 In saying that living well lies in doing what his human nature seeks, Marcus is echoing generations of Stoic philosophers.  Cleanthes says the goal (telos) is ‘living in agreement with nature’; Chrysippus, ‘living according to the experience of what happens by nature’; Diogenes, ‘being reasonable in the selection and rejection of what is according to nature’; Archedemus, ‘living completing all appropriate actions’; Antipater, ‘living continually selecting what is according to nature and rejecting what is contrary to nature’ (Arius Didymus 6a). These formulae indicate that the goal is to act in accordance with nature, and to be in a certain cognitive state in relation to one’s acts according to nature: in agreement, on the basis of experience, being reasonable, continually (dienekôs, i.e. consistently, stably?), all of which imply understanding. 