Nothing, however, gives the mind so much pleasure as fond and faithful friendship. What a blessing it is to have those to whose waiting hearts every secret may be committed with safety, whose knowledge of you you fear less than your knowledge of yourself, whose conversation soothes your anxiety, whose opinion assists your decision, whose cheerfulness scatters your sorrow, the very sight of whom gives you joy! We shall of course choose those who are free, as far as may be, from selfish desires; for vices spread unnoticed, and quickly pass to those nearest and do harm by their contact. And so, just as in times of pestilence we must take care not to sit near those whose bodies are already infected and inflamed with disease, because we shall incur risks and be in danger from their very breath, so, in choosing our friends, we shall have regard for their character, so that we may appropriate those who are marked with fewest stains; to combine the sick with the sound is to spread disease. Yet I would not lay down the rule that you are to follow, or attach to yourself, none but a wise man. For where will you find him whom we have been seeking for so many centuries? In place of the best man take the one least bad! Opportunity for a happier choice scarcely could you have, were you searching for a good man among the Platos and the Xenophons and the rest of that glorious company of the Socratic breed, or, too, if you had at your command the age of Cato, which bore many men who were worthy to be born in Cato’s time, just as it also bore many that were worse than had ever been known, and contrivers of the most monstrous crimes; for both classes were necessary in order that Cato might be understood—he needed to have good men that he might win their approval, and bad men that he might prove his strength. But now, when there is such a great dearth of good men, you must be less squeamish in making your choice. Yet those are especially to be avoided who are melancholy and bewail everything, who find pleasure in every opportunity for complaint. Though a man’s loyalty and friendliness be assured, yet the companion who is always upset and bemoans everything is a foe to tranquillity.
On the Tranquillity of Mind 7.3