Laudator Temporis Acti

Plato, Menexenus 10 (240 d-e; tr. Tom Griffith):

That is the situation you have to think yourself into if you want to grasp what kind of people they really were who met the onslaught of the barbarians at Marathon, who punished the arrogance of the whole of Asia, and who were the first to set up memorials commemorating victory over the barbarians. They acted as guides and teachers to the rest of Greece, the lesson being that the power of the Persians was not irresistible, that all the numbers in the world, and all the wealth in the world, are no match for courage. For my part, therefore, I maintain that those men are not merely our fathers in a physical sense, but also fathered freedom both for us and for everybody in mainland Greece. That was the action to which the Greeks looked when they screwed up their courage to take their chance in the later battle for their freedom. They were pupils of the heroes of Marathon.

ἐν τούτῳ δὴ ἄν τις γενόμενος γνοίη οἷοι ἄρα ἐτύγχανον ὄντες τὴν ἀρετὴν οἱ Μαραθῶνι δεξάμενοι τὴν τῶν βαρβάρων δύναμιν καὶ κολασάμενοι τὴν ὑπερηφανίαν ὅλης τῆς Ἀσίας καὶ πρῶτοι στήσαντες τρόπαια τῶν βαρβάρων, ἡγεμόνες καὶ διδάσκαλοι τοῖς ἄλλοις γενόμενοι ὅτι οὐκ ἄμαχος εἴη ἡ Περσῶν δύναμις, ἀλλὰ πᾶν πλῆθος καὶ πᾶς πλοῦτος ἀρετῇ ὑπείκει. ἐγὼ μὲν οὖν ἐκείνους τοὺς ἄνδρας φημὶ οὐ μόνον τῶν σωμάτων τῶν ἡμετέρων πατέρας εἶναι, ἀλλὰ καὶ τῆς ἐλευθερίας τῆς τε ἡμετέρας καὶ ξυμπάντων τῶν ἐν τῇδε τῇ ἠπείρῳ· εἰς ἐκεῖνο γὰρ τὸ ἔργον ἀποβλέψαντες καὶ τὰς ὑστέρας μάχας ἐτόλμησαν διακινδυνεύειν οἱ Ἕλληνες ὑπὲρ τῆς σωτηρίας, μαθηταὶ τῶν Μαραθῶνι γενόμενοι.