Conclusions: Testing General Principles of Law in International Investment Law: between Principles and Rules of International Law

Summing up the analysis put forward in Part III of the volume on General Principles and the Coherence of International Law, the contribution aims to provide three perspectives under international investment law through which to assess whether general principles of law provide a catalyst for normative legal cohesion. The assessment in question, both on the substantive and the procedural law levels, is of a two-pronged character. First, it considers whether general principles of law may provide a factor for internal consistency within international investment law itself. Second, it tests the role played by general principles in the relationship between international investment law and public international law; namely, either in the sense of attesting mutual integration or rather testifying to some form of sub-systemic lex specialis ratione materiae or even to a hybrid and self-contained regime.