It is based on a presentation at a workshop at the University of Leicester on “The Neglected Methodologies of International Law: Empirical, Socio-Legal and Comparative,” on January 31, 2018. The chapter explores a question that many have voiced but which is difficult to answer: why do differences persist in approaches to research and scholarship about international law, as between the United States and Europe, and even within the Anglo-American tradition as between British and American traditions? There are likely many reasons and this is not a study of “causes.” It is an exercise in interpretation. It locates the differences in traditions of inquiry about the law in general and international law more particularly in two frames, one based in the rise of the analytical and empirical sciences in the United States and the other in the rise of the critical tradition in the wake of American Legal Realism. The chapter proceeds on an assumption that to understand how international legal scholars perceive their methods is to be explored from the perspective of the history of the social sciences and the humanities generally. It places the current work of international legal scholars in the context in which they operate within the broader university and community of scientists and humanists.