Chapter XIII: Preface (1)

Lucilius, my much esteemed friend--While a great gulf separates 1 philosophy from the other learned arts, there is to my mind an equally wide gulf in philosophy itself between the portion which relates to human conduct and that which deals with the nature and power of heaven. The latter is more exalted and more speculative, it allows itself wide liberty. It is not satisfied with mere observation, it surmises that there is a greater and fairer realm placed by nature beyond human sight. Between these two divisions of philosophy, in short, there is as wide a gulf as between their subjects, God and man.

The one teaches us what should be done on earth;[25] the other, what 2 is done in heaven. The one dispels our errors and flashes a light by which to thread the mazes of life; the other far transcends this gloom in which we grope, rescues us from the darkness, and leads us to the very source of light itself. For myself, I am grateful to nature, not so much when I see her on the side that is open to the world, as when I am permitted to enter her shrine. Then one may seek to know of what stuff the universe is made, who is its author or guardian, what is the nature of God. Is He wholly absorbed in Himself, or does He sometimes regard us? does He do something daily, or has He done once for all? is He a portion of the world, or the whole world? may He issue new decrees even to-day and thus modify the laws of fate, or is it an infringement of His majesty and an acknowledgment of error to alter what has once been made? for surely the same must always please Him who can be 3 pleased only with what is best. Nor yet withal is His freedom or power diminished, for He is a law unto Himself.

[25] In other words, the principles of human conduct.

Life would have been a useless gift, were I not admitted to the study of such themes. What cause for joy would it be to be set merely in the number of those who live? In order to digest food and drink? To repair a diseased, enfeebled body, that would perish unless it were continually refilled, and thus lead the life of a sick man’s attendant? To fear death, to which our very birth destines us? Away with the priceless boon! Life is not worth the heat and the sweat. How 4 despicable a creature is man, unless he rise above the earth! What great thing can we do as long as we have to wrestle with our passions? Even if we prevail, we but conquer monsters. What cause have we to esteem ourselves because we are not quite so bad as the very worst? I can see no great reason for self-satisfaction because one’s strength is rather above the average of those in the same hospital. You are still far from good health and vigour. Or, again, you have escaped vices of soul, the hypocrite’s brow, the flatterer’s speech fashioned to serve another’s will, the dissembler’s heart, the miser’s spirit, which robs all, but yet mortifies itself. You are a prey neither to luxury, which loses basely and repairs its losses still more basely; nor to ambition, which leads to place of worth only by unworthy means. But 5 yet you have accomplished nothing. You have escaped many perils, but not yet [that of] self! The virtue we aim at raises to a splendid eminence; not so much because escape from vice is in itself a blessed thing, but rather because the soul is emancipated, prepared for the knowledge of heavenly things, and rendered worthy of entering into communion with God.

The full consummation of human felicity is attained when, all vice trampled under foot, the soul seeks the heights and reaches the inner recesses of nature. What joy then to roam through the very stars, to look down with derision on the gilded saloons of the rich and the whole earth with its store of gold! Gold, did I say? Yes, all the gold the earth ever produced and sent into currency, and all that she keeps hidden in secret to glut the avarice of posterity. Only when one has surveyed the whole universe can one truly despise grand colonnades, 6 ceilings glittering with ivory, trim groves and cooling streams transported into wealthy mansions. From above, one can now look down upon this narrow world, covered for the most part by sea, and, even where it rises above the sea, an ugly waste either parched or frozen. The philosopher says to himself: Is this the plot that so many tribes portion out by fire and sword? How ludicrous are their frontiers! The Dacian must not pass the lower Danube; the Strymon must shut off the 7 Thracians; the Euphrates must be the barrier of the Parthians; the Danube must form the boundary between Sarmatian and Roman; the Rhine must set a limit to Germany; the Pyrenees must raise their chain between Gallic and Spanish provinces; between Egypt and Ethiopia a desert of barren sands must stretch! Why, if ants are ever endowed with human intelligence, will not they in like manner portion out a threshing-floor into many provinces?

But when you rise to what is truly great, then, as often as you 8 see armies marching forth with floating banners, and the cavalry now scouting in front, now massed on the flanks, as if some great design were toward, you will pleasantly remark:

The black swarm is hurrying through the plains.

