Ability Modals as Causal Modals

Abstract

Can and be able to can be used to describe what is possible in light of a subjects abilities. These modals give rise to several logical anomalies, which have led to analyses that stray far from standard Kratzer-style treatments (see [2], [10], [19] a.o.). I suggest that the source of the anomalies is a presupposition sitting on top of a standard existential semantics. The resulting account is both more conservative and more successful at accommodating the data than the alternatives. The presupposition of S can/is able to A states (roughly) that a state of S is causally sufficient for A. Interestingly, this account diverges from many existing account in that it does not invoke a notion of agency.