Part I : The Histories of the Sources of International Law; Section I Sources in the Scholastic Legacy; 1 Peter Haggenmacher: Sources in the Scholastic Legacy: Ius Naturae and Ius Gentium Revisited by Theologians; 2 Annabel S. Brett: Sources in the Scholastic Legacy: The (Re)construction of the Ius Gentium in the Second Scholastic; Section II Sources in the Modern Tradition; 3 Dominique Gaurier: Sources in the Modern Tradition: An Overview of the Sources of the Sources in the Classical Works of International Law; 4 Randall Lesaffer: Sources in the Modern Tradition: The Nature of Europe's Classical Law of Nations; Section III Sources in the 19th Century European Tradition; 5 Milos Vec: Sources in the 19th Century European Tradition: The Myth of Positivism; 6 Lauri Malksoo: Sources in the 19th Century European Tradition: Insights from Practice and Theory; Section IV The History of Article 38 of the Statute of the International Court of Justice; 7 Ole Spiermann: The History of Article 38 of the Statute of the International Court of Justice: 'A Purely Platonic Discussion'?; 8 Malgosia Fitzmaurice: The History of Article 38 of the Statute of the International Court of Justice: The Journey from the Past to the Present; Section V Sources in the Anti-Formalist Tradition; 9 Monica Garcia-Salmones Rovira: Sources in the Anti-Formalist Tradition: A Prelude to Institutional Discourses in International Law; 10 Upendra Baxi: Sources in the Anti-Formalist Tradition: 'That Monster Custom, Who Doth All Sense Doth Eat'; Section VI Sources in the Meta-History of International Law; 11 Tony Carty and Anna Irene Baka: Sources in the Meta-History of International Law: A Phenomenological Reversal of Hegel-From Liberal Nihilism and the Anti-Metaphysics of Modernity to an Aristotelian Ethical Order; 12 Mark Weston Janis: Sources in the Meta-History of International Law: A Little Meta-Theory-Paradigms, Article 38, and the Sources of International Law; Section VII Legal History as a Source; 13 Robert Kolb: Legal History as a Source: From Classical to Modern International Law; 14 Samuel Moyn: Legal History as a Source: The Politics of Knowledge; Part II The Theories of the Sources of International Law; Section VIII Sources in Legal Positivist Theories; 15 David Lefkowitz: Sources in Legal Positivist Theories: Law as Necessarily Posited and the Challenge of Customary Law Creation; 16 Jorg Kammerhofer: Sources in Legal Positivist Theories: The Pure Theory's Structural Analysis of the Law; Section IX Sources in Legal Formalist Theories; 17 Jean d'Aspremont: Sources in Legal Formalist Theories: The Poor Vehicle of Legal Forms; 18 Frederick Schauer: Sources in Legal Formalist Theories: Source Formality, With Special Attention to International Law; Section X Sources in Interpretation Theories; 19 Ingo Venzke: Sources in Interpretation Theories: The International Law-Making Process; 20 Duncan B. Hollis: Sources in Interpretation Theories: An Interdependent Relationship; Section XI Sources in the Meta-Theory of International Law; 21 Matthias Goldmann: Sources in the Meta-Theory of International Law: Exploring the Hermeneutics, Authority, and Publicness of International Law; 22 Alexandra Kemmerer: Sources in the Meta-Theory of International Law: Hermeneutical Conversations; Section XII Legal Theory as a Source; 23 Iain Scobbie: Legal Theory as a Source: Institutional Facts and the Identification of International Law; 24 Alain Papaux and Eric Wyler: Legal Theory as a Source: Doctrine as Constitutive of International Law; Part III The Functions of the Sources of International Law; Section XIII Sources and the Legality and Validity of International Law; 25 Pierre d'Argent: Sources and the Legality and Validity of International Law: What Makes Law 'International'?; 26 Mary Ellen O'Connell and Caleb Day: Sources and the Legality and Validity of International Law: Natural Law as Source of Extra-Positive Norms; Section XIV Sources and the Systematicity of International Law; 27 Michael Giudice: Sources and the Systematicity of International Law: A Philosophical Perspective; 28 Gleider I. Hernandez: Sources and the Systematicity of International Law: A Co-Constitutive Relationship?; Section XV Sources and the Hierarchy of International Law; 29 Erika de Wet: Sources and the Hierarchy of International Law: The Place of Peremptory Norms and Article 103 of the UN Charter Within the Sources of International Law; 30 Mario Prost: Sources and the Hierarchy of International Law: Source Preferences and Scales of Values; Section XVI Sources and the Normativity of International Law; 31 Detlef von Daniels: Sources and the Normativity of International Law: A Post-Foundational Perspective; 32 Nicole Roughan: Sources and the Normativity of International Law: From Validity to Justification; Section XVII Sources and the Legitimate Authority of International Law; 33 Richard Collins: Sources and the Legitimate Authority of International Law: A Challenge to the 'Standard View'?; 34 Jose Luis Marti: Sources and the Legitimate Authority of International Law: Democratic Legitimacy and the Sources of International Law; Section XVIII Sources and the Subjects of International Law; 35 Robert McCorquodale: Sources and the Subjects of International Law: A Plurality of Law-Making Participants; 36 Bruno de Witte: Sources and the Subjects of International Law: The European Union's Semi-Autonomous System of Sources; Section XIX Sources and the Enforcement of International Law; 37 Yuval Shany: Sources and the Enforcement of International Law: What Norms International Law-Enforcement Bodies Actually Invoke?; 38 Antonios Tzanakopoulos and Eleni Methymaki: Sources and the Enforcement of International Law: Domestic Courts-Another Brick in the Wall?; Part IV The Regimes of the Sources of International Law; Section XX Sources of International Human Rights Law; 39 Samantha Besson: Sources of International Human Rights Law: How General is General International Law?; 40 Bruno Simma: Sources of International Human Rights Law: Human Rights Treaties; Section XXI Sources of International Humanitarian Law and International Criminal Law; 41 Raphael van Steenberghe: Sources of International Humanitarian Law and International Criminal Law: Specific Features; 42 Steven R. Ratner: Sources of International Humanitarian Law and International Criminal Law: War Crimes and the Limits of the Doctrine of Sources; Section XXII Sources of International Environmental Law; 43 Catherine Redgwell: Sources of International Environmental Law: Formality and Informality in the Dynamic Evolution of IEL Norms; 44 Jutta Brunnee: Sources of International Environmental Law: Interactional Law; Section XXIII Sources of International Organizations' Law; 45 Jan Klabbers: Sources of International Organizations' Law: Reflections on Accountability; 46 August Reinisch: Sources of International Organizations' Law: Why Custom and General Principles are Crucial; Section XXIV Sources of International Trade Law; 47 Joost Pauwelyn: Sources of International Trade Law: Sources of Law in WTO Dispute Settlement; 48 Donald H. Regan: Sources of International Trade Law: Understanding What the Vienna Convention Says About Identifying and Using 'Sources for Treaty Interpretation'; Section XXV Sources of International Investment Law; 49 Jorge E. Vinuales: Sources of International Investment Law: Theoretical Foundations of Unruly Practices; 50 Stephan W. Schill: Sources of International Investment Law: Multilateralization, Arbitral Precedent, Comparativism, Soft Law; Section XXVI Sources of International Law in Domestic Law; 51 Ingrid B. Wuerth: Sources of International Law in Domestic Law: Domestic Constitutional Structure and the Sources of International Law; 52 Cedric Ryngaert: Sources of International Law in Domestic Law: Relationship Between International and Municipal Law Sources

