1 INSTRUMENTAL DESIRES, INSTRUMENTAL RATIONALITY by Michael Smith and Edward Harcourt II – Edward Harcourt ABSTRACT I argue that the incoherence Smith claims to identify in agents who desire that q, believe that p is a necessary means to q, but fail to desire that p is illusory, since it rests on the false assumption that every property I know to be possessed by an object of my desire is an object of my desire. Though the failure of Smith’s account of the irrationality of this pattern of attitudes leaves it open that the pattern is indeed irrational, I argue that there are instances of it that are not irrational where the desires are desires for what the agent knows to be impossible for him. This conclusion casts doubt on the overall strategy – that of making a Humean theory of action explanation do duty as a theory of instrumental rationality - which implies that the norms of instrumental rationality apply to desires simply as such. I then try to criticize the strategy in such a way as to leave the Humean theory of action explanation unaffected. Michael Smith presents the theory of instrumental rationality as a generalization of a familiar Humean theory of the explanation of action. According to the Humean theory, every action is caused and rationalized by a belief and a desire. And according to Smith if not to Hume, these are on the one hand a desire that a certain state of affairs obtains, and on the other a means-end belief to the effect that the action is apt to bring the desired state of affairs about. This pair of attitudes, when related in the right way, jointly constitute an instrumental desire to perform the action; and they are related in the right way just when they cause and rationalize an action which, in the agent’s belief, is a means to bringing about the state of affairs which is the object of his desire. Explanations of this form apply, if the Humean theory is true, to every action simply as such. But thanks to the kind of content the explanatory desire and belief always have, the form of explanation in question is instrumental rationalization. So every action is instrumentally (though not necessarily otherwise) rational in virtue of the kind of explanation it must have just because it’s an action; and agents are instrumentally rational just to the extent that their desires and means-end beliefs are related (as of course they may not be) in such a way as to give rise to actions capable of this kind of explanation. What is more, one and the same form of explanation applies not only to actions but also to desires, even when, as with desires concerning the past, these are connected with action only remotely. So the norms of instrumental rationality apply not only to action but also to desire-formation. Smith’s is thus an extremely economical theory of instrumental rationality: a theory – Hume’s - already widely believed to play one role in the philosophy of action turns out unexpectedly, or so it is argued, to be able to play another. Moreover the fact that Smith seeks to locate the requirements of instrumental rationality within the theory of motivating reasons will give pause especially perhaps to those familiar with The Moral Problem in which Smith envisages, beyond these, an array of normative reasons for action foreign to the classical Humean picture. 1 1 See e.g. Michael Smith, The Moral Problem (Oxford: Blackwell, 1994), pp. 94-6.