Leslie Stevenson is reader in logic and metaphysics at the University of St. Andrews in Fife, Scotland. He is the author of Seven Theories of Human Nature, The Metaphysics of Experience, and many articles on language, mind, and science. Henry Byerly is professor of philosophy at the University of Arizona. He is the author of A Primer of Logic and has published many articles on biology as well as on the philosophy of science. Leslie Stevenson is reader in logic and metaphysics at the University of St. Andrews in Fife, Scotland. He is the author of Seven Theories of Human Nature, The Metaphysics of Experience, and many articles on language, mind, and science.

Henry Byerly is professor of philosophy at the University of Arizona. He is the author of A Primer of Logic and has published many articles on biology as well as on the philosophy of science.