Immanuel Kant's Critique of Pure Reason — trans. F. Max Müller

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been thought synthetically a priori. The concepts of unity, truth, and perfection, therefore, do not supplement the transcendental table of the categories, as if it were imperfect, but they serve only, after the relation of these concepts to objects has been entirely set aside, to bring their employment under general logical rules, for the agreement of knowledge with itself.

SUPPLEMENT XIII

[See vol. ii. p. 84]

Locke, for want of this reflection, and because he met with pure concepts of the understanding in experience, derived them also from experience, and yet acted so inconsistently that he attempted to use them for knowledge which far exceeds all limits of experience.

David Hume saw that, in order to be able to do this, these concepts ought to have their origin a priori ; but as he could not explain how it was possible that the understanding should be constrained to think concepts, which by themselves are not united in the understanding, as necessarily united in the object, and never thought that possibly the understanding might itself, through these concepts, be the author of that experience in which its objects are found, he was driven by necessity to derive them from experience (namely, from a subjective necessity, produced by frequent association in experience, which at last is wrongly supposed to be objective^ that is, from habit) .

He acted, however, very consistently, by declaring it to be impossible to go with these concepts, and with the principles arising from them, beyond the limits of experience. This empirical deduction, which was adopted by both philosophers, cannot be reconciled with the reality of our scientific knowledge a priori, namely, pure mathematics Siud general natural science y and is therefore refuted by facts.

The former of these two celebrated men opened a wide door to fantastic extravagance, because reason, if it has once established such pretensions, can no longer be checked by vague praises of moderation ; the other, thinking that he had once discovered so general an illusion of our faculty of knowledge, which had formerly been accepted as reason, gave himself over entirely to scepticism. We now intend to make the experiment whether it is not possible to conduct

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reason safely between these two rocks, to assign to her definite limits, and yet to keep open for her the proper field for all her activities ?

I shall merely premise an explanation of what I mean by the categories. They are concepts of an object in general by which its intuition is regarded as determined with reference to one of the logical functions in judgments. Thus the function of the categorical judgment was that of the relation of the subject to the predicate ; for instance, all bodies are divisible. Here, however, with reference to the pure logical employment of the understanding, it remained undetermined to which of the two concepts the function of the subject, or the predicate, was to be assigned. For we could also say, some divisible is body. But by bringing the concept of body under the category of substance, it is determined that its empirical intuition in experience must always be considered as subject and never as predicate only. The same applies to all other categories.

SUPPLEMENT XIV

[See vol. ii. p. 84]

OF THE DEDUCTION OF THE PURE CONCEPTS OF THE UNDERSTANDING

Second Section Transcendental Deduction of the Pure Concepts of the Understanding

§ 15 Of the Possibility of Connecting (conjunctio) in General