Aristotle, On Prophecy in Sleep 463a
“But it is not completely illogical to imagine that some of the fantasies that arise during sleep are to blame for deeds that are related to them.
For just as when we are about to do something or in the middle of some action or have just finished it, we are deeply engaged with those deeds and we also carry them out in a dream–and this is because the inspiration that comes from the events of the day has made space for it–so too the stimulus that arises in sleep may be the initial cause of daytime deeds, because the possibility of doing these things found its own space at night.
This is why dreams can be both indications of things and the causes of them as well.”
Ἀλλὰ μὴν καὶ ἔνιά γε τῶν καθ᾿ ὕπνον φαντασμάτων αἴτια εἶναι τῶν οἰκείων ἑκάστῳ πράξεων οὐκ ἄλογον· ὥσπερ γὰρ μέλλοντες πράττειν καὶ ἐν ταῖς πράξεσιν ὄντες ἢ πεπραχότες πολλάκις εὐθυονειρίᾳ τούτοις σύνεσμεν καὶ πράττομεν (αἴτιον δ᾿ ὅτι προωδοποιημένη τυγχάνει ἡ κίνησις ἀπὸ τῶν μεθ᾿ ἡμέραν ἀρχῶν), οὕτω πάλιν ἀναγκαῖον καὶ τὰς καθ᾿ ὕπνον κινήσεις πολλάκις ἀρχὴν εἶναι τῶν μεθ᾿ ἡμέραν πράξεων διὰ τὸ προωδοποιῆσθαι πάλιν καὶ τούτων τὴν διάνοιαν ἐν τοῖς φαντάσμασι τοῖς νυκτερινοῖς. οὕτω μὲν οὖν ἐνδέχεται τῶν ἐνυπνίων ἔνια καὶ σημεῖα καὶ αἴτια εἶναι.
For in that sleep of death what dreams may come
When we have shuffled off this mortal coil,
Must give us pause. There’s the respect
That makes calamity of so long life.
The Rock Horry Picture Show
Don’t dream it, be it