 A note of caution is essential here: it is important to distinguish the more modest project of explaining what it is to act intentionally in terms of intending and doing from the more ambitious project of explaining what it is for S to act intentionally in terms of goings-on of which S is not the agent. The latter project is implied by Wittgenstein’s notorious arithmetic: “What is left over when I subtract the fact that my arm goes up from the fact that I raise my arm?” (Wittgenstein 1953, §621). Some philosophers attempt to answer this question, explaining what it is to do A intentionally without appeal to doing A. But one need not share that aim in giving an account of intentional action in terms of intention as a mental state: one can take for granted that I am raising my arm, for instance, and ask what more is involved in raising my arm intentionally (Setiya 2011, §2; Setiya 2016b, pp. 3–9).