My article explores the source ‘general principles of international law’ from the point of view of comparative law scholarship. As international law’s agenda becomes wider and more ambitious, areas of overlap between international and municipal law become ever larger, and interactions between the two levels more numerous. It might seem reasonable to assume that general principles of law, a source which establishes an important point of contact between international and municipal law, would come into its own in such an environment. This has not been the case, however. One possible explanation is hesitation on the part of international judges to identify rules whose formal validity as rules of international law is rather tenuous. Another possible explanation is the highly unsatisfactory nature, both in theory and in practice, of the methodology currently applied to identify general principles of law. The debates at the international level regarding general principles map onto those at the municipal level concerning the ‘borrowing’ of rules from one legal system by another. It makes sense, therefore, to look into the controversies over ‘borrowing’ that play out in scholarship on comparative law, in order to gain some insights into the difficulties generated by the source general principles of law, as well as ways of alleviating these difficulties. I argue that particular attention ought to be paid to strands of comparative law scholarship which take issue with a functional approach – to put it starkly, an approach that treats legal rules as pieces that can be extracted from one machine and inserted into another – and which place emphasis on the processes through which legal systems can learn from one another.
Blog of the European Journal of International Law