*''The Foundations of Christian Bioethics''. Lisse: Swets & Zeitlinger, 2000. (ISBN 902651557X)
*''The Foundations of Bioethics'', 2nd edition. New York: Oxford University Press, 1996. (ISBN 0195057368)
*''Bioethics and Secular Humanism: The Search for a Commmon Common Morality''. Trinity Press, 1991. (ISBN 1563380005)
*''Mind-Body: A Categorical Relation''. Nijhoff: Springer, 1973. (ISBN 9024715504)