Constitutivism About Instrumental Desire and Introspective Belief

This essay is about two familiar theses in the philosophy of mind: constitutivism about instrumental desires, and constitutivism about introspective beliefs, and the arguments for and against them. Constitutivism about instrumental desire is the thesis that instrumental desires are at least partly constituted by the desires and means-end beliefs which explain them, and is a thesis which has been championed most prominently by Michael Smith. Constitutivism about introspective belief is the thesis that introspective beliefs are at least partly constituted by the mental states they are about, and is a thesis which has been championed most prominently by Sydney Shoemaker. Despite their similarities, the fortunes of these two theses could not be more opposed: constitutivism about instrumental desire is widely accepted, and constitutivism about introspective belief is widely rejected. Yet, the arguments for both theses are roughly analogous. This essay explores these arguments. I argue that the argument which is widely taken to be the best argument for constitutivism about instrumental desires---what I call the argument from necessitation---does not provide the support for the thesis it is widely taken to provide, and that it fails for much the same reasons that it fails to provide support for constitutivism about introspective belief. Furthermore, I argue that the best argument for constitutivism about instrumental desires---what I will call the argument from cognitive dynamics---is also a good argument, if not equally good, for constitutivism about introspective belief (at least when the thesis is suitably qualified).