Preceded by a pre-talk for graduate students, 1:30PM Benjamin Library

Please let Justin know if you'd like to come to dinner following the talk.

According to the classical quantificational analysis of modals, an agent has the ability to perform a given act iff (roughly) relevant facts about the agent and her environment are compatible with performing the act. The analysis faces a number of problems, many of which can be traced to the fact that it takes even accidental performance of an act as proof of the relevant ability.

I argue that ability statements are systematically ambiguous: on one reading, accidental performance really is enough; on another, more is required. Specifically, on the second reading, the agent must be capable of performing the relevant act as the result of a decision that warrants believing that they will perform the act. I argue that this notion of ability is tailored to a central use of ability judgements in normative contexts, and explain how both readings can be captured within the quantificational framework, provided we allow conversational context to impose restrictions not just on the “accessible worlds” (the facts that are held fixed), but also on what counts as a performance of the relevant act among these worlds.