To Demonicus (21-22)

Train yourself in self-imposed toils, that you may be able to endure those which others impose upon you.[*] Practice self-control in all the things by which it is shameful for the soul to be controlled,[*] namely, gain, temper, pleasure, and pain. You will attain such self-control if you regard as gainful those things which will increase your reputation and not those which will increase your wealth; if you manage your temper towards those who offend against you as you would expect others to do if you offended against them; if you govern your pleasures on the principle that it is shameful to rule over one’s servants and yet be a slave to one’s desires; and if, when you are in trouble, you contemplate the misfortunes of others and remind yourself that you are human.

Guard more faithfully the secret which is confided to you than the money which is entrusted to your care; for good men ought to show that they hold their honor more trustworthy than an oath. Consider that you owe it to yourself no less to mistrust bad men than to put your trust in the good. On matters which you would keep secret, speak to no one save when it is equally expedient for you who speak and for those who hear that the facts should not be published.