Plutarch, On Divine Vengeance (Moralia 549c-e)
“An immediate slap or kick following a mistake or offense corrects a horse and sends him where he needs to go but whippings and screaming and pulling the reins later, after time has passed, seems to have some other function than teaching, which in fact causes pain without instruction. In the same way, wickedness which is beaten down and reined in through criticism each time it stumbles and fails might be made humble, and fearful of a god who is not a procrastinating judge when setting right the actions and passions of human beings.
A justice that falls on the wicked with a slow foot and in its own time, as Euripides says, is more mechanical than thoughtful because it is random, late, and ill-fit to the deed. This is why I don’t see any use in what people call the slow grinding of the gods’ mills, a process that renders punishment obscure and blunts any fear of being bad.”
καθάπερ γὰρ ἵππον ἡ παραχρῆμα τὸ πταῖσμα καὶ τὴν ἁμαρτίαν διώκουσα πληγὴ καὶ νύξις ἐπανορθοῖ καὶ μετάγει πρὸς τὸ δέον, οἱ δὲ ὕστερον καὶ μετὰ χρόνον σπαραγμοὶ καὶ ἀνακρούσεις καὶ περιψοφήσεις ἑτέρου τινὸς ἕνεκα μᾶλλον γίνεσθαι δοκοῦσιν ἢ διδασκαλίας, δι᾿ ὃ τὸ λυποῦν ἄνευ τοῦ παιδεύειν ἔχουσιν, οὕτως ἡ καθ᾿ ἕκαστον ὧν πταίει καὶ προπίπτει ῥαπιζομένη καὶ ἀνακρουομένη τῷ κολάζεσθαι κακία μόλις ἂν γένοιτο σύννους καὶ ταπεινὴ καὶ κατάφοβος πρὸς τὸν θεὸν ὡς ἐφεστῶτα τοῖς ἀνθρωπίνοις πράγμασι καὶ πάθεσιν οὐχ ὑπερήμερον δικαιωτήν· ἡ δὲ ἀτρέμα καὶ βραδεῖ ποδὶ κατ᾿ Εὐριπίδην καὶ ὡς ἔτυχεν ἐπιπίπτουσα Δίκη τοῖς πονηροῖς τῷ αὐτομάτῳ μᾶλλον ἢ τῷ κατὰ πρόνοιαν ὅμοιον ἔχει τὸ πεπλανημένον καὶ ὑπερήμερον καὶ ἄτακτον. ὥστε οὐχ ὁρῶ τί χρήσιμον ἔνεστιν τοῖς ὀψὲ δὴ τούτοις ἀλεῖν λεγομένοις μύλοις τῶν θεῶν καὶ ποιοῦσι τὴν δίκην ἀμαυρὰν καὶ τὸν φόβον ἐξίτηλον τῆς κακίας.”