In the contemporary world, there are many democratic states whose minority nations have pushed for constitutional reform, greater autonomy, and asymmetric federalism. Substate national movements within countries such as Spain, Canada, Belgium, and the United Kingdom are heterogeneous: some nationalists advocate independence, others seek an autonomous special status within the state, and yet others often seek greater self-government as a constituent unit of a federation or federal system. What motivates substate nationalists to prioritize one constitutional vision over another is one of the great puzzles of ethnonational constitutional politics. In Visions of Sovereignty, Jaime Lluch examines why some nationalists adopt a secessionist stance while others within the same national movement choose a nonsecessionist constitutional orientation. Based on extensive fieldwork in Canada and Spain, Visions of Sovereignty provides an in-depth examination of the Quebecois and Catalan national movements between 1976 and 2010. It also elaborates a novel theoretical perspective: the "moral polity" thesis. Lluch argues persuasively that disengagement between the central state and substate nationalists can lead to the adoption of more prosovereignty constitutional orientations. Because many substate nationalists perceive that the central state is not capable of accommodating or sustaining a plural constitutional vision, their radicalization is animated by a moral sense of nonreciprocity. Mapping the complex range of political orientations within substate national movements, Visions of Sovereignty illuminates the political and constitutional dynamics of accommodating national diversity in multinational democracies. This elegantly written and meticulously researched study is essential for those interested in the future of multinational and multiethnic states.