Cosmopolitan originalism: Revisiting the role of international law in constitutional interpretation

The issue of consulting international law in the interpretation of national constitutions is polarising. Both in Australia and abroad, judicial and academic responses have lacked precision and subtlety. While originalists have decried the idea of using contemporary international law to construe constitutions, non-originalists have argued that constitutions should be updated to better reflect international human rights law. This article presents a middle road between two untenable extremes. It revisits the problematic association between originalism and localism, and explores the prospect of cosmopolitan originalism. While insisting upon fidelity to the text of the Australian Constitution, this article recognises that international law is a valuable interpretive resource. In order to challenge the reluctance of originalists to consult contemporary international law, this article outlines several pathways, compatible with moderate originalism, which permit recourse to international law. The role of the common law, the ambiguity inherent in constitutional texts and the distinctive features of international law help to overcome traditional originalist objections. This article finds that although originalism constrains the role which international law can play in constitutional interpretation, originalism is not a barrier to robust engagement with international law.