Elias, Commentary on Aristotle’s Categories 109.12–15
“When [Diogenes] was asked by the tyrant one day who the people were who were conspiring against his power the most, he pointed to his bodyguards. The tyrant believed him and was assassinated after he killed them. [Diogenes] believed it was good to tell a lie for the killing of a tyrant.”
ἐρωτηθεὶς γὰρ οὗτός ποτε ὑπό του τυράννου τίνες εἰσὶν οἱ μάλιστα ἐπιβουλεύοντες τῇ τυραννίδι αὐτοῦ, τοὺς δορυφόρους ἔδειξεν· ὁ δὲ πεισθεὶς καὶ ἀνελὼν αὐτοὺς διεφθάρη· ἀγαθὸν γὰρ ἐνόμισε τὸ ψεύσασθαι διὰ τὴν τοῦ τυράννου ἀναίρεσιν.