For Kant, the human cognitive faculty has two sub-faculties: sensibility and the understanding. Each has pure forms which are necessary to us as humans: space and time for sensibility; the categories for the understanding. But Kant is careful to leave open the possibility of there being creatures like us, with both sensibility and understanding, who nevertheless have different pure forms of sensibility. They would be finite rational beings and discursive cognizers. But they would not be human. And this raises a (...) question about the pure forms of the understanding. Does Kant leave open the possibility of discursive cognizers who have different categories? Even if other discursive cognizers might not sense like us, must they at least think like us? We argue that textual and systematic considerations do not determine the answers to these questions and examine whether Kant thinks that the issue cannot be decided. Consideration of his wider views on the nature and limits of our knowledge of mind shows that Kant could indeed remain neutral on the issue but that the exact form his neutrality can take is subject to unexpected constraints. The result would be an important difference between what Kant says about discursive cognizers with other forms of sensibility and what he is in a position to say about discursive cognizers with other forms of understanding. Kantian humility here takes on a distinctive character. (shrink)

In this chapter, I expound Hegel’s critique of Kant, which he first and most elaborately presented in his early essay Faith and Knowledge (1802), by focusing on the criticism that Hegel levelled against Kant’s (supposedly) arbitrary subjectivism about the categories. This relates to the restriction thesis of Kant’s transcendental idealism: categorially governed empirical knowledge only applies to appearances, not to things in themselves, and so does not reach objective reality, according to Hegel. Hegel claims that this restriction of knowledge to (...) appearances is unwarranted merely on the basis of Kant’s own principle of transcendental apperception, and just stems from Kant’s empiricist bias. He argues that Kant’s principle of apperception as the foundational principle of knowledge is in fact incompatible with his empiricism. Hegel rightly appraises the centrality of transcendental apperception for the constitution of objectivity. But he is wrong about its incompatibility with Kant’s empirical realism. By virtue of a misapprehension of the formal distinction between the accompanying ‘I think’, i.e. the analytical principle of apperception, and what Hegel calls “the true ‘I’” of the original-synthetic unity of apperception, Hegel unjustifiably prises apart the productive imagination, which is supposedly this “true ‘I’”, and the understanding, which is supposedly just a derivative, subjective form of the productive imagination; the latter, according to Hegel, is Reason or Being itself, and is the truly objective. This deflationary reading of the understanding, which hypostatises the imagination as the supreme principle, rests on a distortion of key elements of Kant’s theory of apperception. In this chapter, I show that Hegel’s charge of inconsistency against Kant, namely, Hegel’s claim that the principle of apperception as the highest principle of cognition does not comport with Kant’s restriction thesis, is the direct consequence of a psychological misreading of Kant’s subjectivism. (shrink)

In this chapter, I show that there is at least one crucial, non-short, argument, which does not involve arguments about spatiotemporality, why Kant’s subjectivism about the possibility of knowledge, argued in the Transcendental Deduction, must lead to idealism. This has to do with the fact that given the implications of the discursivity thesis, namely, that the domain of possible determination of objects is characterised by limitation, judgements of experience can never reach the completely determined individual, i.e. the thing in itself (...) or the unlimited real, but only objects as objects of possible experience. As such, it can be shown by reference to a key argument from Kant, that Hegel’s famous criticism that Kant is not licensed, on the basis of his core arguments concerning the original-synthetic unity of apperception, to restrict our knowledge to appearances, is mistaken on purely systematic grounds. More specifically, I argue that idealism follows already from the constraints that the use of the categories, in particular the categories of quality, places on the very conceivability of things in themselves. My claim is that, although it is not only possible but also necessary to think things in themselves, it does not follow that by merely thinking them we have a full grasp of the nature of things in themselves, as some important commentators claim we have. We must therefore distinguish between two kinds of conceiving of things in themselves: conceiving in the standard sense of ‘forming the notion of’, and conceiving in the narrow sense of ‘having a determinate intellectual grasp’. So although we must be able notionally to think things in themselves, as the grounds of their appearances, we cannot even conceive, through pure concepts, of how they are in themselves in any determinate, even if merely intellectual, sense. To put it differently, we cannot have a positive conception of things in themselves (this is in line with Kant’s distinction between noumena in the negative and positive senses; cf. B307–9). For support, I resort to a much overlooked chapter in the Critique, concerning the transcendental Ideal, where Kant discusses what it is for a thing to be a thing in itself proper, namely, something that is thoroughly determined. This concerns the real ontological conditions of things, which are not satisfied by the modal categories alone, namely, their existence conditions. I claim that the chief reason why, given Kant’s view of determinative judgement, we cannot determine a thing in itself is because of two connected reasons: (1) a thing in itself is already fully determined and therefore not further determinable and (2) we cannot possibly determine all of the thing’s possible determinations. In this context, I also discuss the notion of material (not: empirical) synthesis—of which Kant speaks in the chapter on the transcendental Ideal—which must be presupposed as the ground of the formal a priori synthesis that grounds possible experience. This material synthesis, which is an idea of reason that defines a thing as thoroughly determined with regard to all of its possible predicates and has mere regulative status, can by implication not be determined by the forms of the understanding, which synthesise only a limited set of predicates. As a result, given this definition of ‘thing in itself’, any object (appearance) as at best44 a limited set of determinations of the thing can never be numerically identical to the thing in itself as thoroughly determined individual. This undercuts a standard assumption about the identity relation between appearances and things in themselves in many contemporary interpretations of Kant’s transcendental idealism. (shrink)