Yesterday I found a very good article on natural rights by Phillip Mitsis (1999),
The Stoic Origin of Natural Rights.
Mitsis argues that "the Stoics offer the most appropriate starting point for considering the origins of natural rights theories."
After just a first reading of the article, it seems to me that, if Mitsis' entire argument is accepted, those with ambitious projects for the extension of human rights will not be able to rely on Stoic doctrine and thought.
"Many contemporary catalogues of human rights include an array of economic, social, and cultural rights covering such things as health care, employment, property, and education. We have seen how the Stoic conception of value would certainly exclude such concerns. But for all that, the Stoics give theoretical expression to the notion of natural human rights. To the extent that they focus on autonomy and ground rights in a system of legal procedures, they diverge from theories of human rights that aim at particular outcomes or at individual welfare, at least if we take our welfare to extend beyond the exercise of our moral personality. The Stoics do not think, for example, that I have a right not to be tortured. But I am free to exercise my rational autonomy and show indifference to my circumstances. And I have a right to take the proper moral attitude to my torture and my torturers. It is my due as a divine, rational spark and as a citizen in the universal cosmopolis. This is perhaps on odd result for a theory of natural rights, but one which in some sense is faced in one form or another by all theories of rights based on the Stoic recognition of the importance of autonomy and choice.
"In carrying out their duties, duties derived from their status as citizens participating in natural law, Stoics act in a way that accords respect for the moral autonomy, equality, and rationality of their fellow citizens. Moreover, they fulfill their offices, offices which they both have a duty and right to fulfill in accordance with Zeus' rational will. Citizens of the cosmopolis do not have a right to universal health care nor do they have a right to smoke; but apart from that, they live in a moral climate conducive to the recognition of their fellow citizens' needs and rights, rights that the Stoics think that we all share in virtue of the fact that we are human."