Plato, Letters 323b

ἀνθέξεσιν ἀλλήλων εἰς μίαν ἀφικέσθαι φιλίας συμπλοκήν. ἂν δέ τις ὑμῶν ἄρα ταύτην πῃ λύειν δοκῇ—τὸ γὰρ ἀνθρώπινον οὐ παντάπασιν βέβαιον—δεῦρο παρʼ ἐμὲ καὶ τοὺς ἐμοὺς πέμπετε μομφῆς κατήγορον ἐπιστολήν· οἶμαι γὰρ δίκῃ τε καὶ αἰδοῖ τοὺς παρʼ ἡμῶν ἐντεῦθεν ἐλθόντας λόγους, εἰ μή τι τὸ λυθὲν μέγα τύχοι γενόμενον, ἐπῳδῆς ἡστινοσοῦν μᾶλλον ἂν συμφῦσαι καὶ συνδῆσαι πάλιν εἰς τὴν προϋπάρχουσαν

and endeavor by thus holding to one another to become united in the bonds of friendship. But in case any one of you should be thought to be breaking up this union in any way—for what is human is not altogether durable—send a letter here to me and my friends stating the grounds of complaint; for I believe that—unless the disruption should happen to be serious—the arguments sent you from here by us, based on justice and reverence, will serve better than any incantation to weld you and bind you together once again into your former state of friendship