This huge publication runs to 10 parts, 35 chapters and 1.47 kilos. It forms part of a series of Palgrave Handbooks in German Idealism, aiming at an overview of the major German idealist philosophers, their historical and philosophical importance and their critics. The goal set out by the series editor is comprehensiveness, accessibility, depth and philosophical rigour, offering both material for the student to enable understanding and for the advanced scholar to provoke new thinking. The Kant volume is the second in the series, and features a galaxy of international scholars as contributors, including familiar names such as Guyer, Walker and Wood, but also distinguished individuals of another generation. The quality of production is excellent, while the notes on sources and key to Abbreviations and the Chronology of Kant’s life are beautifully and clearly set out. (One puzzle for this reviewer though is the choice of cover illustration: Caravaggio’s 1607 painting of David with the Head of Goliath from the Kunsthistoriches Museum in Vienna.)

This volume begins conventionally enough with biographical background before moving to metaphysics and epistemology, logic, ethics, aesthetics, science, religion, politics, anthropology, affectivity and history. The book ends with the continuing developments and debates among contemporary philosophers. The goal of comprehensiveness is comfortably met and the calibre of its contributors amply assures the goals of depth and rigour.

I select a few chapters at random upon which to comment with a view to providing a flavour of the book.

Naragon’s account (chapter 2) of ‘Kant’s Life’ provides a concise account that divides between the pre-critical phase, with comment on its formative influences (identified especially as pietism), Newton and Rousseau. The impact of the thinking of Leibniz and Wolff or, in moral philosophy, that of the Scottish sentimentalists, receives less emphasis – appropriately occupying the next chapter by Sanchez-Rodriguez on Kant’s transformation of the Leibnizian-Wolffian philosophy. Here is an excellent example of how the book offers an integrated whole and not merely a series of isolated essays. But one must add that the third chapter is challenging to the reader in that it starts from the assertion that, even at the end of the eighteenth century, substantial and important early writings of Leibniz were still poorly known so we cannot be certain of Kant’s familiarity with all aspects of Leibniz’s thought. Kant’s knowledge of Leibniz was through Wolff and Baumgarten. Kant’s critical transformation of his view of Leibniz (that view being complicated by the need to interpret it through the views of others) was to provide an answer to British empiricism as well as a critique of metaphysics. The two Kantian works that are key to this chapter (besides the third Critique) are What Real Progress Has Metaphysics Made in Germany since the Time of Leibniz and Wolff? of 1793 and On a Discovery whereby Any New Critique of Pure Reason is to be made Superfluous by an Older One of 1790. Neither of these are the best known works in the Kantian corpus, and the reader would require previous knowledge of both Kantian reflective judgement and of Leibniz, Wolff and Baumgarten. This chapter appears aimed primarily therefore at the Kant scholar rather than the less-experienced student.

Guyer’s chapter (chapter 4) on ‘Transcendental Idealism: What and Why?’ is familiar ground for its author – few philosophers have written more commentary on Kant’s metaphysics. (His previous contributions on the deduction of the categories appear in at least two previous collections.) Here however, Guyer is concerned with transcendental idealism itself and the chapter achieves approachability and meets one of the claims of the book in offering a clear exposition to the student as well as a succinct summary for the more advanced scholar. Having offered a basic definition at the outset, Guyer discusses the ‘conceptual’ and ‘ontological’ approaches to transcendental idealism and whether things in themselves are, as he believes, non-spatiotemporal. On the conceptual approach, spatiotemporality is merely omitted. He makes the provocative comment that ‘it is better to correctly understand Kant’s doctrine and reject it than to defend it by misunderstanding it’ (pp. 75–6). This leads to a consideration of the arguments rather than a limited examination of terminology which is incapable of solving the question: he lists a number of quotations that illustrate this. Even the term ‘appearances’ is used ambiguously. Guyer will conclude that the things that necessarily appear to us spatiotemporally are not themselves spatiotemporal. He goes on to discuss his preferred argument of the several that Kant offers for transcendental idealism. Towards the end of the chapter he reminds us that holding things in themselves as the ground of our representations is a coherent claim but addresses the anxiety of some commentators that for Kant the influence of things in themselves upon our representations is such that he must assume a ‘noumenal causality’. But things in themselves cannot cause our representations because causation is a spatiotemporal relation based on succession in accordance with a rule: a simple but important reminder wherein causality exists.

