This Oxford Handbook examines the sources of international law, how the understanding of sources changed throughout the history of international law; how the main legal theories understood sources; the relationship between sources and the legitimacy of international law; and how sources differ across the various sub-areas of international law.

PART I : THE HISTORIES OF THE SOURCES OF INTERNATIONAL LAW; SECTION I SOURCES IN THE SCHOLASTIC LEGACY; SECTION II SOURCES IN THE MODERN TRADITION; SECTION III SOURCES IN THE 19TH CENTURY EUROPEAN TRADITION; SECTION IV THE HISTORY OF ARTICLE 38 OF THE STATUTE OF THE INTERNATIONAL COURT OF JUSTICE; SECTION V SOURCES IN THE ANTI-FORMALIST TRADITION; SECTION VI SOURCES IN THE META-HISTORY OF INTERNATIONAL LAW; SECTION VII LEGAL HISTORY AS A SOURCE; PART II THE THEORIES OF THE SOURCES OF INTERNATIONAL LAW; SECTION VIII SOURCES IN LEGAL POSITIVIST THEORIES; SECTION IX SOURCES IN LEGAL FORMALIST THEORIES; SECTION X SOURCES IN INTERPRETATION THEORIES; SECTION XI SOURCES IN THE META-THEORY OF INTERNATIONAL LAW; SECTION XII LEGAL THEORY AS A SOURCE; PART III THE FUNCTIONS OF THE SOURCES OF INTERNATIONAL LAW; SECTION XIII SOURCES AND THE LEGALITY AND VALIDITY OF INTERNATIONAL LAW; SECTION XIV SOURCES AND THE SYSTEMATICITY OF INTERNATIONAL LAW; SECTION XV SOURCES AND THE HIERARCHY OF INTERNATIONAL LAW; SECTION XVI SOURCES AND THE NORMATIVITY OF INTERNATIONAL LAW; SECTION XVII SOURCES AND THE LEGITIMATE AUTHORITY OF INTERNATIONAL LAW; SECTION XVIII SOURCES AND THE SUBJECTS OF INTERNATIONAL LAW; SECTION XIX SOURCES AND THE ENFORCEMENT OF INTERNATIONAL LAW; PART IV THE REGIMES OF THE SOURCES OF INTERNATIONAL LAW; SECTION XX SOURCES OF INTERNATIONAL HUMAN RIGHTS LAW; SECTION XXI SOURCES OF INTERNATIONAL HUMANITARIAN LAW AND INTERNATIONAL CRIMINAL LAW; SECTION XXII SOURCES OF INTERNATIONAL ENVIRONMENTAL LAW; SECTION XXIII SOURCES OF INTERNATIONAL ORGANIZATIONS' LAW; SECTION XXIV SOURCES OF INTERNATIONAL TRADE LAW; SECTION XXV SOURCES OF INTERNATIONAL INVESTMENT LAW; SECTION XXVI SOURCES OF INTERNATIONAL LAW IN DOMESTIC LAW

Critically examines the doctrines, practices, discourses, and debates on the sources of international law Offers insight from well-established and respected academics, whose contributions seek to extend the limits of traditional thinking on the scope of international law itself Provides analysis through a dialectical structure with the first author directly addressing the issue, and the second offering critical comment and their own theoretical and analytical insights

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.

Critically examines the doctrines, practices, discourses, and debates on the sources of international law Offers insight from well-established and respected academics, whose contributions seek to extend the limits of traditional thinking on the scope of international law itself Provides analysis through a dialectical structure with the first author directly addressing the issue, and the second offering critical comment and their own theoretical and analytical insights