Chapter XVI: Introduction (2)

XII. ‘However, let us assume, if you choose, that it is [Sidenote: C] contrary to nature that earth-like bodies should have their motions in heaven; and now let us look quietly, with no heroics, at the inference, which is this, not that the moon is not an earth, but that she is an earth not in its natural place. So the fire of Aetna is fire underground, which is contrary to nature, yet is fire; and air enclosed in bladders is light and volatile by nature, but has come perforce into a place unnatural to it. And the soul, the soul itself,’ I went on, ‘has it not been imprisoned in the body contrary to nature, a swift, and, as you hold, a fiery soul in a slow, cold body, the invisible within the sensible? Are we therefore to say that soul in body is nothing, and not rather that Reason, that divine thing, has been made subject to weight and density, that one which ranges all heaven [Sidenote: D] and earth and sea in a moment’s flight has passed into flesh and sinews, marrow and humours, wherein is the origin of countless passions?[324] Your Lord Zeus, is he not, so long as he preserves his own nature, one great continuous fire? Yet we see him brought down, and bent, and fashioned, assuming, and ready to assume, any and every complexion of change. Look well to it, my friend, whether when you shift all things [Sidenote: E] about, and remove each to its “natural” place, you are not devising a system to dissolve the universe and introducing Empedoclean strife, or rather stirring up the old Titans against Nature, in your eagerness to see once more the dreadful disorder and dissonance of the myth? All that is heavy in a place by itself, and all that is light in another,

_Where neither sun’s bright face is separate seen,
Nor earth’s rough brood, nor ocean any more_,

[Sidenote: F] as Empedocles says! Earth had nothing to do with heat, water with wind; nothing heavy was found above, nothing light below; without commixture, without affection were the principles of all things, mere units, each desiring no intercourse with each or partnership, performing their separate scornful motions in mutual flight and aversion, a state of things which must always be, as Plato[325] teaches, where God is absent, the state of bodies deserted by intelligence and soul. So it was until the day when Providence brought Desire into Nature, and [Sidenote: 927] Friendship was engendered there, and Aphrodite, and Eros, as Empedocles tells us and Parmenides too and Hesiod,[326] so that things might change their places, and receive faculties from one another in turn, and, from being bound under stress, and forced, some to be in motion some to rest, might all begin to give in to the Better, instead of the Natural, and shift their places and so produce harmony and communion of the Whole.

XIII. ‘For if it be true that no other part of the universe departed from Nature, but that each rests in its natural place, not needing any transposition or rearrangement, and never from the first having needed any, I am at a loss to know what there is for Providence to do, or of what Zeus, “in art most excellent”,[327] is the maker and the artist-father. There would [Sidenote: B] be no need of tactics in an army if each soldier knew of himself how to take and keep place and post at the proper time; nor of gardeners or builders if the water of its own nature is to flow over the parts which need it, and moisten them, or if bricks and beams should of themselves adopt the movements and inclinations which are natural, and arrange themselves in their fitting places. If such a theory strike out Providence [Sidenote: C] altogether, and if it be God’s own attribute to order and discriminate things, what marvel is it that Nature has been so disposed and partitioned that fire is here and stars there, and again that earth is planted where it is and the moon above, each held by a firmer bond than that of Nature, the bond of Reason? Since, if all things are to observe natural tendencies, and to move each according to its nature, let the sun no longer go round in a circle, nor Phosphorus, nor any of the other stars, because it is the nature of light and fiery bodies to move upwards, not in a circle! But if Nature admits of such local variation as that fire, here seen to ascend, yet when it reaches heaven, joins in the general rotation, what marvel if heavy [Sidenote: D] and earthlike bodies too, when placed there, assume another kind of motion, mastered by the circumambient element? For it is not according to Nature that light things lose their upward tendency in heaven, and yet heaven cannot prevail over those which are heavy and incline downwards. No, heaven at some time had power to rearrange both these and those, and turned the nature of each to what was better.

XIV. ‘However, if we are at last to have done with notions enslaved to usage,[328] and to state fearlessly what appears to be true, it is probable that no part of a whole has any order, or position, or movement of its own which can be described in absolute terms as natural. But when each body places itself at the disposal of that on account of which it has come into being, [Sidenote: E] and in relation to which it naturally exists or has been created, to move as is useful and convenient to it, actively and passively and in all its own states conforming to the conservation, beauty, or power of that other, then, I hold, its place, movements and disposition are according to Nature. In man certainly, who has, if anything has, come into being according to Nature, [Sidenote: F] the heavy and earth-like parts are found above, mostly about the head, the hot and fiery in the middle regions; of the teeth one set grows from above, the other from below, yet neither contrary to Nature; nor can it be said of the fire in him that when it is above and flashes in his eyes it is natural, but when it is in stomach or heart, unnatural; each has been arranged as is proper and convenient.

