Lewis E. Hahn is a professor emeritus of philosophy at Southern Illinois University Carbondale, where he currently is editor of the "Library of Living Philosophers." He has published numerous books and articles over the past sixty years. Among his books are "A Contextualistic Theory of Perception," "The Elements of Logic "(with Cecil H. Miller), and "Value: A Cooperative Inquiry "(with Ray Lepley, John Dewey, and others).