The History of (Essential) State Functions

Abstract

Article 4(2) of the Treaty on European Union plays a central role in balancing the exercise of European Union competences with respect for the national identities and essential state functions of the Member States. Despite its constitutional significance, the precise scope and meaning of “essential state functions” remain contested. This paper adopts a historical and theoretical approach to clarify the origins and normative foundations of the concept, tracing its intellectual development from early theories of sovereignty through Enlightenment constitutional thought to modern democratic state theory. Building on this historical analysis, the paper applies a post-functionalist framework informed by the concept of practical identity to explain how essential state functions operate as expressions of national and constitutional identity within the European constitutional order. It argues that essential state functions are not merely administrative competences but normative practices through which states sustain their constitutional self-understanding and democratic legitimacy over time. The study further demonstrates that the deliberate openness of Article 4(2) TEU – particularly the relationship between constitutional structures and essential state functions – provides the flexibility necessary to accommodate constitutional diversity within the Union, while also giving rise to interpretative challenges that continue to shape the evolving balance between European integration and Member State autonomy.