Hume, Passion, and Action by Elizabeth S. Radcliffe (review)

Elizabeth Radcliffe's book is an important and original contribution to scholarship on Hume's ethics and moral psychology. Throughout, she deftly combines important discussions of Hume's predecessors and contemporaries that serve to contextualize his views with in-depth analysis of Hume's texts. At the same time, she shows an impressive familiarity with more recent scholarship on Hume's and Humean ethics, and deploys much of this recent scholarship to frame her own interpretation of Hume's ethics and moral psychology. That sophisticated and nuanced interpretation focuses particularly on the relations between and the respective roles played by belief, the passions, and moral sentiments in motivation and agency.

The book has seven chapters and an appendix; this latter is devoted to a more detailed examination of philosophical accounts of the passions, reason, and action in the seventeenth and eighteenth centuries. Radcliffe's overarching aim in the book is to show the force of Hume's "inertness of reason argument" and his "motivation argument." Radcliffe calls the method she deploys "coherentist," and it is designed to understand better Hume's actual arguments, particularly from the Treatise, with regard to motivation and agency. Her approach thus contrasts strikingly with those who take a more rational reconstructionist line in an attempt to show what Hume could or should have said. Radcliffe takes Hume to be committed to several theses regarding the inertness of reason (it can neither itself motivate nor oppose a passionate motive), the nonrepresentative character of the passions, and the sense in which moral taste or sentiments have an influence on motivation.

After establishing that motivating passions are desires that move us to achieve some object or end, Radcliffe turns in chapter 2 to Hume's argument about reason's inertness, situating it in relation to the arguments of the rationalists he sought to oppose. The rationalists held that reason established the content of morality, for instance through our rational apprehension of the relation of fitness between some action and goodness. In turn, a judgment that something is good suffices to produce a motivating passion. Radcliffe argues that on Hume's account a belief can represent something as good only because taste or sentiment has been fundamental to our (typically pleasurable) experience of the goodness of that thing. Without something like a felt concern or a sense of attraction that may in turn produce a desire, a mere belief about something as good simply cannot motivate. In the next chapter, Radcliffe offers a careful discussion of Hume's different characterizations of the nature of belief, maintaining that the central function of belief is that of representing. Chapter 4 takes up Hume's claim that the passions are original existences and thus do not represent; this further establishes that, given their different contents and functions, belief and passion do not stand in practical opposition to each other.

In chapter 5, which is rich in detail, Radcliffe turns to an analysis of the motivation argument. A main aim here is to preserve the validity of Hume's argument by making the best sense of its first premise, which holds that "morals" have an influence on actions and affections. Radcliffe considers several possible interpretations. One examines what she calls the natural motive interpretation, focusing on Hume's claim, in Treatise 3.2, that a regard to the virtue of an action cannot be the first virtuous motive because the moral sentiment of approval must confer the status of virtue on a natural motive. A second interpretation focuses on whether moral sentiments, as the means of discerning moral distinctions (e.g. virtuous or vicious), is also the source of moral motivation. Radcliffe finds both the natural motive interpretation and the moral discernment interpretation (which she once defended) problematic. Her preferred interpretation has the motivation to act morally deriving from moral sentiment, while those sentiments are not themselves motives to action. This interpretation attributes an internalist position to Hume, thereby preserving the validity of the motivation argument.

The final two...