The notion of Differentiated Integration is increasingly used in the literature on European integration. Often employed interchangeably with the notion of "flexible integration, diverging views on its nature have led to the emergence of various definitions and, to some extent, a semantic confusion. A lack of consensus characterizes the academic literature; some authors even avoid putting an explicit definition on the term.

The main objective of this book is to seek answers for the following questions: How can one define Differentiated Integration in the European Union? Should...