Abstract
This chapter introduces the ‘mosaic of integration theory’ as a pluralist approach and heuristic device which centres on the variety of research questions and objectives raised by the broad spectrum of integration theorists operating in different areas and pursuing different purposes. The metaphor of the ‘mosaic’ indicates that each theoretical approach can be seen as a stone that adds to the picture of the EU as an unfinished and changing order. The mosaic approach rests on general conceptual definitions, for example, of ‘integration’ and ‘theory’ based on distinctions between ‘narrow’ and ‘broader’ definitions of integration: broader definitions of integration include both a social process (the shifting of loyalties) and a political process (the construction of new political institutions) while narrower definitions centre on the political institutions. The chapter differentiates three distinct uses of theory that are represented by this book’s contributions and form part of the mosaic approach, for example, theory as ‘explanation and understanding’, as ‘description and analysis’, or as ‘critique and normative intervention’. These uses are applied to study politics, polity, and policy as the three main areas of integration over distinct periods. Finally, the chapter introduces this book’s common research questions about economic, refugee, and security crises, and introduces all contributions.