He received his Ph.D. from the University of Pittsburgh. His primary interests are in philosophy of language, metaphysics, philosophy of logic, and history of early modern philosophy. His publications include “A New Puzzle About Intentional Identity” (Journal of Philosophical Logic, 1986), “The Fifth Meditation” (The Philosophical Review, 1990), “A Case for a Heretical Deontic Semantics” (Journal of Philosophical Logic, 1991), “Propositions, Circumstances, Objects,” (Journal of Philosophical Logic, 1994), “A Perspectivalist Semantics for the Attitudes” (Noûs, 1995), and “Intersubjective Intentional Identity” (Journal of Philosophy, October 2006). He is a recipient of three university teaching awards. He has been a visitor at the University of Pittsburgh and at the University of North Carolina at Chapel Hill.