Philip Kitcher, Frey Distinguished Visiting Professor for the Fall of 2001, specializes in the philosophy of science, biology and mathematics.  Sample publications:  Abusing Science: The Case Against Creationism (1982).  The Nature of Mathematical Knowledge (1983).  Vaulting Ambition: Sociobiology and the Quest for Human Nature (1985); The Advancement of Science (1993);  The Lives to Come: The Genetic Revolution and Human Possibilities (1996);."The Evolution of Human Altruism," Journal of Philosophy (1993); "The Naturalists Return," Philosophical Review (1992);   "The Division of Cognitive Labor," Journal of Philosophy (1990);  "Explanatory Unification and the Causal Structure of the World," Minnesota Studies in the Philosophy of Science, XIII  (1989);  "The Return of the Gene," (with Kim Sterelny), Journal of Philosophy (1988);   "Precis of Vaulting Ambition and Reply to Peer Commentary," The Behavioral and Brain Sciences (1987);   "Van Fraassen on Explanation," (with Wesley Salmon), Journal of Philosophy (1987);  "Two Approaches to Explanation," Journal of Philosophy (1985);  "1953 and All That: A Tale of Two Sciences," Philosophical Review (1984);  "Species," Philosophy of Science (1984); "Genes," British Journal for the Philosophy of Science (1982);  "Explanatory Unification," Philosophy of Science (1981);   "A Priori Knowledge," Philosophical Review (1980);   "Frege's Epistemology," Philosophical Review (1979); "Theories, Theorists, and Theoretical Change," Philosophical Review (1978);  "Kant and the Foundations of Mathematics," Philosophical Review (1975).