Like any other great thinker in the history of philosophy, Kant has been the subject of so many commentaries that the original texts and context in which they were written seems lost. Rather than expositing the texts and uncovering the meaning of what they say, commentaries become comments on other commentaries. As a result, commentaries lose their original purpose and become a barrier, not only between the reader and the philosopher but, even worse, between the reader and his or her own thinking.
Against this background it is highly welcome that Kenneth R. Westphal has written a book on Kant’s Transcendental Deduction of the categories that promises to unburden itself from the ‘commentary genre’ (p. 1). Westphal expresses his own frustration with the state of the debate on Kant’s Transcendental Deduction in the introduction of his book (section 1). On one hand, the issues that Kant deals with should provide important insights to issues debated in contemporary philosophy and cognitive science. On the other hand, these insights are clouded by so much misunderstanding that everything of value seems to have gone to waste, and this in spite of the abundant commentaries provided by Kant scholars.
Removing these misunderstandings and presenting Kant’s insights so that they can serve the contemporary debates in philosophy and cognitive science is Westphal’s overarching aim. To this end Westphal declares that he wants to provide a commentary that engages directly with the text – a fresh start. ‘Fresh’ in the literal sense that it contains a new translation of the B-edition of Kant’s Transcendental Deduction, but fresh also in the sense that it puts the scholarly debate in the background – for the moment at least. The shortness and text-focused ambitions of Westphal’s book also enable him to present his translation next to Kant’s original text, with his commentaries (‘elucidations’) on facing pages. This makes it easier for the reader to compare Westphal’s commentaries with what goes on in Kant’s own text, setting the stage for a kind of trialogue between Kant, the reader and Westphal.
Providing a commentary that is text-oriented and consciously disengaged from previous commentaries is less easy than it sounds and takes a lot of self-discipline. In Westphal’s case this means resisting the temptation to make cross-references to other parts of Kant’s Critique of Pure Reason, in particular the A-edition of the Transcendental Deduction. It also means putting his own previous studies of Kant within brackets and not engaging with contesting commentaries, like those of Guyer (Reference Guyer1987) and Howell (Reference Howell1992) among others, which are less convinced about the value of Kant’s achievement.
Westphal also openly declares that his approach involves setting aside issues, some of which are rather controversial. To these issues belongs the thesis that Kant’s philosophy is independent of his transcendental idealism. The specialist will of course easily recognize the significance of this claim, but a student of Kant might need some further elaboration to understand what is at stake here. Fortunately for his readers, Westphal does not just assume that his independence-thesis applies to the Transcendental Deduction. On the contrary, he explains that his comments aim to show that the Transcendental Deduction can and must be understood ‘without appeal to transcendental idealism’ (p. 3). Far from being a settled premise of Westphal’s commentary the application of the independence-thesis becomes a reoccurring topic, not only in Westphal’s remarks on the explicit assumptions of his reading (section 2), but also in the very commentary itself (section 3) and partly also in the two concluding essays (sections 4 and 5) on space and time, and perceptual judgements respectively.
The key to Westphal’s reading here is his cognitive-semantic interpretation of Kant’s distinction between sensibility and understanding (pp. 8–11). Sensibility provides us with sensory intuitions oriented towards the spatiotemporal particulars they present (p. 31). However, in order to know and thus demonstratively refer to some definite spatiotemporal particular, this particular needs to be identified and brought in relation to the transcendental unity of self-consciousness/apperception (‘I think’; B132) so that it can be thought, which is an achievement of understanding (pp. 8–9, 35, 37, 73). This involves the possibility of applying sortal concepts to any determinate, putative object of demonstrative reference and property ascription (pp. 19, 21, 25, 83, 89). Finally, since these sortal concepts are nothing but specifications of categories, this goes to show that categories apply to any object of sensory intuition that can be known in a judgement (pp. 37, 89). The aims of Kant’s Transcendental Deduction are therefore perfectly understandable in terms of epistemic presuppositions of valid object recognition and cognitive judgements, rather than conditions of object generation (as with transcendental idealism) (pp. 10–11, 25–7, 35). Experiential judgement involves demonstrative references to sensibly given objects that our sensibility cannot present except as spatiotemporal particulars. However, none of this entails that space or time are mere features of our sensibility or that general kinds or laws are mere products of our understanding.
