Abstract

According to Williamson’s epistemology of modality, we know metaphysical necessities by means of our knowledge of some specific counterfactualconditionals. In particular, Williamson’s idea is that we come to have knowledge of metaphysical necessities—which have the form □A—via our knowledge ofcounterfactual conditionals which have the form ~A□→┴. In this paper I claim that there are two different ways in which Williamson’s position can plausibly bearticulated, and that both ways lead to circularity.