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

by Norman Kemp Smith

But when, on the other hand, the problems of the Dialectic are viewed in their distinction from those of the Analytic, and their independent character is recognised, they appear in a perspective which sets them in a very different light. Reason is a faculty co-ordinate with understanding, and yields a priori concepts distinct in function, no less than in nature, from the categories. To mark this distinction Kant entitles the concepts of Reason Ideas. They demand both a metaphysical and a transcendental deduction. These requirements are fulfilled through their derivation from the three forms of syllogism, and by the proof that they exercise an indispensable function, at once limiting and directing the understanding. As limiting concepts, they condition the consciousness of those Ideal standards through which the human mind is enabled to distinguish between appearance and things in themselves. As regulative, they prescribe the problems which the understanding in its search for knowledge is called upon to solve.

These two tendencies, sceptical and constructive, are never, indeed, in complete opposition. Common to both, rendering possible the psychological explanation of the metaphysical impulse, which even the negative standpoint demands, is the doctrine of the regulative function of Ideal principles. This doctrine, which already appears in the Dissertation of 1770, was later developed into the Critical theory of transcendental illusion; and by means of that theory Kant succeeded in bringing the two standpoints into a very real and vital connection with one another. At first sight it may seem to achieve their complete reconciliation, accounting for their distinction while rendering them mutually complementary; and Kant’s teaching may perhaps be so restated as to bear out that impression. But the harmony is never completely attained by Kant. Here, as in the Analytic, there is an equipoise of tendencies that persist in opposition.

Kant’s mediating doctrine of transcendental illusion may first be stated. It rests upon a distinction between appearance and illusion. Appearance (Erscheinung) is a transcript in phenomenal terms of some independent reality; and of such appearances we can acquire what from the human point of view is genuine knowledge. On the other hand, all professed insight into the nature of the transcendent or non-empirical is sheer illusion (Schein), and purely subjective. There are three species of illusion, logical, empirical and transcendental. Logical illusion stands apart by itself. It is due merely to inattention or ignorance; and vanishes immediately the attention is aroused. Empirical and transcendental illusion, on the other hand, have a twofold point of agreement, first, in being unavoidable, and secondly, in that they originate in our practical needs. We may know that the moon at its rising is no larger than in mid-heavens, that the ocean is no higher in the distance than at the shore; this makes not the least difference in the perceptions as they continue to present themselves. That the illusions are adapted to our practical needs, and are consequently beneficial, is less often observed. Changes in the colour, form, and size of objects as they recede from us, the seeing of the parallel sides of a street as converging, enable us to achieve what would not otherwise be possible. By their means we acquire the power of compressing a wide extent of landscape into a single visual field, of determining distance, and the like. Their practical usefulness is in almost exact proportion to the freedom with which they depart from the standards of the independently real. Kant argues that, in these respects, transcendental illusion is analogous to the empirical. Just as the illusory characteristics of our perceptions are to be understood only in terms of their practical function, so the Ideas of pure Reason have always a practical bearing, and can only be explained and justified in terms of the needs which they satisfy. As theoretical enquirers, we accept all that affords us orientation in the attainment of knowledge; as moral agents, we postulate the conditions which are necessary for the realisation of the moral imperative. And as the Ideals of natural science are found (such is Kant’s contention) to be in general form akin to those of the moral consciousness, they thus acquire a twofold footing in the mental life, maintaining their place there quite independently of theoretical proof. Though illusory, they are unavoidable; and though theoretically false,[1337] they are from a practical point of view both legitimate and indispensable.

Kant, in developing this thesis, might profitably have pointed to still another respect in which the analogy holds between sense-experience and transcendental beliefs. The illusions of sense-perception come in the ordinary processes of experience to be detected as such by the mind. From the theoretical standpoint of the outside observer who compares the situation of one percipient with that of another, and so is enabled to cancel the differences which variety of situation carries with it, the useful illusions of ordinary experience are reduced to the level of mere appearance. In contradicting one another they reveal their subjective character, and also at the same time afford data for determining the objective conditions to which their subjectively necessary existence is causally due. In similar fashion the transcendental illusions result in contradictions, which compel the mind to recognise that the Ideals to which it is committed by its practical needs are of a merely subjective character, and may never be legitimately interpreted as representing the actual nature of the independently real.

The chief transcendental illusion, and ultimately the cause of all the others, consists in the belief that the Ideals of explanation which satisfy Reason must in general outline represent the nature of ultimate reality. What the individual seeks to discover he naturally believes to exist prior to the discovery. As practical beings, we regard the objects of sense-experience as absolute realities—they are the realities of practical life, and we are practical rather than theoretical beings—and the existing empirical sciences, conceived as Ideally completed, are therefore viewed as yielding an adequate representation of ultimate reality. But such a belief involves us in contradictions. The world of phenomena in space and time is endlessly relative. It can have no outer bounds or first beginning, and no smallest parts; and in the series of causal antecedents there can be no member that is not effect as well as cause. Viewed as representing a pre-existent goal, the Ideas of Reason are imaginary completions of the intrinsically and merely relative, and are in their very notion self-contradictory. All that is definite in their content conflicts with their absoluteness; and yet, as it would seem, only in their empirical reference can they hope for objective verification.

