Yves Charles Zarka is Professor of Political Philosophy at the Université Paris Descartes (Sorbonne), the general editor of Oeuvres de Hobbes (Vrin), and has also published La décision métaphysique de Hobbes (Vrin). He edits the journal Cités (PUF) and, among his works on contemporary political philosophy, has recently published Refaire l'Europe (PUF), Refonder le cosmopolitanisme (PUF), and L'inappropriabilité de la Terre (Armand Colin)." James Griffith is Assistant Professor in the History of Political Thought at the Bratislava International School of Liberal Arts.