Altman contributes the tenth chapter in giving ‘a practical account of Kantian freedom’, a challenge that Kant acknowledged was difficult (CPR, A543/B571). He begins by considering the uncaused cause and cause as a phenomenon. Altman points out that in the Groundwork Kant appeals to ideas of freedom whereas in the second Critique he appeals to a fact of reason. Our freedom, he says, is apparent when we deliberate about actions and become aware of moral constraint – a fact of reason of which we are immediately conscious (cf. 5: 32); and additionally it is freedom that enables us to think of ourselves as a priori causes: ‘We represent ourselves in terms of our actions as effects that we see before our eyes’ (Groundwork, 4: 450). After this brief exposition, Altman considers moral motivation. Respect for the moral law can function as an incentive and against motivational scepticism. Transcendental freedom is defined as the assumption of a causality undetermined by a previous cause – an absolute causal spontaneity beginning from itself. Having set this stage, Altman then moves on to argue that Kant can accommodate freedom and determinism with a practical account of freedom. Yet many think it is not clear how we can be practically and transcendentally free if causal determinism is true. However, he does not think that compatibilism is a satisfactory theory to account for Kant’s theory of freedom, despite the appeal of two different descriptions of a single action in physical and mental properties offered by compatibilists (cf. p. 222). The compatibilist’s view of causal determinism makes moral responsibility in the Kantian sense impossible. Objections are also found in so-called post-compatibilism, according to which human actions can be explained in terms of purposes rather than causes.

Again this links to a later chapter in the book (chapter 33), by Robert Hanna, whose argument runs from the premise that the activity of living organisms is non-conceptual. But Hanna’s claim that Kant is a non-conceptualist is rejected by Altman who objects that Hanna’s ‘self-organising thermodynamic systems’ are situated in time, whereas Kant believes the will to be outside time to avoid determinism. Perhaps, Altman suggests, quoting Allen Wood, Kant commits himself to ‘the compatibility of compatibilism and incompatibilism’, and Altman moves on to libertarianism (which claims that free will is compatible with determinism) and to relevant considerations of moral agency. For Altman, rational moral agency depends on a ‘corresponding unity of one’s actions as one’s own from moment to moment’ (p. 229). A rational moral agent must have some sense of past and future relating current actions to others. The self of moral agency, says Altman, has memory, character traits and the persistence of moral values. Moral agency thus links to personal identity.

I think it is clear that the complexities of the issues around freedom necessitate compressing several related views into a packed format. The chapter is one of the longest in the entire book and a fuller exposition would demand more space – and for this reader would have been welcome. It ends with a ‘practical account’ where it is argued that Kant addresses the problem of free will only by arguing a role for theoretical reason and practical reason to validate different things. The ‘practical account’ described is also called the ‘regulative idea theory’, the ‘deflationary view’ or a kind of ‘commitment theory’ by a number of other named commentators, but inevitably an exposition of these terms is brief and one is directed to the key publications in a footnote. The chapter ends by acknowledging that we cannot understand the possibility of freedom theoretically; rather, when we act, we make the unavoidable assumption that we must hold ourselves to account. Overall, this is a chapter that warrants repeated reading and careful study for the richness of its analysis.

