The Discourses of Epictetus, tr. by P.E Matheson, , at sacred-texts.com
The man who mixes with other people a good deal either for talk or for a wine-party or generally for social purposes, must needs either grow like them himself or convert them to his likeness; for if you put a quenched coal by one that is burning, either it will put the burning 'one out, or will catch fire from it. As the risk then is so serious, you must be cautious in indulging lightly in the society of the untrained, for it is impossible to rub up against one who is covered with soot and not get sooty oneself. What are you going to do, if he talks about gladiators, about horses, about athletes, worse still if he talks about men: 'So-and-so is bad', 'So-and-so is good': 'That was well done', 'That was ill done': again, if he mocks or jeers, or shows a malicious humour? Has any of you the perfect skill of the lyre-player, who takes up his lyre and has only to touch the strings to know which are out of tune and so tune his instrument? Which of you has the faculty that Socrates had, of drawing to his side those who met him in any kind of society?
[paragraph continues] How could you have? You must needs be converted by your untrained companions.
Why then are they stronger than you? It is because these unsound sayings of theirs are based upon judgements, but your fine words come merely from your lips: that is why they are without life or vigour, that is why a man may well loathe the sound of your exhortations and your wretched 'virtue', which you prate of so glibly. That is how the untrained get the better of you: for judgement is powerful everywhere, judgement suffers no defeat. Therefore, until your fine ideas are firmly fastened in you, and until you acquire some power to secure them, I advise you to be cautious in associating with the untrained: otherwise anything you take note of in the lecture-room will melt away day by day like wax in the sun. Therefore go away somewhere far from the sun, as long as your ideas are in this waxen state. For this reason philosophers even advise us to leave our own countries, because old habits are a drag on us and prevent us from beginning to acquire a new set of habits, and we cannot bear men meeting us and saying, 'Look, So-and-so is turning philosopher, behaving like this and like that.' On the same principle physicians send away patients who are ill for long to a new country and a new climate, and rightly so. Do the same. Adopt new habits: fix your opinions, exercise yourselves in them. No, you leave the lecture-room to go to a show, a gladiatorial display, a colonnade, a circus: then you come back here from them and return there again, and nothing affects you. So you acquire no habit that gives you distinction; you pay no regard or attention to yourself: you do not watch yourself and ask, 'How do I deal with the impressions that meet me? Naturally, or unnaturally? How am I to answer their call? Rightly or wrongly? Do I warn things beyond my will that they have no concern with me?' I say, if you are not yet in this state, then fly from your former habits, fly from the uneducated, if you wish to begin at last to be more than ciphers.