Abstract

One interesting and potentially attractive feature of the sensitivity account of knowledge is that it not only preserves knowledge of ordinary propositions, but also concedes the skeptic's intuition that we do not know skeptical hypotheses do not obtain. This paper challenges the sensitivity‐based reply to the skeptic, advocated by Robert Nozick, among others. Sensitivity generates an implausibly bizarre result that although we do not know we are not brains in vats (because a belief to this effect is insensitive), a real BIV who is in a much worse epistemic situation can sensitively believe that it is not in the good case. This result reveals a fundamental problem with the sensitivity conditional: its antecedent is not suitable for picking out possibilities that are relevant for our epistemic evaluation. I then offer a systematic explanation of why it is the safety account—the main competitor of sensitivity—that picks out a more suitable set of possibilities. A consequence of this comparison is that the safety account delivers an overall more satisfying reply to the skeptic than sensitivity does.