Nicene and Post-Nicene Fathers: Series I/Volume IV/Manichaean Controversy/On Two Souls/Chapter 13
Chapter 13.—From Deliberation on the Evil and on the Good Part It Results that Two Classes of Souls are Not to Be Held to. A Class of Souls Enticing to Shameful Deeds Having Been Conceded, It Does Not Follow that These are Evil by Nature, that the Others are Supreme Good.
19. But if I had taught, or at any rate had myself learned, that they rave and err regarding those two classes of souls, why should I have thenceforth thought them worthy of being heard or consulted about anything? That I might learn hence, that these two kinds of souls are pointed out, which in the course of deliberation assent puts now on the evil side, now on the good? Why is not this rather the sign of one soul which by free will can be borne here and there, swayed hither and thither? For it was my own experience to feel that I am one, considering evil and good and choosing one or the other, but for the most part the one pleases, the other is fitting, placed in the midst of which we fluctuate. Nor is it to be wondered at, for we are now so constituted that through the flesh we can be affected by sensual pleasure, and through the spirit by honorable considerations. Am I not therefore compelled to acknowledge two souls? Nay, we can better and with far less difficulty recognize two classes of good things, of which neither is alien from God as its author, one soul acted upon from diverse directions, the lower and the higher, or to speak more correctly, the external and the internal. These are the two classes which a little while ago we considered under the names sensible and intelligible, which we now prefer to call more familiarly carnal and spiritual. But it has been made difficult for us to abstain from carnal things, since our truest bread is spiritual. For with great labor we now eat this bread. For neither without punishment for the sin of transgression have we been changed from immortal into mortal. So it happens, that when we strive after better things, habit formed by connection with the flesh and our sins in some way begin to militate against us and to put obstacles in our way, some foolish persons with most obtuse superstition suspect that there is another kind of souls which is not of God.
20. However even if it be conceded to them that we are enticed to shameful deeds by another inferior kind of souls, they do not thence make it evident that those enticing are evil by nature, or those enticed, supremely good. For it may be, the former of their own will, by striving after what was not lawful, that is, by sinning, from being good have become evil; and again they may be made good, but in such manner that for a long time they remain in sin, and by a certain occult suasion traduce to themselves other souls. Then, they may not be absolutely evil, but in their own kind, however inferior, they may exercise their own functions without any sin. But those superior souls to whom justice, the directress of things, has assigned a far more excellent activity, if they should wish to follow and to imitate those inferior ones, become evil, not because they imitate evil souls, but because they imitate in an evil way. By the evil souls is done what is proper to them, by the good what is alien to them is striven after. Hence the former remain in their own grade, the latter are plunged into a lower. It is as when men copy after beasts. For the four-footed horse walks beautifully, but if a man on all fours should imitate him, who would think him worthy even of chaff for food? Rightly therefore we generally disapprove of one who imitates, while we approve of him whom he imitates. But we disapprove not because he has not succeeded, but for wishing to succeed at all. For in the horse we approve of that to which by as much as we prefer man, by so much are we offended that he copies after inferior creatures. So among men, however well the crier may do in sending forth his voice, would not the senator be insane, if he should do it even more clearly and better than the crier? Take an illustration from the heavenly bodies: The moon when shining is praised, and by its course and its changes is quite pleasing to those that pay attention to such things. But if the sun should wish to imitate it (for we may feign that it has desires of this sort), who would not be greatly and rightly displeased. From which illustrations I wish it to be understood, that even if there are souls (which meanwhile is left an open question) devoted to bodily offices not by sin but by nature, and even if they are related to us, however inferior they may be, by some inner affinity, they should not be esteemed evil simply because we are evil ourselves in following them and in loving corporeal things. For we sin by loving corporeal things, because by justice we are required and by nature we are able to love spiritual things, and when we do this we are, in our kind, the best and the happiest. 
21. Wherefore what proof does deliberation, violently urged in both directions, now prone to sin, now borne on toward right conduct, furnish, that we are compelled to accept two kinds of souls, the nature of one of which is from God, of the other not; when we are free to conjecture so many other causes of alternating states of mind? But that these things are obscure and are to no purpose pried into by blear-eyed minds, whoever is a good judge of things sees. Wherefore those things rather which have been said regarding the will and sin, those things, I say, that supreme justice permits no man using his reason to be ignorant of, those things which if they were taken from us, there is nothing whence the discipline of virtue may begin, nothing whence it may rise from the death of vices, those things I say considered again and again with sufficient clearness and lucidity convince us that the heresy of the Manichæans is false.
- Augustin’s carefulness to explain that he is only indulging in personification is doubtless due to the fact that with the Manichæans the sun and the moon were objects of worship.—A.H.N.
- In his Retractations, Augustin explains that he did not really regard this as an open question, but speaks of it as such only so far as this particular discussion is concerned. He simply declines to enter upon a consideration of it in this connection.—A.H.N.
- Here also the use of the word "nature" gave Augustin trouble in his later years. He claims in the Retractations that he uses the word in the sense of "nature that has been healed" and that "cannot be vitiated," and seeks to show that he did not mean to exclude divine grace.—A.H.N.