That host is a throng of ants, its evolutions are in a back garden. In what do we excel the ants, save in the measure of the puny little body? That is a mere point in which you sail, and war, and dispose your kingdoms. Your kingdoms are lilliputian even when they stretch from Ocean to Ocean. Only on high are the domains spacious; to their 9 possession the mind is admitted, provided always that it bring with it no taint of the body, but wipe off all stain and pass forth like an armed man, lightly equipped, nimble, modest in his wants. When the soul reaches those regions, it receives nourishment and growth; as if freed from the shackles of earth, it returns to the true source of its being. A proof of its divine origin is furnished by the pleasure it derives 10 from what is divine; here it feels itself at home, not in a strange land. Without alarm it views the setting of the stars and their rising, and the mazy orbits of the heavenly bodies that yet move all in unison. It notes when each star first shows its light on earth, when it attains its meridian height, observes its orbit and the limits of its descent. An interested spectator, it examines and investigates every detail. And why should it not? It feels that they are akin to itself. Then contempt for the narrow limits of its former dwelling succeeds. For 11 what after all is the space that lies from India to the farthest shores of Spain? A few days’ journey if a prosperous wind waft the vessel. But that heavenly region affords a route during full thirty years to the swiftest of the planets, rushing with untiring velocity, never once hal ting.

Here at last the soul comes to learn what it has long sought, it begins to know God. But what is God? The universal intelligence. What is 12 God, did I say? All that you see and all that you cannot see. His greatness exceeds the bounds of thought. Render Him His true greatness and He is all in all, He is at once within and without His works. What, then, is the difference between the divine nature and the human? In us the better part is spirit, in Him there is nothing except spirit. He 13 is wholly reason: though mortal eyes are so sealed by error that men believe this frame of things to be but a fortuitous concourse of atoms, the sport of chance. And yet than this universe could aught be fairer, more carefully adjusted, more consistent in plan? But men will have it that it is tossed about at random in the confusion of thunder, cloud, and storm, and the other forces by which the earth and its purlieus are haunted.

Nor is this merely the madness of vulgar error; even the philosophers are tainted by it. Men there are who think that they themselves have 14 a mind, one, too, that foresees and orders events in detail whether relating to themselves or to others. But this frame of things, in which we men along with the rest of creation are set, they deem void of counsel, hurried hither and thither at random; or at best, nature, they suppose, does not know what her own aim is. How profitable then, think you, will it be to ascertain the truth on such questions and exactly to define each position! For example, what is the extent of the power of God? Does He create matter or does He employ matter already given? Does the pre-existing archetype give shape to matter, or does the matter determine the shape? Can God perform anything He wishes, or does material fail Him in many cases, just as a great artist often produces inferior work, not through any defect in his art, but because the 15 material on which it is exercised is refractory? To search into such things, to learn them, to meditate upon them--why, is it not in effect to transcend the limits of mortality and to be enrolled a citizen of a higher state? What good will it do you, you ask. Well, if nothing else, I shall, at any rate, know that measured by divine standard all earthly things are mean. But of this more anon.

I

To come now to my purpose--listen to the explanation offered by 1 Natural Philosophy concerning _the Fires_ which the atmosphere drives athwart. Their oblique course and amazing velocity furnish proof that they are thrust out with great violence. Evidently they do not come forth of themselves, they are shot out. There are many different forms of them. A certain kind of them Aristotle calls a She-Goat. If you ask me why, I must retort by asking you first to explain why they are also called Kids. It will, perhaps, be more to the purpose not to 2 cross-examine one another with questions such as: What does such and such an author say? Answer me. Better examine the cause of the phenomenon itself than form surmises as to why Aristotle has applied the name She-Goat to a ball of fire. This was the shape of the one as big as the moon that appeared when Paulus was engaged in the war against Perseus. In our own days we have more than once seen a huge ball-shaped flame which broke up in the very middle of its course. We 3 saw a similar portent about the time of the death of the late Emperor Augustus. We again saw one when Sejanus was executed. A warning of the same kind preceded the death of Germanicus.

You may, perhaps, exclaim: Are you then so benighted as to suppose that the gods send out previous intimation of the death of great men? Do you imagine that anything on earth is so great that the Universe should perceive its loss? That question must be reserved for another season. We shall then see whether a fixed succession is observed in all events, and whether one event is so bound up with another that what precedes is either cause or at least token of what follows. We shall then see, 4 too, whether the gods trouble themselves about human concerns, and whether the mere series of events reveals by unmistakable signs what its effects must be. Meantime, I venture the opinion that fires of the class referred to are produced by violent friction of the atmosphere. The pressure inclines toward one or other side, and as there is no yielding there, an internal struggle ensues. From violent action of this kind arise the different varieties of fires--beams, balls, torches, and gleams. When the shock is less severe, and the atmosphere is merely grazed, as it were, smaller lights are emitted,

And the flying stars drag their hairy tail.

Then their thin fires mark a slender path, which they prolong across 5 the sky. For that reason no night is without sights of the kind; no great movement of the atmosphere is required to produce them. In fact, to put it shortly, they are due to the very same cause as thunderbolts, only they require less force.

