Categories

3. Categories in Kant

The basic problem of specifying what a category theory is, is unavoidably aggravated by Kant, the second major historical influence to shape the tradition (see Kant, I. §4). Kant arrives at his alternative categories by considering the conditions which allow there to be a logic of judgments, a procedure which he explicitly attributes to Aristotle, while emphasizing the divergence of their conclusions (Kant 1781/7: A80, B105). He asks: Which judgement forms does logic treat of? His answer is that all judgements have a ‘quantity’ (universal, particular or singular) and a ‘quality’ (affirmative, negative or infinite). They must all instantiate one of the ‘relations’ (categorical, hypothetical or disjunctive), and one of the ‘modalities’ (problematic, assertoric or apodeictic) (Kant 1781/7: A70, B95). Kant proposes to derive his categories from these forms or aspects of judgment, obtaining the corresponding list of unity, plurality and totality under ‘quantity’; reality, negation and limitation under ‘quality’; inherence and subsistence, causality and dependence, and community under ‘relation’; and possibility–impossibility, existence–non-existence and necessity–contingency under ‘modality’ (Kant 1781/7: A80, B106). He pretends that their derivation from the types of judgement makes his categories superior to Aristotle’s, because this procedure supposedly guarantees that all the concepts of pure understanding, and no others, are systematically discovered.

Every element of empirical reality must fall into place within this scheme, since the categories exhaust the understanding’s a priori concepts. Kant’s eventual aim in the Transcendental Deduction is to prove that, since every experience involves judgement, every possible experience must involve use of the categories. Specifically, his claim is that one must conceive of experience as experience of a world organized by the categories.

The conviction that Aristotelian genera of being and Kantian concepts of understanding cannot, pace Kant, be in competition, is hard to avoid since the philosophical projects which gave a point to these various theories are so diverse. But we should not hastily conclude that these schemes have nothing of philosophical importance in common. Aristotle’s transitions from what we are likely to classify as linguistic or conceptual data to robustly realist theses seem surprisingly bold, even unmotivated; but that is precisely because we are heirs to the Kantian legacy which insists on our right to empirical realism but concedes the obligation to earn it by espousing transcendental idealism.

Aristotle blithely assumes that the fabric of the world is accessible to us, disclosed by the range of predications people, at any rate those of a philosophical disposition, have been disposed to make; he mounts no argument for the reliable accuracy of predication. True, it is not as if later Aristotelians ignored the issue of what the categories are categories of. Because the Categories was incorporated into the Organon – which came to be the traditional logic course, culminating in the analysis of arguments – some interpreters were indeed inclined to the position that the Categories, which began the logic course, ought to deal with the simples from which propositions making up arguments are constructed, and so favoured the identification of categories with words. Other strands in the tradition preferred a realistic interpretation, while nevertheless asserting a thorough-going isomorphism between the structures of the world, our concepts and the words in which we express ourselves (this ‘isomorphic’ interpretation is vividly and compendiously presented in, for example, the Renaissance Conimbricenses commentary on the Organon). Still, even Aristotelians sensitive to the question ‘what are categories categories of?’, neglected the gulf which might separate our conceptual and linguistic resources from what really is: such isomorphism is viable only if grounded in a pre-modern assurance that an impersonal teleology or a divine providence secures and protects the fit between us and the world.

Kant’s transcendentalism attempts to redeem such hostages to scepticism. We might accordingly conceive of both theories of categories as intimately concerned with the relation of language or our conceptual equipment to the world. To the Kantian, Aristotle seems primitive because he naïvely fails to perceive the paramount challenge confronting philosophy; to the modern follower of Aristotle, the Kantian seems the decadent victim of unjustifiable doubts.