According to a simple theory of the relationship between 'want' ascriptions and the desires they ascribe, when I learn that ⌜A wants p⌝ is true, I learn that the truth of p is necessary and sufficient for satisfying one of A’s desires. I argue that this simple theory is false: ⌜A wants p⌝ can be true and underspecific: p may be necessary but not sufficient for the satisfaction of one of A’s desires. I show that existing semantics for 'want' cannot (...) account for this kind of underspecificity, and I propose a desire-based semantics for ‘want’ that can. I go on to argue that my semantics has empirical and methodological advantages over existing theories of ‘want’ that give truth conditions in terms of an agent’s preferential and doxastic state rather than their desires. -/- . (shrink)