What Does Decision Theory Have to Do with Wanting?

Abstract

Abstract Decision theory and folk psychology purport to represent the same phenomena: our belief-like and desire- and preference-like states. They also purport to do the same work with these representations: explain and predict our actions. But they use different concepts. Can we account for the concepts of one with the other’s? If not, we’d have two competing representations and systems of prediction and explanation, a dubious dualism. Many might then reject one of the two pictures, yet neither can be jettisoned lightly. Folk psychology structures daily life, and decision theory pervades various scientific disciplines. I’m interested in accounting for two central folk psychological concepts—believing and wanting—with decision theory. Many have attempted this task for believing. (The Lockean Thesis says that such an account exists.) This paper concerns the parallel task for wanting. I give necessary and sufficient conditions, stated in terms of decision theory, for when you’re truly said to want. I propose an alternative to orthodox accounts that link wanting to preference (e.g. Stalnaker (1984), Lewis (1986)). My account explains the context-sensitivity of want ascriptions, makes sense of conflicting desires, and accommodates phenomena that motivate traditional theses on which ‘want’ has multiple senses (e.g. all-things-considered vs. pro tanto).