Julian Wuerth’s Kant on Mind, Action, and Ethics is a major study of Kant’s views on the nature of the mind. Wuerth’s primary aim is to show that Kant accepted a robust, complex metaphysical view of the mind in his mature theoretical and practical philosophy. In support of this aim, Wuerth offers an extremely detailed reading of many of Kant’s overlooked texts, in particular, the student notes on lectures he gave throughout his career. Out of these hundreds of difficult pages of primary text, he assembles a ‘map of the mind’ that identifies what Kant saw as our fundamental capacities. In our estimation, most of Wuerth’s central claims are correct, and his book presents a serious challenge to anti-metaphysical and metaphysically simple readings of Kant.
The virtues of Wuerth’s detailed textual arguments are difficult to capture in a short review. Instead, we will describe the main claims of each chapter of the book and offer some critical remarks.
Chapter 1 is an extended critique of Patricia Kitcher’s early work on Kant. Wuerth’s real focus, though, is on showing that Kant regarded the soul as a simple, noumenal substance, contra anti-metaphysical interpretations like Kitcher’s. A major motivation for Kitcher’s reading was the view that, in the Critique, Kant aimed to give a non-question-begging refutation of Hume’s view of the soul as a bundle of ideas or modes. Wuerth argues that Kant had no such concern, and that his reliance on pure apperception (distinguished from inner sense) shows that he had no doubts that we are directly aware of the self as a substance that cannot be reduced to mere modes or accidents.
In chapter 2, Wuerth continues this line of thought by examining Kant’s pre-Critical discussions of our awareness of ourselves as simple substances. He takes Kant to find a middle course between the rationalist and empiricist traditions on this topic by positing a ‘pseudo-empirical’ immediate self-awareness. This awareness, though, is wholly indeterminate, involving only (in the terms of Kant’s mature philosophy) unschematized categories. This awareness is the basis, Wuerth claims, of Kant’s argument that any unity of thoughts requires a unified substance.
Chapter 3 turns to the connections between this view of self-awareness and idealism in Kant’s pre-Critical thought. Wuerth argues that the core of Kant’s idealism, which emerges well before the Critique, is the ‘contribution thesis’, according to which any affections substances have because of interaction are shaped by both their own passive capacities and the active capacities of external things. This shaping precludes our having fully direct perceptions of other things. Yet our self-awareness need not involve interaction, and so in this case alone can we have straightforward epistemic access to a noumenal substance.
Chapter 4 concerns Kant’s pre-Critical arguments against rational psychology. Kant never, Wuerth argues, denies that we have immediate awareness of ourselves as noumenal substances. Instead, he argues, Kant’s focus is on the way the rational psychologists ascribe permanence (and so immortality) to the soul. In fact, Wuerth claims, Kant holds that the self is our paradigm of substance. The mistake Kant diagnoses is the conflation of noumenal substance with phenomenal substance, since only the latter can be known to be permanent.
The longest chapter of the book, chapter 5, aims to show that Kant’s mature views about the metaphysics and epistemology of the soul are, in their essentials, continuous with the pre-Critical views described in the earlier chapters. This includes the claim that pure self-awareness is the origin of our concept of substance. Part of Wuerth’s strategy for showing this continuity is to argue that Kant continued to talk of our immediate awareness of ourselves as simple, noumenal substances (in an ‘ontologically-significant sense’) well after the publication of the Critique. Wuerth expands on the noumenal/phenomenal distinction in conjunction with Kant’s distinction between understanding and sensibility, and gives some details about the relevant sense in which our self-awareness is indeterminate. The chapter also discusses some striking passages in which Kant describes the relation of the soul to the observable nervous system. It concludes with a discussion of the Paralogisms, largely centred on showing that Kant’s metaphysical commitments there go beyond even those ascribed to him by Karl Ameriks.
In chapter 6 Wuerth gives the reader a very detailed account of Kant’s theory of the mind and all of its faculties, sub-faculties, their powers and accidents, and how they relate to one another. Wuerth is eager to remind us here that the faculty of cognition is not, as is often supposed, the only faculty of the mind. He argues that there are two other faculties (desire, pleasure and pain) distinct not only in degree but in kind. The distinction between higher and lower faculties is presented and unpacked here as well.
In chapter 7 Wuerth’s aim is to put the map of the mind elaborated in chapter 6 to work. His target here is Henry Sidgwick and his criticism of Kantian ethics. Sidgwick thought that Kant’s identification of the I that chooses with pure practical reason makes it unintelligible how we could be morally responsible for immoral choices. Wuerth uses the last chapter’s findings to argue that Kant made no such identification and that Sidgwick’s criticism is misplaced. He also notes that many prominent commentators have supposed that by the late 1790s Kant had made the requisite distinctions to render himself immune from Sidgwick’s criticism. Wuerth agrees, but goes further and maintains that, even by the time of the Groundwork, Kant had all the pieces in place to defend himself from this charge.
