Shelter for the cognitively homeless

One of the main strands of the Cartesian tradition is the view that the mental realm is cognitively accessible to us in a special way: whenever one is in a mental state of a certain sort, one can know it just by considering the matter. In that sense, the mental realm is thought to be a cognitive home for us, and the mental states it comprises are luminous. Recently, however, Timothy Williamson has argued that we are cognitively homeless: no mental state is in fact luminous. But his argument depends on an excessively strong account of luminosity. I formulate a weaker conception of luminosity that is unaffected by Williamson's argument and yet is substantial enough to satisfy those who wish to retain this part of the Cartesian tradition.