Abstract

Habermas and Rawls presented distinctive theories of new world order at the turn of the new century: the Constitutionalization of International Law and the Law of Peoples. Both theories aim to promote peace and justice all over the world. Unfortunately, their theories have been ignored by mainstream IR theorists. Since few scholars make a deep comparative study between Rawls’s Law of Peoples and Habermas’s Constitutionalization of International Law to reveal their crucial difference, this paper aims to fill this gap by clarifying their essential difference and preliminarily exploring how to formulate their proper relationship. I argue that Habermas’s project is a legalistic peace theory. In contrast, Rawls’s Law of Peoples is a modified form of democratic peace theory, putting hope for international peace on the improvement of the domestic political system of sovereign entities. Finally, I present a tentative suggestion to address their relationship, returning to Kant’s systems approach.