_Mark well the tortoise and the trumpet-shell_,

says Empedocles, and, we may add, the nature of every shell-fish, and

_Earth uppermost, flesh under thou shalt see._

Yet the stony substance does not squeeze or crush the growth[329] [Sidenote: 928] within, nor again does the heat fly off and be lost because of its lightness; they are mingled and co-ordinated according to the nature of each.

XV. ‘And so it is probably with the universe, if it be indeed a living structure; in many places it contains earth, in many others fire, water, and wind, which are not forced out under stress, but arranged on a rational system. Take the eye; it is not where it is in the body owing to pressure acting on its light substance, nor has the heart fallen or slipped down [Sidenote: B] into the region of the chest because of its weight; each is arranged where it is because it was better so. Let us not then suppose that it is otherwise with the parts of the universe; that earth lies here where it has fallen of its own weight, that the sun, as Metrodorus of Chios used to think, has been pressed out into the upper region because of his lightness, like a bladder, or that the other stars have reached the places which they now hold as if they had been weighed in a balance and kicked the beam. No, the rational principle prevailed; and some, like eyes to give light, are inserted into the face of the Whole and revolve; the sun acts as a heart, and sheds and distributes out of himself heat and light, as it were blood and breath. [Sidenote: C] Earth and sea are to the universe, according to Nature, what stomach and bladder are to the animal. The moon, lying between sun and earth, as the liver or some other soft organ between heart and stomach, distributes here the gentle warmth from above, while she returns to us, digested, purified, and refined in her own sphere, the exhalations of earth. Whether her earth-like solid substance contributes to any other useful purposes, we cannot say. We do know that universally the Better prevails over the law of Stress. How can the view of the Stoics lead us to any probable result? That view is, that the luminous and subtle part of the atmosphere has by its rarity formed the [Sidenote: D] sky, the dense and consolidated part stars, and that, of the stars, the moon is the dullest and the grossest. However, we may see with our eyes that the moon is not entirely separated from the atmosphere, but moves within a great belt of it, having beneath itself a wind-swept region, where bodies are whirled, and amongst them comets. Thus these bodies have not been placed in the scales according to the weight or lightness of each, but have been arranged upon a different system.’

XVI. This said, as I was passing the turn to Lucius, the [Sidenote: E] argument now reaching the stage of demonstration, Aristotle said with a smile: ‘I protest that you have addressed your whole reply to those who assume that the moon herself is half fire, and who say of all bodies in common that they have an inclination of their own, some an upward one, some a downward. If there is a single person who holds that the stars move in a circle according to Nature, and are of a substance widely [Sidenote: F] different from the four elements, it has not occurred to our memory, even by accident; so that I am out of the discussion, and you also, Lucius.’ ‘No, no, good friend’, said Lucius. ‘As to the other stars, and the heaven in general, when your school asserts that they have a nature which is pure and transparent, and removed from all changes caused by passion, and when they introduce a circle of eternal[330] and never-ending revolution, perhaps no one would contradict you, at least for the present, although there are countless difficulties. But when the theory comes down and touches the moon, it no longer retains in her case the “freedom from passion” and the beauty of form of that body. Leaving out of account her other irregularities and points of difference, this very face which appears upon her has come there either from some passion proper to herself or by admixture of some other substance. [Sidenote: 929] Indeed, mixture implies some passion, since there is a loss of its own purity when a body is forcibly filled with what is inferior to itself. Consider her own torpor and dullness of speed, and her heat, so faint and ineffectual, wherein, as Ion[331] says—

_The black grape ripens not_;

to what are we to assign this, but to weakness in herself and passion, if passion can have place in an eternal and Olympian body? It comes to this, dear Aristotle; look on her as earth, and she appears a very beautiful object, venerable and highly adorned; but as star, or light, or any divine or heavenly body, I fear she may be found wanting in shapeliness and grace, and do no credit to her beautiful name, if out of all the multitude in heaven she alone goes round begging light of others, as Parmenides says, [Sidenote: B]

_For ever peering toward the sun’s bright rays._

Now when our comrade, in his dissertation, was expounding the proposition of Anaxagoras, that “the sun places the brightness in the moon”, he was highly applauded. But I am not going to speak of things which I learned from you or with you, I will gladly pass on to the remaining points. It is then probable that the moon is illuminated not as glass or crystal by the sunlight shining in and through her, nor yet by way of accumulation of light and rays, as torches when they multiply their light. For then we should have full moon at the beginning of the month just as much as at the middle, if she does not conceal or block the sun, but allows him[332] to pass through [Sidenote: C] because of her rarity, or if he, by way of commixture, shines upon the light around her and helps to kindle it with his own. For it is not possible to allege any bending or swerving aside on her part at the time of her conjunction, as we can when she is at the half, or is gibbous or crescent. Being then “plumb opposite”, as Democritus puts it, to her illuminant, she receives and admits the sun, so that we should expect to see her shining herself and also allowing him to shine through her. Now she is very far from doing this; she is herself invisible at those times, and she often hides him out of our sight.

