Ph.D., Brown University, 1970
His areas of concentration are the philosophy of law, ethical theory, and medical ethics. He has published around two dozen articles in journals such as Mind, American Philosophical Quarterly, International Philosophical Quarterly, Philosophy and Public Affairs, and The Journal of Philosophy, and he is also co-editor (with Michael J. Meyer) of The Constitution of Rights (Cornell University Press, 1992). He has ongoing research on the topic of dignity.