Clouds that encounter each other with little force cause flashes of lightning; if impelled by greater violence, thunderbolts. Aristotle offers the following explanation: The earth gives forth many 6 different exhalations, some moist, some dry, some cold, some containing the seeds of fire. And little wonder if the earth’s evaporation is of all varied kinds. Why, even in the heavens the colour of objects does not show uniform; the red of the Dog-star is brighter, that of Mars duller; Jupiter has no red, his sheen is prolonged into pure light. 7 Well, in the great abundance of minute bodies emitted by the earth and driven up to the higher regions, of necessity some of the elements that reach the clouds furnish material for fires. They do not require any collision in order to burn, the breath of the sun’s rays is sufficient to kindle them. So with us, shavings sprinkled with sulphur catch fire at some distance. Probably, therefore, tinder of this kind gathering 8 within the clouds is easily kindled; greater or less fires are produced just as there has been more or less substance in the elements.

On the other hand, to suppose either that actual stars fall or leap across the sky, or that some portion of them is taken away or pared off, is sheer folly. If this had been so, they would ere this have 9 disappeared. For there is not a single night on which there is not a very large number of stars that seem to break up as they pass across the sky. Yet they are all found again in their wonted places: each one maintains its size unimpaired. It follows, therefore, that the fires referred to have their origin below the stars, and that, being without solid foundation on fixed abode, they quickly perish. Why, then, you ask, do they not cross the sky by day as well as by night? The next 10 thing you will say will be that there are no stars by day because they are not visible! The stars are, of course, there, but obscured by the sun’s brightness. Similarly, meteor fires like torches cross the sky by day too, but they are hidden by the brightness of the daylight. If, as sometimes happens, a burst of light shoots out strong enough to assert its brilliance even in the face of day, then they do become visible. In fact, our own age has more than once seen torches by day, some 11 rushing from east to west, others from west to east.

Sailors consider it a sign of storm when there are many shooting stars. If their appearance really is a sign of wind, they must occur in the quarter where wind is found, in other words, in the atmosphere which lies between the earth and the moon. In violent storms at sea there sometimes appear, as it were, stars settling on the sails. The sailors who are in jeopardy then suppose that they are being aided by the power of Castor and Pollux. They have really ground for better 12 hope in this appearance, because it makes plain that the storm is breaking, and the wind falling. Otherwise the fires would flit about without settling. When Gylippus was on the voyage to Syracuse, a star appeared, resting on the very tip of his lance. In the camp of the Romans at times pikes appeared to be on fire, no doubt because fires of this kind glided down on to them: these fires are often wont to strike animals and trees, just like thunderbolts. If, however, they 13 are discharged with less force, they merely glide down and settle, and do not inflict stroke or wound. Again, some are forced out from among clouds, others come from a clear sky, if the atmosphere has got into a condition to emit fire. In like manner, it occasionally thunders with a clear sky, and from the same cause as with a cloudy one, the atmosphere undergoing internal collision. Even when the air is comparatively clear and dry, it may become condensed, and form bodies similar to clouds, the clashing of which causes the sound of the thunder. From time to 14 time, therefore, arise meteors like beams and like shields, and the semblance of vast fires over the sky, if a force similar in kind but greater in degree encounter suitable material.

II

Let us now see how the brightness is produced that sometimes envelops 1 the heavenly bodies. History has put on record that, on the day of the late Emperor Augustus’ entrance into Rome on his return from Apollonia, a parti-coloured circle, such as is wont to be seen in a rainbow, appeared round the sun. The Greeks call this a _Halo_; our most appropriate name for it is a Crown. Let me explain how it is formed. When a stone is thrown into a pond, the water is observed to part 2 in numerous circles, which, very narrow at first, gradually widen out more and more until the impulse disappears, lost in the surface of the smooth water beyond. Let us suppose something of the same kind to occur in the atmosphere. When condensed it is capable of receiving an impact: the light of sun, moon, or any heavenly body encountering it forces it to recede in the form of circles. Moisture, be it observed, and air, and everything else that takes shape from a blow, is driven into the same form as that possessed by the object that strikes it. Now every kind of light is round. Therefore, the air when struck by light will 3 assume this form. Accordingly the Greeks gave the name Threshing-floor (_i.e._ Halo) to a brightness of this kind, because spaces set apart for threshing corn were, as a rule, round.

Be the better name threshing-floors, or be it crowns, there is no reason to suppose that they are formed in the neighbourhood of the heavenly bodies. They are a very long distance from them, though as seen from the earth they seem to touch and encircle them. In reality such an image is formed not very far from the earth, but the wonted 4 frailty of human vision is deceptive, and we imagine the ring is formed close round the heavenly body itself. But no such thing could possibly occur in the neighbourhood of the sun and stars, as there is nothing but thin ether there. It is only when bodies have become rough and dense that shape can be impressed upon them. In subtle bodies there is no point on which form can lay hold or to which it can adhere. A phenomenon of the same nature as the halo may often be witnessed in baths, because the atmosphere is thick and dark: it is most frequent when the wind is in the south, when the air is heaviest and most dense.

