Cosmopolitanism is concerned to disclose the ethical, cultural, and legal basis of political order in a world where political communities and states matter, but not only and exclusively. In circumstances where the trajectories of each and every country are tightly entwined, the partiality, one-sidedness and limitedness of “reasons of state” need to be recognized. While states are hugely important vehicles to aid the delivery of effective regulation, equal liberty, and social justice, they should not be thought of as ontologically privileged. They can be judged by how far they deliver these public goods and how far they fail; for the history of states is marked, of course, not just by phases of bad leadership and corruption but also by the most brutal episodes. A cosmopolitanism relevant to our global age must take this as a starting point, and build an ethically sound and politically robust conception of the proper basis of political community, and of the relations among communities.

Two accounts of cosmopolitanism bear on its contemporary meaning. The first was set out by the Stoics, who were the first to refer explicitly to themselves as cosmopolitans, seeking to replace the central role of the polis in ancient political thought with that of the cosmos in which humankind might live together in harmony (Horstmann, 1976). The Stoics developed this thought by emphasizing that we inhabit two worlds – one which is local and assigned to us by birth and another which is “truly great and truly common” (Seneca).