_So from above for men_,

as Empedocles says, [Sidenote: D]

_She quenched his beams, shrouding a slice of earth
Wide as the compass of the glancing moon_;

as though his light had fallen, not upon another star, but upon night and darkness.

‘The view of Posidonius, that it is because of the depth of the moon’s body that the light of the sun is not passed through to us, is wrong on the face of it. For the air, which is unlimited, and has a depth many times that of the moon, is filled throughout with sunlight and brightness. There is left then that of Empedocles, that the illumination which we get from the moon [Sidenote: E] arises in some way from the reflexion of the sun as he falls upon her. Hence her light reaches us without heat or lustre, whereas we should expect both if there were a kindling by him or a commixture of lights. But as voices return an echo weaker than the original sound, and missiles which glance off strike with weaker impact,

_E’en so the ray which smote the moon’s white orb_

reaches us in a feeble and exhausted stream, because the force is dispersed in the reflexion.’

XVII. Here Sylla broke in: ‘All these things no doubt [Sidenote: F] have their probabilities; but the strongest point on the other side was either explained away or it escaped our comrade’s attention; which was it?’

‘What do you mean?’ said Lucius. ‘The problem of the half-moon, I suppose?’

‘Precisely,’ said Sylla, ‘for as all reflexion takes place at equal angles, there is some reason in saying that when the moon is in mid-heaven at half-moon, the light is not carried from her on to the earth, but glances off beyond it; for the sun, being [Sidenote: 930] on the horizon, touches the moon with his rays, which will therefore, being reflected at equal angles, fall on the further side and beyond us, and will not send the light here; or else there will be a great distortion and variation in the angle, which is impossible.’

‘I assure you’, said Lucius, ‘that point was mentioned also;’ and here he glanced at Menelaus the mathematician, as he went on: ‘I am ashamed, dear Menelaus,’ he said, ‘in your presence to upset a mathematical assumption which is laid down as fundamental in all the Optics of Mirrors. But I feel obliged to say’, he continued, ‘that the law which requires reflexion in all cases to be at equal angles is neither self-evident [Sidenote: B] nor admitted. It is impugned in the instance of convex mirrors, when magnified images are reflected to the one point of sight. It is impugned also in that of double mirrors, when they are inclined towards one another so that there is an angle between them, and each surface returns a double image from one face, four images in all, two on the right, two on the left, two from the outer parts of the surfaces, two dimmer ones deep within the mirrors.[333] Plato[334] gives the cause why this takes place. He has told [Sidenote: C] us that if the mirrors be raised on either side, there is a gradual shifting of the visual reflexion as it passes from one side to the other. If then some images proceed directly to us, while others glance to the opposite side of the mirrors, and are returned thence to us, it is impossible that reflexion in all cases takes place at equal angles. They observe[335] that these images meet in one point, and further claim that the law of equal angles is disproved by the streams of light which actually proceed from the moon to the earth, holding the fact to be [Sidenote: D] far more convincing than the law. However, if we are so far to indulge the beloved geometry as to make her a present of this law, in the first place it may be expected to hold of mirrors which have been made accurately smooth. But the moon has many irregularities and rough parts, so that the rays proceeding from a large body, when they fall on considerable eminences, are exposed to counter-illuminations and reciprocal dispersion; the cross-light is reflected, involved, and accumulated as though it reached us from a number of mirrors. In the next place, even if we allow that the reflexions are produced at equal [Sidenote: E] angles upon the actual surface of the moon, yet, when the distance is so great, it is not impossible that the rays may be broken in their passage, or glance around, so that the light reaches us in one composite stream. Some go further, and show by a figure that many lights discharge their rays along a line inclined to the hypothenuse; but it was not possible to construct the diagram while speaking, especially before a large audience.[336]

