Plutarch, De fraterno amore
Goodwin, Ed.

And Nature hath given us very near examples of the use of brothers, by contriving most of the necessary parts of our bodies double, as it were, brothers and twins,—as hands, feet, eyes, ears, nostrils,—thereby telling us that all these were thus distinguished for mutual benefit and assistance, and not for variance and discord. And when she parted the very hands into many and unequal fingers, she made them thereby the most curious and artificial of all our members; insomuch that the ancient philosopher Anaxagoras assigned the hands for the reason of all human knowledge and discretion. But the contrary to this seems the truth. For it is not man's having hands that makes him the wisest animal, but his being naturally reasonable and capable of art was the reason why such organs were conferred upon him. And this also is most manifest to every one, that the reason why Nature out of one seed and source formed two, three, and more breth ren was not for difference and opposition, but that their being apart might render them the more capable of assisting one another. For those that were treble-bodied and hundred-handed, if any such there were, while they had all their members joined to each other, could do nothing without them or apart, as brothers can who can live together and travel, undertake public employments and practise husbandry, by one another's help, if they preserve but that principle of benevolence and concord that Nature hath bestowed upon them. But if they do not, they will not at all differ in my opinion from feet that trip up one another, and fingers that are unnaturally writhen and distorted by one another. Yea, rather, as things moist and dry, cold and hot, partake of one nature in the same body, and by their consent and agreement engender the best [p. 38] and most pleasant temperament and harmony,—without which (they say) there is neither satisfaction nor benefit in either riches or kingship itself, which renders man equal to Gods,—but if excess and discord befall them, they miserably ruinate and confound the animal; so, where there is an unanimous accordance amongst brothers, the family thrives and flourishes, and friends and acquaintance, like a well furnished choir, in all their actions, words, and thoughts maintain a delightful harmony.

But jarring feuds advance the worst of men,

such as a vile ill-tongued slave at home, an insinuating parasite abroad, or some other envious person. For as diseases in bodies nauseating their ordinary diet incline the appetite to every improper and noxious thing; so calumny freely entertained against relations, and through prejudging credulity enhanced into suspicion, occasions an adopting the pernicious acquaintance of such as are ready enough to crowd into the room of their betters.