The tenets we have been speaking of have been proved to be nothing more than a false guide for life; but the way of truth will aim at reaching the real and true God. But for its knowledge and accurate comprehension, there is need of none other save of ourselves. Neither as God Himself is above all, is the road to Him afar off or outside ourselves, but it is in us and it is possible to find it from ourselves, in the first instance, as Moses also taught, when he said(1) : "The word" of faith "is within thy heart." Which very thing the Saviour declared and confirmed, when He said: "The kingdom of God is within you(2) ." 2. For having in ourselves faith, and the kingdom of God, we shall be able quickly to see and perceive the King of the Universe, the saving Word of the Father. And let not the Greeks, who worship idols, make excuses, nor let any one else simply deceive himself, professing to have no such road and therefore finding a pretext for his godlessness. 3. For we all have set foot upon it, and have it, even if not all are willing to travel by it, but rather to swerve from it and go wrong, because of the pleasures of life which attract them from without. And if one were to ask, what road is this? I say that it is the soul of each one of us, and the intelligence which resides there. For by it alone can God be contemplated and perceived. 4. Unless, as they have denied God, the impious men will repudiate having a soul; which indeed is more plausible than the rest of what they say, for it is unlike men possessed of an intellect to deny God, its Maker and Artificer. It is necessary then, for the sake of the simple, to shew briefly that each one of mankind has a soul, and that soul rational; especially as certain of the sectaries deny this also, thinking that man is nothing more than the visible form of the body. This point once proved, they will be furnished in their own persons with a clearer proof against the idols.
§31. Proof of the Existence of the Rational Soul. (1) Difference of Man from the Brutes. (2) Man's Flower of Objective Thought. Thought is to Sense as the Musician to His Instrument. The Phenomena of Dreams Bear This Out.
Firstly, then, the rational nature of the soul is strongly confirmed by its difference from irrational creatures. For this is why common use gives them that name, because, namely, the race of mankind is rational. 2. Secondly, it is no ordinary proof, that man alone thinks of things external to himself, and reasons about things not actually present, and exercises reflection, and chooses by judgment the better of alternative reasonings. For the irrational animals see only what is present, and are impelled solely by what meets their eye, even if the consequences to them are injurious, while man is not impelled toward what he sees merely, but judges by thought what he sees with his eyes. Often for example his impulses are mastered by reasoning; and his reasoning is subject to after-reflection. And every one, if he be a friend of truth, perceives that the intelligence of mankind is distinct from the bodily senses. 3. Hence, because it is distinct, it acts as judge of the senses, and while they apprehend their objects, the intelligence distinguishes, recollects, and shews them what is best. For the sole function of the eye is to see, of the ears to hear, of the mouth to taste, of the nostrils to apprehend smells, and of the hands to touch. But what one ought to see and hear, what one ought to touch, taste and smell, is a question beyond the senses, and belonging to the soul and to the intelligence which resides in it. Why, the hand is able to take hold of a sword-blade, and the mouth to taste poison, but neither knows that these are injurious, unless the intellect decide. 4. And the case, to look at it by aid of a simile, is like that of a well-fashioned lyre in the hands of a skilled musician. For as the strings of the lyre have each its proper note, high, low, or intermediate, sharp or otherwise, yet their scale is indistinguishable and their time not to be recognized, without the artist. For then only is the scale manifest and the time right, when he that is holding the lyre strikes the strings and touches each in tune. In like manner, the senses beingdisposed in the body like a lyre, when the skilled intelligence presides over them, then too the soul distinguishes and knows what it is doing and how it is acting. 5. But this alone is peculiar to mankind, and this is what is rational in the soul of mankind, by means of which it differs from the brutes, and shews that it is truly distinct from what is to be seen in the body. Often, for example, when the body is lying on the earth, man imagines and contemplates what is in the heavens. Often when the body is quiet(3) , and at rest and asleep, man moves inwardly, and beholds what is outside himself, travelling to other countries, walking about, meeting his acquaintances, and often by these means divining and forecasting the actions of the day. But to what can this be due save to the rational soul, in which man thinks of and perceives things beyond himself?
We add a further point to complete our demonstration for the benefit of those(4) who shamelessly take refuge in denial of reason. How is it, that whereas the body is mortal by nature, man reasons on the things of immortality, and often, where virtue demands it, courts death? Or how, since the body lasts but for a time, does man imagine of things eternal, so as to despise what lies before him, and desire what is beyond? The body could not have spontaneously such thoughts about itself, nor could it think upon what is external i to itself. For it is mortal and lasts but for a time. And it follows that that which thinks what is opposed to the body and against its nature must be distinct in kind. What then can this be, save a rational and immortal soul? For it introduces the echo of higher things, not outside, but within the body, as the musician does in his lyre. 2. Or how again, the eye being naturally constituted to see and the ear to hear, do they turn from some objects and choose others? For who is it that turns away the eye from seeing? Or who shuts off the ear from hearing, its natural function? Or who often hinders the palate, to which it is natural to taste things, from its natural impulse? Or who withholds the hand from its natural activity of touching something, or turns aside the sense of smell from its normal exercise(5) ? Who is it that thus acts against the natural instincts of the body? Or how does the body, turned from its natural course, turn to the counsels of another and suffer itself to be guided at the beck of that other? Why, these things prove simply this, that the rational soul presides over the body. 3. For the body is not even constituted to drive itself, but it is carried at the will of another, just as a horse does not yoke himself, but is driven by his master. Hence laws for human beings to practise what is good and to abstain from evil-doing, while to the brutes evil remains unthought of and undiscerned, because they lie outside rationality and the process of understanding. I think then that the existence of a rational soul in man is proved by what we have said.
