Sally Sedgwick's Hegel's Critique of Kant is, in ways, a rescue project. Its targets are Hegel's objections to Kant's Critical system, which Sedgwick takes to be in need of rescuing from the grips of uncharitable interpreters and overzealous defenders of Kant. As such, that project is entirely successful. Sedgwick's interpretations of the nature and roots of Hegel's critique should be immediately adopted as the new standard line. While her arguments might not persuade (and are not aimed at) staunch advocates of uncharitable readings of Hegel, anyone interested in an interpretation that renders Hegel's claims as interesting and plausible challenges to Kant will gain a great deal from this book. The same goes for Kantians looking to defend the Critical system from Hegel's objections: the most plausible versions of those objections to date are here, and so such Kantians would do well to start directing their responses to Sedgwick's versions.

For the purposes of this review, I will focus my attention on tracing the main line of objection that Sedgwick portrays Hegel as presenting. This will mean skipping over the excellent work that Sedgwick does in the first two chapters of the book of arguing persuasively that Hegel's critique of Kant will not depend on any misunderstanding of Kant's texts, and of equally persuasively tracing the roots of Hegel's own solution to this critique to certain features of Kant's notion of an intellectual intuition.

Beginning in the third chapter, Sedgwick turns to Hegel's ultimate and most serious challenge to Kant's Critical system. She argues that rather than, as is typically supposed, finding some contradiction therein, Hegel's actual critique centres on an inadequacy of that system.

Obviously, the force of this critique will depend on the nature of subjective idealism and its consequences. Here is Sedgwick on the former:

Here the key to this characterization of subjective idealism lies in the nature of the contingency in the relation between concepts and sensible particulars. It is important to note, as Sedgwick does, that this is not the contingency that is opposed to the necessity of the categories. That necessity is the necessity of the categories as a precondition of experience itself. Insofar as experience is possible, it is only so because sensible particulars can be subsumed under the categories. The contingency with which Sedgwick's Hegel is concerned is found in the possibility of this relation itself, i.e. in the possibility of having sensible particulars that can be subsumed under the categories.

The idea is that while we can know that experience is only possible insofar as sensible particulars are subsumable under the categories, we cannot know that sensible particulars are always and everywhere susceptible to such subsumption. To put it diachronically, for all we know, the next sensible particular to be given might be so radically different from the ones that we have thus far encountered (but not experienced) that the categories simply could not be applied to it. In fact, for all we know, this has already been the case with indefinitely many sensible particulars, and thus our conception of the world might be radically mistaken, even with all that Kant has earned in the Deduction.

It is this radical sceptical conclusion that Sedgwick portrays as the real focus of Hegel's critique. As Sedgwick astutely points out on Hegel's behalf, however, this conclusion does not follow merely from the assumption that conceptual form is the contribution of the subject of experience. For the sceptical conclusion to follow, one must make an additional substantive inference, one that Sedgwick finds Kant making.

Again, we have to be careful here to understand the charge in the correct way. Sedgwick is not casting a critical eye on Hegel's behalf towards Kant's empirical realism. The charge is not that Kant gives us any reason to be sceptical about the applicability of the categories to all and only objects of possible experience. The worry is instead about the possibility that even in so applying the categories our cognition might be radically misrepresenting the nature of reality (things-as-they-are-in-themselves).

As Sedgwick points out, this is a conclusion with which Kant is perfectly content. He does not see anything sceptical about it, but takes his own critique to reveal that the categories, along with our forms of intuition, are the necessary preconditions of possible experience, and that the hope for a more robust correspondence of representation with reality is the mistaken expectation of the transcendental realist.

It is Sedgwick's Hegel's contention, however, that Kant ends that critique too hastily. What Kant overlooks is precisely his own assumption that, because the concepts used to shape experience are contributed by the subject, these concepts cannot be supposed to reflect reality itself. Sedgwick portrays Hegel as driven to discover what it would mean for this assumption to be false, and what he finds is that it requires understanding the experiencing subject itself as dependent on reality for its concepts.

