De Facie Quae in orbe Lunae Apparet

In a word, how is the earth said to be the middle, and of what is it the middle? For the universe is infinite; and infiniteness having neither beginning nor end, it is convenient also that it should not have any middle; for the middle is a certain end or limit, but infiniteness is a privation of all sorts of limits. Now he that affirms the earth to be the middle, not of the universe but of the world, is certainly a pleasant man, if he does not think that the world itself is subject to the same doubts and difficulties. For the universe has not left a middle even to the very world, but this being without any certain seat or foundation, it is carried in an infinite voidness to no proper end; or if perhaps it has stopped, it has met with some other cause or stay, not according to the nature of the place. As much may be conjectured of the moon, that by the means of another soul and another Nature, or (to say better) of another difference, the earth continues firm here below, and the moon moves. Besides this, see whether they are not ignorant of a great inconvenience and error. For if it is true that all which is without the centre of the earth, however it be, is above, there will then be no part of the world below; but the earth and all that is upon it

will be above; and in brief, every body that shall be placed about the centre will be above, and there will be nothing below or underneath, but one only point which has no body, which will of necessity make head against and oppose all the rest of the world’s nature, if above and beneath are naturally opposite to one another. Nor is this the only absurdity that will follow; but all heavy and ponderous bodies will also lose the cause for which they move and tend downwards hither, for there will be no body below to which they should move; and as for that which is incorporeal, it is not probable, neither will they themselves allow, that it should be so forcible as to draw and retain all things about itself. But if it is unreasonable and contrary to Nature that the whole world should be above, and that there should be nothing below but an incorporeal and indivisible term or limit, then is this, as we say, yet more reasonable, that the region above and that below being divided the one from the other, have nevertheless each of them a large and spacious room.

Nevertheless, supposing, if you please, that it is against Nature for earthly bodies to have any motions in heaven, let us consider leisurely and mildly-and not violently, as is done in tragedies—that this is no proof of the moon’s not being earth, but only that earth is in a place where by nature it should not be; for the fire of Mount Aetna is indeed against nature under ground, nevertheless it ceases not to be fire. And the wind contained within bottles is indeed of its own nature light and inclined to ascend, but is yet by force constrained to be there where naturally it should not be. And is not our very soul, I beseech you in the name of Jupiter, which, as yourselves say, is light, of a fiery substance, and imperceptible to sense, included within the body, which is heavy, cold, and palpable? Yet do we therefore say that the soul does not belong to the body; or that it is not a divine substance

under a gross and heavy mass, or that it does not in a moment pass through heaven, earth, and sea, pierce into the flesh, nerves, and marrow, and into the humors which are the cause of a thousand passions? And even your Jupiter, such as you imagine him and depaint him to be, is he not of his own nature a great and perpetual fire? Yet now he submits, is pliable, and transformed into all things by several mutations. Take heed therefore, good sir, lest, by transferring and reducing every thing to the place assigned it by Nature, you so philosophize as to bring in a dissolution of the whole world, and put all things again into that state of enmity mentioned by Empedocles, or (to speak more properly) lest you raise up again those ancient Titans and Giants to put on arms against Nature, and endeavor to introduce again that fabulous disorder and confusion, where all that is heavy goes one way apart, and all that is light another;

Where neither sun’s bright face is seen,

Nor earth beheld, spread o’er with green,

Nor the salt sea,

as Empedocles has it. Then the earth felt no heat, nor the sea any wind; no heavy thing moved upwards, nor any light thing downwards; but the principles of all things were solitary, without any mutual love or dilection one to another, not admitting any society or mixture together; but shunning and avoiding all communication, moving separately by particular motions, as being disdainful, proud, and altogether carrying themselves in such manner as every thing does from which (as Plato says) God is absent; that is, as those bodies do in which there is neither soul nor understanding; till such time as, by Divine Providence, desire coming into Nature engendered mutual amity, Venus, and Love,—as Empedocles, Parmenides, and Hesiod have it,—to the end that changing their natural places, and reciprocally communicating their faculties, some being by necessity bound to motion, others to quiet and rest, and all tending to the better, every thing remitting a little of its power and yielding a little from its place, ---they might make at length a harmony, accord, and society together.