Such are the problems of the Dialectic, so far as they can be formulated in terms common to the two opposed standpoints. Their deeper significance, and the grounds of Kant’s alternating treatment of them, only appear when he raises the further questions, what those Ideals of explanation which Reason prescribes really are, and how, if they conflict with the content of experience, it is possible that they should be conceived at all. To these questions Kant propounds both a sceptical and an Idealist answer. The former, in bare outline, may be stated as follows. The so-called Ideas are based upon experience and are derived from it. The understanding removes the limitations to which its pure concepts are subject in sense-experience, and proceeds to use them in their widest possible application, i.e. to things in general. As thus employed, they are without real significance, and are indeed self-contradictory. To form the Idea of the unconditioned, we have to omit all those conditions through which alone anything can be apprehended, even as possible. To construct the concept of absolute or unconditioned necessity, we have similarly to leave aside the conditions upon which necessity, as revealed in experience, in all cases depends; in eliminating conditions, we eliminate necessity in the only forms in which it is conceivable by us. Such Ideas are, indeed, simply schematic forms, whereby we body forth to ourselves, in more or less metaphorical terms, the concept of a maximum. They are imaginary extensions, in Ideal form, of the unity and system which understanding has discovered in actual experience, and which, under the inspiration of such Ideals, it seeks to realise in ever-increasing degree. If the understanding, as thus insisting upon Ideal satisfaction, be entitled Reason, the Ideas must be taken as expressing a subjective interest, and as exhausting their legitimate employment in the regulation of the understanding. Their transcendental deduction will consist in the proof that they are necessary to the understanding for the perfecting of its experience. They do not justify us in attempting to decide, in anticipation of actual experience, how far the contingent collocations and the inexhaustible complexities of brute experience are really reducible to a completely unified system; but they quite legitimately demand that through all discouragements we persist in the endeavour towards their realisation. In any case, it is by experience that the degree of their reality has to be decided. We judge of things by the standard of that for which they exist, and not vice versa. As the sole legitimate function of the Ideas is that of inspiring the understanding in its empirical employment, they must never be interpreted as having metaphysical significance. As the Ideas exist solely for the sake of experience, it is they that must be condemned, if the two really diverge. We do not say “that a man is too long for his coat, but that the coat is too short for the man.”[1338] It is experience, not Ideas, which forms the criterion alike of truth and of reality.

Kant’s teaching, when on Idealist lines, is of a very different character. Reason is distinct from understanding, and yet is no less indispensably involved in the conditioning of experience. All consciousness is consciousness of a whole which precedes and conditions its parts. Such consciousness cannot be accounted for by assuming that we are first conscious of the conditioned, and then proceed through omission of its limitations to form to ourselves, by means of the more positive factors involved in this antecedent consciousness, an Idea of an unconditioned whole. The Idea of the unconditioned is distinct in nature from all other concepts, and cannot be derived from them. It must be a pure a priori product of what may be named the faculty of Reason. Its uniqueness is what causes its apparent meaninglessness. As it is involved in all consciousness, it conditions all other concepts; and cannot, therefore, be defined in terms of them. Its significance must not be looked for save in that Ideal, to which no experience, and no concept other than itself, can ever be adequate. That in this Ideal form it has a very real and genuine meaning is proved by our capacity to distinguish between appearance and reality. For upon it this distinction, in ultimate analysis, is found to rest. Consciousness of limitation presupposes a consciousness of what is beyond the limit; consciousness of the unconditioned is prior to, and renders possible, our consciousness of the contingently given. The Idea of the unconditioned must therefore be counted as being, like the categories, though in a somewhat different manner, a condition of the possibility of experience. With it our standards both of truth and of reality are inextricably bound up.[1339] The Ideas in which it specifies itself, so far from depending upon empirical verification, are the touchstone by which we detect the unreality of the sensible world, and by which a truer reality, such as would be adequate to the Ideal demands of pure Reason, is prefigured to the mind.

These two standpoints are extremely divergent in their consequences. Each leads to a very different interpretation of the content of the Ideas, of their function in experience, and of their objective validity. On the one view, their content is merely empirical, and sense-experience is our sole criterion of truth and reality; on the other, they have to be recognised as containing a pure a priori concept, and are themselves the standards by which even empirical truth can alone be determined. In the one case, they are Ideals projected by experience for its own empirical guidance; they are built upon contingent experience, and depend upon it alike for the content which makes them conceivable and for their validity. In the other, they are presuppositions of experience, at once conditioning its possibility and revealing its merely phenomenal character. According to the sceptical view, Reason is concerned only with itself and its own subjective demands; on the Idealist view, it is a metaphysical faculty, and outlines possibilities that may perhaps be established by practical Reason.

Such, in broad outline, are the central doctrines of the Dialectic. They constitute an extraordinarily stimulating and suggestive body of Critical teaching. In no other division of the Critique do the power and originality of Kant’s thinking gain such abundant, forceful and illuminating expression. The accumulated results of the painstaking analyses of the earlier sections contribute a solidity and fulness of meaning, which render the argument extremely impressive, even to those who are out of sympathy with Kant’s ultimate purposes. Its persistent influence, on sceptical no less than on Idealist lines, and often conveyed by very devious channels, can frequently be detected even in thinkers—Herbert Spencer is an instance—who would indignantly repudiate the charge of being indebted to such a source.

THE HISTORY AND DEVELOPMENT OF KANT’S VIEWS IN REGARD TO THE PROBLEMS OF THE DIALECTIC[1340]