According to the ‘standard story’ in the philosophy of action, actions are those movements of a creature’s body that are caused and rationalized by the creature’s mental states. The attractions of the causal condition have been widely discussed. The rationalization condition is nearly ubiquitous, but it is notoriously obscure, and its motivation has rarely been made explicit. This paper presents a new argument for including the rationalization condition in the causal theory of action, and sketches a broadly Davidsonian theory of (...) what rationalization is. (shrink)