  Some have proposed that it is possible to acquire new intrinsic desires by reasoning. According to Michael Smith, if one believes that, were one rational, one would desire that p, then this will tend to generate an intrinsic desire that p. Thus, if I believe that, were I rational, I would want to give money to the Third World, then this will tend to generate an intrinsic desire in me to give money to the Third World (Smith 1994). There is a difficulty here in evaluating Smith's idea. It certainly seems as though thinking about what I would—were I only perfectly rational—want to do is the sort of thing that can generate a new desire in me. But it is less clear that the desire generated is intrinsic as opposed to a realizer desire (a realizer for the desire to do what is rational, or perhaps moral). Phenomenologically, it seems difficult to distinguish the two, and so it is not easy to evaluate Smith's theory. These difficulties have not prevented philosophers from trying, however (e.g., Dreier 2000).