With these, then, the man is beguiled, not led to acquaintance with the things that present themselves by any train of thought, but wandering among confused and inconsequent delusions. But just as in his bodily operations, while each of the parts individually acts in some way according to the power which naturally resides in it, there arises also in the limb that is at rest a state sympathetic with that which is in motion, similarly in the case of the soul, even if one part is at rest and another in motion, the whole is affected in sympathy with the part; for it is not possible that the natural unity should be in any way severed, though one of the faculties included in it is in turn supreme in virtue of its active operation. But as, when men are awake and busy, the mind is supreme, and sense ministers to it, yet the faculty which regulates the body is not dissociated from them (for the mind furnishes the food for its wants, the sense receives what is furnished, and the nutritive faculty of the body appropriates to itself that which is given to it), so in sleep the supremacy of these faculties is in some way reversed in us, and while the less rational becomes supreme, the operation of the other ceases indeed, yet is not absolutely extinguished; but while the nutritive faculty is then busied with digestion during sleep, and keeps all our nature occupied with itself, the faculty of sense is neither entirely severed from it (for that cannot be separated which has once been naturally joined), nor yet can its activity revive, as it is hindered by the inaction during sleep of the organs of sense; and by the same reasoning (the mind also being united to the sensitive part of the soul) it would follow that we should say that the mind moves with the latter when it is in motion, and rests with it when it is quiescent.

Ἐν τούτοις οὖν φαντασιοῦται ὁ ἄνθρωπος͵ οὐχ εἱρμῷ τινι πρὸς τὴν τῶν φαινομένων ὁμιλίαν ἀγόμενος͵ ἀλλὰ πεφυρμέναις τισὶ καὶ ἀνακολούθοις ἀπάταις περιπλανώμενος. Καθάπερ δὲ κατὰ τὰς σωματικὰς ἐνεργείας͵ [169] τῶν μερῶν ἰδιαζόντως τι κατὰ τὴν ἐγκειμένην αὐτῷ φυσικῶς δύναμιν ἐνεργοῦντος γίνεταί τις καὶ τοῦ ἠρεμοῦντος μέρους πρὸς τὸ κινούμενον συνδιάθεσις, ἀναλόγως καὶ ἐπὶ τῆς ψυχῆς͵ κἂν τὸ μὲν αὐτῆς ἠρεμοῦν͵ τὸ δὲ κινούμενον τύχῃ͵ τὸ ὅλον τῷ μέρει συνδιατίθεται. Οὐδὲ γὰρ ἐνδέχεται συνδιασπασθῆναι πάντη τὴν κατὰ φύσιν ἑνότητα͵ κρατούσης ἐν μέρει τινὸς τῶν κατ' αὐτὴν δυνάμεων διὰ τῆς ἐνεργείας. Ἀλλ' ὥσπερ ἐγρηγορότων τε καὶ σπουδαζόντων ἐπικρατεῖ μὲν ὁ νοῦς͵ ὑπηρετεῖ δὲ ἡ αἴσθησις͵ οὐκ ἀπολείπεται δὲ τούτων ἡ διοικητικὴ τοῦ σώματος δύναμις (ὁ μὲν γὰρ νοῦς πορίζει τὴν τροφὴν τῇ χρείᾳ͵ ἡ δὲ αἴσθησις τὸ πορισθὲν ὑπεδέξατο͵ ἡ δὲ θρεπτικὴ τοῦ σώματος δύναμις ἑαυτῇ τὸ δοθὲν προσῳκείωσεν)· οὕτω καὶ κατὰ τὸν ὕπνον ἀντιμεθίσταταί πως ἐν ἡμῖν ἡ τῶν δυνάμεων τούτων ἡγεμονία, καὶ κρατοῦντος τοῦ ἀλογωτέρου παύεται μὲν ἡ τῶν ἑτέρων ἐνέργεια͵ οὐ μὴν παντελῶς ἀποσβέννυται. Ἐπειγομένης δὲ τηνικαῦτα διὰ τοῦ ὕπνου πρὸς τὴν πέψιν τῆς θρεπτικῆς δυνάμεως καὶ πᾶσαν τὴν φύσιν πρὸς ἑαυτὴν ἀσχολούσης͵ οὔτε παντελῶς διασπᾶται ταύτης ἡ κατ' αἴσθησιν δύναμις (οὐ γὰρ ἐνδέχεται τὸ ἅπαξ συμπεφυκὸς διατέμνεσθαι)͵ οὔτε ἀναλάμπειν ἡ αὐτῆς ἐνέργεια δύναται͵ τῇ τῶν αἰσθητηρίων ἀργίᾳ κατὰ τὸν ὕπνον ἐμπεδηθεῖσα. Κατὰ τὸν αὐτὸν δὲ λόγον καὶ τοῦ νοῦ πρὸς τὸ αἰσθητικὸν εἶδος τῆς ψυχῆς οἰκειουμένου͵ ἀκόλουθον ἂν εἴη καὶ κινουμένου τούτου συγκινεῖσθαι λέγειν αὐτὸν καὶ ἠρεμοῦντος συγκαταπαύεσθαι.