This book aims to give a sympathetic account of Kant’s notion of noumenal freedom of will ‘in terms of analytic philosophy’ (p. xiv). I should confess right away that I did not understand some of its key arguments, because I struggled with Greenberg’s writing in passages like these:
Since ascription is a logical and not a causal relation, and since effects cannot be ascribed to objects, at least not in the objects’ causal role in question – cause and effect being a relation between logically distinct things, which keeps the effects from being properties that can be ascribed to their causes – being perceived is not ascribable to the object insofar as the object has the causal efficacy with respect to its being perceived, despite the fact that being perceived is ascribable to the same object that plays a role in the causal origin of its being perceived. (p. 36)
Since the maxim, connoting utter subjectivity, is Kant’s notion in his practical philosophy of the required existence of the subject, or agent, who is causally involved in an action subject to moral judgment, we conclude that for Kant the applicability or use of moral judgment with respect to an action – a use that can apply the utterly general or objective moral law, i.e. the Categorical Imperative – [MK: is? applies? is or applies?] only to the just as utterly singular or subjective maxim of the action. (p. 56)
Sentences like these were a great, oftentimes insurmountable hindrance to my comprehension.
Greenberg’s central argument, as he presents it at the beginning, seems to be as follows. (1) Kant’s notion of atemporal noumenal causality has been rejected as unintelligible both by recent commentators such as Allen Wood (p. xiii) and by recent analytic philosophers. (2) The causal theory of perception put forward by Grice and Strawson has been deemed intelligible, sometimes acceptable, by recent analytic philosophers. (3) The Gricean causal theory of perception invokes a non-natural, atemporal notion of causality (see e.g. pp. 14–15). (4) The Gricean theory can be adapted to Kant’s theory of noumenal freedom. (5) Hence, anyone who deems the Gricean causal theory of perception intelligible, perhaps acceptable, cannot dismiss Kant’s notion of atemporal noumenal causality as unintelligible or unacceptable.
Concerning (1), it would have been good for Greenberg to clarify why the ‘unintelligibility’ of Kant’s account of noumenal freedom is a problem that a sympathetic commentator should wrestle with. ‘Unintelligible’ can mean ‘incoherent’, but it is not clear (and Greenberg gives no reason) why Kant’s account might seem incoherent. ‘Unintelligible’ can also mean ‘inscrutable’ or ‘impossible to understand’, but Kant himself (happily, it seems) admits that his account of noumenal freedom is unintelligible in that sense (see e.g. Groundwork (henceforth, G), 4: 463; Metaphysics of Morals (MM), 6: 378).
A large part of Greenberg’s book (pp. 14–40) is dedicated to (3). I find it hard to believe that naturalistically minded philosophers like Strawson would endorse an atemporal, non-natural account of perception, but I also admit that I simply do not understand, and hence cannot evaluate, Greenberg’s argument for that conclusion. I shall only note that this conclusion entails that a perceived object’s causal efficacy with regard to sense-data is causally unconditioned (p. 24), and hence ‘free’ (p. 34). The idea that a table is as free in causing perceptual data as a moral agent strikes me as absurd, on Kantian grounds.
When he elucidates (4), Greenberg proposes that Kant has both a ‘causal theory of action’ that involves the causality of freedom and a ‘non-causal theory of action’ that involves the deterministic causality of nature (pp. 46–55). The designation of Kant’s phenomenal view of human actions as ‘non-causal’ strikes me as peculiar, since Kant holds that observable human actions are the effects of empirical causes (see e.g. G, 4: 453). Greenberg’s point might be that whatever is the effect of a merely natural cause is not an action but an event (see p. 7). That may seem like a merely semantic issue, but Greenberg’s ‘non-causal theory of action’ contains questionable substantive claims as well: he argues that in natural causation an event such as taking revenge is not an effect of the will and the agent’s maxim plays no role in the causation of the effect (p. 49; this conflicts, for instance, with A549/B577). Greenberg holds that on the ‘non-causal’ theory, an action can be ‘ascribed’ but not ‘causally attributed’ to the will (pp. 49–50). I do not understand this distinction.
In the context of expounding the ‘causal theory of action’, Greenberg rejects an interpretation that he attributes to Henry Allison, Allen Wood and Andrews Reath (pp. 52–5): ‘they include Kant’s maxims as part of his theory of the causal efficacy of the will regarding its actions instead of their being determinations or descriptions of its effects, i.e. its actions, which is my view of where they belong’ (p. 53). The idea that maxims regulate the causal efficacy of the will strikes me as rather plausible: maxims are the subjective principles of volition that govern the intentional, productive efforts of rational agents. Moreover, the alternative that Greenberg offers is puzzling: it is not clear (to me) what he could mean by ‘determinations of its effects’ other than ‘causal determinations’. To be sure, a maxim does, in part, ‘describe effects’, but why should this prevent the maxim from being causally efficacious? Greenberg’s objection to Allison et al. is: ‘their interpretation would make it impossible for an agent to do anything about any external condition of her will, such as her desire for pleasure, since as part of the cause of an action, an external condition cannot be part of the action that is the effect’ (p. 53). I do not understand this objection. Suppose Steffi freely incorporates into her maxim the desire for the type of pleasure that she expects from chocolate. (This is Allison’s model of free choice under external conditions that Greenberg rejects.) Here Steffi’s will is affected but not causally determined by the desire for chocolate as an external condition. (Greenberg wrongly equates ‘affection’ with ‘determination’ on p. 48. For Kant’s distinction between the two notions, see e.g. MM, 6: 213.) But this external condition is not also the projected effect of the free choice. Rather, Steffi seeks to perform an action (e.g. buying a chocolate bar) that allows her to satisfy the standing desire or external condition.
