The last two decades have seen a truly stupendous amount of writing on cosmopolitan ideas, covering a huge variety of conceptions of international, cosmopolitan or global justice. This is hardly surprising in a globalising world. Nor is it surprising that those who now write about cosmopolitan ideas are quite often keen to invoke Kant's reputation and authority for positions they think important. However, contemporary cosmopolitan thought is extremely diverse, and many of the positions and arguments now discussed differ from Kant's views on international and cosmopolitan justice and advocate positions that are remote from those that he advanced.

I shall not say much about contemporary discussions of global, international or cosmopolitan justice, or about other cosmopolitan themes, let alone offer a complete taxonomy. They range from attempts to derive principles of justice from a global Original Position, arguments for other specific forms of distributive justice, and arguments for establishing more inclusive political authorities (from a stronger United Nations to a world state), to positions that insist more narrowly on the equal standing or rights of all human beings, but see neither political plurality (multiple states) nor economic inequalities as invariably unjust. Clearly Kant's position cannot lend its authority to all, nor perhaps to any, contemporary forms of cosmopolitanism. However, by setting out rather baldly some of Kant's central claims about cosmopolitan right and justice, and gesturing towards their links with wider themes in his work, it may be easier to see which parts of his legacy might be of interest for contemporary political thought.

Authorised coercion

Kant does not see principles of right or justice merely as specifying the proper configuration or distribution of rights or resources, or the proper structures for political and economic institutions. He does not focus on patterns or distributions of holdings or resources, or on conceptions of justice as fairness, or on specific equalities: none of these can be directly enforced. He sees enforceability as a central requirement for right and justice, which bears on external aspects of action. Internal aspects of action, by contrast, cannot in principle be enforced, and Kant repeatedly insists that duties that cannot in principle be enforced are not duties of right, but (for example) duties to self, or duties of virtue.