"Idealized desire accounts of well-being seem to make it very difficult to base life-changing decisions in considerations of our own well-being. Since changes in who we are in turn change the content of our idealized desires, it is not clear whether our decisions about who to become should be based on our current desires or the desires of the various persons we might become. And since we cannot always anticipate what our transformed selves will care about before we are transformed, we must also make these decisions without knowledge of what the idealized desires of our future selves might be.
While related conceptual versions of these problems exist, in this paper I put them aside to focus on the question of action guidance: given these two sources of ignorance, can idealized desire accounts of well-being really tell us anything useful about how to decide who to become? In answer, I argue that they can tell us far more than we might expect, and develop an account of the action guidance that they offer."