For if there had not been any other part of the world against Nature, but every thing had been in the same place and quality it naturally ought to be, without standing in need of any change or transposition or having had any occasion for it from the beginning, I know not what the work of Divine Providence is or in what it consists, or of what Jupiter has been the father, creator, or worker. For there would not in a camp be any need of the art of ranging and ordering of battles, if every soldier of himself knew and understood his rank, place, and station, and the opportunity he ought to take and keep; nor would there be any want of gardeners or builders, if water were of itself framed to flow where it is necessary, and irrigate such plants as stand in need of watering, or if bricks, timber, and stones would of their own inclinations and natural motion range and settle themselves in due and fitting places and orders. Now if this discourse manifestly takes away Providence, and if the ordering and distinction of things that are in the world belongs to God, why should we wonder at Nature’s having been so disposed and ordained by him, that the fire should be here, and the stars there, and again the earth should be situated here below, and the moon above, lodged in a prison found out by reason, more sure and straight than that which was first ordained by Nature? For if it were of absolute necessity that all things should follow their natural instinct and move according to the motion given them by Nature, neither the Sun, Venus, nor any other planet would any more run a circular course; for light and fiery substances have by Nature their motion directly upwards. And if

perhaps Nature itself receives this permutation and change by reason of the place, so that fire should here in a direct line tend upwards, but being once arrived at heaven, should turn round with the revolution of the heavens; what wonder would it be, if heavy and terrestrial bodies, being in like manner out of their natural place, were vanquished by the ambient air, and forced to take another sort of motion? For it cannot with any reason be said that heaven has by Nature the power to take away from light things the property of mounting directly upwards, and cannot likewise have the force to overcome heavy things and such as tend downwards; but that sometimes making use of this power, and sometimes of the proper nature of the things, it still orders every thing for the best.

But if, laying aside those servile habits and opinions to which we have enslaved ourselves, we must frankly and fearlessly deliver our judgment, it seems clear to me, that there is not any part of the universe which has a peculiar and separate rank, situation, or motion, that can simply be said to be natural to it. But when every thing exhibits and yields up itself to be moved, as is most profitable and fit for that for whose sake it was made and to which it is by Nature appointed,—suffering, doing, or being disposed, as is most expedient and meet for the safety, beauty, and power of the same,—then it appears to have its place, motion, and disposition according to Nature. As a proof of this, we may observe that man, who, if any thing in the world be so, is made and disposed according to Nature; has upwards, especially about his head, heavy and terrestrial things, and about the middle of his body such as are hot and participate of fire; of his teeth also some grow upwards and some downwards, and yet neither the one nor the other are contrary to Nature; neither is the fire which shines in his eyes according to Nature, and that which is in his heart and stomach against it; but it is in

each place properly and beneficially seated. Moreover, consider the nature of all shell-fishes; and, that I may use the words of Empedocles,

Look on the crabs, the oysters of the sea,

And shell-fish all, which heavy coats enfold,

The tortoise too with arched back, whom we

Covered with crust, as hard as stone, behold.

View them but well, and plain it will appear,

They hardened earth above their bodies bear.

And yet this crust, stone-like, hard, and heavy, as it is thus placed over their bodies, does not press and crush their natural habit, nor on the contrary does their heat fly upwards by reason of its lightness, and vanish away, but they are mingled and composed one with another, according to the nature of each one.

Wherefore it is also probable that the world, if it is an animal, has in many parts of its body earth, and in as many fire and water and air, not thrust and driven into it by force, but ordered and disposed by reason. For neither was the eye by its lightness forced into that part of the body where it is, nor the heart by its gravity pressed down into the breast; but both the one and the other were thus placed because it was better and more expedient. In like manner we ought not to think of the parts of the world, either that the earth settled where it is, being beaten down thither by its ponderosity; or that the sun was carried upwards by its levity, like a bottle or bladder full of wind (which, being plunged into the bottom of the water, immediately rises up again), as Metrodorus of Chios was persuaded; or that the other stars, as if they had been put into a balance, were swayed this way or that way, according to their weight or lightness, and so mounted higher or lower to the places they now possess. But reason having prevailed in the constitution of the world, the stars have, like to glittering eyes, been fixed in the firmament, as it were in the face of the universe, there to turn continually

about; and the sun, having the force and vigor of the heart, sends and distributes its heat and light, like blood and spirits, throughout all; the earth and sea are in the world, as the paunch and bladder in the body of a living creature; and the moon placed between the sun and the earth, as the liver, or some other soft entrail between the heart and the belly, transmits down thither the heat of the superior bodies, and draws round about her the vapors which arise from hence, subtilizing them by way of concoction and purification. And whether its solid and terrestrial quality has any other property serving for some profitable use, is indeed unknown to us; but everywhere that which is better prevails over what is by necessity. For what probability can we draw from that which they Affirm? They say, that the most subtile and luminous part of the air, by reason of its rarity, became heaven; but what was thickened and closely driven together was made into stars, of which the moon being the heaviest is compacted of the grossest and muddiest matter. And yet it is plainly to be seen, that the moon is not separated or divided from the air, but moves and makes her revolution through that which is about her, to wit, the region of the winds, and where the comets are engendered and keep their course. These bodies then were not by a natural inclination thus placed and situated as they are, but have by some other reason been so ordered and disposed.

