„We ought so to behave to one another as to avoid making enemies of our friends, and at the same time to make friends of our enemies.“
— Pythagoras ancient Greek mathematician and philosopher -585 - -495 v.Chr
As quoted in Diogenes Laërtius, Lives and Opinions of Eminent Philosophers, "Pythagoras", Sect. 23, as translated in Dictionary of Quotations http://archive.org/details/dictionaryquota02harbgoog (1906) by Thomas Benfield Harbottle, p. 320
Original: (el) ἀλλήλοις θ᾽ ὁμιλεῖν, ὡς τοὺς μὲν φίλους ἐχθροὺς μὴ ποιῆσαι, τοὺς δ᾽ ἐχθροὺς φίλους ἐργάσασθαι. ἴδιόν τε μηδὲν ἡγεῖσθαι.