Begin by prescribing to yourself some character and demeanor, such as you may preserve both alone and in company.
Be mostly silent; or speak merely what is needful, and in few words. We may, however, enter sparingly into discourse sometimes, when occasion calls for it; but let it not run on any of the common subjects, as gladiators, or horse-races, or athletic champions, or food, or drink, -the vulgar topics of conversation; and especially not on men, so as either to blame, or praise, or make comparisons. If you are able, then, by your own conversation, bring over that of your company to proper subjects; but if you happen to find yourself among strangers, be silent.
Let not your laughter be loud, frequent, or abundant.
Avoid taking oaths, if possible, altogether; at any rate, so far as you are able.
Avoid public and vulgar entertainments; but if ever an occasion calls you to them, keep your attention upon the stretch, that you may not imperceptibly slide into vulgarity. For be assured that if a person be ever so pure himself, yet, if his companion be corrupted, he who converses with him will be corrupted likewise.
Provide things relating to the body no farther than absolute need requires; as meat, drink, clothing, house, retinue. But cut off everything that looks towards show and luxury.
Before marriage, guard yourself with all your ability from unlawful intercourse with women; yet be not uncharitable or severe to those who are led into this, nor frequently boast that you yourself do otherwise.
If any one tells you that such a person speaks ill of you, do not make excuses about what is said of you, but answer: “He was ignorant of my other faults, else he would not have mentioned these alone.”
It is not necessary for you to appear often at public spectacles; but if ever there is a proper occasion for you to be there, do not appear more solicitous for any other than for yourself; that is, wish things to be only just as they are, and only the best man to win; for thus nothing will go against you. But abstain entirely from acclamations and derision and violent emotions. And when you come away, do not discourse a great deal on what has passed, and what contributes nothing to your own amendment. For it would appear by such discourse that you were dazzled by the show.
Be not prompt or ready to attend private recitations; but if you do attend, preserve your gravity and dignity, and yet avoid making yourself disagreeable.
When you are going to confer with any one, and especially with one who seems your superior, represent to yourself how Socrates or Zeno would behave in such a case, and you will not be at a loss to meet properly whatever may occur.
When you are going before any one in power, fancy to yourself that you may not find him at home, that you may be shut out, that the doors may not be opened to you, that he may not notice you. If, with all this, it be your duty to go, bear what happens, and never say to yourself, “It was not worth so much.” For this is vulgar, and like a man bewildered by externals.
In society, avoid a frequent and excessive mention of your own actions and dangers. For however agreeable it may be to yourself to allude to the risks you have run, it is not equally agreeable to others to hear your adventures. Avoid likewise an endeavor to excite laughter. For this may readily slide you into vulgarity, and, besides, may be apt to lower you in the esteem of your acquaintance. Approaches to indecent discourse are likewise dangerous. Therefore when anything of this sort happens, use the first fit opportunity to rebuke him who makes advances that way; or, at least, by silence and blushing and a serious look, show yourself to be displeased by such talk.