Part I. Furthering debate between leading theories of Law -- The Explantory Role of the Weak Natural Law Thesis -- In Defense of Hart -- Law's Authority is not a Claim to Preemption -- The Normative Fallacy Regarding Law's Authority -- The Problem about the Nature of Law vis-a-vis Legal Rationality Revisited : Towards an Integrative Jurisprudence -- Part II. The Power of Legal Systems -- Law as Power : Two Rule of Law Requirements -- A Comprehensive Hartian Theory of Legal Obligation : Social Pressure, Coercive Enforcement, and the Legal Obligations of Citizens -- Law and the Entitlement to Coerce -- Part III. Conceptual Analysis -- Farewell to Conceptual Analysis (in Jurisprudence) -- What Do We Want Law to Be? Philosophical Analysis and the Concept of Law -- Part IV. New Directions -- Legal as a Thick Concept -- Making Old Questions New : Legality, Legal System, and State -- Legal Disagreements and the Dual Nature of Law -- Is There One Right Answer to the Question of the Nature of Law?