This collection of papers discusses a series of issues that constitute what Stern calls the ‘spine’ of Kantian ethics: obligation, value, agency, autonomy and rationality (11). The first part of the book focuses on these issues within Kant’s ethics itself and in conversation with contemporary debates about realism and constructivism, and internalism and scepticism. The second part investigates how some subsequent philosophers have received Kant’s ethics and approached these issues in their own work. Stern is a close reader and a nuanced and resourceful interpreter of these texts. While I have reservations about some of the central theses of the book, I would highly recommend it to anyone interested in Kant’s ethics and its reception in the German Idealist, British Idealist and contemporary traditions.

Stern introduces his collection of essays with a discussion of the problem that obligation poses for Kant’s ethics of autonomy (1). The problem is this: it is maintained—by Schopenhauer and Anscombe, amongst others—that the concepts of duty and obligation only make sense within a theological context, where a superior and independent lawgiver, God, issues moral commands to inferior and dependent human beings, backed by rewards and punishments. However, acting morally for the sake of gaining reward or avoiding punishment is heteronomous. How then is it possible to combine these two fundamental concepts of Kant’s ethics: obligation and autonomy?

In Chapter 1, Stern develops a reading of Kant’s account of moral obligation that aims to address these concerns. Stern argues that Kant explains moral obligation by contrasting the finite human will, which is subject to obligation, with the perfect holy will, which is not. A holy will necessarily acts in accordance with the moral law because it lacks any sensuous nature that would oppose morality. By contrast, a finite will has sensuous dispositions or inclinations that oppose morality, which explains why it must be constrained or necessitated to act morally. Kant’s solution to the problem of obligation is his doctrine of the autonomy of the will. The ground of obligation is neither an external divine will, nor an obscure value built into the nature of things, but the finite agent’s own intelligible, noumenal, autonomously law-giving will. The agent’s own will takes the place of God’s will in obligating that same agent’s will qua sensible, phenomenal and affected by inclinations (18–19, 86–88).

Stern then shows how his account of obligation can be used to address the realism/anti–realism debate in current Kant scholarship. Stern attributes to Kant a ‘hybrid view’ that plays a key role in much of the rest of the book. On this view Kant walks the line between realism and anti–realist constructivism: he is a value realist, where moral facts about the right and the good obtain ‘independently of human attitudes, responses or choices’, but an obligation anti–realist, where a finite agent is obligated ‘precisely because of these attitudes, responses or choices’ (31). Stern bases his attribution of value realism to Kant on his claim that not even God could choose the content of the moral law, so its content ‘obtains independently of any relation to an agent’ (32). He also appeals to Kant’s description of rational beings existing as ends in themselves (32–33).

By contrast, Stern argues that his account of Kant’s views on obligation shows that it is not independent of human attitudes, responses or choices, but rather that ‘we give the content of morality its obligatory form, insofar as this depends on our limitedness as finite creatures, so that this obligatoriness is just the way in which what is right and wrong presents itself to us’ (33). The virtue of Kant’s hybrid view, Stern contends, is that its value realism avoids the arbitrariness that threatens anti–realist constructivism, while its obligation anti–realism avoids the metaphysical ‘queerness’ of intrinsically normative entities. These are significant dialectical advantages, but, as I shall explain in my critical comments below, this interpretation has difficulties both philosophically and as an interpretation of Kant.

In Chapters 2–5, Stern provides an interesting and instructive engagement with Christine Korsgaard’s constructivist interpretation of Kant’s ethics. In Chapter 2, he argues that Korsgaard’s claim that realism is incompatible with autonomy fails against his hybrid view of value and obligation, so it cannot be used as an argument for constructivism and value anti–realism (54–56). Chapter 3 considers Korsgaard’s much-discussed and much-criticized transcendental argument for the value of humanity as an end in itself. Stern argues that if one accepts Korsgaard’s value anti–realism, then her argument is more plausible than has been acknowledged in the literature (72–73).

Stern’s discussion of Kantian and Korsgaardian responses to H. A. Prichard’s worry that much ethical theorizing is based on a mistake, in Chapters 4 and 5, is one of the highlights of the book. Prichard’s concern is that attempts to justify moral claims to the moral sceptic would have to appeal to non-moral concerns, so that the moral action done for these non-moral reasons would, in Kant’s terms, be in conformity with duty, but not from duty, and thus lack moral worth (76). Stern offers a careful and penetrating discussion of the various forms of scepticism toward which Kant’s and Korsgaard’s views could be directed and whether their anti–sceptical arguments would violate Prichard’s restrictions on moral justification.

In Chapter 4, Stern claims that Kant develops his hybrid view of value and obligation to engage transcendental sceptical concerns about the very possibility of morality and obligation from within the moral point of view, and not to try to lure the amoralist into being moral. This opens up the possibility that Korsgaard’s ‘normative question’ might be able to avoid Prichardian objections by being directed toward such a transcendental form of scepticism.