Halos sometimes are dissolved gradually and fade away, sometimes they 5 are broken up on one side. In the latter case seafaring men look for wind in the direction in which the circle of the crown has been broken. If the parting is on the north, there will be a north wind, if on the west, zephyrs will follow. This is a proof that these crowns are formed in the region of the sky in which the winds are usually formed. The upper regions of air have no crowns because they have no winds either. An additional proof of the connection of winds and halos is afforded 6 by the fact that the halo is never formed unless the atmosphere is at rest, and the wind, as it were, inactive. Under other circumstances it is not usually observed.

The atmosphere when it is at rest may be fashioned to any pattern by being driven or drawn in any direction. But when it is in motion, light cannot even strike it. It takes no shape and offers no resistance, because the part first affected is always dissipated by the motion. Therefore it is that no heavenly body can ever be surrounded by a 7 figure of the kind referred to unless when the atmosphere is dense and motionless, and so preserves the ray of round light that strikes upon it. Nor is it without good reason. Recollect the analogy mentioned a little ago. A pebble thrown into a pond or lake or any other circumscribed piece of water produces innumerable circles; but it has not the same effect if thrown into a river. And why so? Because in the latter case the water as it hurries on prevents the formation of any definite figure. So in the atmosphere the same thing happens; when 8 it is stationary, it may receive a pattern; when it rushes in rapid motion, it evades all control, warding off every blow and every form as it approaches. When these crowns, of which I have spoken, have disappeared uniformly on all sides, and vanished in their own tracks, it is an indication of equilibrium in the atmosphere: there is perfect quietness and you may then look out for rain. When they break up 9 at one side, it means wind in that quarter. If they burst at several points, a storm is brewing. The reason of this may be gathered from the explanations I have now given. If the ring fade all round, it is evident that the atmosphere is equable, and therefore calm. But if it is broken through on one side, evidently there must be an inclination of the air in that direction: hence that quarter will produce wind. But when the halo is rent and torn on all sides, plainly an attack is being made on it from several quarters at once, and a disquieted atmosphere is assailing it on this side and on that. So this disturbance of the heavens, the repeated effort and striving in all directions, 10 betokens evidently that a storm is coming up with sudden shiftings of the wind.

These crowns may be observed generally by night round the moon and other stars, but very seldom by day; in fact, so rarely in the latter case, that certain of the Greeks have denied that they appear at all by day. But history proves that they do. The cause of the infrequency of their appearance by day is that the sun’s light is stronger then, and the atmosphere itself when stirred and warmed by it is less dense. The moon’s power, on the other hand, is feebler, and is therefore more easily resisted by the surrounding air. The rest of the heavenly 11 bodies are equally weak, and unable by their own force to burst through the atmosphere. So their shape is impressed and retained in the more solid and less yielding medium. For, in order to produce the phenomenon, the atmosphere must neither be so thick as to exclude or dissipate the light that streams in on it, nor yet so thin and rare as to furnish no hold to the rays that fall upon it. This particular consistency is obtained at night: the sluggish air is at that time struck with the faint light from moon or stars without violence or rudeness, and, being thicker than it is wont to be by day, is tinged thereby.

III

On the contrary, _the Rainbow_ does not occur by night, except on 1 very rare occasions, inasmuch as the moon has not sufficient strength to pierce the clouds and suffuse them with hues such as they receive from the brilliant light of the sun. The shape and varied colours of the rainbow are due to the peculiarities of different kinds of clouds. Some parts of the clouds are swollen, others hollow; some are too dense to transmit sunlight, others too rare to exclude it. This difference in 2 consistency causes alternations of light and shade, and produces that marvellous variety presented by the rainbow. Another explanation is offered in instances like the following: When a pipe bursts anywhere, the water is observed to be forced by pressure through the small opening; the drops seen against a slanting sun reproduce the appearance of the rainbow. Again, if you will at any time watch a fuller at work, you will observe the same appearance: when he has filled his mouth with water and spirts it lightly on the clothes stretched on pegs, the air thus besprinkled exhibits plainly the various colours that shine in the bow. One cannot doubt that the reason of this lies in the moisture. 3 For a rainbow never occurs except when there are clouds about.

Let us inquire how it is produced. Some authorities say that there are certain drops of water that transmit light, while some are too compact to be translucent. Thus the brightness is the effect of the former; the shadow, of the latter; by the intermingling of the two is formed the rainbow, part of which is bright, to wit, that which admits sunlight, part darker, namely, that which has shut out the light and cast a shadow from itself over the objects nearest it. Others again deny that 4 this is so. Shade and light, they say, might be the cause if the rainbow had only two colours, and thus was made up of light and shade.

But now, though there gleam a thousand diverse hues,
Their changes withal elude the eyes that behold.
The hues that touch seem actually one, yet the edges are quite different.

