City of God, Book XXI
But who can explain the strange properties of fire itself, which blackens everything it burns, though itself bright; and which, though of the most beautiful colors, discolors almost all it touches and feeds upon, and turns blazing fuel into grimy cinders? Still this is not laid down as an absolutely uniform law; for, on the contrary, stones baked in glowing fire themselves also glow, and though the fire be rather of a red hue, and they white, yet white is congruous with light, and black with darkness. Thus, though the fire burns the wood in calcining the stones, these contrary effects do not result from the contrariety of the materials. For though wood and stone differ, they are not contraries, like black and white, the one of which colors is produced in the stones, while the other is produced in the wood by the same action of fire, which imparts its own brightness to the former, while it begrimes the latter, and which could have no effect on the one were it not fed by the other. Then what wonderful properties do we find in charcoal, which is so brittle that a light tap breaks it and a slight pressure pulverizes it, and yet is so strong that no moisture rots it, nor any time causes it to decay. So enduring is it, that it is customary in laying down landmarks to put charcoal underneath them, so that if, after the longest interval, any one raises an action, and pleads that there is no boundary stone, he may be convicted by the charcoal below. What then has enabled it to last so long without rotting, though buried in the damp earth in which [its original] wood rots, except this same fire which consumes all things?
Again, let us consider the wonders of lime; for besides growing white in fire, which makes other things black, and of which I have already said enough, it has also a mysterious property of conceiving fire within it. Itself cold to the touch, it yet has a hidden store of fire, which is not at once apparent to our senses, but which experience teaches us, lies as it were slumbering within it even while unseen. And it is for this reason called “quick lime,” as if the fire were the invisible soul quickening the visible substance or body. But the marvellous thing is, that this fire is kindled when it is extinguished. For to disengage the hidden fire the lime is moistened or drenched with water, and then, though it be cold before, it becomes hot by that very application which cools what is hot. As if the fire were departing from the lime and breathing its last, it no longer lies hid, but appears; and then the lime lying in the coldness of death cannot be requickened, and what we before called “quick,” we now call “slaked.” What can be stranger than this? Yet there is a greater marvel still. For if you treat the lime, not with water, but with oil, which is as fuel to fire, no amount of oil will heat it. Now if this marvel had been told us of some Indian mineral which we had no opportunity of experimenting upon, we should either have forthwith pronounced it a falsehood, or certainly should have been greatly astonished. But things that daily present themselves to our own observation we despise, not because they are really less marvellous, but because they are common; so that even some products of India itself, remote as it is from ourselves, cease to excite our admiration as soon as we can admire them at our leisure.
The diamond is a stone possessed by many among ourselves, especially by jewellers and lapidaries, and the stone is so hard that it can be wrought neither by iron nor fire, nor, they say, by anything at all except goat’s blood. But do you suppose it is as much admired by those who own it and are familiar with its properties as by those to whom it is shown for the first time? Persons who have not seen it perhaps do not believe what is said of it, or if they do, they wonder as at a thing beyond their experience; and if they happen to see it, still they marvel because they are unused to it, but gradually familiar experience [of it] dulls their admiration. We know that the loadstone has a wonderful power of attracting iron. When I first saw it I was thunderstruck, for I saw an iron ring attracted and suspended by the stone; and then, as if it had communicated its own property to the iron it attracted, and had made it a substance like itself, this ring was put near another, and lifted it up; and as the first ring clung to the magnet, so did the second ring to the first. A third and a fourth were similarly added, so that there hung from the stone a kind of chain of rings, with their hoops connected, not interlinking, but attached together by their outer surface. Who would not be amazed at this virtue of the stone, subsisting as it does not only in itself, but transmitted through so many suspended rings, and binding them together by invisible links? Yet far more astonishing is what I heard about this stone from my brother in the episcopate, Severus bishop of Milevis. He told me that Bathanarius, once count of Africa, when the bishop was dining with him, produced a magnet, and held it under a silver plate on which he placed a bit of iron; then as he moved his hand with the magnet underneath the plate, the iron upon the plate moved about accordingly. The intervening silver was not affected at all, but precisely as the magnet was moved backwards and forwards below it, no matter how quickly, so was the iron attracted above. I have related what I myself have witnessed; I have related what I was told by one whom I trust as I trust my own eyes. Let me further say what I have read about this magnet. When a diamond is laid near it, it does not lift iron; or if it has already lifted it, as soon as the diamond approaches, it drops it. These stones come from India.
