Abstract

In his insightful paper Williamson is primarily concerned to cast doubt on the thesis that if one has evidence in support of one’s belief then one knows what that evidence is. By casting doubt on that claim Williamson wants to argue that the skeptic cannot establish that the evidence one has for believing certain commonplace true propositions is the same as the evidence one would have for believing corresponding false propositions in phenomenologically indistinguishable skeptical scenarios. Despite the fact that one wouldn’t be able to know that one is hallucinating when one is, it doesn’t follow that one’s evidence for believing that one’s perception is veridical, when it is, is no different, and no better, than the evidence one possesses when one is the victim of hallucination.