Constitutional Identity and the Ontological Reproduction of Statehood in the European Union

European constitutional debates frequently orbit the technicalities of institutional legitimacy, the allocation of competences, or the democratic performance of the European Union (EU). Whether framed through the lens of the "democratic deficit," the principle of subsidiarity, or constitutional pluralism, these mainstream approaches operate on a foundational assumption: the Member State exists as a given, ontologically stable entity. It is presumed to be a sovereign, territorially bounded polity possessing supreme constitutional authority. While this assumption facilitates functional analysis, it obscures a more profound question: how do states ontologically reproduce themselves in a political order that fundamentally undermines the exclusivity and unity of sovereignty? Critical scholarship in political sociology and international relations challenges the premise that states are pre-given actors with fixed interests. Instead, many theorists argue that states emerge through performative, institutional, and discursive practices that continuously produce the state as a recognizable entity. Similarly, genealogical accounts demonstrate that sovereignty and territoriality are historically contingent constructs, rather than natural or inevitable features of the political landscape. From this perspective, statehood is not a structural prerequisite but an ontological project—an ongoing accomplishment. The EU serves as a unique pressure cooker that renders this ontological dimension visible. By generating a supranational constitutional order that claims primacy and direct effect, the EU destabilizes the apparent naturalness of state sovereignty and exposes its contingent foundations. Member States remain states, yet they must operate within an order where sovereignty is shared, constitutional normativity is dispersed, and citizens hold multiple political subject positions. This condition produces what some call "ontological insecurity"—a disruption of a state's narrative continuity and its sense of existential coherence. This paper argues that the doctrine and practice of constitutional identity functions as a key mechanism through which EU Member States reproduce themselves ontologically. Although scholars and courts typically frame constitutional identity as a legal device to protect non-transferable competencies, safeguard national values, or resist EU encroachment, such accounts remain overly doctrinal. This paper posits that constitutional identity performs a deeper function: it articulates the necessary conditions for a state to exist as that state, stabilizing its normative, institutional, symbolic, territorial, and peoplehood ontologies. The argument proceeds in six steps: developing a conceptual framework for state ontology; reconceiving constitutional identity as a technology of ontological boundary-work; analyzing empirical cases (such as for instance Germany, Poland, Hungary, France, Spain, Italy, Latvia/Lithuania); examining the EU as an ontological competitor; theorizing the implications for European political order; and concluding with an evaluation of this ontological device.