Professor Tappenden (PhD Princeton, 1992) has published on paradoxes, negation, vagueness, analytic truth, Frege's philosophy of mathematics and logic, and mathematical explanation. His current research is principally concerned with historically informed philosophy of mathematics, with special attention to shared themes in Riemann's complex analysis/algebraic geometry and the mathematical foundations developed by Frege and Dedekind. A book on these topics Philosophy and the Origins of Contemporary Mathematics: Frege and his Mathematical Context -- is to appear with Oxford University Press. An overview of some of the material in that book appears in "The Riemannian Background to Frege's Philosophy" in The Architecture of Modern Mathematics: Essays in History and Philosophy, J. Ferreirós & J. J. Gray eds. (Oxford University Press). The historical research supports an investigation into the metaphysics and epistemology of mathematical concepts. The most recent papers in this stream of research are "Mathematical Concepts and Definitions" and "Mathematical Concepts: Fruitfulness and Naturalness" forthcoming in The Philosophy of Mathematical Practice, P. Mancosu ed. (Oxford University Press). Professor Tappenden previously taught at the University of Pittsburgh, and has held visiting positions at Berkeley and Harvard. In 2006-2007 he was a fellow at the Michigan Institute for the Humanities.