The main research problem underlying this volume is the relation between the idea of European unity and the tradition of modern political thought. The project of Modernity originates in the search for an order that would enable and guarantee peace and security and that would make possible the emancipation of the individual in the intersubjective autonomy with others. That programme, always open to crisis and exposed to the threat of turning to its opposite, is still far from fulfilment. The crisis of Europe is therefore essentially the crisis of Modernity itself. That is why we found it necessary to question the potentials, ambiguities, problems and challenges to the project of Modernity and to reconsider its constitutive concepts: politics/political, state, sovereignty, civil society, democracy. Rather than trying to apply the thought of the classical authors to the present moment, essays collected in this volume open a myriad of paths to the heart of Modernity, calling upon us to rethink the diversity of collective European heritage in the light of our contemporary European moment.