Plato, Laws 870c

ἐσόμενον, ἀλλὰ δικαίως πλουτεῖν καὶ σωφρόνως· καὶ φόνοι οὕτως οὐκ ἂν γίγνοιντο ἐν πόλεσιν φόνοις δεόμενοι καθαίρεσθαι. νῦν δέ, ὅπερ ἀρχόμενοι τούτων εἴπομεν, ἓν μὲν τοῦτʼ ἐστὶ καὶ μέγιστον ὃ ποιεῖ φόνου ἑκουσίου τὰς μεγίστας δίκας. δεύτερον δὲ φιλοτίμου ψυχῆς ἕξις, φθόνους ἐντίκτουσα, χαλεποὺς συνοίκους μάλιστα μὲν αὐτῷ τῷ κεκτημένῳ τὸν φθόνον, δευτέροις δὲ τοῖς ἀρίστοις τῶν ἐν τῇ πόλει. τρίτον δὲ οἱ δειλοὶ καὶ ἄδικοι φόβοι πολλοὺς δὴ φόνους

and if this were so, no murders that needed purging by murders would occur in States. But, as things now stand, this love of riches is—as we said when we began this subject—one cause, and a very great cause, which produces the most serious of trials for willful murder. A second cause is the temper of the ambitious soul, which breeds envies that are dangerous associates for the man that feels the envy, in the first place, and dangerous also for the best citizens in the State. Thirdly, fears bred of cowardice and iniquity