Epictetus. (c.A.D. 50–c.A.D. 138). The Golden Sayings of Epictetus.
The Harvard Classics. 1909–14.
LVII
That was a good reply which Diogenes made to a man who asked him for letters of recommendation.—“That you are a man, he will know when he sees you;—whether a good or bad one, he will know if he has any skill in discerning the good and the bad. But if he has none, he will never know, though I write to him a thousand times.”—It is as though a piece of silver money desired to be recommended to some one to be tested. If the man be a good judge of silver, he will know: the coin will tell its own tale.