Disjunctive luminosity

Abstract

Williamson's influential anti-luminosity argument aims to show that our own mental states are not “luminous,” and that we are thus “cognitively homeless.” Among other things, this argument represents a significant challenge to the idea that we enjoy basic self-knowledge of our own occurrent mental states. In this paper, I summarize Williamson's anti-luminosity argument, and discuss the role that the notion of “epistemic basis” plays in it. I argue that the anti-luminosity argument relies upon a particular version of the basis-relative safety condition on knowledge. This commitment is significant because basic self-knowledge seemingly lacks any kind of distinct epistemic basis, such as inference, observation, testimony, etc., despite representing a genuine kind of knowledge of contingent matters of fact. I consider a disjunctivist account (due to Bar-On and Johnson), according to which true basic self-beliefs indeed lack an epistemic basis in any kind of epistemic method (such as inference), yet are still epistemically grounded in the mental states they concern. I argue that this account of self-knowledge is compatible with standard understandings of the basis relative safety condition on knowledge, but rejects the particular version required by the anti-luminosity argument.