‘Don’t come with your lessons in morality’: ontological imperialism and the MERCOSUR-EU intellectual property negotiations

International trade governance is often framed as neutral and technocratic, emphasizing fairness, modernization, and mutual benefit. Yet, vast inequalities between the Global North and South persist, not as mere byproducts of developmental progress but the endurance of an imperial order historically structured by domination, extraction, and racialized hierarchies. Scholarship has illuminated the material and institutional mechanisms underpinning these inequalities, including through trade; however, less attention has been paid to their ontological foundations – that is, to the categories that define what counts as legitimate economic activity and which interests, claims, and forms of authority are recognized as legitimate within trade governance. This article develops the concept of ontological imperialism to capture how such categories are embedded in trade agreements and negotiations in ways that stabilise hierarchy at the level of meaning as well as material exchange. Drawing on 62 semi-structured interviews with negotiators, business representatives, and civil society actors, alongside official negotiation texts and statements, the paper examines the Southern Common Market-European Union (MERCOSUR-EU) trade negotiations as a case study of ontological imperialism in trade-related intellectual property governance. While MERCOSUR states resisted some Trade Related Intellectual Property Rights (TRIPS)-plus provisions, the broader negotiation framework constrained alternative approaches, reinforcing Western legal and economic logics. The study contributes to debates on imperialism in international political economy (IPE), trade governance, and decolonial critiques, demonstrating how trade agreements do not simply reflect inequalities but actively reproduce them, narrowing the horizons of legitimate economic policy and development.