The concept of an international legal concept

International lawyers refer to concepts such as ‘State immunity’, ‘the high seas’, ‘jus cogens’ and many others as genre-specific – as ‘concepts of international law’. This practice presupposes a definition that can help to distinguish concepts of international law from other concepts used by participants in international legal discourse. This article draws attention to the great complexity of this issue. It starts from the assumption that all genre-specific concepts have an importance for the structuring and development of the branch of activity to which they are said to belong. It arrives at the conclusion that there is in fact not just one way of defining a concept of international law, but several. These definitions are inextricably tied to different conceptions of law. The article argues that it is important that international lawyers openly acknowledge this relationship between different theories of law and different conceptions of an international legal concept. Doing so will enhance the rationality of legal communication and the productivity of international legal discourse.