Fundamental liberties of states, if they exist, should be seen essentially as analogues of civil liberties in national legal systems, ie, as ‘privileges’ in the sense in which Hohfeld employed that term. In the natural-law era, there was no room for any conception of fundamental liberties of states, since natural law was basically a law of duties rather than of rights. Only with Hobbes did the idea arise of a rights-based natural law. In the eighteenth century, Wolff and Vattel advanced the idea of a duty of states to strive towards perfection—but this was a duty rather than a liberty. Only in the positivist era of the nineteenth century, with its strongly state-centred ethos and its stress on the independence of states, did a concept of fundamental liberties of states emerge, with various lists proposed by various authors. Even there, the idea was meaningful only in the context of legislative (as opposed to a contractual) picture of customary international law. Various positivist writers advanced lists of fundamental liberties. Some positivist writers, however, such as Westlake, opposed the idea, as did Kelsen later. Nor is there significant support for the idea in state practice. Repudiations of treaties, most notably, have not entailed an invocation of fundamental liberties. Neither self-defence nor non-intervention qualifies as a liberty. Similarly, neither the principle of freedom (from the Lotus case), nor the persistent objector principle lend support to the concept of fundamental liberties of states.