Williamson and the Argument from Luminosity

P. X. Monaghana1

a1 University of Iowa


Many of the results of Timothy Williamson's Knowledge and Its Limits depend upon his argument that many, if not all, of our mental states fail to be luminous in the sense that if we are in them, then we are in a position to know that we are in them. The purpose of this article is to show that his argument is unsound. I conclude by distinguishing between partial and total luminosity, and by arguing that even if mental states are not totally luminous, they are at least partially so.