Luminosity in the stream of consciousness

Williamson’s (Knowledge and its limits, Oxford University Press, Oxford, 2000, Chapter 4) “anti-luminosity” argument aims to establish that there are no significant luminous conditions. “Far from forming a cognitive home”, luminous conditions are mere “curiosities” (2000, p. 109). Even supposing Williamson’s argument succeeds in showing that there are no significant luminous states his conclusion has not thereby been established. When it comes to determining what is luminous, mental events and processes are among the best candidates. It is events and processes, after all, which constitute the stream of consciousness. Judgment, for instance, is plausibly self-conscious. If I am judging then plausibly I must know that I am. Similarly, deliberation is plausibly self-conscious. To be deliberating about some matter I plausibly must know that I am. That one is judging and that one is deliberating are thus plausibly luminous conditions. Furthermore, I argue, Williamson’s anti-luminosity argument fails to speak against this suggestion. This reveals that Williamson’s argument is more limited in scope than has been thought—something likely missed due to a misplaced focus on mental states in the luminosity debate as well as in epistemology and the philosophy of mind more generally. For all Williamson shows, there may be luminous events and processes of a sort apt to constitute a cognitive home. I conclude by considering how the anti-luminosity argument might be reinstated in the judgment case and argue that the natural way to do so fails.