I. INTRODUCTIONTo what extent are the existence and content of law dependent on morality? Legal Positivism is generally understood to answer: Not at all; the existence of law is one thing, its merit or demerit another thing entirely. Positivism’s historical rival, Natural Law Theory, is widely understood to answer: To a very large extent indeed: An unjust law seems to be no law at all. Recent developments in jurisprudence have rendered these understandings highly questionable and potentially misleading. Natural law theorists like John Finnis and Robert George deny that justice was ever thought by contemporary or traditional defenders of natural law theory to be a necessary condition of law,See, e.g., John Finnis, The Truth in Legal Positivism, and Robert P. George, Natural Law and Positive Law, both in THE AUTONOMY OF LAW (R. George ed. 1996). whereas positivists like H.L.A. Hart, Jules Coleman, and this author assert that morality can indeed play a key role in determining the existence and content of valid laws. But not all self-avowed positivists agree with the line pursued by Hart et al. Many follow the lead of positivism’s greatest contemporary critic, Ronald Dworkin, in claiming that this new brand of positivism, variously termed “incorporationism,”See, e.g., Jules Coleman, Authority and Reason, in THE AUTONOMY OF LAW, supra note 1; and Incorporationism, Conventionality, and the Practical Difference Thesis, 4 LEGAL THEORY 381–425 (1998). “soft positivism,”H.L.A. Hart, Postscript in THE CONCEPT OF LAW (P. Bullock & J. Raz eds., 1994). or “inclusive legal positivism,”Waluchow, INCLUSIVE LEGAL POSITIVISM (1994), hereinafter referred to as ILP. Inclusive positivism, the legal theory, will be referred to as ILP. is either an untenable version of positivism or no version of positivism at all. Among the central challenges to ILP posed by its positivist critics is an objection first raised by Joseph Raz: that ILP (like Natural Law Theory and Dworkin’s “law as integrity”) is inconsistent with the practical authority that law necessarily claims for itself.