A thought-provoking treatise firmly and welcomingly entrenched in the positivist trasition, attempting to explain the juridical nature of the European Union and its relationship with the member states in the context of the notions of statehood and sovereignty. Neil MacCormick considers a new juridical and political concept - a post-sovereign commonwealth with its own distinct legal order subject to the constitutional constraints imposed by the member states. In this post-sovereign world there lies no one sovereign but a diffusion of power to regional, state or European levels. It is a world of international pluralism. It seems - although this is not necessarily accepted - that it is a pluralism which obtains its legitimacy from an international legal order, capable of engendering more of the same until there is one such pluralistic order. The EU - if it fits the post-sovereign mould - provides the template for this new world. The treatise contains interesting discussions on the importance and nature of democracy and on nationalism. At the heart of this treatise lie some very interesting ideas. The face of this treatise, however, is some occasional dense writing. The reasoning is not always persuasive. Nevertheless it is well worth a close reading and repays careful thought.