XVIII. ‘Upon the whole question,’ he went on, ‘I am at a loss to see how they bring up the half-moon against us; the point fails equally upon her gibbous and crescent phases. For if the moon were a mass of air or fire which the sun illuminated, [Sidenote: F] he would not have left half her sphere always in shadow and darkness as seen by us; but even if he touched her in his circuit only in a small point, the proper consequence would follow, she would be affected all through, and her entire substance changed by the light penetrating everywhere with ease. When wine touches water on its extreme surface, or a drop of blood falls into liquid, the whole is discoloured at once, and turned to crimson. But the air itself, we are told, is not filled with sunshine by emanations or beams actually mingling with it, but by a change and alteration caused by something like a prick or touch. Now, how can they suppose that when star touches star or light light, it does not mingle with or alter the substance throughout, but only illuminates [Sidenote: 931] those points which it touches superficially? The circular orbit of the sun as he passes about the moon, which sometimes coincides with the line dividing her visible and invisible parts, and at other times rises to right angles with that line so as to cut those parts in two, and in turn be cut by her, produces her gibbous and crescent phases by the varying inclination and position of the bright part relatively to that in shadow. This proves beyond all question that the illumination is contact not commixture, not accumulation of light but its circumfusion. But the fact that she is not only illuminated herself but also sends [Sidenote: B] on the image of her brightness to us, allows us to insist the more confidently on our theory of her substance. For reflexions do not take place on a rarefied body, or one formed of subtle particles, nor is it easy to conceive light rebounding from light, or fire from fire; the body which is to produce recoil and reflexion must be heavy and dense, that there may be impact upon it and resilience from it. To the sun himself the air certainly allows a passage, offering no obstructions or resistance; whereas if timber, stones, or woven stuffs be placed to meet his light many cross rays are caused, and there is illumination all [Sidenote: C] round them. We see the same thing in the way his light reaches the earth. The earth does not pass his ray into a depth as water does, nor yet throughout her whole substance as air does. Just as his orbit passes round the moon, gradually cutting off a certain portion of her, so a similar orbit passes round the earth, illuminating a similar part of it and leaving another unilluminated, for the part of either body which receives light appears to be a little larger than a hemisphere. Allow me to speak geometrically in terms of proportion. Here are three bodies approached by the sun’s light, earth, moon, air; we see that the moon is illuminated like the earth, not like the air; but bodies naturally affected in the same way by the same must be themselves similar.’

XIX. When all had applauded Lucius, ‘Bravo!’ said I, [Sidenote: D] ‘a beautiful proportion fitted to a beautiful theory; for you must not be defrauded of your own.’ ‘In that case,’ he said, with a smile, ‘I must employ proportion a second time, in order that we may prove the moon like the earth, not only as being affected in the same way by the same body, but also as producing the same effect on the same. Grant me that no one of the phenomena relating to the sun is so like another as an eclipse to a sunset, remembering that recent concurrence[337] of sun and moon, which, beginning just after noon, showed us [Sidenote: E] plainly many stars in all parts of the heavens, and produced a chill in the temperature like that of twilight. If you have forgotten it, Theon here will bring up Mimnermus and Cydias, and Archilochus, and Stesichorus and Pindar[338] besides, all bewailing at eclipse time “the brightest star stolen from the sky” [Sidenote: F] and “night with us at midday”, speaking of the ray of the sun as “a track of darkness” and, besides all these, Homer[339] saying that the faces of men are “bound in night and gloom” and “the sun is perished out of the heaven”, i.e. around the moon, and how this occurs according to Nature, “when one moon perishes and one is born”. The remaining points have been reduced, I think, by the accuracy of mathematical methods to the one[340] certain principle that night is the shadow of earth, whereas an eclipse of the sun is the shadow of the moon when it falls within our vision. When the sun sets he is blocked from our sight by the earth; when he is eclipsed, by the moon. [Sidenote: 932] In both cases there is overshadowing; in his setting it is caused by the earth, in his eclipses by the moon, her shadow intercepting our vision. From all this it is easy to draw out a theory as to what happens. If the effect is similar, the agents are similar; for the same effects upon the same body must be due to the same agents. If the darkness of eclipses is not so profound, and does not affect the atmosphere so forcibly, let us not be surprised; the bodies which cause respectively night and eclipse are similar in nature, but unequal in size. The Egyptians, I believe, say that the moon’s bulk is one two-and-seventieth part of the earth’s, Anaxagoras made her as large as Peloponnesus; but [Sidenote: B] Aristarchus[341] proves that the diameter of the earth bears to that of the moon a ratio which is less than sixty to nineteen, and greater than a hundred and eight to forty-three. Hence the earth because of its size removes the sun entirely from our sight, the obstruction is great and lasts all night; whereas if the moon sometimes hides the sun entirely, yet the eclipse does not last long and has no breadth; but a certain brightness is apparent around the rim, which does not allow the shadow to be deep and absolute. Aristotle,[342] I mean the ancient philosopher, after giving other reasons why the moon is more [Sidenote: C] often visibly eclipsed than the sun, adds this further one, that the sun is eclipsed by the interposition of the moon,[343] [the moon by that of the earth and of other bodies also.] But Posidonius gives this definition of what occurs: an eclipse of the sun is a concurrence of the shadow of the moon with our vision[344] ... for there is no eclipse, except to those whose view of the sun can be intercepted by the shadow of the moon. In allowing that the shadow of the moon reaches to us, I do not know what he has left himself to say. There can be no shadow of a star; shadow means absence of light, and it is the nature of light to remove shadow, not to cause it.