These things being said, as I was giving Lucius his turn to follow and continue the discourse,—there being nothing left to be added but the demonstrations of this doctrine,—Aristotle smiling said: I am a witness, that you have directed all your contradictions and all your refutations against those who, supposing the moon to be half fire, affirm in general that all bodies do of their own accord tend either upwards or downwards; but if there is

any one who holds that the stars have of their own nature a circular motion, and that they are of a substance wholly different from the four elements, you have not thought of saying any thing, so much as accidentally or by the way, against him; and therefore I am wholly unconcerned in your discourse.

Indeed, good sir, said Lucius, if you should suppose the other stars, and the whole heaven apart, to be of a pure and sincere nature, free from all change and alteration of passion, and should bring in also a circle, in which they make their motion by a perpetual revolution, you would not perhaps find any one now to contradict you, though there are in this infinite doubts and difficulties. But when the discourse descends so far as to touch the moon, it cannot maintain in her that perfection of being exempt from all passion and alteration, nor that heavenly beauty of her body. But to let pass all other inequalities and differences, the very face which appears in the body of the moon necessarily proceeds from some passion of her own substance or the mixture of another; for what is mixed suffers, because it loses its first purity, being filled by force with that which is worse. Besides, as for the slowness and dulness of her course, her feeble and inefficacious heat, by which, as Ion says,

The black grape comes not to maturity,

to what shall we attribute them but to her weakness and passion, if an eternal and celestial body can be subject to passion?

In brief, my friend Aristotle, if the moon is earth, she is a most fair and admirable thing, and excellently well adorned; but if you regard her as a star or light or a certain divine and heavenly body, I am afraid she will prove deformed and foul, and disgrace that beautiful appellation, if of all bodies, which are in heaven so numerous, she

alone stands in need of light borrowed of another, and, as Parmenides has it,

Looks always backwards on the sun’s bright rays.

Our friend therefore indeed, having in a lecture of his demonstrated this proposition of Anaxagoras, that the sun communicates to the moon what brightness she has, was well esteemed for it. As for me, I will not say what I have learned of you or with you, but having taken it for granted, will pass on to the rest. It is then probable that the moon is illuminated, not like a glass or crystal, by the brightness of the sun’s rays shining through her, nor yet again, by a certain collustration and conjunction of light and brightness, as when many torches set together augment the light of one another. For so she would be no less full in her conjunction or first quarter than in her opposition, if she did not obstruct or repel the rays of the sun, but let them pass through her by reason of her rarity, or if he did by a contemperature shine upon her and kindle the light within her. For we cannot allege her declinations and aversions in the conjunction or new moon, as when it is half-moon or when she appears crescent or in the wane; but being then perpendicularly (as Democritus says) under him that illuminates her, she receives and admits the sun; so that then it is probable she should appear, and he shine through her. But this she is so far from doing, that she is not only then unseen, but also often hides the sun, as Empedocles has it:

The sun’s bright beams from us she turns aside,

And of the earth itself as much doth hide,

As her orb’s breadth can cover;

as if the light of the sun fell not upon another star, but upon night and darkness. And as for what Posidonius says, that the depth of the moon’s body is the cause why the light of the sun cannot pierce through her to us, this is evidently refuted; for the air, which is infinite and of a far greater depth than the body of the moon, is nevertheless all over illustrated and enlightened by the rays of the sun.

It remains then that, according to the opinion of Empedocles, the light of the moon which appears to us comes from the repercussion and reflection of the sun’s beams. And for this reason it comes not to us hot and bright, as in all probability it would, if her shining proceeded either from inflammation or the commixtion of two lights. But as voices reverberated cause an echo more obscure and less express than the speech that was pronounced, and as the blows of darts and arrows, rebounding from some wall against which they are shot, are more mild and gentle;

So Titan’s lustre, smiting the moon’s orb,

yields but a faint and feeble reflection and repercussion of brightness upon us, its force being abated and weakened by the refraction.

Sylla then, taking up the discourse, said: There is indeed a great deal of probability in all that you have spoken. But as to the strongest objection that is brought against it, has it, think you, been any way weakened by this discourse? Or has our friend quite passed it over in silence?

What opposition do you mean, said Lucius? Is it the difficulty about the moon, when one half of her appears enlightened?

