This chapter offers an account of ‘instrumental rationality’, by clarifying (a) the nature of instrumental reasoning, and (b) what it is to do instrumental reasoning in a rational way. Joseph Raz was wrong to claim that instrumental rationality is a ‘myth’ (although some philosophers have been seduced by myths about instrumental rationality); the accounts of John Broome and Kieran Setiya cover only a small fraction of instrumental reasoning; and orthodox decision theory involves idealizing assumptions that prevent it from having anything to say about instrumental reasoning. In fact, instrumental reasoning exemplifies a more general phenomenon: because we make decisions in a piecemeal way, we have to integrate these decisions together. To do this rationally, one’s intentions must make it rational for one to have a certain sort of expectation that one will carry out one’s intentions, and that this will result in one’s acting in a suitably valuable way.
Keywords: rationality; instrumental reasoning; decision theory; practical reason; intention
Chapter. 14799 words.
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