Open Access

Thomas Kleinlein

• In this chapter, I examine the relationship between customary international law and general principles of law. Both are distinct sources of public international law (Art. 38(1)(b) and (c) of the Statue of the International Court of Justice). In a first step, I analyze the different meanings of principles as a “source” of international law. Second, I consider different approaches to principles as a norm type in legal theory. Third, I discuss attempts in international legal doctrine to facilitate conceptual issues by either unifying general principles as a source with the source of customary international law or by equating general principles as a source and as a norm type. Finally, I propose that the delimitation between customary international law and general principles of law as sources of international law should follow the distinction between situations dominated by factual reciprocity (which justify customary norms) and situations where such factual reciprocity is absent (which justify general principles). The jurisgenerative processes leading to the emergence of general principles of international law are processes of changing identities and argumentative self-entrapment.