Plato, Laws 731a

τινων αὐτὸν μὲν ψέγειν, τὸ δὲ κτῆμα μηδὲν μᾶλλον διὰ τὸν κεκτημένον ἀτιμάζειν, ἀλλὰ κτᾶσθαι κατὰ δύναμιν. φιλονικείτω δὲ ἡμῖν πᾶς πρὸς ἀρετὴν ἀφθόνως. ὁ μὲν γὰρ τοιοῦτος τὰς πόλεις αὔξει, ἁμιλλώμενος μὲν αὐτός, τοὺς ἄλλους δὲ οὐ κολούων διαβολαῖς· ὁ δὲ φθονερός, τῇ τῶν ἄλλων διαβολῇ δεῖν οἰόμενος ὑπερέχειν, αὐτός τε ἧττον συντείνει πρὸς ἀρετὴν τὴν ἀληθῆ, τούς τε ἀνθαμιλλωμένους εἰς ἀθυμίαν καθίστησι τῷ ἀδίκως ψέγεσθαι, καὶ διὰ ταῦτα

then the man himself must be blamed, but his possession must not be disesteemed any the more because of its possessor,—rather one should strive to gain it with all one’s might. Let every one of us be ambitious to gain excellence, but without jealousy. For a man of this character enlarges a State, since he strives hard himself and does not thwart the others by calumny; but the jealous man, thinking that calumny of others is the best way to secure his own superiority, makes less effort himself to win true excellence, and disheartens his rivals by getting them unjustly blamed; whereby he causes the whole State