In Chapter 5, Stern examines Korsgaard’s claims that Kant’s argument for the Formula of Humanity formulation of the categorical imperative (FH) is an anti–sceptical argument that demonstrates the advantages of constructivism over realism in dealing with scepticism. Stern provides a detailed reading of Kant’s text to invert Korsgaard’s argument: there is no anti–sceptical argument in Kant’s discussion of FH, so the text provides no grounds for reading Kant as a constructivist rather than a realist. He then argues that Kant’s text shows that he argues more in line with the value realism that Stern favours: Kant presupposes the validity of the categorical imperative and the moral point of view, and then concludes that it is our value as rational agents that lies behind this moral point of view (103).

In Chapters 6 and 7, Stern makes use of his hybrid view to analyse the principle ‘ought implies can’ that is often attributed to Kant. Stern distinguishes between a strong reading of the claim, on which our capacities put constraints upon what is valuable (right or good), and a weaker view, where what is valuable is determined independently of our capacities and what is obligatory depends upon our capacity to fulfil our obligation. He then argues that only the weaker view can be ascribed to Kant, so that the content of the moral law is determined independently of our capacities, while the content of our obligations is not. Stern sees this result as reinforcing his hybrid account of value and obligation (7). Finally, in Chapter 7, he looks at the various ways in which the ‘ought implies can’ principle can be justified within different theories of obligation.

The second part of the book traces Kant’s influence and reception in subsequent philosophers. Chapters 8 to 11 look at how Kantian themes manifest themselves in the German and British Idealist tradition, with articles on Hegel, T. H. Green, and F. H. Bradley. Chapter 8 offers a new and interesting take on an old debate: Hegel’s ‘empty formalism’ objection to Kant’s formula of universal law formulation of the categorical imperative (FUL). Stern argues that Hegel’s real point here is not that Kant’s FUL formulation of the supreme principle of morality is empty, but rather the particularist objection that the search for such a supreme principle of morality is misguided.

Chapter 9 raises Prichard’s question about the viability of ethical theorizing again, this time regarding the ethical views of Hegel, Green and Bradley. Stern argues that Green’s view faces difficulties avoiding the charge that it provides non-moral reasons to be moral (158), whereas Bradley and Hegel have the resources to address Prichard’s concern (167). Chapters 10 and 11 provide enlightening discussions of the accounts of obligation and perfectionism in Green and Bradley. In his discussion of obligation in Chapter 10, Stern makes use of his ‘hybrid view’ interpretation of Kant to shed light on obligation in Green and Bradley. He argues that Green’s account of obligation resembles Kant’s hybrid view of obligation (182), whereas Bradley’s view resembles Hegel’s ‘social command’ account of obligation (186–87). Chapter 11 discusses how Green and Bradley developed different accounts of perfectionism in the wake of Kant’s critique of that position. These chapters will be especially interesting to Kantians and Hegelians wishing to familiarize themselves with the work of the British Idealists within the context of those traditions.

The remaining chapters of the book are more loosely connected to the rest of the book, but still contain interesting insights on William James’s and Kant’s arguments for freedom (Chapter 12), Løgstrup’s claim that Kant’s focus on duty distorts his conception of a virtuous agent (Chapter 13), and the divine command theory in conversation with Stephen Darwall and G. E. M. Anscombe (Chapter 14).

One cannot help but be impressed by the interpretive acuity and argumentative dexterity with which Stern engages the various texts and positions in this collection of papers. However, as I mentioned above, I do have concerns about some of the central claims of the book, specifically Stern’s account of obligation and the ‘hybrid thesis’ in Kant. In Chapter 1, Stern claims that Kant invokes the distinction between a holy will and a finite will to explain obligation. Finite agents experience morality as involving obligation, constraint and necessitation, and holy wills do not, because finite agents have dispositions and inclinations that run counter to morality, whereas holy wills do not (and cannot). However, this appeal to inclinations cannot be an explanation of obligation, but rather an account of the obstacles that oppose an agent’s efforts to act upon an already given obligation. Stern’s proposed account of obligation presupposes that the moral law ‘holds’ universally, that is, that it determines both holy and finite wills necessarily (17), and then explains why this determination is realized as a necessitation and a constraint in a finite will, but not in a holy will. The question is, however, what it is for the moral law to ‘hold’ for a finite will in the first place. What is it that constitutes the necessitation relation?

In order to see this problem more clearly, we can turn our attention to what such an account of obligation would involve from a Kantian perspective. Stern is correct to focus on the Groundwork, where Kant formulates the problem of the possibility of an imperative in terms of how the necessitation of the will that the imperative expresses must be conceived: ‘This question does not inquire how the performance of the action that the imperative commands can be thought, but only how the necessitation of the will, which the imperative expresses in the problem, can be thought [or conceived, or made sense of: gedacht]’ (Groundwork 417 cited on 18 in Stern). According to this passage, an explanation or account of obligation would be an account of how the necessitation of the will can be conceived.

A natural expectation at this point would be a detailed account of the constitutive components of this necessitation relation—both the relata and the relation itself. First, how must an absolutely necessitating law be conceived? What is its content? What property is it in virtue of which law necessitates the will? Second, how must an absolutely necessitated will be conceived? What kinds of capacities, dispositions, incentives and representations does it have, qua necessitated? Third, how should this necessitation relation itself be conceived? Is it a logical constraint of consistency on (universalized) maxims? Is it a causal relation that brings about an incentive to obey it in the agent? Is it some kind of sui generis rational relation?