The very same, answered Sylla. For there is some reason, seeing that all reflection is made by equal angles, that when the half-moon is in the midst of heaven, the light proceeding from her should not be carried upon the earth, but glance and fall beyond and on one side of it. For the sun, being placed in the horizon, touches the moon with its beams; which, being equally reflected, will therefore

necessarily fall on the other bound of the horizon, and not send their light down hither; or else there will be a great distortion and difference of the angle, which is impossible.

And yet, by Jupiter, replied Lucius, this has not been forgotten or overpassed, but already spoken to. And casting his eye, as he was discoursing, upon the mathematician Menelaus; I am ashamed, said he, in your presence, dear Menelaus, to attempt the subverting and overthrowing of a mathematical position, which is supposed as a basis and foundation to the doctrine of the catoptrics concerning the causes and reasons of mirrors. And yet of necessity I must. For it neither appears of itself nor is confessed as true, that all reflections are at equal angles; but this position is first checked and contradicted in concave mirrors, when they represent the images of things, appearing at one point of sight, greater than the things themselves. And it is also disproved by double mirrors, which being inclined or turned one towards the other, so that an angle is made within, each of the glasses or plain superficies yields a double resemblance; so that there are four images from the same face, two answerable to the object without on the left side, and two others obscure and not so evident on the right side in the bottom of the mirror. Of which Plato renders the efficient cause; for he says, that a mirror being raised on the one and the other side, the sight varies the reflection, falling from one side to the other. And therefore, since of the views or visions some immediately have recourse to us, and others, sliding to opposite parts of the mirror, do again return upon us from thence, it is not possible that all reflections should be made at equal angles. Though those who closely impugn our opinion contend that, by these reflections of light from the moon upon the earth, the equality of angles is taken away, thinking this to be much more probable than the other.

Nevertheless, if we must of necessity yield and grant

thus much to our dearly beloved geometry, first, this should in all likelihood befall those mirrors which are perfectly smooth and exquisitely polished; whereas the moon has many inequalities and roughnesses, so that the rays proceeding from a vast body, and carried to mighty altitudes, receive one from another and intercommunicate their lights, which, being sent to and fro and reciprocally distributed, are refracted and interlaced all manner of ways, and the counter-lights meet one another, as if they came to us from several mirrors. And then, though we should suppose these reflections on the superficies of the moon to be made at equal angles, yet it is not impossible that the rays, coming down unto us by so long an interval, may have their flexions, fractions, and delapsions, that the light being compounded may shine the more. Some also there are who prove by lineary demonstration, that many lights send a ray down by a line drawn below the line of reflection; but to make the description and delineation of it publicly, especially where there were many auditors, would not be very easy.

But in brief, said he, I wonder how they come thus to allege against us the half-moon, there being the same reason when she is gibbous and crescent. For if the sun enlightened the moon, as a mass of ethereal or fiery matter, he would never surely leave one hemisphere, or half of her globe always appearing dark and shadowy to sense, as it is seen to be; but how little soever he touched her superficies, it would be agreeable to reason that it should be wholly replenished and totally changed by that light of his, which by reason of its agility and swiftness so easily spreads and passes through all. For, since wine touching water only in one point, or one drop of blood falling into any liquor, dyes and colors it all with a red or purple color; and since they say, that the very air is altered and changed with light, not by any defluxions or beams intermingled,

but by a sudden conversion and change made in one only point; how can they imagine that one star touching another star, and one light another light, should not be immediately mingled, nor make any thorough confusion or change, but only exteriorly illuminate that whose superficies it touches? For that circle which the sun makes by fetching a compass and turning towards the moon,—sometimes falling upon the very line that distinguishes her visible part from her invisible, and sometimes rising up directly, so that it cuts her in two and is reciprocally cut by her, causing in her, by several inclinations and habitudes of the luminous to the dark, those various forms by which she appears gibbous and crescent,—that more than any thing else demonstrates, that all this illumination of the moon is not a mixture, but only a touching; nor a conflux or gathering together of sundry lights, but only an illustration round about.

