Professor Buchanan specializes in the philosophy of language and the philosophy of mind. He also works in philosophical logic, epistemology, and the foundations of cognitive science. His dissertation, Content, Context, and Communicative Intentions, argues that context-sensitive constructions undermine the standard proposition-based theory of linguistic communication. He has published \"Are Truth and Reference Quasi-Disquotational?\" (Philosophical Studies , 2003) and \"Has the Problem of Incompleteness Rested on a Mistake?\" (Mind, 2005, with Gary Ostertag).