The Light and its Colors: The Intrinsic Unity of International Law

This article advances a philosophical thesis about the ontological structure of international law: that the international legal system possesses an intrinsic unity, while the pluralism observable in its regional, cultural, and doctrinal variations constitutes an accidental property in the technical Aristotelian sense; a contingent feature that does not alter the essential nature of the system. Drawing on the substance/accident distinction as developed in Aristotelian metaphysics and refined in the Avicennian tradition, the article argues that the validity of international legal norms inheres in the system as a whole, not in any of its regional manifestations. The Eastern perspective on international law, examined here as a paradigm case, does not constitute a parallel or competing legal order; it represents one expression among several of the same underlying normative structure. The article distinguishes carefully between formal unity (shared secondary rules), substantive unity (peremptory norms reflecting fundamental values), and ontological unity (the essential character of the legal system as such), arguing that the first two rest upon the third. It proposes five practice-level criteria – shared sources, reciprocal recognition, common validity-conferring structures, institutional interoperability, and mutual intelligibility of legal argumentation – whose cumulative satisfaction supplies the strongest available evidence of that ontological unity, and whose joint failure would defeat the thesis. The article engages directly with the postcolonial critique that universalism reproduces imperial logic, and contends that genuine ontological universalism, which welcomes diverse manifestations, must be distinguished sharply from the false universalism that imposes one tradition’s contingent features as universal essence. Readers who resist the metaphysical commitment may read the substance/accident framework as a heuristic for distinguishing constitutive from contingent features of legal practice; the substantive thesis is the same in either register.