What is social justice? In "Theories of Justice" Brian Barry provides a systematic and detailed analysis of two kinds of answers. One is that justice arises from a sense of the advantage to everyone of having constraints on the pursuit of self-interest. The other answer connects the idea of justice with that of impartiality. Though the first book of a trilogy, "Theories of Justice" stands alone and constitutes a major contribution to the debate about social justice that began in 1971 with Rawls's "A Theory of Justice."