Plutarch, On Brotherly Love 490f-491a
“Friendships transform your character and there is no greater sign of a difference in character than in choosing different friends. This is why neither eating nor drinking nor playing and spending time with a brother is so firm a foundation of agreement as shared friendship, enmity, and enjoying time with the same people and, in turn, hating and shunning alike. For common friendships do not endure slander or feuds—instead, if some anger or complaint should arise, it is resolved by the intervention of friends who accept this responsibility and mediate if they are well-disposed toward both sides and have a similar good-will in common. Just as tin may rejoin broken bronze and bonds it together when soldered to both sides because it is suited similarly to both, so too it is right that a friend who is well-suited and shared by both brothers can increase their goodwill. But those are unbalanced and unshared are disharmonious, just as off-key notes in a musical scale. Just so, it is possible to wonder whether Hesiod was right or not when he said: “Never make a friend equal to a brother.” (Works and Days, 707).
ἠθοποιοῦσι γὰρ αἱ φιλίαι, καὶ μεῖζον οὐθέν ἐστιν ἠθῶν διαφορᾶς σημεῖον ἢ φίλων αἱρέσεις διαφερόντων. ὅθεν οὔτε τὸ συνεσθίειν ἀδελφῷ καὶ συμπίνειν οὔτε τὸ συμπαίζειν καὶ συνδιημερεύειν οὕτω συνεκτικόν ἐστιν ὁμονοίας ὡς τὸ συμφιλεῖν καὶ συνεχθραίνειν ἥδεσθαι τε τοῖς αὐτοῖς συνόντα καὶ πάλιν βδελύττεσθαι καὶ φεύγειν. οὐδὲ γὰρ διαβολὰς αἱ κοιναὶ φιλίαι φέρουσιν οὐδὲ συγκρούσεις· ἀλλὰ κἂν γένηταί τις ὀργὴ καὶ μέμψις, ἐκλύεται διὰ μέσου τῶν φίλων ἐκδεχομένων καὶ διασκεδαννύντων, ἄνπερ ἀμφοτέροις οἰκείως ἔχωσι καὶ πρὸς ἀμφοτέρους ὁμοῦ τῇ εὐνοίᾳ συννεύωσιν. | ὡς γὰρ ὁ κασσίτερος ῥαγέντα τὸν χαλκὸν συναρμόττει καὶ συγκεράννυσι τῷ ψαύειν ἑκατέρου πέρατος οἰκείως ὁμοπαθὴς γινόμενος, οὕτως δεῖ τὸν φίλον εὐάρμοστον ὄντα καὶ κοινὸν ἀμφοτέροις τοῖς ἀδελφοῖς προσκαταπυκνοῦν τὴν εὔνοιαν· οἱ δ’ ἄνισοι καὶ ἄμικτοι καθάπερ ἐν διαγράμματι μουσικῷ φθόγγοι διάζευξιν οὐ συναφὴν ποιοῦσιν. ἔστιν οὖν διαπορῆσαι πότερον ὀρθῶς ἢ τοὐναντίον ὁ ῾Ησίοδος εἶπε
(OD 707)
‘μηδὲ κασιγνήτῳ ἶσον ποιεῖσθαι ἑταῖρον.’
