He received a Bachelor of Arts in Honours Literae Humaniores in 1971 from Balliol College, Oxford, and a PhD in philosophy from Princeton University in 1975. He was Professor of Philosophy at Lehigh University from 1975 to 1989. He was Professor of Philosophy at Calvin College from 1989 to 2003. He has been the Noah Porter Professor of Philosophical Theology at Yale University since 2003.
The son of the British utilitarian R. M. Hare, Hare has created an ethical theory which integrates Kantian deontological ethics with utilitarian consequentialism. Unlike his father's, Hare's philosophy is specifically Christian and includes elements of Divine command theory.
In his 1996 book The Moral Gap, he outlined and analyzed various philosophers' responses to the gap — which he finds to be identified in Kant's writings — between human ethical ability and human ethical duty; between what is possible and what is required. He sees this "moral gap" as ultimately unbridgable apart from religion.
- God and Morality: A Philosophical History, (Malden, Mass.: Blackwell Publishing, 2007). ISBN 0-631-23607-4
- Why Bother Being Good?, (Downers Grove, Ill.: InterVarsity Press, 2002). ISBN 0-8308-2683-1
- God’s Call, (Grand Rapids, Mich.: Eerdmans, 2001). ISBN 0-8028-4997-0
- The Moral Gap (New York: Oxford University Press, 1996). ISBN 0-19-826957-9
- Ethics and International Affairs, 1982, with Carey B. Joynt
- Plato's Euthyphro, 1981