ἔγνω δὲ φώρ τε φῶρα καὶ λύκος λύκον → the thief knows the thief and the wolf knows the wolf, and thief knows thief and wolf his fellow wolf, set a thief to catch a thief
herir, dañar ἰάπτεται· ἄτει, βλάπτει Sch.Nic.Al.251c.
