EPICTETUS. DISCOURSES. Book iii. §14. ¶4.WHAT, then, is it to be properly educated? To learn how to adapt natural preconceptions to particular cases, conformably to nature; and, for the future, to distinguish that some things are in our own power, others not. In our own power are choice, and all actions dependent on choice; not in our power, the body, the parts of the body, property, parents, brothers, children, country, and, in short, all with whom we are engaged in society. Where, then, shall we place good? To what kind of things shall we adapt the preconception of it? To that in our own power.
EPICTETUS. DISCOURSES. Book i. §22. ¶2.