Melissa Barry

In Slaves of the Passions, Mark Schroeder provides a systematic, rigorously argued defense of a Humean theory of reasons for action, taking pains to respond to influential objections to the view. While inspired by Hume, Schroeder makes it clear that he aims to develop a Humean theory, not necessarily one that Hume himself embraced, and for this reason little is said about Hume in the book. One respect in which Schroeder takes himself to be departing from Hume is in developing a normative account. On his reading, Hume held that only beliefs could stand in the reason relation (187, n11), whereas Schroeder, like many contemporary Humeans, holds that actions can as well. He sets out to develop a theory of this..

Realists about practical reasons agree that judgments regarding reasons are beliefs. They disagree, however, over the question of how such beliefs motivate rational action. Some adopt a Humean conception of motivation, according to which beliefs about reasons must combine with independently existing desires in order to motivate rational action; others adopt an anti-Humean view, according to which beliefs can motivate rational action in their own right, either directly or by giving rise to a new desire that in turn motivates the action. I argue that the realist who adopts a Humean model for explaining rational action will have a difficult time giving a plausible account of the role that desire plays in this explanation. I explore four interpretations of this role and argue that none allows a Humean theory to explain rational action as convincingly as an anti-Humean theory does. The first two models, in different ways, make acting on a reason impossible. The third allows this possibility, but only by positing a reason-sensitive desire that itself demands an explanation. The fourth avoids this explanatory challenge only by retreating to an empty form of the Humean view. In contrast, an anti-Humean theory can provide an intuitively plausible explanation of rational action. I conclude that the realist about reasons should adopt an anti-Humean theory to explain rational action.