Part 27

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]