To show that morality is in one's interest, the challenge put forward by Hobbes's Foole, we must first be clear what is meant by something's being in one's interest. Defining self-interest in an external or objective sense (so that claiming morality really satisfies her self-interest, albeit in ways she will never appreciate) will not placate the Foole. Self-interest, for the Foole, must be understood in terms that she will endorse. Are such terms possible? Subjective interpretations of self-interest have been accused (...) of incoherence for two separate reasons. First, calling 'good' that which we desire gets the order backward, since the desirability feature is what causes us to desire it. Second, subjective accounts cannot properly explain the phenomenon of mistaken desires, or accommodate reflection on our desires with the intent on warding off such mistakes. My goal here is to show how a subjective account of self-interest is not self-defeating in these ways. (shrink)