Self-knowledge and externalism

A person’s authoritative self-knowledge about the contents of his or her own beliefs is thought to cause problems for content externalism, for it appears to yield arguments constituting a wholly non-empirical source of empirical knowledge: knowledge that certain particular objects or kinds exist in the environment. I set out this objection to externalism, and present a new reply. Possession of an externalist concept is an epistemological skill: it depends upon the subject’s possession of demonstratively-based knowledge about the object or kind to which it refers. Thus, a person’s knowledge that he or she has an externalist belief, since this depends upon actually having that belief, and therefore upon possessing the relevant externist concept, presupposes knowledge about the object/kind in question, which provides a direct and perfectly empirical source of knowledge that this object/kind exists. Hence, the putatively problematic arguments do not constitute a non-empirical source of such empirical knowledge