Legal Theory As a Source of International Law
This chapter argues that legal theory provides conceptions of the sources of international law that differ according to time and place. It employs Neil MacCormick’s explanation of institutional order to argue that conceptual understandings of law, including international law, are socially constructed. The chapter starts from John Austin’s denial that international law possesses the quality of law and then considers the function that sovereignty has played in some explanations of international law and its sources. Afterwards, the analysis focuses on the paradigm shift that Hugo Grotius introduced into natural law, and consequently into international law, by substituting consent for theology as its underpinning explanation. The chapter also considers twentieth-century transatlantic variants of natural law and examines three influential British theorists—James Brierly, Gerald Fitzmaurice, and Hersch Lauterpacht. Finally, before drawing some conclusions, the chapter examines the more instrumentalist naturalism of the New Haven School.