The question of the sources of international law inevitably raises some well-known scholarly controversies: where do the rules of international law come from? And more precisely: through which processes are they made, how are they ascertained, and where does the international legal order begin and end? This is the static question of the pedigree of international legal rules and the boundaries of the international legal order. Second, what are the processes through which these rules are made? This is the dynamic question of the making of these rules and of the exercise of public authority in international law.


The Oxford Handbook of the Sources of International Law is the very first comprehensive work of its kind devoted to the question of the sources of international law. It provides an accessible and systematic overview of the key issues and debates around the sources of international law. It also offers an authoritative theoretical guide for anyone studying or working within but also outside international law wishing to understand one of its most foundational questions. This Handbook features original essays by leading international law scholars and theorists from a range of traditions, nationalities and perspectives, reflecting the richness and diversity of scholarship in this area.

Professor Samantha Besson holds the Chair of Public International Law and European Law at the University of Fribourg. She studied in Fribourg, Oxford, Bern and New York. She has taught as a visiting professor at the Universities of Oxford, Geneva, Zurich, Duke, Lausanne, and Lisbon. She has also been working in different capacities for The Hague Academy of International Law, first as the Coordinator of the Annual Seminar for Practitioners between 2009 and 2013 and, most recently, as a Director of Studies in July 2013.
Professor Jean d'Aspremont is Chair of Public International Law at the University of Manchester. He also holds a Chair of International Legal Theory at the University of Amsterdam. He studied in Cambridge and Louvain. Before moving to Amsterdam and Manchester, he was Assistant Professor of International Law at the University of Leiden and Director of the LL.M. in Public International Law. He also used to be Guest Professor at the University of Louvain as well as at the University of Lille. He is Editor-in-Chief of the Leiden Journal of International Law.