There is another sort of fire which is intermediate, and which reaches and mingles with the moisture of the eye without flashing; and in this, the fire mingling with the ray of the moisture, produces a colour like blood, to which we give the name of red. A bright hue mingled with red and white gives the colour called auburn. The law of proportion, however, according to which the several colours are formed, even if a man knew he would be foolish in telling, for he could not give any necessary reason, nor indeed any tolerable or probable explanation of them. Again, red, when mingled with black and white, becomes purple, but it becomes umber when the colours are burnt as well as mingled and the black is more thoroughly mixed with them. Flame colour is produced by a union of auburn and dun, and dun by an admixture of black and white; pale yellow, by an admixture of white and auburn. White and bright meeting, and falling upon a full black, become dark blue, and when dark blue mingles with white, a light blue colour is formed, as flame-colour with black makes leek green. There will be no difficulty in seeing how and by what mixtures the colours derived from these are made according to the rules of probability. He, however, who should attempt to verify all this by experiment, would forget the difference of the human and divine nature. For God only has the knowledge and also the power which are able to combine many things into one and again resolve the one into many. But no man either is or ever will be able to accomplish either the one or the other operation.

These are the elements, thus of necessity then subsisting, which the creator of the fairest and best of created things associated with himself, when he made the self-sufficing and most perfect God, using the necessary causes as his ministers in the accomplishment of his work, but himself contriving the good in all his creations. Wherefore we may distinguish two sorts of causes, the one divine and the other necessary, and may seek for the divine in all things, as far as our nature admits, with a view to the blessed life; but the necessary kind only for the sake of the divine, considering that without them and when isolated from them, these higher things for which we look cannot be apprehended or received or in any way shared by us.

 [68b] τὸ δὲ τούτων αὖ μεταξὺ πυρὸς γένος͵ πρὸς μὲν τὸ τῶν ὀμμάτων ὑγρὸν ἀφικνούμενον καὶ κεραννύμενον αὐτῷ͵ στίλβον δὲ οὔ· τῇ δὲ διὰ τῆς νοτίδος αὐγῇ τοῦ πυρὸς μειγνυμένου χρῶμα ἔναιμον παρασχομένῃ͵ τοὔνομα ἐρυθρὸν λέγομεν. λαμπρόν τε ἐρυθρῷ λευκῷ τε μειγνύμενον ξανθὸν γέγονεν· τὸ δὲ ὅσον μέτρον ὅσοις͵ οὐδ΄ εἴ τις εἰδείη͵ νοῦν ἔχει τὸ λέγειν͵ ὧν μήτε τινὰ ἀνάγκην μήτε τὸν εἰκότα λόγον καὶ μετρίως ἄν τις εἰπεῖν εἴη δυνατός. [68c] ἐρυθρὸν δὲ δὴ μέλανι λευκῷ τε κραθὲν ἁλουργόν· ὄρφνινον δέ͵ ὅταν τούτοις μεμειγμένοις καυθεῖσίν τε μᾶλλον συγκραθῇ μέλαν. πυρρὸν δὲ ξανθοῦ τε καὶ φαιοῦ κράσει γίγνεται͵ φαιὸν δὲ λευκοῦ τε καὶ μέλανος͵ τὸ δὲ ὠχρὸν λευκοῦ ξανθῷ μειγνυμένου. λαμπρῷ δὲ λευκὸν συνελθὸν καὶ εἰς μέλαν κατακορὲς ἐμπεσὸν κυανοῦν χρῶμα ἀποτελεῖται͵ κυανοῦ δὲ λευκῷ κεραννυμένου γλαυκόν͵ πυρροῦ δὲ μέλανι πράσιον. [68d] τὰ δὲ ἄλλα ἀπὸ τούτων σχεδὸν δῆλα αἷς ἂν ἀφομοιούμενα μείξεσιν διασῴζοι τὸν εἰκότα μῦθον. εἰ δέ τις τούτων ἔργῳ σκοπούμενος βάσανον λαμβάνοι͵ τὸ τῆς ἀνθρωπίνης καὶ θείας φύσεως ἠγνοηκὼς ἂν εἴη διάφορον͵ ὅτι θεὸς μὲν τὰ πολλὰ εἰς ἓν συγκεραννύναι καὶ πάλιν ἐξ ἑνὸς εἰς πολλὰ διαλύειν ἱκανῶς ἐπιστάμενος ἅμα καὶ δυνατός͵ ἀνθρώπων δὲ οὐδεὶς οὐδέτερα τούτων ἱκανὸς οὔτε ἔστι νῦν οὔτε εἰς αὖθίς ποτε ἔσται.  

[68e] Ταῦτα δὴ πάντα τότε ταύτῃ πεφυκότα ἐξ ἀνάγκης ὁ τοῦ καλλίστου τε καὶ ἀρίστου δημιουργὸς ἐν τοῖς γιγνομένοις παρελάμβανεν͵ ἡνίκα τὸν αὐτάρκη τε καὶ τὸν τελεώτατον θεὸν ἐγέννα͵ χρώμενος μὲν ταῖς περὶ ταῦτα αἰτίαις ὑπηρετούσαις͵ τὸ δὲ εὖ τεκταινόμενος ἐν πᾶσιν τοῖς γιγνομένοις αὐτός. διὸ δὴ χρὴ δύ΄ αἰτίας εἴδη διορίζεσθαι͵ τὸ μὲν ἀναγκαῖον͵ τὸ δὲ θεῖον͵ καὶ τὸ μὲν θεῖον ἐν ἅπασιν ζητεῖν κτήσεως ἕνεκα εὐδαίμονος βίου͵ [69a] καθ΄ ὅσον ἡμῶν ἡ φύσις ἐνδέχεται͵ τὸ δὲ ἀναγκαῖον ἐκείνων χάριν͵ λογιζόμενον ὡς ἄνευ τούτων οὐ δυνατὰ αὐτὰ ἐκεῖνα ἐφ΄ οἷς σπουδάζομεν μόνα κατανοεῖν οὐδ΄ αὖ λαβεῖν οὐδ΄ ἄλλως πως μετασχεῖν.