Abstract

The existing literature on the rational underdetermination problem often construes it as one resulting from the ubiquity of objective values. It is therefore sometimes argued that subjectivists need not be troubled by the underdetermination problem. But on closer examination, it turns out, they should. Or so I will argue. The task of the first half of this paper is explaining why. The task of the second half is finding a subjectivist solution the rational underdetermination problem. The basic problem, I argue, is as follows. Idealizing subjectivism generates too many ideal selves to deliver determinate or commensurable options regarding what non-ideal deliberating agents ought to do. My solution: these idealized options should be assessed from the only perspective we can, in fact, occupy, namely, that of our non-ideal, actual selves. Deciding what to do therefore becomes, in part, an exercise in deciding who to be. But one might now worry this just moves the arbitrariness bump in the rug. Privileging the perspective of our actual self seems contrary to the rationale for idealizing in the first place. I consider two solutions to the problem, one democratic, the other modelled on trusteeship. In the end, I argue, our actual self has complete freedom to choose the ideal self it grants rational authority. In the final part of the paper, I present my positive proposal as a solution to the underdetermination problem confronting the idealizing subjectivist and then argue that, so understood, this account vindicates a tidied-up version of how some reflective people already do deliberate in their everyday lives. This, in turn, suggests that a decision-procedure closely connected to the account is both possible and attractive.