In it sight detects something that is red, something that is orange, something that is blue; and there are other colours too, laid on in finest lines just like a skilful painting, so that, as the poet remarks above, it is impossible to discover whether the colours differ from one another until the last of them is compared with the first. The junction 5 of colour with colour deceives the sight: with such marvellous skill does nature starting from what is like end in what is totally unlike. What good, then, do the two alleged colours, light and shade, do in a case of this kind, when the presence of an endless variety must be accounted for? Again, certain authorities are of opinion that the following is the method of formation of the rainbow: In the quarter of the sky where rain is falling, they say, the drops of falling rain are so many mirrors; from each mirror, therefore, is reflected an image of the sun. By and by, many, in fact, countless, images, descending and crossing abruptly, are all blended together. Therefore the rainbow is just a blending of a great number of images of the sun. They appeal to the following argument in proof of this: On a clear day, say they, 6 set out a thousand basins, and they will all contain images of the sun. Or arrange single drops of water on single leaves; they will each have an image of the sun. On the other hand, an immense pond will have no more than one image. Why so? Just because every smooth surface that is fenced off, and surrounded by its own boundaries, is a mirror. Again, divide a pond of very large size into several small ponds by inserting partition walls; it will show as many images of the sun as it has divisions. Leave it as it was, spreading out to its full extent, and it will show but one reflection of him. The small extent of the liquid or 7 pond makes no manner of difference. If the surface is circumscribed, it forms a mirror. Well then, those countless drops, which are carried down by a falling shower, are so many mirrors, and contain so many reflections of the sun. To an observer right in front of them they present the appearance of being mixed up: the intervals which part them from each other are not distinguished, their mere distance from the observer prevents discrimination of them. By and by instead of individual drops there is seen a single blurred mass that contains them all.

Aristotle agrees with this opinion. His words are: Beams of light are reflected by sight from every smooth surface. Now, nothing is 8 smoother than water and air. Therefore, our sight is reflected back on us from thick air. Indeed, where the vision is dull and feeble, the slightest stroke of air checks it. Some people suffer from an affection which causes them to think that they are meeting their own image, and they see everywhere the reflection of themselves. And why? Because the power of their eyes is so weak that it cannot overcome the resistance of even the nearest layer of the atmosphere. What dense air effects in ordinary cases, any kind of air is sufficient to effect in the cases referred to by Aristotle. For whatever the nature of the air, it is strong enough to defeat weak sight. Now, much more is our vision reflected upon us by water because it is denser and cannot be pierced; it absolutely stops the rays from our eyes, and turns them back to the source whence they proceeded. Well then, when there are numerous 9 raindrops, they are just so many mirrors. But on account of their smallness they express the sun’s colour without

distinct shape. By and by when the same colour is reflected in the countless drops that fall without intermission, it begins to take on the appearance not of numerous images with intervals between, but of a single, long, uninterrupted image.

But how, you may object, can you tell me that there are many thousands of images there, where I can see none at all? Besides, as there is but one colour in the sun, why are there different colours in the 10 reflections of him? These objections which you have put forward, as well as others that no less call for refutation, I will endeavour to refute. And let me say, first of all, that nothing is more deceptive than our eyesight, not merely in objects whose careful examination is prevented by distance in position,[26] but even in objects seen close at hand. An oar, though quite whole, presents the appearance of being broken when seen in clear shallow water. Apples seen through glass appear much larger than they really are. In long colonnades, pillars 11 set at intervals present an apparently unbroken continuity of line. Or go back to the case of the sun himself; his orb, which reason proves to be larger than the whole earth, is so contracted by human sight that some of the philosophers have maintained that it is only a foot in diameter. He is, we know, the swiftest of all luminaries, yet none of us can see him move; nor should we believe that he does advance, were it not evident from time to time that he has advanced. The world itself glides on with headlong speed; within an instant of time it unfolds its risings and its settings, yet none of us is aware of its movement. What cause, then, is there for wonder if our eyesight cannot separate 12 the drops of the rain showers, and loses the distinction of the images on account of the vast distance at which they are beheld? At any rate no one can doubt this, that the rainbow is a reflection of the sun, formed in a hollow cloud full of moisture. This is made plain from the simple fact that the image is never seen except opposite the sun, high up or low down, in inverse relation, just as he sinks or elevates his course. When he descends, it is higher; when he is high in the heavens, it is more sunken. A cloud of the required kind is often at the side 13 of the sun without producing a rainbow, because it does not catch his image straight in front.

[26] The received text gives “diversity of colours.”

