Critique of Pure Reason
Lecture notes, January 29, 1997: Transcendental Deduction I
G. J. Mattey
The production of the list of pure concepts of the understanding (categories) from the table of judgments is known as the "metaphysical deduction." It has been roundly criticized as being ad hoc, no the product of a "single principle," as Kant hand maintained. Nonetheless, we shall try to see what the principle is, in the hope that the discovery of Kant's strategy can shed some light on his overall treatment of the categories.
The key point of similarity between judgments and concepts is that both introduce unity into representations. A judgment subsumes an intuition under a concept or places one concept in the sphere of another. Thus in a categorical judgment, the subject is included in the sphere of the predicate concept. In general, Kant called the unity produced in judgments an "analytical unity," and held that there are twelve forms by which the unification takes place.
Although Kant's target is pure concepts of the understanding (concepts which have their origin in the understanding itself), I will begin my discussion of the unifying function of concepts by showing the unity in empirical concepts. When I am given a number of intuitions, I can discern in them some common characters ("marks," or Merkmale). A number of characters together make up the intension of a general concept. In Locke's example, the characters hard, malleable, ductible, fusible and others go together to make up the concept of metal. We form the concept by observing objects sharing these characteristics. The unity provided by the concept is both that of the intension (the sum total of the characters making up its intension) and that of the extension, the sum total of intuitions which fall under the concept (my watch, a plate in my study, my car's engine, etc.). Note that both the intension and extension are elements given in experience.
A pure concept of the understanding, on the other hand, has no given intension or extension. What "maniforld," then, could it bring to unity? Kant's answer is that in sensibility we find a manifold of pure intuition which is not given, not empirical. This gives a basis for the generation of pure concepts: through them we can apply to objects properties pertaining to space and time themselves.
An example of the procedure of generating concepts based on pure intuition is that of thinking a triangle in general. One does so by "drawing it in thought." I begin with a point, extend it to a line, attach another line to its endpoint, and finally attach a third line back to the original point. The connecting act ("synthesis") is a function of what Kant calls the "imagination." What is connected to generate the thought of the triangle is a "manifold" of points and lines. So there are three ingredients of the generation: the manifold, the synthesis of the manifold, and the unity attained by the synthesis. Note that the intension of the concept has no empirical elements, nor does its extension (regions of space).
The process of combination is described only metaphorically. Kant says that the manifold must be "gone through, taken up and connected." The German word for 'concept' is 'Begriff,' and the corresponding verb is 'begreifen,' which literally means 'to grasp.' So what Kant has in mind is illustrated by the act of grasping, as when one brings together a bunch of popcorn in one's hand.
Having shown in outline how concepts give unity to a manifold of intuition, and pure intuition in particular, I shall now turn to another crucial aspect of concepts. The role of the understanding is to think by means of concepts through the making of judgments. (Kant sometimes calls the human understanding "discursive.") It is only through thinking that we represent objects of experience. An object of experience, for Kant, is not a mere "this," not merely a given intuition, but a "this-such," an intuition which has been conceptualized. We understand something (it becomes an object for us) when we can classify it in some way, e.g. as a figure or a triangle, or an equilateral triangle, by making a judgment which brings the intuition under the concept. Kant states that we must "make our intuitions intelligible, that is, to bring them under concepts" (A51/B75).
It must be noted that Kant frequently writes of intuitions as being objects. In defining his key terms, Kant stats that, "An objective perception is cognition (cognitio). This is either intution or concept (intuitus vel conceptus). The former relates immediately to the object and is single, the latter refers to it mediately by means of a feature which several things have in common." In his opening remarks in the Transcendental Logic, he states that through receptivity "an object is given to us," and through spontaneity, "the object is thought through that representation" (A50/B74). Again, "Without sensibility, no object would be given to us, without understanding, no object would be thought" (A52/B75).
But in Section 14, when recapitulating the distinction, Kant notes that the objects of intuition are only given as appearances (which he had earlier defined, at A20/B34, as an "undetermined" object). "Now all experience does indeed contain, in addition to the intuition of the senses through which something is given, a concept of an object as being thereby given, that is to say, as appearing" (A93/B126). The categories are conditions under which something can be thought and object in general, and thus allows us to think appearances as objects of experience. So the categories will have as their extension objects of possible experience, and further, are necessary conditions for there being objects of experience at all.
Naturally, this raises the question of the meaing of the term 'experience.' Steeped as we are in the empiricist tradition, it is difficult for us to see why objects of experience are not simply the "objective perceptions" Kant called intuitions. Obviously, Kant wants to say that perception alone falls short of experience. This is an absolutely vital claim on his part, yet it is hardly explained. Taking our cue from the Prolegomena, we can say that the hallmark of experience is its objectivity, while appearance alone may be merely subjective. The distinction finally comes out in Section 19, where Kant distinguishes the "subjective validity" of 'If I support a body, I feel an impression of weight," from the "objective validity of "It, the body, is heavy." "Thus to say 'The body is heavy' is not merely to state that the two representations have always been conjoined in my perception, however toften that perception be repeated; what we are asserting is that they are combined in the object, no matter what the state of the subject may be" (B142). Now we can see that judgments about objects of experience are just those which are said to have objective validity. This is the "rich" sense in which something is thought as an object when it is brought under concepts. It is clearly more than the basic sense of "a single thing," which is "as yet undetermined."
The question now before us, then, is why the use of categories, "concepts of objects in general," are necessary for us to think things as objects of experience. Why cannot empirical concepts, gleaned from the appearances, suffice? Before being in a position to answer this question, we must reopen the notion of unified representation. If a manifold is synthetized and brought to unity under concepts, there must be unity in the consciousness through which this all takes place. That is, it must be one and the same 'I' which performs these functions through its faculties of sensibility, imagination and understanding.
But more importantly, I must be able to represent myself as the same in all these representative acts. In so doing, I become conscious of myself as identical throughout them. I cannot call all these representations my own unless I am capable of prefixing 'I think' to them all. Kant, following Leibniz, called self-consciousness 'apperception.' If I am to think myself as one and the same throughout all of my representations, this apperception must be a unity. Thus, Kant claims, there is a unity of apperception underlying all acts of combination which I can call my own. This unity he calls "transcendental" because it is the ground for a priori cognition of objects (though we have not yet seen how it is so).
The link with categories is that any unity in the pure concepts of understanding is subject to a "higher" or "original" unity, that of apperception. "It is the unity of consciousness that alone constitutes the relation of representations to an object, and therefore their objective validity and the fact that they are cognitions; and upon it therefore rests the very possibility of the understanding" (B137). How the unity of consciousness "constitutes" the relation of representations to an object, and hence supports the objective validity of the categories, becomes the primary task of the Transcendental Deduction.