By chapter 8 Wuerth has his sights on Christine Korsgaard. His concern is that Korsgaard’s interpretation of Kant and consequently her own ethical theory are open to the same criticism that Wuerth had just defended Kant from in the last chapter. Korsgaard does not note Kant’s distinction in kind between sensible desires and intellectual desires, according to Wuerth. The result is the attribution to Kant of the sort of confusions of the intelligible with the sensible that he was trying to combat in the Amphiboly chapter of the first Critique. Wuerth maintains that Korsagard’s ‘intellectualized’ picture makes no room for the possibility of knowingly committing an immoral action.
Chapter 9 focuses on Korsgaard’s metaethical anti-realism, according to which moral value arises from an implicit assumption of the value of agency. Wuerth counters that Kant’s position is that we have cognition of antecedently existing moral truths, such as the value of humanity. Wuerth takes issue with Korsgaard’s regress interpretation of Kantian ethics. According to this interpretation, Kant grounds his moral philosophy in an argument that it is incoherent not to recognize the value of humanity. Wuerth’s own position is that Kant’s concern was not with coherence and that immoral choices can be fully coherent.
Most of Wuerth’s arguments struck us as convincing. However, we would like to briefly note five concerns.
First, Wuerth claims that he is responding to a gap in the literature. However, a number of the claims he advances have been defended by others in the past decade. He discusses only one piece of literature published after 2005 (a 2010 article by Ian Proops). What makes this particularly odd is that large portions of his book contain detailed discussions of early works by scholars (such as Patricia Kitcher, Wayne Waxman and Christine Korsgaard) who have since published extensively on the relevant topics. Yet Wuerth says nothing about their more recent work, and almost nothing about the criticisms other scholars have made along similar lines to his.
Second, unlike some other recent commentators, Wuerth has relatively little to say about Kant’s predecessors. That is not a problem in itself, given his aims. There are points, however, where Wuerth seems to rely on traditional but problematic stories of Kant’s relation to previous philosophers. For instance, chapter 2 argues that Kant steers a course between empiricist and rationalist views of self-knowledge. The account of self-knowledge Wuerth ascribes to Kant, however, comes very close to that of (e.g.) Leibniz in the New Essays, who also claims that we form the idea of substance through immediate self-awareness (Leibniz Reference Leibniz1996: 51–3). Insofar as Kant’s views of the mind were formed in reaction to his predecessors, there is room to worry that Wuerth has overlooked some crucial details behind Kant’s motivations.
Third, Wuerth’s survey of the textual support for a metaphysical reading of Kant on the mind is impressive. He gives relatively little attention, however, to the passages in Kant’s published works that have motivated anti-metaphysical readings. For example, he reads Kant as saying that the self is the origin of our concept of substance, yet says nothing about the derivation of this concept and other categories from forms of judgement in the Metaphysical Deduction of the first Critique. Nor does he directly discuss Kant’s apparent claims that the representation ‘I’ is a mere form, or that the categories are meaningless if applied to things in themselves. Without explaining how such passages can be read in metaphysical terms, Wuerth’s argument remains vulnerable to a straightforward objection. An advocate of an anti-metaphysical reading might grant that Kant regularly made metaphysical statements when lecturing to his students, but insist that the Critique must be taken as the decisive statement of Kant’s views.
Fourth, Wuerth takes Kant to be saying both that (a) we are aware of ourselves apart from our determinations/accidents in a way that is unfit to yield knowledge and (b) we derive the category of substance from this awareness. There is a tension between these two claims. How can we be aware of a thing apart from its determinations and still end up with some kind of awareness as to how the thing is? It is hard to see how this sort of awareness can be both bereft of epistemic goods and furnish us with the paradigm of a central metaphysical concept.
Fifth, our final worry concerns the accuracy of Wuerth’s construal of Korsgaard’s position. He seems to be saying that Korsgaard is committed to the view that the only actions we can rationally choose are in accordance with the moral law. This seems to be a caricature of Korsgaard. She certainly is committed to saying that having any practical reasons at all presupposes moral obligations to humans qua humans. But in Sources of Normativity she is quite clear that not only do we in fact have practical reasons other than moral obligations, it is incoherent to maintain that all obligations are moral obligations (Korsgaard Reference Korsgaard1996: 125).
In closing, we want to emphasize the value of Wuerth’s book. It offers a detailed, textually grounded argument that should be carefully considered by anyone interested in understanding Kant’s view of the mind.