But that the soul is made immortal is a further point in the Church's teaching which you must know, to show how the idols are to be overthrown. But we shall more directly arrive at a knowledge of this from what we know of the body, and from the difference between the body and the soul. For if our argument has proved it to be distinct from the body, while the body is by nature mortal, it follows that the soul is immortal, because it is not like the body. 2. And again, if as we have shewn, the soul moves the body and is not moved by other things, it follows that the movement of the soul is spontaneous, and that this spontaneous movement goes on after the body is laid aside in the earth. If then the soul were moved by the body, it would follow that the severance of its motor would involve its death. But if the soul moves the body also, it follows all the more that it moves itself. But if moved by itself(6) , it follows that it outlives the body. 3. For the movement of the soul is the same thing as its life, just as, of course, we call the body alive when it moves, and say that its death takes place when it ceases moving. But this can be made clearer once for all from the action of the soul in the body. For if even when united and coupled with the body it is not shut in or commensurate with the small dimensions of the body, but often(7) , when the body lies in bed, not moving, but in death-like sleep, the soul keeps awake by virtue of its own power, and transcends the natural power of the body, and as though travelling away from the body while remaining in it, imagines and beholds things above the earth, and often even holds converse with the saints and angels who are above earthly and bodily existence, and approaches them in the confidence of the purity of its intelligence; shall it not all the more, when separated from the body at the time appointed by God Who coupled them together, have its knowledge of immortality more clear? For if even when coupled with the body it lived a life outside the body, much more shall its life continue after the death of the body, and live without ceasing by reason of God Who made it thus by His own Word, our Lord Jesus Christ. 4. For this is the reason why the soul thinks of and bears in mind things immortal and eternal, namely, because it is itself immortal. And just as, the body being mortal, its senses also have mortal things as their objects, so, since the soul contemplates and beholds immortal things, it follows that it is immortal and lives for ever. For ideas and thoughts about immortality never desert the soul, but abide in it, and are as it were the fuel in it which ensures its immortality. This then is why the soul has the capacity for beholding God, and is its own way thereto, receiving not from without but from herself the knowledge and apprehension of the Word of God.
§34. The Soul, Then, If Only It Get Rid of the Stains of Sin is Able to Know God Directly, Its Own Rational Nature Imaging Back the Word of God, After Whose Image It Was Created. But Even If It Cannot Pierce the Cloud Which Sin Draws Over Its Vision, It is Confronted by the Witness of Creation to God.
We repeat then what we said before, that just as men denied God, and worship things without soul, so also in thinking they have not a rational soul, they receive at once the punishment of their folly, namely, to be reckoned among irrational creatures: and so, since as though from lack of a soul of their own they superstitiously worship soulless gods, they are worthy of pity and guidance. 2. But if they claim to have a soul, and pride themselves on the rational principle, and that rightly, why do they, as though they had no soul, venture to go again st reason, and think not as they ought, but make themselves out higher even than the Deity? For having a soul that is immortal and invisible to them, they make a likeness of God in things visible and mortal. Or why, in like manner as they have departed from God, do they not betake themselves to Him again? For they are able, as they turned away their understanding from God, and feigned as gods things that were not, in like manner to ascend with the intelligence of their soul, and turn back to God again. 3. But turn back they can, if they lay aside the filth of all lust which they have put on, and wash it away persistently, until they have got rid of all the foreign matter that has affected their soul, and can shew it in its simplicity as it was made, that so they may be able by it to behold the Word of the Father after Whose likeness they were originally made. For the soul is made after the image and likeness of God, as divine Scripture also shews, when it says in the person of Gods(8) : "Let us make man after our Image and likeness." Whence also when it gets rid of all the filth of sin which covers it and retains only the likeness of the Image in its purity, then surely this latter being thoroughly brightened, the soul beholds as in a mirror the Image of the Father, even the Word, and by His means reaches the idea of the Father, Whose Image the Saviour is. 4. Or, if the soul's own teaching is insufficient, by reason of the external things which cloud its intelligence, and prevent its seeing what is higher, yet it is further possible to attain to the knowledge of God from the things which are seen, since Creation, as though in written characters, declares in a loud voice, by its order and harmony, its own Lord and Creator.