Letter 832: Anger is a fire: useful when controlled, devastating when unleashed.

To Archontios. On the point that the devil does not possess foreknowledge, but conjectures particulars from the movements within us. The devil does not know the things that pass in the mind, O most gentle one; for this is the exclusive prerogative of the divine power alone, which also formed our hearts in private. Rather, from the movements of the body he hunts out the designs of the soul. For instance, did he see someone gazing about inquisitively and feasting his eyes on the beauty of others? Seizing upon that man's impulse, he straightway incites such a one either to adultery or to fornication. Did he see a man irascible and quick-tempered? At once he whets the sword and urges him on to murder. Did he see a man greedy for base gain? He drives him toward acts of robbery and injustice. Did he see a man given over to the belly? Straightway he sketches out for him also the passions that go together with the belly, and supplies the materials for advancing his own purpose into deed. For why does he not push all men into the same passions? Because the one has chosen this and the other that by preference; and to the one this is pleasing, to the other that. From the movements of the body, then, he infers also the rotten places of the souls; and thus he weaves his snares.

Ὅτι οὐκ ἔχει πρόγνωσιν ὁ διάβολος, ἀλλ’ ἐκ τῶν ἐν ἡμῖν κινημάτων στοχάζεται τὰ καθέκαστον. Οὐ τὰ κατὰ διάνοιαν οἶδεν, ὦ πραύτατε, ὁ διάβολος· τῆς γὰρ θείας μόνης ἐστὶ τοῦτο ἐξαίρετον δυνάμεως, τῆς καὶ πλασάσης κατὰ μόνας τὰς καρδίας ἡμῶν · ἀλλ’ ἀπὸ [τῶν] τοῦ σώματος (3) κινημάτων (3) τὰ τῆς ψυχῆς θηρεύει βουλεύματα. Οἷον εἴδέ τινα περιέργως ὁρῶντα, καὶ ἑστιῶντα τοὺς ὀφθαλμοὺς τοῖς ἀλλοτρίοις κάλλεσι ; λαβὼν ἐκείνου τὴν ὁρμήν, εὐθὺς ἢ εἰς μοιχείαν, ἢ εἰς πορνείαν τὸν τοιοῦτον ἐρεθίζει. Εἶδεν ὄργιλον καὶ θυμώδη ; εὐθὺς τὸ ξίφος ἀκονᾷ, καὶ εἰς φόνον παρορμᾷ. Εἶδεν αἰσχροκερδῆ ; εἰς λῃστείας προτρέπει καὶ ἀδικίας. Εἶδε γαστρὸς ἥττονα ; εὐθὺς καὶ τὰ μετὰ γαστέρων (4) αὐτῷ πάθη ὑπογράφει, καὶ ὕλας παρέχει πρὸς τὸ εἰς ἔργον χωρῆσαι τὸν οἰκεῖον σκοπόν. Διὰ τί γὰρ μὴ πάντας εἰς τὰ αὐτὰ πάθη ὠθεῖ ; Ἐπειδὴ ὁ μὲν τοῦτο, ὁ δὲ ἐκεῖνο μᾶλλον προήρηται · καὶ τῷ μὲν τοῦτο, τῷ δὲ ἐκεῖνο ἀρέσκει. Ἀπὸ τῶν κινημάτων οὖν τοῦ σώματος, καὶ τὰ τῶν ψυχῶν σαθρὰ τεκμαίρεται · καὶ οὕτω πλέκει τοὺς δόλους.