This book provides a comprehensive introduction to global legal thought. It argues that economic globalization and digitalization have induced significant insecurity about the future of human social organization. While traditional international law as a system based on the consent of national states is in the process of rapid adaptation to its new social preconditions, a variety of transnational regulatory levels compete for legal authority. In this process of change, there is more need than ever to guide the theoretical understanding because academic concepts have a crucial influence on the emerging practice of global law. This book highlights which choices are available and argues that global law requires taking a stand in mutually irreconcilable choices.