The theory that practical reasoning is wholly instrumental says that the only practical function of reason is to tell agents the means to their ends, while their ends are fixed by something other than reason itself. In this essay I argue that Hume has an instrumentalist theory of practical reasoning. This thesis may sound as unexciting as the contention that Kant is a rationalist about morality. For who would have thought otherwise? After all, isn't the ‘instrumentalist’ line in contemporary discussions of this topic descended directly from Hume himself? Contrast the following recent comment from Robert Audi's book on practical reasoning, holding the standard line, with the comment from Christine Korsgaard following it:

Hume argues against the seventeenth-century rationalists that reason is impotent to motivate action and to originate morality. Hume's arguments have standardly been considered the foundation for the Humean theory of motivation in contemporary philosophy. The Humean theory alleges that beliefs require independent desires to motivate action. Recently, however, new commentaries allege that Hume's argument concerning the inertness of reason has no bearing on whether beliefs can motivate. These commentaries maintain that for Hume, beliefs about future pleasurable and painful objects on their own can produce the desires that move us to action. First, I show that this reading putsHumeat odds withHumeans, since the latter are committed, not only to the view that beliefs and desires are both necessary to action, but also to the view that beliefs do not produce desires. Second, I review textual, philosophical and historical grounds for my interpretation of Hume's argument for the inertness of reason. I argue that the new line on Hume, while consistent with a certain reading of the Treatise, is not supported by the Dissertation on the Passions and the second Enquiry, where Hume argues that all motivation has an origin in “taste”, which I take to be different from belief. Thus, Hume's arguments do support the contemporary Humean theory of motivation.

A survey of theories on the passions and action in seventeenth- and eighteenth-century Britain and western Europe reveals that few, if any, of the major writers held the view that reason in any of its functions executes action without a passion. Even rationalists, like Cambridge Platonist Ralph Cudworth and English clergyman Samuel Clarke, recognized the necessity of passion to action. On the other hand, many of these intellectuals also agreed with French philosophers Jean-François Senault, René Descartes, and Nicolas Malebranche that, for passions to be useful or to become virtues, they must be governed by reason. Without the moderation of reason, passions will be unruly, distort our notions of good, and disrupt our rational volitions. In response to these popular early modern perspectives, Enlightenment thinker David Hume offered a now-famous argument that reason without passion cannot motivate, drawing the further conclusion that reason cannot govern the passions, either. Given that no one in Hume's era seemed to defend the claim that reason alone can motivate action, what was Hume's intention?

The following symposium was featured at the seventy-seventh meeting of the Pacific Division of the American Philosophical Association on the occasion of J. B. Schneewind's retirement from the Chair of the Board of Officers. It was my honour to serve as the chair of this session on 28 March 2003.