This book develops a general philosophical theory about the nature of law and its relationship with morality called inclusive legal positivism. In addition to articulating and defending his own version of legal positivism, which is a refinement and development of the views of H.L.A. Hart as expressed in his classic book The Concept of Law, the author clarifies the terms of current jurisprudential debates about the nature of law. These debates are often clouded by failures to appreciate that different theorists are offering different kinds of theories and attempting to answer different questions. The clarity of Waluchow's work will help to remove the confusion often present in jurisprudential debate.