Chapter XII.--Difference Between the Mind and the Soul, and the Relation Between Them.
In like manner the mind also, or animus, which the Greeks designate NOUS, is taken by us in no other sense than as indicating that faculty or apparatus  which is inherent and implanted in the soul, and naturally proper to it, whereby it acts, whereby it acquires knowledge, and by the possession of which it is capable of a spontaneity of motion within itself, and of thus appearing to be impelled by the mind, as if it were another substance, as is maintained by those who determine the soul to be the moving principle of the universe  --the god of Socrates, Valentinus' "only-begotten" of his father  Bythus, and his mother Sige. How confused is the opinion of Anaxagoras! For, having imagined the mind to be the initiating principle of all things, and suspending on its axis the balance of the universe; affirming, moreover, that the mind is a simple principle, unmixed, and incapable of admixture, he mainly on this very consideration separates it from all amalgamation with the soul; and yet in another passage he actually incorporates it with  the soul. This (inconsistency) Aristotle has also observed: but whether he meant his criticism to be constructive, and to fill up a system of his own, rather than destructive of the principles of others, I am hardly able to decide. As for himself, indeed, although he postpones his definition of the mind, yet he begins by mentioning, as one of the two natural constituents of the mind,  that divine principle which he conjectures to be impassible, or incapable of emotion, and thereby removes from all association with the soul. For whereas it is evident that the soul is susceptible of those emotions which it falls to it naturally to suffer, it must needs suffer either by the mind or with the mind. Now if the soul is by nature associated with the mind, it is impossible to draw the conclusion that the mind is impassible; or again, if the soul suffers not either by the mind or with the mind, it cannot possibly have a natural association with the mind, with which it suffers nothing, and which suffers nothing itself. Moreover, if the soul suffers nothing by the mind and with the mind, it will experience no sensation, nor will it acquire any knowledge, nor will it undergo any emotion through the agency of the mind, as they maintain it will. For Aristotle makes even the senses passions, or states of emotion. And rightly too. For to exercise the senses is to suffer emotion, because to suffer is to feel. In like manner, to acquire knowledge is to exercise the senses; and to undergo emotion is to exercise the senses; and the whole of this is a state of suffering. But we see that the soul experiences nothing of these things, in such a manner as that the mind also is affected by the emotion, by which, indeed, and with which, all is effected. It follows, therefore, that the mind is capable of admixture, in opposition to Anaxagoras; and passible or susceptible of emotion, contrary to the opinion of Aristotle. Besides, if a separate condition between the soul and mind is to be admitted, so that they be two things in substance, then of one of them, emotion and sensation, and every sort of taste, and all action and motion, will be the characteristics; whilst of the other the natural condition will be calm, and repose, and stupor. There is therefore no alternative: either the mind must be useless and void, or the soul. But if these affections may certainly be all of them ascribed to both, then in that case the two will be one and the same, and Democritus will carry his point when he suppresses all distinction between the two. The question will arise how two can be one--whether by the confusion of two substances, or by the disposition of one? We, however, affirm that the mind coalesces with  the soul,--not indeed as being distinct from it in substance, but as being its natural function and agent.