Preface Are the nationals of EU member states also citizens of the European Union? This is what Art. 20 of the Treaty on the Functioning of the European Union says they are. But what precisely does it mean to be a citizen of a union which some observers still describe as an international organization that just coordinates the interests of its member states across a wider range of policies than most others do? The present volume addresses this question in an unusual way. There is already a large number of excellent books on the topic that collect stand-­ alone chapters from authors presenting different answers.1 Readers interested in historical, legal and political science perspectives on EU citizenship should consult these volumes. Yet in such publications, scholars rarely speak and behave as citizens are supposed to do – they present their views without engaging with each other in a dialogue on questions that citizens are concerned about. The present book is different; it is a collection of debates, each of which asks a question that is at the core of the present EU citizenship dilemmas. In a political debate, speakers are expected to listen to each other and to address each other. The three debates in this book are the results of online debates that have been actually structured like a conversation. The first contribution in each debate is a kick-off that defends a specific answer to the lead question. The subsequent contributions were not all commissioned at the same time but over several months and each author was asked to respond not only to the question and the kick-off text, but to take into account or criticise also the views of the previous responses without repeating points already made by others. Contributions are short, written in a non-technical 1 See e.g. Bellamy, R. and Warleigh, A. (eds.) (2001), Citizenship and governance in the European Union. London, New York: Continuum; Bellamy, R., Castiglione, D. and Santoro, E. (eds.) (2004), Lineages of European Citizenship: Rights, Belonging and Participation in Eleven Nation-States. New York: Palgrave Macmillan; Isin, E. F. and Saward, M. (eds.) (2013), Enacting European Citizenship. Cambridge: Cambridge University Press; Kochenov, D. (ed.) (2017), EU Citizenship and Federalism: The Role of Rights. Cambridge: Cambridge University Press; Thym, D. (ed.) (2017), Questioning EU citizenship: judges and the limits of free movement and solidarity in the EU. Oxford; Portland, Oregon: Hart Publishing. vii