Leon R. Kass is the Addie Clark Harding Professor (on leave) in the Committee on Social Thought and the College at the University of Chicago and Hertog Fellow in Social Thought at the American Enterprise Insti-tute. Currently Chairman of the President's Council on Bioethics, he is the author of three books, most recently "Life, Liberty, and the Defense of Dignity: The Challenge for Bioethics, " and coauthor of two more. He lives in Washington, D.C., and Chicago.