This chapter assesses the theoretical adequacy of legal positivism in explanation of several forms and features of transnational law. We suggest that while legal positivism emerged as a philosophical account of state law in the seventeenth, eighteenth, and nineteenth centuries, its connection to state law is best viewed as historical and contingent rather than conceptual and necessary. Among the two core commitments of legal positivism, while the separation thesis requires no modification from its original form, the social fact thesis must be revised and developed to explain the character of transnational law. We also show how the exercise of revising a philosophical theory of law such as legal positivism provides an opportunity to illustrate the continuity between conceptual, empirical, and evaluative studies of transnational law.
