Principles are part of international law as much as of other legal orders. Nonetheless, beyond principles referred to the functioning of IL, or the sector related discipline in discrete fields, those fundamental principles identifying the raison d’etre, purpose and value of the legal international order, as a whole, remain much disputed, to say the least. In addressing such a problem, one that deeply affects interpretation and legal adjudication, this article acknowledges the limits and weakness of legal positivism in making sense of the inter- and supra-national legal order(s). It appraises also the novel from the late Ronald Dworkin, concerning IL, and its consequence for interpretivism in the international environment, so different from State political communities and their ‘integrity’. Finally, some recent cases before international Courts shall be considered, that expose difficulties stemming from traditional legal positivist strictures, and explain how judicial reasoning actually profits from asking further questions of principles. All the more so, if the issues at stake happen to be covered by two or more diverging legal regimes, that would, per sé, lead to opposite outcomes.