The methodology indicated in doctrinal writings is generally described as involving two steps: first, the identification of a principle that is common to municipal legal orders belonging to the main legal systems of the world; secondly, the distillation of the essence of the principle.17 To these is often added a third, namely modifying the principle to suit the particularities of international law.18 This methodology is a fairly good reflection of the voluntarist approach to general principles, which, as I have noted, is the object of a reasonably solid doctrinal and jurisprudential consensus. However, the manner in which general principles have been handled by the ICJ and its predecessor, the PCIJ, reveals a disjuncture between doctrine and the practice of judges. While positivism, and more in particular the voluntarist approach, appears to have prevailed, an analysis of the jurisprudence reveals that, in fact, an approach tinged with natural law thinking has generally been employed. Alfred Verdross's classification of general principles describes well the approach taken: general principles may be understood as principles derived directly from the concept of law, such as good faith; as principles derived from the nature of a legal institution, such as principles necessary for conventions; or as principles derived from municipal law.19 In fact, judges of the PCIJ did.