Leon R. Kass is the Addie Clark Harding Professor in the Committee on Social Thought and the College at the University of Chicago and Hertog Fellow in Social Thought at the American Enterprise Institute. A native of Chicago, Dr. Kass was educated at the University of Chicago where he earned his B.S. and M.D. degrees (1958; 1962) and at Harvard where he took a Ph.D. in biochemistry (1967). Afterwards he did research in molecular biology at the National Institutes of Health, while serving in the United States Public Health Service. Shifting directions from doing science to thinking about its human meaning, he has been engaged for over thirty-five years with ethical and philosophical issues raised by biomedical advance, and, more recently, with broader moral and cultural issues. From 1970-72, Dr. Kass served as Executive Secretary of the Committee on the Life Sciences and Social Policy of the National Research Council/National Academy of Sciences, whose report, Assessing Biomedical Technologies, provided one of the first overviews of the emerging moral and social questions posed by biomedical advance. He taught at St. John’s College, Annapolis, MD, and served as Joseph P. Kennedy, Sr., Research Professor in Bioethics at the Kennedy Institute of Ethics at Georgetown University, before returning in 1976 to the University of Chicago where he has been an award-winning teacher deeply involved in undergraduate education and committed to the study of classic texts. He has been a member of the National Council on the Humanities of the National Endowment for the Humanities. His books include: Toward a More Natural Science: Biology and Human Affairs; The Hungry Soul: Eating and the Perfecting of Our Nature; The Ethics of Human Cloning (with James Q. Wilson); Wing to Wing, Oar to Oar: Readings on Courting and Marrying (with Amy A. Kass); Life, Liberty, and the Defense of Dignity: The Challenge for Bioethics; and The Beginning of Wisdom: Reading Genesis. His widely reprinted essays in biomedical ethics have dealt with issues raised by in vitro fertilization, cloning, genetic screening and genetic technology, organ transplantation, aging research, euthanasia and assisted suicide, and the moral nature of the medical profession. From 2001 to 2005, Dr. Kass served two terms as Chairman of the President’s Council on Bioethics; under his leadership the Council published six major books and a white paper on topics ranging from human cloning and human dignity to ethical caregiving in our aging society. In 2003, he was one of four inaugural recipients of the Bradley Prize. In May 2009 the Jefferson Lecture was given for the National Endowment for the Humanities. Dr. Kass is married (48 years) to Amy Apfel Kass, Senior Lecturer in the Humanities at the University of Chicago and Senior Fellow at the Hudson Institute. The Kasses have two married daughters and four granddaughters.