Skepticism and Underdetermination

Abstract

As noted earlier, the possibility of alternative hypotheses equally accounting for our sensory experiences is widely viewed as a source of skeptical doubt. In Chapter 5 we discussed one way of utilizing this insight drawing on the principle of closure to set up a (Cartesian) skeptical argument. In this chapter, I shall deal with another way of constructing such arguments that helps itself with, not the principle of closure but, the so-called underdetermination principles (Yalcin 1992; Brueckner 1994). To explain, I begin by distinguishing between knowledge and justification analogs of the principle of underdetermination. While acknowledging the plausibility of a restricted version of the knowledge version, it shall be argued that this has nothing to do with facts involving underdetermination.