Let it then be supposed to be that which is called nature, being a principle of motion and rest, in that which is moved and at rest, essentially and not according to accident. For this is something more simple, and is fabricative of composite forms. If, however, it is in the things fabricated, and does not subsist separate from nor prior to them, but stands in need of them for its being, it will not be unindigent; though its possesses something transcendent with respect to them, viz. the power of fashioning and fabricating them. For it has its being together with them, and has in them an inseparable subsistence; so that, when they are it is, and is not when they are not, and this in consequence of perfectly verging to them, and not being able to sustain that which is appropriate. For the power of increasing, nourishing, and generating similars, and the one prior to these three, viz. nature, is not wholly incorporeal, but is nearly a certain quality of body, from which it alone differs, in that it imparts to the composite to be inwardly moved and at rest. For the quality of that which is sensible imparts that which is apparent in matter, and that which falls on sense. But body imparts interval every way extended; and nature, an inwardly proceeding natural energy, whether according to place only, or according to nourishing, increasing, and generating things similar. Nature, however, is inseparable from a subject, and is indigent, so that it will not be in short the principle, since it is indigent of that which is subordinate. For it will not be wonderful, if being a certain principle, it is indigent of the principle above it; but it would be wonderful if it were indigent of things posterior to itself, and of which it is supposed to be the principle.
By the like arguments we may show that the principle cannot be irrational soul, whether sensitive, or orectic. For if it appears that it has something separate, together with impulsive and Gnostic enemies, yet at the same time it is bound in body, and has something inseparable from it; since it is notable to convert itself to itself, but its enemy is mingled with its subject. For it is evident that its essence is something of this kind; since if it were liberated and in itself free, it would also evince a certain independent enemy, and would not always be converted to body; but sometimes it would be converted to itself; or though it were always converted to body, yet it would judge and explore itself. The energies, therefore, of the multitude of mankind, (though they are conversant with externals,) yet, at the same time they exhibit that which is separate about them. For they consult how they should engage in them, and observe that deliberation is necessary, in order to effect or be passive to apparent good, or to decline something of the contrary. But the impulses of other animals are uniform and spontaneous, are moved together with the sensible organs, and require the senses alone that they may obtain from sensibles the pleasurable, and avoid the painful. If, therefore, the body communicates in pleasure and pain, and is affected in a certain respect by them, it is evident that the psychical energies, (i.e. energies belonging to the soul) are exerted, mingled with bodies, and are not purely psychical, but are also corporeal; for perception is of the animated body, or of the soul corporalized, though in such perception the psychical idiom predominates over the corporeal; just as in bodies, the corporeal idiom has dominion according to interval and subsistence. As the irrational soul, therefore, has its being in something different from itself, so far it is indigent of the subordinate: but a thing of this kind will not be the principle.