The Discourses of Epictetus (2.3)

Diogenes rightly answered one who desired letters of recommendation from him: At first sight he will know you to be a man; and whether you are a good or a bad man, if he has any skill in distinguishing, he will know likewise; and if he has

not, he will never know it, though I should write a thousand times. Just as if you were a piece of coin, and should desire to be recommended to any person as good, in order to be tried; if it be to an assayer, he will know your value, for you will recommend yourself.

We ought, therefore, in life also to have something analogous to this skill in gold; that one may be able to say, like the assayer, Bring me whatever piece you will, and I will find out its value; or, as I would say with regard to syllogisms, Bring me whomsoever you will, and I will distinguish for you whether he knows how to solve syllogisms, or not. Why? Because I can do that myself, and have that faculty which is necessary for one who can discern persons skilled in such solutions. But how do I act in life? I sometimes call a thing good, at other times bad. What is the cause of this? Something contrary to whit occurs to me in syllogisms,—ignorance and inexperience.