I did my doctorate at Oxford in the philosophy of mind and language, though I was also developing interests in Descartes, Locke and Hume. Before moving to Brown, I taught at Oxford, as a Fellow of Oriel College.
My present research is on issues in metaphysics and the theory of perception, and their connections with the history of the subject. Special areas of interest include: Theory of Color and Color-Perception, from the Ancient Greeks to the present; Color-Blindness; and the Notion of Substance, and what became of that idea in the 17th and 18th centuries and after. In addition, I am working on a book on Iris Murdoch's The Sovereignty of Good and am editing a collection of essays on her work.
I have recently been a Visiting Professor in Paris, in the Department of Cognitive Studies at the Ecole normale supérieure, and at the Institut Jean Nicod.