XX. ‘But tell me’, he went on, ‘what proof was mentioned [Sidenote: D] next?’ ‘That the moon was eclipsed in the same way’, I said. ‘Thank you for reminding me’, he said. ‘But now am I to turn at once to the argument, assuming that you are satisfied, and allow that the moon is eclipsed when she is caught in the shadow, or do you wish me to set out a studied proof, with all the steps in order?’ ‘By all means,’ said Theon, ‘let us have the proof in full. For my own part, I still somehow need to be convinced; [Sidenote: E] I have only heard it put thus, that when the three bodies, earth, sun, and moon, come into one straight line eclipses occur, the earth removing the sun from the moon, or the moon the sun from the earth; that is, the sun is eclipsed when the moon, the moon when the earth, is in the middle of the three, the first case happening at her conjunction, the second at the half-month.’

Lucius replied: ‘These are perhaps the most important points mentioned; but first, if you will, take the additional argument drawn from the shape of the shadow. This is a cone, such as is caused by a large spherical body of fire or light overlapping a smaller body also spherical. Hence in eclipses the lines which mark off the dark portions of the moon from the bright give circular sections. For when one round body approaches [Sidenote: F] another, the lines of mutual intersection are invariably circular like the bodies themselves. In the second place, I think you are aware that the first parts of the moon to be eclipsed are those towards the East, of the sun those towards the West, [Sidenote: 933] and the shadow of the earth moves from East to West, that of[345] the moon on the contrary to the East. This is made clear to the senses by the phenomena, which may be explained quite shortly. They go to confirm our view of the cause of the eclipse. For since the sun is eclipsed by being overtaken, the moon by meeting the body which causes the eclipse,[346] it is likely, or rather it is necessary, that the sun should be overtaken from behind, the moon from the front, the obstruction beginning from the first point of contact with the obstructing body. The moon comes up with the sun from the West as she races against him, the earth from the East because it is moving from the opposite direction. As a third point, I will ask you to [Sidenote: B] notice the duration and the magnitude of her eclipses. If she is eclipsed when high up and far from the earth, she is hidden for a short time; if near the earth and low down when the same thing happens to her, she is firmly held and emerges slowly out of the shadow; and yet when she is low her speed is greatest, when high it is least. The cause of the difference lies in the shadow; for being broadest about the base, like all cones, and tapering gradually, it ends in a sharp, fine head. Hence, if the moon be low when she meets the shadow, she is caught in the largest circles of the cone, and crosses its most profound and darkest part; if high, she dips as into a shallow pond, because the shadow is thin, and quickly makes her way out. [Sidenote: C] I omit the points of detail mentioned as to bases and permeations, which can also be rationally explained as far as the subject-matter allows. I go back to the theory put before us founded on our senses. We see that fire shines through more visibly and more brightly out of a place in shadow, whether because of the density of the darkened air, which does not allow it to stream off and be dispersed, but holds its substance compressed where it is, or whether this is an affection of our senses; as hot things are hotter when contrasted with cold, and pleasures are more intense by contrast with pains, so bright things stand out more clearly by the side of dark, setting the imagination on the alert by the contrast. The former cause appears the more [Sidenote: D] probable, for in the light of the sun everything in the nature of fire not only loses its brightness, but is outmatched and becomes inactive and blunted, since the sun’s heat scatters and dissipates its power. If then the moon possess a faint, feeble fire, being a star of somewhat turbid substance, as the Stoics themselves say, none of the effects which she now exhibits ought to follow, but the opposite in all respects; she ought to appear when she is now hidden, and be hidden when she now appears; be hidden, that is, all the time while she is dimmed by the surrounding [Sidenote: E] atmosphere, but shine brightly out at intervals of six months, or occasionally at intervals of five, when she passes under the shadow of the earth. (For of the 465 full moons at eclipse intervals, 404 give periods of six months, the remainder periods of five.) At such intervals then the moon ought to appear shining brightly in the shadow. But, as a fact, she is eclipsed and loses her light in the shadow, and recovers it when she has cleared the shadow; also she is often seen by day, which shows that she is anything but a fiery or starlike body.’

