This chapter introduces the central legal and political interpretations of the European Union (EU). The Court of Justice of the European Union (CJEU) suggests a federalist legal account when it speaks of EU law as a ‘new legal order’ and as ‘autonomous’ from international law and the law of the member states. This doctrine has met with resistance by the courts of the member states, which have refused to apply EU law without reference to their domestic constitution. The courts’ views can be seen as either a ‘constitutional’ approach, which we find in Neil MacCormick’s ‘pluralism’ under international law, or in the ‘pluralism’ defended by Mattias Kumm, Neil Walker, and others. But the general legal architecture of the EU is not only a theoretical but also a political problem. These legal interpretations correspond to rival political approaches, namely ‘federalism’, ‘statism’, and a new view proposed in this book ‘internationalism’. The most challenging political view of the EU, articulated for example by the historian Noel Malcolm, believes that it is actually a serious risk to self-government and democracy. Any legal and political interpretation of the treaties supporting the legitimacy of the EU requires that we have an effective response to this democratic challenge. Can the EU be democratically legitimate?