Helga Varden tackles an uncommon subject for most Kant anthologies in chapter 15: that of Kant and sexuality. Kant is not the first philosopher to come to mind in considering this aspect of human experience, given his often negative and now strikingly offensive views. Varden, however, thinks Kant has something to offer. Her chapter opens with a series of questions – and still more questions as she analyses Kant’s account of human nature from perspectives of animality, humanity and personality: three dispositions that Kant asserts are ‘to the good (and that) demand compliance with it’ (cf. Religion, 6: 28). How does holding a stranger close at a time of distress, holding a loved one, a newborn or the cat fit into considerations of our sexuality for Kant? (Or at all?) It is difficult to see these actions as stemming from duty. Yet social animals benefit from affectionate care, although applying this to a predator (a lion, a rat) raises obvious debates on relevance to sexuality and human nature. Kant, avers Varden, believes our sexuality is procreative and therefore heterosexual: other forms of sexuality are ‘corruptions of our nature resulting from a propensity to evil’ (p. 343). Varden concedes that many scholars find Kant ‘deeply unconvincing’ in his views on sexuality. (This seems a rather mild way of expressing it.) Her response of seeking to analyse Kant’s broader moral thinking so that his angry homophobic account can be bypassed leads one to ask whether such an attempt is worthwhile. Why not admit that he simply demonstrates the beliefs of the time that (most of) Western society has rejected and move on? Kant offers not an ‘apparent heterosexism’ (p. 344), but a thoroughgoing one. Nevertheless, Kantian morality should have something to say about sexuality if Kant’s empirical assumptions are rejected. This is attempted in the final third of the chapter. This is more polemical, charging Kant that he should have been ‘much more careful than he was’ (p. 347). The chapter ends with a consideration of Kant’s Doctrine of Right and applies this to buying and selling sexual services, the state’s role in poverty relief, safe shelter, etc. It therefore moves away from philosophical discussion of sexuality itself into a wider societal perspective relating to Kant’s metaphysics. Its implications are far-reaching, controversial, polemical and important.

Chapter 23, by Lawrence Pasternack, offers an examination of Kant on faith: what constitutes religious assent on Kant’s view concerning the limits to knowledge? Starting with a reminder of Kant’s remarks on establishing the limits of knowledge ‘in order to make room for faith’ (Bxxx), Pasternack gives a welcome, if uncontroversial exposition of Glaube aided by a diagrammatic taxonomy. As he points out, Kant’s discussions of faith have been overlooked until very recently. Two questions are then addressed: first, what is wrong with religious knowledge; and secondly, what is it about faith that makes it, rather than knowledge, the proper mode of assent for religion? He notes that Kant rejects both reason and revelation as a basis for supersensible knowledge, emphasizing that Kant does not turn to faith because of the limits of knowledge, but rather asserts that it is for the sake of faith that we must place limits on knowledge. But how far is it true that faith can be chosen? Pasternack links this to the highest good, its postulates, the primacy of practical reason, Gesinnung and why ‘morality inevitably leads to religion’ (cf. Religion, 6: 8, n.). Perhaps the most interesting section of this chapter is his equation of historical and ecclesiastical faith and its contrast with a pure rational system of religion. Miracles and rituals are given a fair, if brief discussion; but Kant’s view of grace fails to feature – perhaps an editorial decision as it is examined in the following chapter by Martin Moors, titled ‘The Fate of Religion within the Boundaries of Mere Reason’. Pasternack’s chapter is a welcome addition to what is now a growing interest in this aspect of Kant’s output.

As a final comment, let me commend Michael Vater’s contribution on the Kantian aftermath (chapter 32). It is never easy to judge how much detail can be justified: a list of names or a text book of nineteenth- and twentieth-century philosophy and philosophers? I think Vater gets this about right: not all the post-Kantians get a mention, but then there do seem to be a lot of them, and the links to figures that a student may have encountered do fit into the story, emphasizing the continuing importance of Kant to the entire discipline of philosophy and its study.

Beyond the sample of chapters upon which I have commented above is the question for the reviewer of the overall purpose of the book. It is certainly not written for the novice Kant student who may seek guidance on a point of particular difficulty as they come to grips with the complexities of Kant’s argument. First of all, such a student should have achieved some understanding of Kant’s central themes; nevertheless it will be valuable as a reference when addressing an essay or dissertation topic demanded by a course of study. Its cost is also likely to be beyond the average undergraduate or newly graduate student. Its physical size makes portability difficult and presumably the publishers have considered the implications of producing it as a two- or three-volume paperback. But the Kant scholar will surely want to have this wonderful collection sitting in their personal bookshelf. There are great riches of Kant exposition and opinion here that will provide many years of delight.