This paper addresses how Elizabeth Anscombe understands the link between action theory and ethics, by focusing on her theory of practical knowledge. I argue that, for Anscombe, a capacity for practical knowledge is best understood as a capacity to do things for reasons, where reasons are the ends pursued by the agent as practically intelligible goods; on this view, knowing what one is doing and knowing the intended good of doing it are two different aspects of one and the same practical knowledge. On my reading of Anscombe, the central task of action theory is to elucidate this capacity for practical knowledge, which is exercised anytime one acts in the characteristically human way (intentionally or voluntarily). The proper task of ethics, by contrast, is to elucidate the perfected exercise of this power in the practically wise or virtuous person-i.e., the one who is properly disposed to act for the right reasons and thus lives well.