[Sidenote: F] XXI. When Lucius had said this, Pharnaces and Apollonides sprang forward together to oppose. Apollonides made way to Pharnaces, who observed that this is a very strong proof that the moon is a star or fire; for she does not disappear entirely in eclipses, but shows through with a grim ashy hue peculiar to herself. Apollonides objected to the word ‘shadow’, a term always applied by mathematicians to a region which is not [Sidenote: 934] lighted, whereas the heavens admit of no shadow. ‘This objection’, I said, ‘is contentious, and addressed to the name, not to the thing in any physical or mathematical sense. If any one should prefer to call the region blocked by the earth not “shadow”, but “an unlighted place”, it is still necessarily true that the moon when it reaches that region is darkened. It is merely childish’, I went on, ‘not to allow that the shadow of the earth reaches it, since we know that the shadow of the moon, falling upon the sight and reaching to the earth, causes an [Sidenote: B] eclipse of the sun. I will now turn to you, Pharnaces. That ashy charred colour in the moon, which you say is peculiar to her, belongs to a body which has density and depth. For no remnant or trace of flame will remain in rarefied bodies, nor can burning matter come into existence, without a substantial body, deep enough to allow of ignition and to maintain it, as Homer[347] has somewhere said:

_When fire’s red flower was flown, and spent the flames,
Which smoothed the embers._

For burning matter is evidently not fire but a body submitted to fire, and altered by it, which fire is attached to a solid stable mass and is permanent there, whereas flames are the kindling [Sidenote: C] and streaming away of rarefied fuel which is quickly dissolved because it is weak.

‘Thus no such clear proof could exist that the moon is earth-like and dense, as this cinder-like colour, if it really were her own proper colour. But it is not so, dear Pharnaces; in the course of an eclipse she goes through many changes of complexion, and scientific men divide these accordingly by time and hour. If she is eclipsed at early evening, she appears strangely black till three and a half hours have elapsed; if at midnight, she emits that red and flame-like hue over her surface which we know; after seven and a half hours the redness begins to be removed, and at last towards dawn she takes a bluish or light-grey hue, [Sidenote: D] which is the real reason why poets and Empedocles invoke her as “grey-eyed”. Now, people who see the moon assume so many hues as she passes through the shadow do wrong in fastening upon one, the cinder-like, which may be called the one most foreign to her, being rather an admixture and remnant of light which shines round her through the shadows, than her own peculiar complexion, which is black and earth-like. But whereas we see on our earth that places in shadow which are near purple or scarlet cloths, or near lakes, or rivers open to the sun, partake in the brilliance of these colours and offer many varied splendours because of the reflexions, what wonder [Sidenote: E] if a great stream of shadow, falling upon a celestial sea of light, not stable or calm but agitated by myriads of stars and admitting of combinations and changes of every kind, presents to us different colours at different times impressed on it by the moon? For a star or a fire could not show when in shadow as black or grey or blue. But our hills and plains and seas are coursed over by many-coloured shapes coming from the sun and [Sidenote: F] by shadows also and mists, resembling the hues produced by white light over a painter’s pigments. For those seen on the sea Homer has endeavoured to find such names as he could, as “violet” for the sea, and “wine-dark” and again “purple wave”, and elsewhere “grey sea” and “white calm”. But the varying colours which appear on land at different times he has passed over as being infinite in number. Now, it is not likely that the moon has one surface as the sea has, but rather that she resembles in substance the earth, of which Socrates[348] [Sidenote: 935] of old used to tell the legend, whether he hinted at the moon, or meant some other body. For it is nothing incredible or wonderful if, having nothing corrupt or muddy in her, but enjoying light from heaven, and being stored with a heat not burning or furious, but mild and harmless and natural, she possesses regions of marvellous beauty, hills clear as flame, and belts of purple, her gold and silver not dispersed within her depths, but flowering forth on the plains in plenty, or set [Sidenote: B] around smooth eminences. Now, if a varying view of these reaches us from time to time through the shadow, owing to some change and shifting of the surrounding air, surely the moon does not lose her honour or her fame, nor yet her Divinity, when she is held by men to be holy earth of a sort and not, as the Stoics say, fire which is turbid, mere dregs of fire. Fire is honoured in barbarous fashions by the Medes and Assyrians, who fear what injures them, and pay observance or rites of propitiation to that, rather than to what they revere. But the name of earth, we know, is dear and honourable to every Greek, we reverence her as our fathers did, like any other God. But, being men, we are very far from thinking of the moon, that [Sidenote: C] Olympian earth, as a body without soul or mind, having no share in things which we duly offer as first-fruits to the Gods, taught by usage to pay them a return for the goods they give us, and by Nature to reverence that which is above ourselves in virtue and power and honour. Let us not then think that we offend in holding that she is an earth, and that this her visible face, just like our earth with its great gulfs, is folded back into great depths and clefts containing water or murky air, which the light of the sun fails to penetrate or touch, but is obscured, and sends back its reflexion here in shattered fragments.’

