Evidentialism and skeptical arguments

Abstract

Cartesian skepticism about epistemic justification (‘skepticism’) is the view that many of our beliefs about the external world—e.g., my current belief that I have hands—aren’t justified. I examine the two most influential arguments for skepticism—the Closure Argument and the Underdetermination Argument—from an evidentialist perspective. For both arguments it’s clear which premise the anti-skeptic must deny. The Closure Argument, I argue, is the better argument in that its key premise is weaker than the Underdetermination Argument’s key premise. Next I examine ways of motivating each argument’s key premise. I argue that attempts to motivate them which appeal to one’s having the same evidence in skeptical scenarios, to skeptical hypotheses’ alleged ability to explain our evidence just as well as real world hypotheses, or to the fact that if skeptical scenarios were true everything would appear just as it does all fail to provide any motivation for the premises or for skepticism. But I close by considering a different argument for the key premises and skepticism that lacks the central defect of these other arguments. Future work on skepticism should focus on this final argument at the expense of the others.