John Rawls's A Theory of Justice was published in 1971. It was immediately recognized as a classic, a work of enormous importance. Robert Nozick, who disagreed with Rawls on many points, described it as “a powerful, deep, subtle, wide-ranging, systematic work in political and moral philosophy which has not seen its like since the writings of John Stuart Mill, if then.” Many others echoed this view.

Between 1971 and his death in 2002 Rawls published several more books and many articles, along with a revised edition of A Theory of Justice. In Rawls's later works, the main outlines of his theory remained intact, but he clarified some points, changed his position on others, and addressed several questions he had largely ignored in Theory, among them international justice, political legitimacy, and the role of religion in a democratic society. Rawls scholars have debated, and will no doubt continue to debate, the significance of these changes and additions, and the extent to which they represent departures from the letter and spirit of Theory.

Rawls clearly regarded Mill as a theorist of the first rank. He learned from Mill, and saw himself, in part, as building on Mill's ideas in On Liberty. It is also clear, both in A Theory of Justice and in his later works, that he saw Mill's arguments as flawed in important ways. In A Theory of Justice he identifies what he sees as the main weaknesses in Mill's defense of liberty.