Muhammad Ali Khalidi is a Palestinian philosopher. He earns his Ph.D., Philosophy, from Columbia University and M.A., Philosophy, from Columbia University B.S., Physics, from American University of Beirut. He is a Presidential Professor of Philosophy at City University of New York (CUNY) Graduate Center. Before that, he was Professor of Philosophy at York University in Toronto. He has also taught at the American University of Beirut, University of Nevada at Reno, and (as a post-doc) at the University of Chicago and Columbia University. His main areas of research are in the philosophy of science (with an emphasis on cognitive science) and the philosophy of mind. He has been particularly focused on analyzing mental phenomena such as: memory, concepts, and innateness, and what role they play in contemporary cognitive science. He is also interested in scientific classification schemes and in the means of distinguishing artificial categories from real ones in both the natural and social sciences.