Chapter XVII.--The Fidelity of the Senses, Impugned by Plato, Vindicated by Christ Himself.
Then, again, when we encounter the question (as to the veracity of those five senses which we learn with our alphabet; since from this source even there arises some support for our heretics. They are the faculties of seeing, and hearing, and smelling, and tasting, and touching. The fidelity of these senses is impugned with too much severity by the Platonists,  and according to some by Heraclitus also, and Diocles, and Empedocles; at any rate, Plato, in the Timæus, declares the operations of the senses to be irrational, and vitiated  by our opinions or beliefs. Deception is imputed to the sight, because it asserts that oars, when immersed in the water, are inclined or bent, notwithstanding the certainty that they are straight; because, again, it is quite sure that that distant tower with its really quadrangular contour is round; because also it will discredit the fact of the truly parallel fabric of yonder porch or arcade, by supposing it to be narrower and narrower towards its end; and because it will join with the sea the sky which hangs at so great a height above it. In the same way, our hearing is charged with fallacy: we think, for instance, that that is a noise in the sky which is nothing else than the rumbling of a carriage; or, if you prefer it  the other way, when the thunder rolled at a distance, we were quite sure that it was a carriage which made the noise. Thus, too, are our faculties of smell and taste at fault, because the selfsame perfumes and wines lose their value after we have used them awhile. On the same principle our touch is censured, when the identical pavement which seemed rough to the hands is felt by the feet to be smooth enough; and in the baths a stream of warm water is pronounced to be quite hot at first, and beautifully temperate afterwards. Thus, according to them, our senses deceive us, when all the while we are (the cause of the discrepancies, by) changing our opinions. The Stoics are more moderate in their views; for they do not load with the obloquy of deception every one of the senses, and at all times. The Epicureans, again, show still greater consistency, in maintaining that all the senses are equally true in their testimony, and always so--only in a different way. It is not our organs of sensation that are at fault, but our opinion. The senses only experience sensation, they do not exercise opinion; it is the soul that opines. They separated opinion from the senses, and sensation from the soul. Well, but whence comes opinion, if not from the senses? Indeed, unless the eye had descried a round shape in that tower, it could have had no idea that it possessed roundness. Again, whence arises sensation if not from the soul? For if the soul had no body, it would have no sensation. Accordingly, sensation comes from the soul, and opinion from sensation; and the whole (process) is the soul. But further, it may well be insisted on that there is a something which causes the discrepancy between the report of the senses and the reality of the facts. Now, since it is possible, (as we have seen), for phenomena to be reported which exist not in the objects, why should it not be equally possible for phenomena to be reported which are caused not by the senses, but by reasons and conditions which intervene, in the very nature of the case? If so, it will be only right that they should be duly recognised. The truth is, that it was the water which was the cause of the oar seeming to be inclined or bent: out of the water, it was perfectly straight in appearance (as well as in fact). The delicacy of the substance or medium which forms a mirror by means of its luminosity, according as it is struck or shaken, by the vibration actually destroys the appearance of the straightness of a right line. In like manner, the condition of the open space which fills up the interval between it and us, necessarily causes the true shape of the tower to escape our notice; for the uniform density of the surrounding air covering its angles with a similar light obliterates their outlines. So, again, the equal breadth of the arcade is sharpened or narrowed off towards its termination, until its aspect, becoming more and more contracted under its prolonged roof, comes to a vanishing point in the direction of its farthest distance. So the sky blends itself with the sea, the vision becoming spent at last, which had maintained duly the boundaries of the two elements, so long as its vigorous glance lasted. As for the (alleged cases of deceptive) hearing, what else could produce the illusion but the similarity of the sounds? And if the perfume afterwards was less strong to the smell, and the wine more flat to the taste, and the water not so hot to the touch, their original strength was after all found in the whole of them pretty well unimpaired. In the matter, however, of the roughness and smoothness of the pavement, it was only natural and right that limbs like the hands and the feet, so different in tenderness and callousness, should have different impressions. In this way, then, there cannot occur an illusion in our senses without an adequate cause. Now if special causes, (such as we have indicated,) mislead our senses and (through our senses) our opinions also, then we must no longer ascribe the deception to the senses, which follow the specific causes of the illusion, nor to the opinions we form; for these are occasioned and controlled by our senses, which only follow the causes. Persons who are afflicted with madness or insanity, mistake one object for another. Orestes in his sister sees his mother; Ajax sees Ulysses in the slaughtered herd; Athamas and Agave descry wild beasts in their children. Now is it their eyes or their phrenzy which you must blame for so vast a fallacy? All things taste bitter, in the redundancy of their bile, to those who have the jaundice. Is it their taste which you will charge with the physical prevarication, or their ill state of health? All the senses, therefore, are disordered occasionally, or imposed upon, but only in such a way as to be quite free of any fault in their own natural functions. But further still, not even against the specific causes and conditions themselves must we lay an indictment of deception. For, since these physical aberrations happen for stated reasons, the reasons do not deserve to be regarded as deceptions. Whatever ought to occur in a certain manner is not a deception. If, then, even these circumstantial causes must be acquitted of all censure and blame, how much more should we free from reproach the senses, over which the said causes exercise a liberal sway! Hence we are bound most certainly to claim for the senses truth, and fidelity, and integrity, seeing that they never render any other account of their impressions than is enjoined on them by the specific causes or conditions which in all cases produce that discrepancy which appears between the report of the senses and the reality of the objects. What mean you, then, O most insolent Academy? You overthrow the entire condition of human life; you disturb the whole order of nature; you obscure the good providence of God Himself: for the senses of man which God has appointed over all His works, that we might understand, inhabit, dispense, and enjoy them, (you reproach) as fallacious and treacherous tyrants! But is it not from these that all creation receives our services? Is it not by their means that a second form is impressed even upon the world?--so many arts, so many industrious resources, so many pursuits, such business, such offices, such commerce, such remedies, counsels, consolations, modes, civilizations, and accomplishments of life! All these things have produced the very relish and savour of human existence; whilst by these senses of man, he alone of all animated nature has the distinction of being a rational animal, with a capacity for intelligence and knowledge--nay, an ability to form the Academy itself! But Plato, in order to disparage the testimony of the senses, in the Phædrus denies (in the person of Socrates) his own ability to know even himself, according to the injunction of the Delphic oracle; and in the Theætetus he deprives himself of the faculties of knowledge and sensation; and again, in the Phædrus he postpones till after death the posthumous knowledge, as he calls it, of the truth; and yet for all he went on playing the philosopher even before he died. We may not, I say, we may not call into question the truth of the (poor vilified) senses,  lest we should even in Christ Himself, bring doubt upon  the truth of their sensation; lest perchance it should be said that He did not really "behold Satan as lightning fall from heaven;"  that He did not really hear the Father's voice testifying of Himself;  or that He was deceived in touching Peter's wife's mother;  or that the fragrance of the ointment which He afterwards smelled was different from that which He accepted for His burial;  and that the taste of the wine was different from that which He consecrated in memory of His blood.  On this false principle it was that Marcion actually chose to believe that He was a phantom, denying to Him the reality of a perfect body. Now, not even to His apostles was His nature ever a matter of deception. He was truly both seen and heard upon the mount;  true and real was the draught of that wine at the marriage of (Cana in) Galilee;  true and real also was the touch of the then believing Thomas.  Read the testimony of John: "That which we have seen, which we have heard, which we have looked upon with our eyes, and our hands have handled, of the Word of life."  False, of course, and deceptive must have been that testimony, if the witness of our eyes, and ears, and hands be by nature a lie.