Arthur L. Caplan is Emmanuel and Robert Hart Professor and chair of the Department of Medical Ethics at the University of Pennsylvania School of Medicine in Philadelphia. He is the author or editor of many books; recent volumes he has coedited include The Human Cloning Debate (Berkeley Hills Books, 2004), Health, Disease and Illness: Concepts in Medicine (Georgetown University Press, 2004) and Who Owns Life? (Prometheus Books, 2002).