Plutarch De fraterno amore 8

[8] What then, someone will say, must one who has a bad brother do? ¹ We must remember this first of all: badness can lay hold on every kind of friendship; and, according to Sophocles, ² For it is impossible to discover that our relations with relatives or comrades or lovers ³ are unmixed with baseness, free from passion, or pure from evil. So the Spartan, when he married a little wife, ⁴ said that of evils one should choose the least; but brothers one would prudently advise to put up with the evils with which they are most familiar rather than to make trial of unfamiliar ones; for the former procedure as being necessary brings no reproach, but the latter is blameworthy because voluntary. No boon-companion or comrade-in-arms or guest but he is who is of the same blood and upbringing, and born of the same father and mother. For such a kinsman it is altogether fitting to concede and allow some faults, saying to him when he errs, and trouble and folly, lest I might, unwittingly,punish harshly and bitterly, because I hate it, some ailment instilled into you from the seed of father or mother. For, as Theophrastus ⁷ said, we must not grow to love those not of our blood and then judge them, but judge them first and love them later; but where Nature does not commit the initiative to judgement in conceiving goodwill toward another nor wait for the proverbial bushel of salt, ⁸ but has begotten with the child at its birth the principle of love, in that case there should be no harsh nor strict censors of his faults. But as it is, what would you say of those who sometimes readily put up with the wrongdoings of strangers and men of no kin to themselves, men picked up at some drinking-bout or play-ground or wrestling-floor, ⁹ and take pleasure in their company, yet are peevish and inexorable toward their own brothers? Why some even breed and grow fond of savage dogs and horses, and many people do so with lynxes and cats, monkeys and lions, yet cannot endure their brothers’ rages or stupidities or ambitions; still others make over their houses and property to concubines and harlots, yet fight it out in a duel with their brothers over a site for a building or a corner of property; and finally, giving the name of hatred of evil ¹⁰ to their hatred of their brothers, they stalk about pompously, accusing and reviling the wickedness in their brothers; yet in others they take no offence at this same quality, but frequently resort to them and are often in their company.