, we must not appeal to experience. The actual is no test of the Ideal; “what is” is no test of what ought to be. And secondly, the moral law, if valid at all, must apply not merely within the limits of experience, but with absolute universality to all rational beings. The moral law, therefore, can neither be given us in experience, nor be proved as one of the conditions necessary to its possibility. Its validity, in other words, can be established neither through experience nor through theoretical reason.

Though such is Kant’s own method of formulating the issue, it exaggerates the difference of his procedure in the two Critiques, and is very misleading as a statement of his real position. In one passage, in the Critique of Practical Reason,[1722] Kant does, indeed, assert that the moral law requires no deduction. It is, he claims, a fact of which we are a priori conscious: so far from itself requiring proof, it enables us to prove the reality of freedom. Yet in the very same section he argues that the deduction of freedom from the moral law is a credential of the latter, and is a sufficient substitute for all a priori justification. According to the first statement we have an immediate consciousness of the validity of the moral law; according to the second statement the moral law proves itself indirectly, by serving as a principle for the deduction of freedom. The second form of statement alone harmonises with the argument developed in the third section of the Foundations of the Metaphysics of Morals, and more correctly expresses the intention of Kant’s central argument in the Critique of Practical Reason. For the difference between the two transcendental proofs in the two Critiques does not really consist in any diversity of method, but solely in the differing character of the premisses from which each starts. The ambiguity of Kant’s argument in the second Critique seems chiefly to be caused by his failure clearly to recognise that the moral law, though a form of pure Reason, exercises, in the process of its transcendental proof, a function which exactly corresponds to that which is discharged by possible experience in the first Critique. Our consciousness of the moral law is, like sense-experience, a given fact. It is de facto, and cannot be deduced from anything more ultimate than itself.[1723] But as given, it enables us to deduce its transcendental conditions. This does not mean that our immediate consciousness of it as given guarantees its validity. The nature of its validity is established only in the process whereby it reveals its necessary implications. The objects of sense-experience are assumed by ordinary consciousness to be absolutely real; in the process of establishing the transcendental conditions of such experience they are discovered to be merely phenomenal. The pure principles of understanding thus gain objective validity as the conditions of a given experience which reveals only appearances. Ordinary consciousness similarly starts from the assumption of the absolute validity of the moral law. But in this case the consciousness of the law is discovered on examination to be explicable, even as a possibility, only on the assumption that it is due to the autonomous activity of a noumenal being. By its existence it proves the conditions through which alone it is explicable. Its mere existence suffices to prove that its validity is objective in a deeper and truer sense than the principles of understanding. The notion of freedom, and therefore all the connected Ideas of pure Reason, gain noumenal reality as the conditions of a moral consciousness which is incapable of explanation as illusory or even phenomenal. Since the consciousness of the moral law is thus noumenally grounded, it has a validity with which nothing in the phenomenal world can possibly compare. It is the one form in which noumenal reality directly discloses itself to the human mind.[1724]

Obviously the essential crux of Kant’s argument lies in the proof that the moral consciousness is only explicable in this manner, as the self-legislation of a noumenal being. Into the merits of his argument we cannot, however, here enter; and I need only draw attention to the manner in which it conflicts with the statement of the preceding section, that the possibility of transcendental freedom is a purely speculative question with which practical Reason is not concerned. The reality of freedom, as a form of noumenal activity, is the cardinal fact of Kant’s metaphysics of morals. For though our consciousness of the moral law is the ratio cognoscendi of freedom, transcendental freedom is the ratio essendi of the moral law.[1725]

“With this faculty [of practical Reason], transcendental freedom is also established; freedom, namely, in that absolute sense in which speculative Reason required it, in its use of the concept of causality, in order to escape the antinomy into which it inevitably falls, when in the chain of cause and effect it tries to think the unconditioned.... Freedom is the only one of all the Ideas of the speculative Reason of which we know the possibility a priori (without, however, understanding it), because it is the condition of the moral law which we know.”[1726] ”[Freedom] is the only one of all the Ideas of pure Reason whose object is a thing of fact and to be reckoned among the scibilia.”[1727] “It is thus very remarkable that of the three pure rational Ideas, God, freedom, and immortality, that of freedom is the only concept of the supersensible which (by means of the causality that is thought in it) proves its objective reality in nature by means of the effects it can produce there; and thus renders possible the connection of both the others with nature, and of all three with one another so as to form a Religion.... The concept of freedom (as fundamental concept of all unconditioned practical laws) can extend Reason beyond those bounds within which every natural (theoretical) concept must inevitably remain confined.”[1728]