Introduction

The process of European integration has evolved through crises of governance towards ever greater integration of the societies of the participating member states, giving rise to new questions about the political organization of the European continent. At the same time, European societies have become ever more diverse, giving rise to new and complex problematiques of coexistence. Europe must now also deal with the consequences of an economic model based on the consumption of finite resources. Beyond specific crises and events, Europe is therefore faced with a multifaceted challenge of ecological, democratic and societal sustainability. To approach the challenges from the point of view of sustainability means to see the ecological, democratic and societal long-term viability of Europe as made possible by the continuous reconstruction of European societies through innovative cultural, social, economic and political practices under the ecological constraints posed by the limits of our planet.