The next part of the book concerns the problem of how immoral actions can be imputed to a free will on Kant’s view (pp. 61–80). Greenberg suggests that this problem is especially salient on his theory because he treats the categorical imperative as ‘a causal law between the cause and the effect – between the will and the commitment’ (p. xiv). For Greenberg, this entails that ‘the [moral] law is the causal connection with an action, and therefore the action is the causal consequent of the connection’ (p. xvi), so that ‘it is from the practical causal law that an action of the will can be posited as the consequent of the law’ (p. 66). Here Greenberg construes (implausibly, to my mind) the categorical imperative as a descriptive causal law. He rejects the standard view that the categorical imperative, far from describing a factual cause–effect relation, is a normative proposition that obligates our will to act in a way (p. 68). Given his view that the categorical imperative is a descriptive ‘practical causal law’, Greenberg faces the problem: ‘how can a law connect a cause and an effect, if the effect does not conform to the law’, i.e. if the effect is an immoral action (p. 65)?
I would summarize Greenberg’s solution in my own words, but once more I must confess that I do not really understand it. Here is what he says at one point:
So, an action is both an effect according to one type of fundamental practical proposition for Kant – the practical causal law – and an object of a different type of fundamental practical proposition for him – the maxim of an action. It is due to this two-fold nature of an action that it can be both a result of the will according to the practical causal law and an object of an immoral maxim, and thus can be a forbidden action. (p. 71)
Evidently the distinction between being an effect and being an object of a practical proposition is central here, but I do not grasp what this distinction amounts to. Moreover, I would have thought that for Kant the adoption of an immoral maxim is itself an action of the will, and hence the immoral maxim itself is an effect of the free will. (Greenberg seems to want to exclude this; see p. 76.) Finally, the part of the above quote that I think I understand, namely, the claim that a forbidden action is an effect of the categorical imperative, strikes me as false. If an action is forbidden, then it cannot be the result of the agent’s representation of what morality requires of her, although (as a proponent of the normative interpretation of the categorical imperative would insist) the agent is still normatively governed by, and thus assessable in terms of, the moral law.
The book contains two further parts that seem only loosely connected to the above-mentioned themes. First, Greenberg addresses the worry about a presumed omission in Kant’s derivation of the universalizability formula of the categorical imperative in the Groundwork (pp. 84–98). Second, Greenberg argues that if we focus on Kant’s conception of practical rather than theoretical knowledge, then we might be able to defend Kant against Kripke’s complaint that Kant conflated the epistemic notion of a priority with the metaphysical notion of necessity (p. 99–111). I found this to be the most accessible part of the book. However, the conclusion struck me as standing in need of further support. For Greenberg, Kripke would have been more favourable to Kant’s view if he had recognized that for Kant objective practical necessity depends on a priori practical knowledge (p. 111). But as far as I can see, Greenberg has given no argument to show that a Kripkean should find the dependency of objective necessity on a priori knowledge more plausible in practice than in theory. Moreover, with regard to Kant, it would have been good to distinguish between different senses in which practical necessity or lawfulness depends on being known. I agree that the moral law, as a law of autonomy, could not govern a human agent unless this very agent knew the law to be true; but at the same time, the moral law does not depend for its truth on being known by any human agent, for it might hold true in virtue of being legislated and known by a different type of rational being (e.g. a divine will, where the difference between ‘knowledge’ and ‘being’ seems moot).
Greenberg’s book addresses central questions about Kant’s views on moral freedom. While his contentions strike me as somewhat implausible, this may be the result of my failure to properly understand them. Perhaps other readers will fare better in this regard. I want to conclude, however, by pointing out a further problem with this book. Early on (p. 4), Greenberg says that it is not to be taken as a standard piece of Kant scholarship ‘which combs through varieties of interpretations of Kantian texts and the secondary literature’. In my view, the book would have benefited from more careful attention to how Kant uses terms such as ‘maxim’, ‘imperative’ or ‘effect of freedom’ – this would have led to necessary qualifications of claims such as ‘The causality of freedom cannot … affect nature’ (p. 114), which fly in the face of central texts (such as A548/B576). Regarding the secondary literature, in my view a book that purports to give a sympathetic treatment of Kant’s views on noumenal freedom cannot afford to entirely ignore ground-breaking work by commentators such as Karl Ameriks or Eric Watkins.
