This paper examines "moderate modal skepticism", a form of skepticism about
metaphysical modality defended by Peter van Inwagen in order to blunt the force of certain modal
arguments in the philosophy of religion. Van Inwagen’s argument for moderate modal skepticism
assumes Yablo's (1993) influential world-based epistemology of possibility. We raise two problems
for this epistemology of possibility, which undermine van Inwagen's argument. We then consider how one might motivate moderate modal skepticism by relying on a different epistemology of possibility, which does not face these problems: Williamson’s (2007: ch. 5) counterfactual-based epistemology. Two ways of motivating moderate modal skepticism within that framework are found unpromising. Nevertheless, we also find a way of vindicating an epistemological thesis that, while weaker than moderate modal skepticism, is strong enough to support the methodological moral van Inwagen wishes to draw.