As Sedgwick puts it elsewhere, this is the thesis that the synthetic unity of apperception, that which is responsible for the original synthesis that makes experience possible, is itself not a product solely of the understanding (as Kant would have it), but also of sensibility. Or better, that it is a product of a faculty from which the notions of spontaneity and receptivity are themselves abstracted.

So Sedgwick understands Hegel's objection to Kant as tracing the following (schematically reproduced) dialectic.

1. (a) Kant takes the synthetic unity of apperception to be the ultimate source of the categories.

2. (b) Kant also takes the synthetic unity of apperception to be a product solely of the understanding.

3. (c) Hegel objects that so conceiving of the synthetic unity of apperception overlooks the essential historicity of the experiencing subject, and thereby also its determination by nature or reality itself.

4. (d) This historicity and determination by reality implies that the synthetic unity of apperception, the understanding and the categories, are all themselves products of, or sensitive to, or determined just as much by, sensibility as by understanding (or by a faculty that is the original source of the abstractions ‘sensibility’ and ‘understanding’).

Notice this list of alternative idioms in the final rendering of Hegel's thesis. It is not for lack of a proper locution that I have resorted to providing such a list. Instead this is a reflection of what I am still left puzzled about after having followed Sedgwick through her otherwise excellent presentation of Hegel's critique. I am left with the question: what does it mean to say that our concepts depend on sensible content for their nature (and in such a way that those concepts end up ‘reflecting’ the nature of things-as-they-are-in-themselves)?

The most straightforward reading of that dependence would make use of Kant's notion of the dependence of cognition on sensibility. That reading would lead to the interpretation that the understanding depends on sensible particulars in the same way as sensibility does. This, however, is precisely the notion that Sedgwick rules out. Hegel's objection to Kant is that his account of what is given in experience by sensibility is untenable. Hegel certainly doesn't mean for us to simply include concepts along with intuitions as given (and Sedgwick is repeatedly clear on this point). Rather, he wants us to rethink the very notions of ‘sensibility’, ‘givenness’, ‘understanding’, etc. Unfortunately, Sedgwick doesn't here tell us what Hegel takes that rethinking to yield. The most she offers is a footnote discussing Pippin's ‘Leaving Nature Behind, or Two Cheers for Subjectivism: On John McDowell’ (Pippin Reference Pippin2005: 186–220):

While this certainly points to a reading of Hegel's ultimate articulation of the overlooked possibility that he finds in Kant, and one that will be familiar and plausible to contemporary scholars working on Hegel, in a book with so much rigour and detail elsewhere it is surprising how little Sedgwick has to say on this topic, the possibility of which ultimately constitutes the entire force of Hegel's objection to Kant as Sedgwick understands it.

Lastly, Sedgwick's final two chapters make it clear that while Hegel is, in general, concerned with certain blind-spots that he thinks plague Kant's Critical system as a result of the necessary historical situatedness of any self-reflective project, this general concern serves more concretely as a call for specific investigations into where Kant might be unwittingly smuggling content into what he (Kant) takes to be merely formal (and thereby a priori and necessary and universal) philosophical claims. The last chapter itself is dedicated to one such instance: Hegel's critique of Kant's solution to the Antinomies.

Given Sedgwick's keen clarifying eye and talent for making obscure and implausible-sounding claims of Hegel's transparent and plausible, this chapter was a bit of a disappointment, as Sedgwick rests content with Hegel's claim that Kant overlooks the possibility that the contradictions generated by the Antinomies are not mistakes of human reason, but instead reveal that ‘everything real contains in itself contradictory determinations’. One would have hoped for a more robust interpretation of Hegel's objections than: Kant ‘presupposes’ that two contrary propositions cannot both be true. Then again, the general form of this line of response is unsurprising insofar as Sedgwick's Hegel's main line of attack on the Critical system is that it neglects the possibility that human reason is itself one of ‘nature's products’ and its representations are reflections of this very nature.

In closing it is worth reiterating that the overall clarity and plausibility that Sedgwick brings to the roots, structure and nature of Hegel's critiques of Kant here are going to prove a boon to anyone working in this area.