Meditations 11.37

Epictetus also said, A man must discover an art (or rules) with respect to giving his assent; and in respect to his movements he must be careful that they be made with regard to circumstances, that they be consistent with social interests, that they have regard to the value of the object; and as to sensual desire, he should altogether keep away from it; and as to avoidance (aversion) he should not show it with respect to any of the things which are not in our power.

(podcast episode) (original Greek)