For it to be legitimate, this study must be carefully circumscribed. The problem it purports to address is not that of the legitimacy of the structures or organs of the European Union but that of the integration of EU law into the legal systems of its Member States. By what title can EU law impose its norms on national legal systems, and so much so that the conditions in which rule-making is organized within those orders are affected to the point of turmoil? On what conditions can EU law be integrated? What consequences does such normative integration hold for the way in which relations among legal systems are described? Our discussion addresses not so much the actual dynamics of legal integration but rather the discourses of justification it produces and on which it rests.