Chapter 6 [V.]—Questions About the Nature of the Body are Sufficiently Mysterious, and Yet Not Higher Than Those of the Soul.
What do you say to the statement, that amongst the works of God there are some which it is more difficult to know than even God Himself,—so far, indeed, as He can be an object of knowledge to us at all? For we have learnt that God is a Trinity; but to this very day we do not know how many kinds of animals, not even of land animals which were able to enter Noahs ark, 2461 He has created—unless by some happy chance you have ascertained this fact. Again, in the Book of Wisdom it is written, “For if they were able to prevail so much, that they could know and estimate the world; how is it that they did not more easily find out the Lord thereof?” 2462 Is it because the subject before us is within us that it is therefore not too high for us? For it must be granted that the nature of our soul is a more internal thing than our body. As if the soul has been no better able to explore the body itself externally by the eyes of that body than internally by its own means. For what is there in the inward parts of the body where the soul does not exist? But yet, even with regard to these several inner and vital portions of our frame, the soul has examined and searched them out by the bodily eyes; and all that it has succeeded in learning of them it has acquired by means of the eyes of the body; and, without doubt, all the material substance was there, even when the soul knew not of it. Since also our inward parts are incapable of living without the soul, it follows that the soul has been more able to give them life than to know them. Well, then, is the souls body a higher object for its knowledge than the souls own self? And therefore if it wishes to inquire and consider when human seed is converted into blood, when into solid flesh; when the bones begin to harden, and when to fill with marrow; how many kinds of veins and nerves there are; by what channels and circuits the former serve for irrigation and the latter for ligature to the entire body; whether the skin is to be reckoned among the nerves, and the teeth among the bones,—for they show some difference, inasmuch as they have no marrow; and in what respect the nails differ from both, being similar to them in hardness, while they possess a quality in common with the hair, in being capable of growing and being cut; what, again, is the use of those veins wherein air, instead of blood, circulates, which they call the arteries 2463 —if, I repeat, the soul desired to come to know these and similar points respecting the nature of its body, ought it then to be said to a man, “Seek not out the things that are too high for thee, neither search the things that are above thy strength?” But, if the inquiry be made into the souls own origin, of which subject it knows nothing, the matter then, forsooth, is not too high or beyond ones strength to be capable of apprehension? And you deem it an absurd thing, and incompatible with reason, for the soul not to know whether it is inbreathed by God, or whether it is derived from the parents, although it does not remember this event as soon as it is past, and reckons it among the things which it has forgotten beyond recall,—like infancy, and all other stages of life which followed close upon birth, though doubtless, when they happened, they were not unaccompanied with sensation. But yet you do not deem it absurd or unreasonable that it should be ignorant of the body which is subject to it, and should know nothing whatever about incidents pertaining to it which are not in the category of things that are past, but of present facts, p. 357 —as to whether it sets the veins in motion in order to produce life in the body, but the nerves in order to operate by the limbs of the body; and if so, why it does not move the nerves except at its especial will, whereas it affects the pulsations of the veins without intermission, even without willing; from what part of the body that which they call the ἡγεμονικόν (the authoritative part of the soul, the reason) exercises its universal rule, whether from the heart or from the brain, or by a distribution, the motions from the heart and the sensations from the brain,—or from the brain, both the sensations and voluntary motions, but from the heart, the involuntary pulsations of the veins; and once more, if it does both of these from the brain, how is it that it has the sensations, even without willing, while it does not move the limbs except it wills? Inasmuch, then, as only the soul itself does all this in the body, how is it that it knows not what it does? or whence its power to do it? And it is no disgrace to it to be so ignorant. Then do you suppose it to be a discredit if it knows not whence or how it was itself made, since it certainly did not make itself? Well, then, none know how or whence the soul effects all its action in the body; do you not therefore think that it, too, appertains to those things which are said to be “too high for us, and above our strength”?
Gen. 7:8, 9.356:2462
These vessels which carry the blood from the heart were formerly supposed, from being found empty after death, to contain only air; and hence, indeed, their name,—for “the artery” was originally the windpipe. Comp. Cicero (De Nat. Deor. ii. 55, 138): “Sanguis per venas in omne corpus diffunditur, et spiritus per arterias”: i.e. Blood is diffused throughout the body by the veins, and air by the arteries.