Stern discusses aspects of Kant’s solution to this problem at various places in his book. For instance, in his discussion of necessitation, Stern cites the Groundwork (Ak. 4: 454–55), where Kant appeals to the distinction between an intelligible law-giving will, which does the necessitating and obligating, and the sensible will, which is necessitated and obligated (Stern 18, 86). He also discusses how the necessitated agent necessarily represents rational nature as an end in itself (98–103), and is necessarily motivated to fulfil its obligations (34–39). However, these elements should ideally all be part of an explanation of what constitutes necessitation and obligation, and not subsequent additions and elaborations in other contexts.

Most importantly for Stern’s own purposes, his account of obligation must explain why the agent’s law-giving intelligible will has the authority to play this necessitating role in relation to the sensible will. If the agent’s own law-giving will is supposed to replace God’s will as the ground of obligation, must not this legislative will be holy as well? If not, that is, if it were possible for the legislative will to act non-morally, then it is difficult to understand how it could have the authority to ground an unconditioned necessitation of the sensible will. A non-holy legislative will could only necessitate under the condition that it is necessitating the sensible will to act according to, and not against, the moral law, but this is no longer unconditioned necessitation. But if it must be holy, then its necessary conformity to the moral law and consequent value would explain its necessitation of the sensible will, and not the agent’s attitudes and choices. And this would appear to render a realist account of obligation, where real value grounds and explains obligation and our attitudes about it.

These observations show that the difficulties with Stern’s account of obligation have consequences for the hybrid view of value and obligation that he attributes to Kant. On this view, Kant is a value realist in the sense that the content of the moral law, what is right and what is good, obtains ‘independently of human attitudes, responses or choices’. Stern is an obligation anti–realist in the sense that a finite agent is obligated ‘precisely because of these attitudes, responses or choices’ (31). In most passages, Stern is consistent in describing the obligatoriness of conforming to the moral law in an anti–realist fashion: as ‘a kind of projection of the fact that the subject’s desires set themselves against the moral course of action’ (86), ‘given what we are, the moral law is a command to us: but that is (so to speak) a fact about us, rather than a fact about the moral law, that it must be such that it can be commanded to human agents’ (118), ‘the moral law engages with us (tells us what to do) because it fits with our capacities’ (119).

For all its dialectical virtues, the hybrid view faces substantial philosophical and interpretive difficulties. Philosophically, the independent accounts of value and obligation make the link between unconditioned value and unconditioned obligation mysterious. If obligation is the result of a mere projection of our desires, attitudes, and choices, then why is our attitude of obligatoriness directed precisely toward what, according to an independent account, has absolute value? Why is this attitude not directed toward relative value, absolute valuelessness or absolute evil? If it is a necessary fact about finite wills that they represent precisely that which has absolute value as absolutely obligatory, what can explain this if not the absolute value itself? Is this a brute psychological fact? It appears as if, on Stern’s view, it is a matter of mere chance that we project absolute obligatoriness onto what has absolute value, and that there is nothing about either the attitude or absolute value that explains why we regard it as absolutely obligatory. But surely this cannot be considered an explanation of obligation, since such an explanation must explain why finite agents necessarily represent what has absolute value as obligatory.

To avoid this conclusion while maintaining a value realist position, something about the moral law and its content must ground and explain, or necessitate our attitude toward it, and make this attitude necessary. But again, it would be difficult to interpret this as an anti–realist account of obligation, since real value would ground our attitudes about necessitation, rather than our attitude grounding necessitation. Indeed, at times, Stern writes as if there is something about the right and the good that necessitates the will: ‘what it is right for them to do must exert some necessitating force’ (21) and ‘it is what is right and good that obligate and necessitate’ (31). While these passages make it appear as if Stern believes that the right and the good ground our obligations, it is difficult to reconcile these passages with Stern’s anti–realism regarding obligation.

For Kant’s part, he can avoid these objections since he does not appear to hold the hybrid view that Stern attributes to him. In both the Groundwork and in the second Critique, it is that which has absolute value that necessitates our moral attitudes. In Groundwork I, Kant writes ‘The immediate determination of the will by the law and the consciousness of this is called respect, so that it is viewed as the effect of the law on the subject and not its cause. Respect is actually the representation of a worth that infringes on my self-love’ (Kant Reference Kant2011: 401n.). And in the second Critique, Kant writes that the freedom of the intelligible will is the ratio essendi, or ground of being, for moral consciousness in the moral law (Ak. 5: 4n.) and that respect is the necessary effect of the law (or its representation) on the will (Ak. 5: 71ff.).Footnote ¹ In these cases, what has value—the law, freedom—grounds and explains attitudes about obligation and necessitation, not vice versa.

These critical comments should not detract from the fact that Stern has written an insightful and carefully-argued book. He does an excellent job of weaving together close textual analysis with contemporary debates, which is no small task. As I mentioned above, the discussions of scepticism, constructivism and the British Idealists are especially valuable contributions to the literature.