In this paper I offer a critique of the view made popular by Davidson that rationalization is a species of causal explanation, and propose instead that in many cases the explanatory relation is constitutive. Given Davidson’s conception of rationalization, which allows that a huge range of states gathered under the heading ‘pro attitude’ could rationalize an action, I argue that whilst the causal thesis may have some merit for some such ‘attitudes’, it has none for others. The problematic ‘attitudes’ are those which can be attributed to the agent only on the basis of her history of doing this sort of thing. In other words, they are among the agent’s habits. I argue that such temporally extended states cannot be the causes of any present occurrence. Instead, I suggest we should think of the present action as partly constituting the state in question, and give a corresponding interpretation of the explanatory relation. Such explanations invite us to abandon a conception of agency narrowly based on psychology, in favour of an enriched one which takes an agent’s habits to partly constitute the agent.