Constraints on Skeptical Hypotheses

In this article I examine the constraints that skeptical hypotheses must satisfy in order to be used to raise significant skeptical challenges. I argue that skeptical hypotheses do not have to be logically, metaphysically or epistemically possible. They only need to depict scenarios that are subjectively indistinguishable from the actual world and must provide some indication of how subjects can believe what they do while failing to have knowledge. I also argue that skeptical challenges can be raised against a priori beliefs, even if those beliefs are necessarily true. In this way I hope to broaden our conception of the legitimate kinds of skeptical challenges that can be raised.