XXII. Here Apollonides broke in: ‘Then in the name of [Sidenote: D] the moon herself,’ he said, ‘do you think it possible that shadows are thrown there by any clefts or gullies, and from thence reach our sight, or do you not calculate what follows, and am I to tell you? Pray hear me out, though you know it all. The diameter of the moon shows an apparent breadth of twelve fingers at her mean distance from us. Now, each of those black shadowy objects appears larger than half a finger, and is therefore more than a twenty-fourth part of the diameter. [Sidenote: E] Very well; if we were to assume the circumference of the moon to be only thirty thousand stades, and the diameter ten thousand, on that assumption each of these shadowy objects on her would be not less than five hundred stades. Now, consider first whether it be possible for the moon to have depths and eminences sufficient to cause a shadow of that size. Next, if they are so large, how is it that we do not see them?’

At this, I smiled on him and said, ‘Well done, Apollonides, to have found out such a demonstration! By it you will prove that you and I too are greater than the Aloades[349] of old, not [Sidenote: F] at any time of day, however, but in early morning for choice, and late afternoon; when the sun makes our shadows prodigious, and thereby presents to our sense the splendid inference, that if the shadow thrown be great, the object which throws it is enormous. Neither of us, I am sure, has ever been in Lemnos, but we have both heard the familiar line,[350]

_Athos the Lemnian heifer’s flank shall shade._

For the shadow of the cliff falls, it seems, on a certain brazen [Sidenote: 936] heifer over a stretch of sea of not less than seven hundred stades. Will you think then that the height which casts the shadow is the cause, forgetting that distance of the light from objects makes their shadows many times longer? Now consider the sun at his greatest distance from the moon, when she is at the full, and shows the features of the face most expressly because of the depth of the shadow; it is the mere distance of the light which has made the shadow large, not the size of the several [Sidenote: B] irregularities on the moon. Again, in full day the extreme brightness of the sun’s rays does not allow the tops of mountains to be seen, but deep and hollow places appear from a long distance, as also do those in shadow. There is nothing strange then if it is not possible to see precisely how the moon too is caught by the light, and illuminated, and yet if we do see by contrast where the parts in shadow lie near the bright parts.

XXIII. ‘But here’, said I, ‘is a better point to disprove the alleged reflexion from the moon; it is found that those who stand in reflected rays, not only see the illuminated but also the illuminating body. For instance, when light from water [Sidenote: C] leaps on to a wall, and the eye is placed in the spot so illuminated by reflexion, it sees the three objects, the reflected rays, the water which caused the reflexion, and the sun himself, from whom proceeds the light so falling on the water and reflected. All this being granted and apparent, people require those who contend that the earth receives the moon’s light by reflexion, to point out the sun appearing in the moon at night, as he appears in the water by day when he is reflected off it. Then, as he does not so appear, they suppose that the illumination is caused by some process other than reflexion, and that, failing reflexion, [Sidenote: D] the moon is no earth.’

‘What answer then is to be given to them?’ said Apollonides, ‘for the difficulty about reflexion seems to apply equally to us.’ ‘Equally no doubt in one sense,’ I answered, ‘but in another sense not at all so. First look at the details of the simile, how “topsy turvy”[351] it is, rivers flowing up stream! The water is below and on earth, the moon is above the earth and poised aloft. So the angles of reflexion are differently formed; in the one case the apex is above in the moon, in the other below on the earth. They should not then require that mirrors should produce every image and like reflexions at any distance, since [Sidenote: E] they are fighting against clear fact. But from those like ourselves who seek to show that the moon is not a fine smooth substance like water, but heavy and earth-like, it is strange to ask for a visible appearance of the sun in her. Why, milk does not return such mirrored images, nor produce optical reflexion, the reason being the unevenness and roughness of its parts. How can the moon possibly send back the vision off [Sidenote: F] herself as the smoother mirrors do? We know that even in these, if any scratch or speck or roughness is found at the point from which the vision is naturally reflected it is obscured; the blemishes are seen, but they do not return the light. A man who requires that she should either turn our vision back to the sun, or else not reflect the sun from herself to us, is a humorist; he wants our eye to be the sun, the image light, man heaven! That the reflexion of the sun’s light conveyed to the moon with the impact of his intense brilliance should be borne back to us is reasonable enough, whereas our sight is weak and slight and merely fractional. What wonder if it deliver a stroke which has no resilience, or, if it does rebound, no continuity, but is broken up and fails, having no store of light to make up for dispersion about the rough and uneven [Sidenote: 937] places. For it is not impossible that the reflexion should rebound to the sun from water and other mirrors, being still strong and near its point of origin; whereas from the moon, even if there are glancings of a sort, yet they will be weak and dim, and will fail by the way because of the long distance. Another point: concave mirrors return the reflected light in greater strength than the original, and thus often produce [Sidenote: B] flames; convex and spherical mirrors one which is weak and dim, because the pressure is not returned from all parts of the surface. You have seen, no doubt, how when two rainbows appear, one cloud enfolding another, the enveloping bow shows the colours dim and indistinct, for the outer cloud lying further from the eye does not return the reflexion in strength or intensity. But enough! Whereas the light of the sun reflected from the moon loses its heat entirely, and only a scanty and ineffectual remnant of its brilliance reaches us, do you really think it possible that when sight has the double course to travel, [Sidenote: C] any remnant whatever should reach the sun from the moon? No! say I. Look for yourselves’, I went on. ‘If the effects of the water and of the moon on our sight were the same, the full moon ought to show us images of earth and plants and men and stars, as other mirrors do. If, on the other hand, our vision is never carried back on to these objects, whether because of its own feebleness or of the roughness of the moon’s surface, then let us never demand that it should be carried by reflexion on to the sun.