As to the variegation in colour, it is due simply to its double source, derived partly from the sun, partly from the moist cloud. The moisture produces lines now blue, now green, now purple-like, and orange or red--the two shades, dull and bright, combining to produce this diversity. So also, a purple garment does not always come out 14 in exactly the same tint from the same dye. Differences depend upon the length of time it has been steeped, the consistency and the amount of moisture in the dye it has imbibed: it may be dipped and boiled more than once, or it may have received only one immersion. In like manner then, when there are the two elements, sun and cloud, in other words, object and mirror, it is little wonder that as many varieties of colour are generated as can be produced from them in higher or lower tone in countless different categories. For example, there is one 15 colour that proceeds from the light of fire, another from a light that is duller and less violent than fire. In other details concerning the rainbow the method of inquiry is full of uncertainty; there is nothing concrete to lay hold upon, and conjecture must be ventured in every direction. But in this question of its origin doubt is precluded; for it is evident that the causes of the rainbow are two in number, sun and cloud. The bow never appears when the sky is clear, and never when it is so cloudy as to hide the sun. It must, therefore, unquestionably arise from these, failing either of which it cannot come into being.

IV

A further consideration must be mentioned, which is just as manifest 1 as the preceding, to prove that the reflection is given back after the fashion of a mirror; it is never given back save from straight opposite to the sun, that is,[27] unless on one side stands the object to be reflected, and on the other the mirror that reveals it. Proofs are adduced by the mathematicians that are not merely convincing but that compel belief of this. Nor can doubt be left in any mind that the rainbow is an image of the sun, imperfectly reflected owing to the defective shape of the mirror. But meantime let us recall other proofs that may, so to speak, be picked up in the street without any 2 reference to mathematics. Among the proofs of this origin of the bow I place the extreme rapidity of its emergence. In a single moment the huge form with its thousand lines is inwoven in the texture of the heavens, and just as rapidly does it fade. Now, nothing is returned so quickly as an image from a mirror. The mirror does not create anything, it merely reveals it. Artemidorus of Parium tells us further even the kind of cloud required to reflect such an image of the sun. If you 3 make a concave mirror, he says, that is, one resembling half of a ball cut through the middle, and take your stand outside the centre, then those who stand beside you will appear in the reflection inverted and nearer to you than to the mirror. The very same thing, according to him, takes place when we look at a round hollow cloud from the side: 4 the image of the sun detaches itself from the cloud, and is nearer us and more turned in our direction. Therefore the red colour is from the sun, the dark blue is from the cloud: the other hues are produced by a blending of these two.

[27] In a writer less prone to repetition the words to the end of the
sentence would seem the insertion of a copyist.

V

But there are arguments on the other side. About mirrors there are 1 two opinions; some people think that only phantoms are seen in them; in other words, the shape of our bodies, an emanation separated from our bodies. Others, however, affirm that images do not exist in the mirror, but that it is the very bodies that are seen, the eyesight being bent back and reflected on itself again. Now, the point is not how do we see whatever it is we see: the question is, how the image should resemble the original in the cloud as in a mirror.[28] Could anything be more 2 unlike than the sun and a rainbow in which neither the colour nor the shape nor the size of the sun is to be seen? A bow is far larger and, in the bright part, far redder than the sun: in the other colours, too, it is different from him. Besides, when you insist on comparing a mirror to the atmosphere (_i.e._ as embodied in a cloud), you must show me in the latter the same smoothness of texture, the same levelness of surface, the same brightness as in the former. But surely no clouds resemble mirrors to this extent. We often pass through the middle of clouds without seeing ourselves in them. People who climb to the tops of mountains look down on cloud, but cannot make out their reflection 3 in it. True enough, but it is separate drops that are separate mirrors, says my opponent. Admitted. Still, I deny that a cloud consists of fully formed drops. It no doubt contains the elements from which the drops are formed, but not as drops. Clouds do not contain even water, but only the material to form water. Granting, for the sake of argument, that there _are_ countless drops in the clouds and that they can reflect an object, yet they do not all produce one and the same reflection, but each its own. Further, you may join mirrors to one another, but they will not unite to form a single reflection: 4 each portion will enclose a likeness of the object. Some mirrors are composed of a large number of very small parts. Set before them one man and a whole people is reflected, each portion producing an image of its own. The portions of the mirror thus united and placed side by side none the less keep their images separate, and out of one man make a crowd. But they do not blend in one that troop; 5 they separate and distinguish the individual faces. Now, a rainbow is bounded by a single outline, the whole presents but one representation.

[28] The reading of the MSS. is admittedly corrupt. I have followed
Ruhkopf’s conjecture, though without conviction. The argument seems
to require _dissimilis_ = unlike, or _non similis_ (cf. c. v. 13),
instead of _similis_ = like (“resemble” in the text): in that case
the meaning would be: how an image unlike the original ought to be
reflected from the cloud as from a mirror. Cf. § 13 below.

