This article is a contribution to the revival of `virtue ethics'. If we regard human rights as a crucial development in the establishment of global institutions of justice and equality, then we need to explore the obligations that correspond to such rights. It is argued that cosmopolitan virtue a respect for other cultures and an ironic stance towards one's own culture spells out this obligation side of the human rights movement. Cosmopolitanism of course can assume very different forms. The article (...) traces various cosmopolitan ethics from the Greeks, Roman Stoics and Christian philosophers. Contemporary cosmopolitanism needs to be ironic to function usefully in hybrid global cultures, but it is open to the charge of being culturally `flat' and elitist. These criticisms are examined through the confrontation between Maurizio Viroli and Martha Nussbaum. While American patriotism is not a promising foundation for ironic cosmopolitanism, the republican tradition of virtue does offer a viable method of developing cosmopolitanism. Ironic cosmopolitan care for other cultures is founded on the commonalities of social existence, of which there are two central components: ontological vulnerability and political precariousness. (shrink)