Philosophy, Department of


Date of this Version



Metaphilosophy 2022; 53:344–361.


This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License


Epistemological accounts that make use of a safety condition on knowledge, historically, face serious problems regarding beliefs that are necessarily true. This is because necessary truths are true in all possible worlds, and so such beliefs can be safe even when the bases for the beliefs are epistemically problematic. The existence of such problematically safe beliefs would undermine a major motivation for the condition itself: the ability to evaluate how well a belief tracks the truth. This paper argues that incorporating impossible worlds into the evaluation of beliefs solves this problem, but only if the relevant account of impossible worlds entails that many impossible worlds are incredibly similar to the actual world. Further, the paper argues that, as a result of including impossible worlds, some philosophical beliefs are unsafe, and many more are potentially unsafe. But, it argues, even if this is the case, we can still make philosophical progress.

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