This rich and remarkable volume offers an overview of the most important schools, movements and trends which make up the theoretical landscape of contemporary international law, as well as the works of over 500 authors. It moves beyond generalization and examines how the relevant literature deals with the basic issues of the international legal system, such as international obligations, legitimacy, compliance, unity and universality, the rule of law, human rights, use of force and economics. It offers insights into the addressees (the state, international organizations, individuals and other private persons), and the construction of international law, including law-making, the relationship between norms, and interpretation. Moreover, it widens the discourse by addressing old, yet enduring, as well as new concerns about the functioning of the international legal system, and presents views of non-international lawyers and political scientists regarding that system. It is a valuable analysis for researchers, students, and practitioners.