Article 38 of the Statute of the International Court of Justice requires the Court to apply as sources, in the first instance, (1) treaties and (2) customary international law. However, this same article also authorizes the court to apply “the general principles of law recognized by civilized nations“. Thus, should neither treaty or custom prove adequate to resolve a contentious question, resort may be had to “general principles” as a subsidiary source. The general principles are commonly recognized as the norms existing in the municipal law of the majority of nations. When such a norm (i.e. the rule against judicial bias) has achieved the requisite degree of usage, it may thus be recognized as a subsidiary source of the substantive content of international law.