Abstract
This essay defends a strong version of the Humean theory of motivation on which desire is necessary both for motivation and for reasoning that changes our desires. Those who hold that moral judgments are beliefs with intrinsic motivational force need to oppose this view, and many of them have proposed counterexamples to it. Using a novel account of desire, this essay handles the proposed counterexamples in a way that shows the superiority of the Humean theory. The essay addresses the classic objection that the Humean theory cannot explain the feeling of obligation, Stephen Darwall's example of motivationally potent reasoning that is not based on preexisting desires, Thomas Scanlon's criticism that the Humean theory fails to account for the structure and phenomenology of deliberation, and the phenomenon of akrasia as discussed by John Searle. In each case a Humean account explains the data at least as thoroughly as opposing views can, while fitting within a simpler total account of how we deliberate and act.