Hierocles, a Stoic of the second century CE, famously deployed an image of the ‘concentric circles’ that surround each of us. The image should not be read as advocating absolute impartiality (in the style of classical utilitarianism) or as illustrating the Stoic theory of oikeiōsis. Instead, it is designed to illustrate how it is ‘appropriate to act’ in certain cases. Like other Stoics, Hierocles bases his investigation of appropriate acts on what is ‘in accordance with nature’. According to his view, (...) each of us has a duty of mutual aid towards every other human being—but a weightier duty towards those who are socially closer than those who are more distant. The fundamental principle is that each of us has the duty of being an ‘ally’ of every other human being in serving the natural purposes of all the circles to which we and that other human being both belong. (shrink)