Document Type


Publication Date



This article draws on the tradition of cosmopolitanism to offer a normative framework for the integration of democratic constitutional systems. The laterally conducted constitutional integration, which takes place outside formal institutional settings, remains under-theorized despite its transformative effect on constitutional law around the world. This article uses Kant’s tripartite system of public law as presented in Perpetual Peace – ius civitatis (domestic political right), ius gentium (international political right), ius cosmopoliticum (cosmopolitan right) – to explain, defend and steer ongoing phenomena of constitutional integration.

By contrast to other scholarly accounts, which associate a cosmopolitan view to top-down approaches to institutional reform at the international level or to universal moral demands, my account takes domestic constitutionalism as both starting and end points. In this sense, I defend a bottom-up version of cosmopolitanism. Cosmopolitanism from the ground-up preserves the primacy of the domestic jurisdictions: each domestic constitutional order retains the filter of its own discourse and structures as it integrates and internalizes the experiences of other constitutional orders. Cosmopolitanism helps to understand ongoing phenomena of constitutional integration because it rejects methodological nationalism in constitutional analysis. It also justifies these phenomena by showing that cross-jurisdictional integration is compatible with the constitutional democratic commitment to self-government.