Westphal’s cognitive-semantic interpretation of Kant’s aims reverberates throughout his choices of issues to put in the foreground of his comments. This explains, for instance, why issues of reference and property ascription are urgent matters of commentary for Westphal, but issues of ontology and cognitive psychology not so much. Westphal is of course entitled to make the choices he finds necessary for his comments, but this freedom also restricts his ability to address passages in which Kant focuses on cognitive processes (pp. 77, 85). In particular, the latter part of the B-edition of the Transcendental Deduction (§§21–7; B144–69) contains many passages in which Kant clearly indicates that considerations of perceptual processes are important for the completeness of the Transcendental Deduction. Perceptions are the outcome of a ‘synthesis of apprehension’ (B160) that coordinates the manifolds of sensory intuition. The relevant point here is that this synthesis, surprisingly, only produces perceptions that extend to putative objects of categorical identification. To see why, Kant underlines that a successful synthesis of apprehension cannot form a stable image of an enduring object, unless it coordinates the purely temporal (and spatial) manifold of the sensory intuition. This ‘figurative synthesis’ (B151) belongs to imagination and is a transcendental act subject to laws of understanding, which brings it in relation to the (synthetic) unity of apperception (B150–2). However, the latter is exactly what makes all perceived objects into candidate objects of valid judgements under the categories. Indirectly, it suggests that all possible objects of perception are products of processes in which the understanding plays an integral and justificatory part.
Westphal’s intellectual honesty forbids him from just ignoring the explosive potential of these suggestions. Instead, he tries to defuse them by arguing that perceptual processes are irrelevant to settling the issue of the reality of the categories (pp. 67, 69). Rather, for this end it is enough to show that categories are necessary to identify and think the spatiotemporal particulars that sensory intuitions present to us (pp. 9, 27, 89, 91). Though the valid use of the categories puts ‘constraints’ on these particulars, it is beyond the scope of the Transcendental Deduction to deal with these constraints and investigate if any object satisfies them (pp. 23, 57, 85, 89, 91). Naively stated it means that when I have gone through the arguments of the Transcendental Deduction, I will know why I cannot think a perceived object, like the white house outside my window, except under a category, for instance the category of quantity. I also happen to perceive the house as a quantity enduring a number of times, but none of this follows from conditions of thought. Hence, according to Westphal there is nothing in the Transcendental Deduction per se which suggests that the de dicto necessity of the categories has power to reach out to the temporal manifold of the contingent particulars I perceive. However, in fact Kant does not admit any such open ends; for the Transcendental Deduction to be successful, it must show that particulars cannot be perceived unless they are necessarily determined in time (and space) according to laws under the categories. Thus, the only thing left open for further investigation is the systematic exhibition of these spatiotemporal determinations (the transcendental schemata; A137–47/B176–87) and their corresponding laws (the principles of pure understanding; A148–235/B187–294).
In sum, Westphal’s approach results in a rather favourable assessment of Kant’s Transcendental Deduction, a ‘corroboration’ as the very title of his book signals. But it must be kept in mind that this assessment rests on a rather deflationary reading, which is a reflection of Westphal’s independence-thesis. This results in a somewhat ambiguous account of what Kant’s Transcendental Deduction really amounts to. On the one hand, it promises that I cannot think and demonstratively refer to an object except under a category, but on the other hand it leaves it entirely open whether a particular could be experienced without a proper use of the categories. Though Westphal declares that it is his ambition to provide an independent commentary, it is in reality subordinated to the ambition of fulfilling the ‘critical interpretative obligations’ (p. 2) of his prior works (Westphal Reference Westphal2004, Reference Westphal2020). It is also here that Westphal shows where his true commitment lies, namely to bring about a serious dialogue between classical German philosophy and contemporary analytic philosophy and cognitive science. Reading Westphal’s book is to incline one’s ear to this dialogue.