But if we cease to admire them because they are now familiar, how much less must they admire them who procure them very easily and send them to us? Perhaps they are held as cheap as we hold lime, which, because it is common, we think nothing of, though it has the strange property of burning when water, which is wont to quench fire, is poured on it, and of remaining cool when mixed with oil, which ordinarily feeds fire.
Chapter 5.—That There are Many Things Which Reason Cannot Account For, and Which are Nevertheless True.
Nevertheless, when we declare the miracles which God has wrought, or will yet work, and which we cannot bring under the very eyes of men, sceptics keep demanding that we shall explain these marvels to reason. And because we cannot do so, inasmuch as they are above human comprehension, they suppose we are speaking falsely. These persons themselves, therefore, ought to account for all these marvels which we either can or do see. And if they perceive that this is impossible for man to do, they should acknowledge that it cannot be concluded that a thing has not been or shall not be because it cannot be reconciled to reason, since there are things now in existence of which the same is true. I will not, then, detail the multitude of marvels which are related in books, and which refer not to things that happened once and passed away, but that are permanent in certain places, where, if any one has the desire and opportunity, he may ascertain their truth; but a few only I recount. The following are some of the marvels men tell us:—The salt of Agrigentum in Sicily, when thrown into the fire, becomes fluid as if it were in water, but in the water it crackles as if it were in the fire. The Garamantæ have a fountain so cold by day that no one can drink it, so hot by night no one can touch it. In Epirus, too, there is a fountain which, like all others, quenches lighted torches, but, unlike all others, lights quenched torches. There is a stone found in Arcadia, and called asbestos, because once lit it cannot be put out. The wood of a certain kind of Egyptian fig-tree sinks in water, and does not float like other wood; and, stranger still, when it has been sunk to the bottom for some time, it rises again to the surface, though nature requires that when soaked in water it should be heavier than ever. Then there are the apples of Sodom which grow indeed to an appearance of ripeness, but, when you touch them with hand or tooth, the peal cracks, and they crumble into dust and ashes. The Persian stone pyrites burns the hand when it is tightly held in it and so gets its name from fire. In Persia too, there is found another stone called selenite, because its interior brilliancy waxes and wanes with the moon. Then in Cappadocia the mares are impregnated by the wind, and their foals live only three years. Tilon, an Indian island, has this advantage over all other lands, that no tree which grows in it ever loses its foliage.
These and numberless other marvels recorded in the history, not of past events, but of permanent localities, I have no time to enlarge upon and diverge from my main object; but let those sceptics who refuse to credit the divine writings give me, if they can, a rational account of them. For their only ground of unbelief in the Scriptures is, that they contain incredible things, just such as I have been recounting. For, say they, reason cannot admit that flesh burn and remain unconsumed, suffer without dying. Mighty reasoners, indeed, who are competent to give the reason of all the marvels that exist! Let them then give us the reason of the few things we have cited, and which, if they did not know they existed, and were only assured by us they would at some future time occur, they would believe still less than that which they now refuse to credit on our word. For which of them would believe us if, instead of saying that the living bodies of men hereafter will be such as to endure everlasting pain and fire without ever dying, we were to say that in the world to come there will be salt which becomes liquid in fire as if it were in water, and crackles in water as if it were in fire; or that there will be a fountain whose water in the chill air of night is so hot that it cannot be touched, while in the heat of day it is so cold that it cannot be drunk; or that there will be a stone which by its own heat burns the hand when tightly held, or a stone which cannot be extinguished if it has been lit in any part; or any of those wonders I have cited, while omitting numberless others? If we were to say that these things would be found in the world to come, and our sceptics were to reply, “If you wish us to believe these things, satisfy our reason about each of them,” we should confess that we could not, because the frail comprehension of man cannot master these and such-like wonders of God’s working; and that yet our reason was thoroughly convinced that the Almighty does nothing without reason, though the frail mind of man cannot explain the reason; and that while we are in many instances uncertain what He intends, yet that it is always most certain that nothing which He intends is impossible to Him; and that when He declares His mind, we believe Him whom we cannot believe to be either powerless or false.