Why Dreaming Worlds aren't Nearby Possible Worlds.

The article examines the challenge posed by the dream sceptical scenario to the safety-based anti-sceptical response in epistemology, which holds that knowledge requires safety—meaning a belief must be true in all nearby possible worlds. While radical sceptical scenarios like the evil demon (ED) and brain in a vat (BIV) are typically considered modally remote and thus not threatening to knowledge, the dream scenario is often viewed as a nearby possibility because dreaming is a common experience. The author argues, however, that the dream sceptical scenario, when properly understood, shares key features with other radical sceptical scenarios—being highly improbable, strange, fantastic, and ad hoc—and therefore should be regarded as modally remote. Consequently, if the safety-based response successfully counters scepticism from ED and BIV scenarios, it should also apply to the dream sceptical scenario, undermining the claim that the latter uniquely threatens knowledge.