He received his Ph.D. from Princeton in 1980. His research interests center on contemporary metaethics and normative ethics, especially consequentialism. He is the author of the book Facts, Norms, and Values and a co-editor (with Stephen Darwall and Allan Gibbard) of Moral Discourse and Practice. He has also written several seminal papers on scientific explanation.
He has been a visiting professor at the University of California, Berkeley, and Princeton University, and is a distinguished professor at the University of Michigan.