Introduction1 Key Positions in the Debate2 The Nexus of Normative DisagreementPART 1 ESTABLISHING THE PGC AS A SUPREME MORAL PRINCIPLE1 The PGC as a Supreme Moral Principle1 Introduction2 The Dialectical Necessity of Morality3 Philosophical Criticisms of the PGC4 Conclusion2 The PGC in Raz's Hierarchy of Reasons1 Introduction2 Raz on the Nature of Reasons3 Resolving Conflicts between Reasons4 ConclusionPART 2 ESTABLISHING PERMISSIBILITY WITH REFERENCE TO THE PGC AS A NECESSARY CONDITION OF A RULE'S LEGAL VALIDITY3 Agency, Morality and Law1 Introduction2 The PGC and Legal Norms3 The Operation of the PGC within a Legal System4 Conclusion4 Raz and Legitimate Legal Authority1 Introduction2 Raz, Legal Authority and the Contingency Thesis3 Authority to Make Law and the Sources Thesis4 Systemic Functionality5 Obligations to Obey the Law6 Conclusion5 Contemporary Inclusive Positivism1 Introduction2 David Lyons and Formalism3 Incorporationism and Jules Coleman4 The Moderate Incorporationism of Matthew Kramer5 ConclusionConclusionBibliographyIndex