Epictetus. (c.A.D. 50c.A.D. 138). The Golden Sayings of Epictetus.
The Harvard Classics. 190914.
Banquets of the unlearned and of them that are without, avoid. But if you have occasion to take part in them, let not your attention be relaxed for a moment, lest you slip after all into evil ways. For you may rest assured that be a man ever so pure himself, he cannot escape defilement if his associates are impure.