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

by Norman Kemp Smith

In A 244[1288] Kant states his position in somewhat different fashion. In abstraction from sense the categories have meaning, but not determinate meaning; they relate not to any specific object, but only to things in general. In this latter reference, however, they possess no objective validity, since in the absence of intuition there is no means of deciding whether or not any real existence actually corresponds to them.

But whichever mode of statement be adopted, the same conclusion follows.

“Accordingly, the transcendental Analytic has this important result, that the most the understanding can achieve a priori is to anticipate the form of a possible experience in general. And since that which is not appearance cannot be an object of experience, the understanding can never transcend those limits of sensibility within which alone objects are given to us. Its principles are merely rules for the exposition of appearances; and the proud title of an Ontology, which presumptuously claims to supply, in systematic doctrinal form, synthetic a priori knowledge of things in general (e.g. the principle of causality), must therefore give place to the modest claims of a mere Analytic of pure understanding.”[1289]

A 248-9[1290] opens a new line of argument which starts from the results obtained in the Aesthetic. The proof that space and time are subjective forms establishes the merely phenomenal character of everything which can be apprehended in and through them, and is meaningless except on the assumption that things in themselves exist. This assumption, Kant argues, is already involved in the very word ‘appearance,’ and unless it be granted, our thinking will revolve in a perpetual circle.[1291] But, he proceeds, this conclusion may easily be misinterpreted. It might be taken as proving the objective reality of noumena, and as justifying us in maintaining a distinction between the sensible and the intelligible worlds, and therefore in asserting that whereas the former is the object of intuition, the latter is apprehended by the understanding in pure thought. We should then be arguing that though in experience things are known only as they appear, through pure understanding a nobler world than that of sense, “eine Welt im Geiste gedacht,” is opened to our view.

But any such interpretation, Kant insists, runs directly counter to the teaching of the Analytic, and is ruled out by the conclusions to which it has led. Categories yield only “rules for the exposition of appearances,” and cannot be extended beyond the field of possible experience. It is true that all our sense-representations are related by the understanding to an object that is “transcendental.” But that object, in its transcendental aspect, signifies only a something = x. It cannot be thought apart from the sense-data which are referred to it. When we attempt to isolate it, and so to conceive it in its independent nature, nothing remains through which it can be thought.

“It is not in itself an object of knowledge, but only the representation of appearances under the concept of an object in general, viewed as determinable through the manifold of those appearances.”

Kant is here again expounding his early doctrine of the transcendental object.[1292] Evidently, at the time at which this passage was written, he had not yet come to realise that such teaching is not in harmony with his Critical principles. It is, as we have seen above, a combination of subjectivism and of dogmatic rationalism.[1293] The very point which he here chiefly stresses was bound, however, when consistently followed out, to reveal the untenableness of the doctrine of the transcendental object; and in the second edition Kant so recast this chapter on phenomena and noumena as to eliminate all passages in which the transcendental object is referred to.[1294]

But to return to Kant’s own argument: the reason why the mind is “not satisfied with this substrate of sensibility,”[1295] and therefore proceeds to duplicate the phenomenal world by a second world of noumena, lies in the character of the agency whereby sensibility is limited. Sensibility is limited by the understanding; and the understanding, overestimating its powers and prerogatives, proceeds to transform the notion of the transcendental object = x into the concept of a noumenon, viewed in a manner conformable to its etymological significance, as something apprehended by reason or pure intuition, i.e. as intuited in some non-sensuous fashion. For only by postulating the possibility of a non-sensuous species of intuition, can the notion of a noumenon, thus positively conceived, be saved from self-contradiction. Otherwise we should be asserting the apprehension of an object independently of appearances, and yet at the same time denying the only means through which such apprehension is possible. Statement of the postulate suffices, however, to reveal its unsupported character. We have no such power of non-sensuous, intuitive apprehension;[1296] nor can we in any way prove that such a power is possible even in a Divine Being. Though, therefore, the concept of noumena is not self-contradictory, it involves more than we have the right to assert; the process whereby the empty notion of a transcendental object = x is transformed into the positive concept of a noumenon is easily comprehensible,[1297] but it is none the less illegitimate. We must, Kant insists, keep strict hold of the central doctrine of Critical teaching, namely, that the categories are applicable only to the data of sense. We can still employ them as pure logical functions, yielding the notion of objects in general (of the transcendental object = x). But this does not widen the sphere of known existences. It only enables us to comprehend the limited and merely phenomenal character of the world experienced.

At this point[1298] Kant’s argument takes a strange and misleading turn. The concept of object in general (the transcendental object = x) has been proved to be involved in the apprehension of appearances as appearances, and in this capacity to be a limiting concept (Grenzbegriff), which, though negative in function, is indispensably involved in the constitution of human experience. Now, however, Kant proceeds to ascribe this function to the concept of the noumenon. That concept is, he repeats, purely problematic. Even the mere possibility of its object, presupposing as it does the possibility of an understanding capable through non-sensuous intuition of apprehending it, we have no right to assert. That the concept is not self-contradictory is the most that we can say of it. None the less, it is to this concept that Kant here ascribes the indispensable limiting function.