Human actions are those human doings that can be explained by their doers’ propositional attitudes. But what are doings? Although the examples so far considered have all been bits of bodily behaviour, not all doings are; Human beings make calculations not only on their fingers and on paper, but also in their heads; and the latter are as good specimens of full human actions as the former. Yet it is convenient to begin with bodily doings. Since they are easier to study than mental ones, it is reasonable to suppose that it will be easier to construct a theory of them, and to extend it to what we do in our heads, than to construct from the beginning a theory covering both.