John Langan is a Jesuit priest with a doctorate in philosophy from the University of Michigan. He also holds graduate degrees in classics and theology. Since 1987 he has been the Rose Kennedy Professor of Christian Ethics in the Kennedy Institute of Ethics at Georgetown. He has also taught at Yale Divinity School, Drew University, and Loyola University Chicago. His research interests include: 1) ethics and international affairs, especially applications of just war theory; 2) business ethics; 3) human rights in theory and practice; 4) capital punishment; 5) Catholic social teaching; 6) the place of religion in liberal political thought; 7) the ethical theories of St. Thomas Aquinas and St. Augustine. He is currently working on a manuscript on the ethics of humanitarian intervention.

Fr. Langan has served as a consultant to the Chemical Bank (New York) and to the U.S. Navy Corps of Chaplains. He currently serves on the boards of the Bon Secours Health System (Maryland), the Society of Christian Ethics, Theological Studies, and the Georgetown University Press. He is chair of the American section of the Council on Christian Approaches to Defense and Disarmament.

Recent publications include: "Developing the Just War Tradition in a Multicultural World," in Peacemaking (Washington DC: US Catholic Conference, 1994); "Nationalism, Ethnic Conflict, and Religion," Theological Studies 56 (March 1995), 122-136; "Ethics, Business, and the Economy," Theological Studies 55 (March 1994), 105-123; "Proportionality, Charity, and the Use of Nuclear Weapons," The Thomist (1996); "Religious Pacifism and and Quietism: A Taxonomic Approach and a Catholic Response," in Pacifism and Quietism in the Abrahamic Faiths, ed. J. Patout Burns (1993). He has edited Catholic Universities in Church and Society (Georgetown University Press, 1993) and A Moral Vision for America (Georgetown University Press, 1998), a collection of the addresses of Cardinal Bernardin on public policy and the consistent ethic of life.