XXIV. ‘We have now’, I said, ‘reported all that was said then, and has not escaped our memory. It is time to call on Sylla, or rather to claim his story, as he was allowed to be a listener on terms. So, if it meet your approval, let us cease our walk, and take our places on the benches and give him a seated [Sidenote: D] audience.’ This was at once agreed, and we had taken our seats, when Theon said: ‘I want as much as any of you, Lamprias, to hear what is now to be said, but first I should like to hear about the alleged dwellers in the moon, not whether there are any such, I mean, but whether there can be; for if the thing is impossible, then it is also absurd that the moon should be an earth; it will appear that she has been created for no end or use, if she bears no fruit, offers no abode to human beings, no existence, no livelihood, the very things for which we say that she has been created, in Plato’s[352] words, “our nurse, and of [Sidenote: E] day and night the unswerving guardian and maker”. You see that many things are said about this, some in jest, some seriously. For instance, that the moon hangs poised over the heads of those who dwell beneath her, as if they were so many Tantali; while as for those who dwell on her, they are lashed on like Ixions by the tremendous speed. Yet hers is not a single motion, but, as [Sidenote: F] it is somewhere put, she is a Goddess of the Three Ways. She moves in longitude over the Zodiac, in latitude, and in depth; one movement is revolution, another a spiral, the third is strangely named “Anomaly” by scientific men, although there is nothing irregular or confused to be seen in her returns to her stations. Therefore it is no wonder if a lion[353] did once fall on to Peloponnesus, owing to the velocity; the wonder is that we do not see every day

_Fallings of men, lives trampled to the dust_,[354]

men tumbling off through the air and turning somersaults. Yet [Sidenote: 938] it is ridiculous to raise a discussion about their remaining there, if they can neither come into being nor subsist at all. When we see Egyptians and Troglodytes, over whose heads the sun stands for the space of one brief day at the solstice and then passes on, all but shrivelled up by the dryness of the air around them, is it likely, I ask you, that people in the moon can endure twelve summers in each year, the sun standing plumb straight above them at every full moon? Then as to winds and clouds and [Sidenote: B] showers, without which plants can neither receive nor maintain existence, it is out of the question to conceive of their being formed, because the surrounding atmosphere is too hot and too rare. For even here the highest mountain tops do not get our fierce and conflicting storms, the air being already in turmoil from its lightness escapes any such condensation. Or are we really to say that, as Athena dropped a little nectar and ambrosia into Achilles’ mouth when he was refusing nourishment, even so the moon, who is called and who is Athena,[355] feeds man by sending up ambrosia day by day, in which form old Pherecydes [Sidenote: C] thinks that the Gods take food! For as to that Indian root, of which Megasthenes tells us that men, who neither eat nor drink but are without mouths,[356] burn a little, and make a smoke, and are nourished by the smells, how is it to be found growing there if there is no rain on the moon?’

XXV. When Theon had finished: ‘Well and kindly done,’ I said, ‘to unbend our brows by your witty argument; it makes us bold in reply, since we have no very harsh or severe criticism to expect. It is a true saying that there is little to choose between those who are vehemently convinced in such matters and those who are vehemently offended at them and incredulous, and will not look quietly into the possibilities. To begin, supposing that men do not inhabit the moon, it does not follow [Sidenote: D] that she has come into being just for nothing. Why, our earth, as we see, is not in active use or inhabited in her whole extent; but a small part of her only, mere promontories or peninsulas which emerge from the abyss, is fertile in animals and plants; of the other parts, some are desert and unfruitful owing to storms and droughts, while most are sunk under the ocean. But you, lover and admirer of Aristarchus that you are, do not attend to Crates and his reading:

_Ocean, the birth and being of us all,
Both men and Gods, covers the most of earth._[357]