Well, but, says our opponent, is not the water that is scattered from a burst pipe, or that is tossed up by the oar, wont to exhibit something similar to these colours that are seen in the bow? True, but not for the reason which you wish to bring out, to wit, that each single droplet receives an image of the sun. As a matter of fact, the 6 drops fall too quickly to be able to form such an image. The medium must be stationary in order to receive the impression of what is to be reproduced.

How, then, it may be asked, does it come about? The drops, I reply, receive the colour, but not the image of the sun. Besides, as Nero Caesar says very elegantly:

The neck of Venus’ dove glitters as the bird tosses its head,

and so the neck of the peacock shines with varied colours as often as it is turned hither and thither. Are we, therefore, to say that feathers of this kind, whose every turn passes into new colours, are 7 mirrors? Well, clouds differ in character from mirrors no less than the birds mentioned, and as chameleons and the other animals whose colour changes. In the latter case the cause is sometimes subjective: the creatures when inflamed with anger or passion vary their hue through the suffusion of moisture: at other times the position of the light, direct or slanting, gives the colour its particular hue. What resemblance, I say, is there between mirrors and clouds? Whereas 8 those are not translucent, these transmit light. Those are dense and compact, these are rare. Mirrors are of uniform material throughout, clouds are made up of various elements brought together at random, and therefore are full of internal strife, and cannot long hold together. Consider further; at sunrise one sees a certain portion of the sky ruddy; at other times one sees clouds of fiery red. This particular colour is received by the clouds from encountering the sun: what, then, is there to prevent the many colours of the bow being derived by them in the same way from him, even though they do not possess the power of mirrors? A little ago, my opponent retorts, you advanced the argument 9 that the rainbow is always produced opposite the sun, because an image could not be reflected from a mirror unless the object were in front of it. We agree in this point, he adds. Yes, for just as the object whose image is to be transferred to the mirror must be set opposite the mirror, in like manner, in order that the clouds may be tinged by the sun’s rays, the sun must occupy a suitable position. He does not produce the same effect if his light streams in on all sides; there must be a proper incidence of the rays to produce the effect. Such are the reasons alleged by those who will have it that the rainbow is a coloured cloud.

Posidonius and those who are of opinion that the phenomenon is produced by reflection as from a mirror, answer their arguments thus: If there 10 were any real colour in a bow, it would persist, and be seen more distinctly, the nearer it is. As it is, the image of the bow is clear only in the distance; it is lost as it begins to approach. I do not agree with this argument in refutation, though I approve the main sentiment which it supports. And I will tell you why. The cloud _is_ coloured, but in such a way that the colour cannot be seen from every point. And no more can the cloud itself: for no one who is in it can see it. What wonder, then, if its colour cannot be seen by one 11 to whom itself is not visible? And yet, although the cloud is not seen, it is there: and so is the colour. It is, therefore, no proof of the deceptiveness of the colour that it ceases to be manifest when one approaches it. For, I repeat, the same happens to the clouds themselves: they are not all a sham merely because under certain conditions they cease to be visible. Besides, when you are told that the cloud is dyed by the sun, it does not mean that that colour of his is mingled, as it were, with a hard, firm, durable body, but with a liquid unstable body that is incapable of more than a very brief impress. Let me add that there are certain artificial colours which 12 display their virtue at a distance. The better and richer the Tyrian purple is, the higher up you must hold it to display its full blaze. It does not cease to possess its colour simply because it does not reveal its best shade in any and every position in which it is exhibited. I am of the same opinion as Posidonius in holding that the bow is formed in a cloud shaped like a hollow round mirror, whose form is that of a section through a ball. This cannot be proved without the aid of 13 geometry: the mathematical proofs leave no doubt that the bow is an image of the sun, but one that does not resemble it. Nor, indeed, are all objects faithfully represented in mirrors. There are some mirrors one is terrified to let one’s eyes rest upon, such is the misshapen and distorted image they reproduce of those who gaze upon them. They deform the likeness they preserve withal. Some, again, there are, a glance at which causes great self-satisfaction in one’s strength: the arms are 14 enormously increased, and the appearance of the whole body is enlarged to superhuman proportions. There are mirrors that turn faces to the right, and mirrors that turn them to the left, others twist and even invert them. What wonder, then, that a mirror of this kind should be formed in a cloud by which a defective appearance of the sun should be presented?

