The Enchiridion   

enemies. On this account the husbandman, the sailor, the merchant,
on this account those who lose wives and children, revile the gods.
For where interest is, there too is piety placed. So that, whoever
is careful to regulate his desires and aversions as he ought, is,
by the very same means, careful of piety likewise. But it is also
incumbent on everyone to offer libations and sacrifices and first
fruits, conformably to the customs of his country, with purity, and
not in a slovenly manner, nor negligently, nor sparingly, nor beyond
his ability.
32. When you have recourse to divination, remember that you know not
what the event will be, and you come to learn it of the diviner; but
of what nature it is you know before you come, at least if you are
a philosopher. For if it is among the things not in our own control,
it can by no means be either good or evil. Don't, therefore, bring
either desire or aversion with you to the diviner (else you will approach
him trembling), but first acquire a distinct knowledge that every
event is indifferent and nothing to you., of whatever sort it may
be, for it will be in your power to make a right use of it, and this
no one can hinder; then come with confidence to the gods, as your
counselors, and afterwards, when any counsel is given you, remember
what counselors you have assumed, and whose advice you will neglect
if you disobey. Come to divination, as Socrates prescribed, in cases
of which the whole consideration relates to the event, and in which
no opportunities are afforded by reason, or any other art, to discover
the thing proposed to be learned. When, therefore, it is our duty
to share the danger of a friend or of our country, we ought not to
consult the oracle whether we will share it with them or not. For,
though the diviner should forewarn you that the victims are unfavorable,
this means no more than that either death or mutilation or exile is
portended. But we have reason within us, and it directs, even with
these hazards, to the greater diviner, the Pythian god, who cast out
of the temple the person who gave no assistance to his friend while
another was murdering him.
33. Immediately prescribe some character and form of conduce to yourself,
which you may keep both alone and in company.
Be for the most part silent, or speak merely what is necessary, and
in few words. We may, however, enter, though sparingly, into discourse
sometimes when occasion calls for it, but not on any of the common
subjects, of gladiators, or horse races, or athletic champions, or
feasts, the vulgar topics of conversation; but principally not of
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 be taken among strangers,
be silent.
Don't allow your laughter be much, nor on many occasions, nor profuse.
Avoid swearing, if possible, altogether; if not, as 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 vulgar manners. For be assured that if a