It is generally understood today-although lawyers not trained in international law may still rebel against the idea-that principles or rules of international law have a real existence and create obligations for States and individuals, even though they may not be enforced by sanctions. That legal norms occupy a place in international law, even though they do not create rights or duties, is a more radical assertion, but one, I believe, which may be defended. Of course, the great majority of norms which are laid down in international agreements are susceptible of enforcement through the wellknown mechanisms, including resort to international tribunals and national courts, which ensure respect for these obligations. But there are norms of various degrees of cogency, persuasiveness, and consensus which are incorporated in agreements between States but do not create enforceable rights and duties. They may be described as " soft" law, as distinguished from the " hard " law consisting of treaty rules which States expect will be carried out and complied with. If one State undertakes to pay another a stipulated sum of money in settlement of certain claims or a State by treaty accepts limitations on its power to tax aliens, it is expected that those duties will be carried out. The differences among various norms of customary international law, in terms of degree of acceptance, of precision, of relevance, are well understood. We speak of a " regional rule of international law," of a " principle of Socialist international law," of an " emergent principle of international law," of an " obsolete rule of international law," of a " generally accepted rule of international law," or even of a " rule enunciated in British practice." The same variety of texture is to be found in international agreements, in which two or more States have agreed upon the formulation of certain norms that will be given application between or amongst them. Judge Baxter As this article (a revised version or the Third F. A. Mann Lecture, delivered in Lincoln's Inn Old Hall, London, on Oct. 16, 1979) was passing through the Press, the Institute teamed, with the greatest regret, of the untimely death of Judge Baxter. He had been for many years Professor of International Law at Harvard University and Editor in Chief of the American Journal of International Law. He was appointed to the International Court of Justice in 1978. His passing will be mourned by all those who knew him, either through personal contact, his writing or his great influence in many fields of International Law.