VI

Among the other arguments it must be mentioned that a rainbow never 1 is seen greater than a semicircle: the higher the sun is, too, the smaller is the bow. As our countryman Virgil says:

And deep drinks
The mighty bow,

when rain is brewing. But the threat the bow conveys is not the same whatever the quarter it has shown itself in. If it rises toward the 2 south, it will bring a heavy fall. The rain in that quarter, such is its force, cannot be mastered by the strongest midday sun. If it shine toward the west, there will be only a dew or a light rain. If it rise in the east or thereabouts, it prognosticates fine weather. If, however, the bow is the sun’s reflection, why does it appear of far larger size than the sun himself? Just because there is a kind of mirror that exhibits objects on a far larger scale than that on which they are presented to it, increasing their form to a portentous magnitude: and in turn there is another kind that reduces the size. And tell me this again, why does an image assume the form of a circle if it does not answer to a circle? You may, perhaps, tell me why the colour 3 of the bow is varied: why its shape is what it is, you will not be able to tell me except by citing some model after which it is formed. Now, other model there is none save that of the sun; when you admit that the rainbow receives its colour from him, it follows that it receives its shape also from him. In short, you and I are agreed that those colours by which its quarter of the heaven is adorned proceed from the sun. But on one point we are not agreed: you say that the colour is real; I maintain that it is only apparent. Whichever it is, real or apparent, it comes from the sun. On your assumption its sudden cessation cannot be explained, seeing that all other bright lights in the sky are dispelled gradually. Its sudden appearance and, at the same time, its 4 sudden extinction make for my contention. For it is a peculiarity of a mirror that the reflection in it is not built up piecemeal, but all at once comes fully into being. Every image in it is destroyed, too, with as great rapidity as it was formed. For to the construction or removal of the images nothing is required but the presentation and withdrawal of the objects.

In the rainbow-cloud whose nature is in question, there is no proper substance or material: there is only a sham and a likeness without reality. Will you be convinced that this is so? The proof is, the 5 rainbow will cease if you conceal the sun. Place another cloud, I repeat, in front of the sun, and all the bright hues of the bow are gone. But what is to be said, you may ask, in explanation of the size of the bow which is considerably greater than that of the sun? I have already said that there are certain mirrors that multiply every object they reflect. I may now add that every object much exceeds its natural size when seen through water. Letters, however small and dim, are comparatively large and distinct when seen through a glass globe filled with water. Apples floating in a glass vessel seem more beautiful than they are in reality. The stars appear bigger if seen through a cloud, 6 because our vision is blurred in the moisture, and cannot accurately grasp its object. This will become plain to demonstration if you fill a cup with water and throw a ring into it. While the ring lies right at the bottom its appearance is visible on the surface of the water. Anything, in fact, that is: seen through moisture appears far larger than. in reality it is. What wonder that the image of the sun, being 7 seen in a moist cloud, should be reproduced on a scale larger than the original, and that for the two reasons indicated? The cloud contains the two elements, one like glass, which can transmit light, and one also of the character of water; at any rate, if it does not just yet contain the actual water, it is now forming it, its nature is already such as can easily be changed into water.

VII

As you have mentioned glass, some one interposes, I can draw from 1 this same material an argument to confute you. Glass sticks are manufactured, either fluted or bulging,[29] with many corners like a club. If one of these sticks is placed obliquely in the path of the sun’s rays, it sends back the colour which is wont to be seen in the rainbow. This proves that there is not here an image of the sun, but an imitation of his colour from reflection. Now, in this argument there are many points that make for my view. First of all, it is plain that 2 there must be some smooth surface like a mirror to reflect the sun. Secondly, it is plain that no colour is formed in the rod, but only a false appearance of colour, such as I mentioned above, which the neck of a pigeon, as it is bent hither and thither, alternately puts on and off. This, I say, is seen likewise in the case of a mirror, which assumes no real colour, but only a certain imitation of the colour of a foreign body.

[29] Another reading gives “twisted.”

Still, this one point requires explanation; it is not the sun’s 3 image that is beheld in that glass stick, because it is not capable of expressing it accurately. True enough it tries to reproduce the image, because the material is smooth and suitable for this purpose. But it fails because its shape is unsymmetrical. If it had been suitably constructed, it would reflect as many images of the sun as it had faces. But since the sides are not distinctly separated from each other, and not bright enough to serve as mirrors, the images are only incipient, not fully expressed; they get confused through being crowded together, and are reduced to the appearance of a single band of colour.

VIII

But to return--why does the bow not complete the full circle in its 1 form, but appear as only a semicircle when stretched to the full extent of its greatest span? Some are of opinion that the reason is that the sun, being much higher than the clouds, strikes them only on the upper side. Hence their lower parts are not touched by his light. Receiving the sun only on one side, the clouds reproduce only one portion of him, and this is never more than a half. There is very little force in this contention. My reason for saying so? The sun, even though he is on 2 the upper side, yet strikes, and therefore colours, the whole cloud. How could it be otherwise? His rays are wont to be transmitted through the clouds and to penetrate any density in them. Further, the proof they advance is flatly in opposition to their main proposition. For if the sun is higher than the clouds, and his beams, therefore, shed only on their upper side, the bow would never come down as far as the earth. Yet it does descend to the very ground. Besides, the bow is never 3 seen except opposite to, not below, the sun. The fact is, the sun’s highness or lowness does not affect the matter: the side of the cloud that faces him is struck by him throughout its whole extent.