H L A Hart's The Concept of Law is the classic text for the study of jurisprudence and legal philosophy and is probably the most important work of legal philosophy written this century. This second edition is particularly valuable as it combines Hart's original text with a postscript, in which he responds to criticisms of his theory levelled by such notable scholars as Dworkin, Fuller and Finnis. Written by him but only discovered after his death, it has been ably edited by Joseph Raz and Penelope Bulloch of Balliol College, Oxford.