  A preliminary point should be mentioned. Do all legal systems have a concept of rights? Their use is pervasive in modern legal systems. We talk of legislatures having the legal right to pass laws, of judges to decide cases, of private individuals to make wills and contracts; as well as of constitutions providing legal rights to the citizens against fellow citizens and against the state itself. Yet it has been suggested that even some sophisticated earlier systems, such as Roman law, had no terminology which clearly separated rights from duties (see Maine (1861), 269–70 ). The question is primarily one for legal historians and will not be pursued here, but it may be remarked that it may still be legitimate when describing those systems to talk of rights in the modern sense, since Roman law, for example, clearly achieved many of the same results as contemporary systems. Presumably, it did so by deploying some of the more basic concepts into which rights can, arguably, be analysed.