Thucydides 3.42.1 (speech of Diodotus; tr. C.F. Smith):
I have no fault to find with those who have proposed a reconsideration of the question of the Mytilenaeans, nor do I commend those who object to repeated deliberation on matters of the greatest moment; on the contrary, I believe the two things most opposed to good counsel are haste and passion, of which the one is wont to keep company with folly, the other with an undisciplined and shallow mind.
οὔτε τοὺς προθέντας τὴν διαγνώμην αὖθις περὶ Μυτιληναίων αἰτιῶμαι οὔτε τοὺς μεμφομένους μὴ πολλάκις περὶ τῶν μεγίστων βουλεύεσθαι ἐπαινῶ, νομίζω δὲ δύο τὰ ἐναντιώτατα εὐβουλίᾳ εἶναι, τάχος τε καὶ ὀργήν, ὧν τὸ μὲν μετὰ ἀνοίας φιλεῖ γίγνεσθαι, τὸ δὲ μετὰ ἀπαιδευσίας καὶ βραχύτητος γνώμης.