Hence the mind of man clearly proves its claim to connection with his nature, itself also co-operating and moving with the nature in its sound and waking state, but remaining unmoved when it is abandoned to sleep, unless any one supposes that the imagery of dreams is a motion of the mind exercised in sleep. We for our part say that it is only the conscious and sound action of the intellect which we ought to refer to mind; and as to the fantastic nonsense which occurs to us in sleep, we suppose that some appearances of the operations of the mind are accidentally moulded in the less rational part of the soul; for the soul, being by sleep dissociated from the senses, is also of necessity outside the range of the operations of the mind; for it is through the senses that the union of mind with man takes place; therefore when the senses are at rest, the intellect also must needs be inactive; and an evidence of this is the fact that the dreamer often seems to be in absurd and impossible situations, which would not happen if the soul were then guided by reason and intellect.

It seems to me, however, that when the soul is at rest so far as concerns its more excellent faculties (so far, I mean, as concerns the operations of mind and sense), the nutritive part of it alone is operative during sleep, and that some shadows and echoes of those things which happen in our waking moments-of the operations both of sense and of intellect-which are impressed upon it by that part of the soul which is capable of memory, that these, I say, are pictured as chance will have it, some echo of memory still lingering in this division of the soul.

Ἐκ τούτων τοίνυν ὁ ἀνθρώπινος νοῦς δείκνυσιν ἐναργῶς ὅτι τῆς φύσεως ἔχεται͵ συνεστώσης μὲν καὶ ἐγρηγορυίας καὶ αὐτὸς συνεργῶν καὶ κινούμενος, παρεθείσης δὲ τῷ ὕπνῳ͵ μένων ἀκίνητος͵ εἰ μή τις ἄρα τὴν ὀνειρώδη φαντασίαν νοῦ κίνησιν ὑπολάβοι κατὰ τὸν ὕπνον ἐνεργουμένην. Ἡμεῖς δέ φαμεν μόνην δεῖν τὴν ἔμφρονά τε καὶ συνεστῶσαν τῆς διανοίας ἐνέργειαν ἐπὶ τὸν νοῦν ἀναφέρειν, τὰς δὲ κατὰ τὸν ὕπνον φαντασιώδεις φλυαρίας ἰνδάλματά τινα τῆς κατὰ τὸν νοῦν ἐνεργείας οἰόμεθα τῷ ἀλογωτέρῳ τῆς ψυχῆς εἴδει κατὰ τὸ συμβὰν διαπλάττεσθαι. Τῶν γὰρ αἰσθήσεων τὴν ψυχὴν ἀπολυθεῖσαν διὰ τοῦ ὕπνου καὶ τῶν κατὰ νοῦν ἐνεργειῶν ἐκτὸς εἶναι κατ' ἀνάγκην συμβαίνει. Διὰ γὰρ τούτων πρὸς τὸν ἄνθρωπον ἡ τοῦ νοῦ συνανάκρασις γίνεται, τῶν οὖν αἰσθήσεων παυσαμένων͵ ἀργεῖν ἀνάγκη καὶ τὴν διάνοιαν. Τεκμήριον δὲ τὸ καὶ ἐν ἀτόποις καὶ ἐν ἀμηχάνοις πολλάκις δοκεῖν εἶναι τὸν φανταζόμενον, ὅπερ οὐκ ἂν ἐγένετο͵ λογισμῷ καὶ διανοίᾳ τῆς ψυχῆς τηνικαῦτα διοικουμένης.

Ἀλλά μοι δοκεῖ ταῖς προτιμοτέραις τῶν δυνάμεων τῆς ψυχῆς ἠρεμούσης (φημὶ δὲ ταῖς κατὰ τὸν νοῦν καὶ τὴν αἴσθησιν ἐνεργείαις) μόνον τὸ θρεπτικὸν αὐτῆς μέρος ἐνεργὸν κατὰ τὸν ὕπνον εἶναι͵ ἐν δὲ τούτῳ τῶν καθ' ὕπαρ γενομένων εἴδωλά τινα καὶ ἀπηχήματα τῶν τε κατ' αἴσθησιν καὶ τῶν κατὰ διάνοιαν ἐνεργουμένων͵ ἅπερ αὐτῷ διὰ τοῦ μνημονευτικοῦ τῆς ψυχῆς εἴδους ἐνετυπώθη, ταῦτα καθὼς ἔτυχεν ἀναζωγραφεῖσθαι͵ ἀπηχήματός τινος μνημονικοῦ τῷ τοιούτῳ εἴδει τῆς ψυχῆς παραμείναντος.