The Enchiridion   

person be ever so sound himself, yet, if his companion be infected,
he who converses with him will be infected likewise.
Provide things relating to the body no further than mere use; as meat,
drink, clothing, house, family. But strike off and reject everything
relating to show and delicacy.
As far as possible, before marriage, keep yourself pure from familiarities
with women, and, if you indulge them, let it be lawfully." But don't
therefore be troublesome and full of reproofs to those who use these
liberties, nor frequently boast that you yourself don't.
If anyone tells you that such a person speaks ill of you, don't make
excuses about what is said of you, but answer: " He does not know
my other faults, else he would not have mentioned only these."
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, don't
appear more solicitous for anyone than for yourself; that is, wish
things to be only just as they are, and him only to conquer who is
the conqueror, for thus you will meet with no hindrance. But abstain
entirely from declamations and derision and violent emotions. And
when you come away, don't discourse a great deal on what has passed,
and what does not contribute to your own amendment. For it would appear
by such discourse that you were immoderately struck with the show.
Go not [of your own accord] to the rehearsals of any
(authors) , nor appear [at them] readily. But, if you do appear, keepyour
gravity and sedateness, and at the same time avoid being morose.
When you are going to confer with anyone, and particularly of those
in a superior station, represent to yourself how Socrates or Zeno
would behave in such a case, and you will not be at a loss to make
a proper use of whatever may occur.
When you are going to any of the people in power, represent to yourself
that you will not find him at home; that you will not be admitted;
that the doors will not be opened to you; that he will take no notice
of you. If, with all this, it is 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 dazed by external things.
In parties of conversation, avoid a frequent and excessive mention
of your own actions and dangers. For, however agreeable it may be
to yourself to mention 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 is a slippery point, which may throw you
into vulgar manners, and, besides, may be apt to lessen you in the
esteem of your acquaintance. Approaches to indecent discourse are
likewise dangerous. Whenever, therefore, anything of this sort happens,
if there be a proper opportunity, rebuke him who makes advances that
way; or, at least, by silence and blushing and a forbidding look,
show yourself to be displeased by such talk.
34. If you are struck by the appearance of any promised pleasure,
guard yourself against being hurried away by it; but let the affair
wait your leisure, and procure yourself some delay. Then bring to
your mind both points of time: that in which you will enjoy the pleasure,
and that in which you will repent and reproach yourself after you