But forasmuch as she is not only enlightened herself, but also sends back hither the image of her illumination, this confirms us yet further in what we say touching her substance. For reflections and reverberations are not made upon any thing which is rare, and of thin and subtile parts; nor is it easily to be imagined how light can rebound from light, or one fire from another. But that which is to make the reverberation or reflection must be solid and firm, that a blow may be given against it and a rebounding made from it. As a proof of this, we see that the air transmits the sun, and gives him a way to pierce quite through it, not obstructing or driving back his rays; but on the contrary from wood, stones, or clothes put in the sun, there are made many reflections of light and many illuminations round about. So we see that the earth is illuminated by him, not to the very bottom, as the water, nor thoroughly and all over, as the air, through which the beams of the sun have a clear passage; but just such a circle as surrounds the

moon surrounds also the earth; and as much of the earth as this circle includes, so much does the sun enlighten, the rest being left without light; for what is illuminated both in the one and in the other is little more than an hemisphere. Permit me therefore now to conclude after the manner of geometricians by proportions. If there are three things which the light of the sun approaches, the air, the moon, and the earth, and if we see that the moon is enlightened by him, not as the air, but as the earth, it is of necessity that those two things must have one and the same nature, which of one and the same cause suffer the same effects.

Now when all the company began highly to commend Lucius’s harangue; This is excellently well done of you, Lucius (said I to him), that you have to so fine a discourse added as fine a proportion, for you must not be defrauded of that which is your due.

Then Lucius, smiling, thus went on: I have yet a second proportion to be added to the former, by which we will clearly demonstrate that the moon altogether resembles the earth, not only because they suffer and receive the same accidents from the same cause, but because they work the same effect on the same object. For you will without difficulty, I suppose, grant me that, of all the accidents which befall the sun, there is none so like to his setting as his eclipse, especially if you but call to mind that recent conjunction which, beginning at noonday, showed us many stars in many places of the heavens, and wrought a temperature in the air like that of the twilight. But if you will not grant me this, our friend Theon here will bring us a Mimnermus, a Cydias, an Archilochus, and besides these, a Stesichorus and a Pindar, lamenting that in eclipses the world is robbed of its brightest light, and saying that night comes on in the midst of the day, and that the rays of the sun wander in the path of darkness; but

above all he will produce Homer, saying that the faces of men are in eclipses seized upon by night and darkness, and the sun is quite lost out of heaven by the conjunction of the moon. And--- it is natural that this should happen,

When one moon’s going, and another comes.

For the rest of the demonstration is, in my opinion, as certain and exactly concluding, as are the acute arguments of the mathematics. As night is the shadow of the earth, so the eclipse of the sun is the shadow of the moon, when it stands in the way of our sight. For the sun is at his setting kept from our sight by the interposition of the earth, and at his eclipse by that of the moon. Now both of these are obscurations; but that of his setting is from the earth, and that of his being eclipsed from the moon, their shadows intercepting our sight. Now the consequences of these things are easily understood. For if the effect is alike, the efficient causes are also alike; because it is of necessity that the same effects, happening in the same subjects, proceed from the same efficients. Now if the darkness in eclipses is not so profound, nor does so forcibly and entirely seize the air, as does the night, we are not to wonder at it; for the substance of the body which makes the night, and of that which causes the eclipse, is indeed the same, though their greatness is not equal. For the Egyptians, if I am not mistaken, hold that the moon is in bigness the two and seventieth part of the earth; and Anaxagoras says, she is as big as Peloponnesus. And Aristarchus shows the overthwart line or diameter of the moon to have a proportion to that of the earth which is less than if sixty were compared to nineteen, and somewhat greater than an hundred and eight compared to forty and three. Whence it happens that the earth, by reason of its greatness, wholly withdraws the sun from our sight; for it is a great obstacle and opposition, and lasts all the night. But although the moon sometimes hides all the sun, yet that eclipse continues not so long nor is so far extended, but there always appears about the circumference a certain brightness, which permits not the darkness to be black, deep, and perfectly obscure.

And Aristotle (I mean the ancient philosopher of that name) rendering the reason why there are oftener seen to happen eclipses of the moon than of the sun, among other causes alleges this, that the sun is eclipsed by the interposition of the moon, and the moon by that of the earth, which is much greater and consequently oftener opposes itself. And Posidonius thus defines this accident: The eclipse of the sun is the conjunction of the sun and moon, the shadow of which darkens our sight.[*](Here again the text is defective, and the sense conjectural. (G.)) For there is no eclipse except to those whose sight the shadow of the moon intercepting hinders them from seeing the sun. Now in confessing that the shadow of the moon descends down to us, I know not what he has left himself to say. It is certainly impossible for a star to cast a shadow; for that which is not enlightened is called a shadow, and light makes no shadow, but on the contrary drives it away.

But what arguments, said he, were alleged after this?

The moon, answered I then, suffered the same eclipse.

You have done well, replied he, to put me in mind of it. But would you have me go on and prosecute the rest of the discourse, as if you had already supposed and granted that the moon is eclipsed, being intercepted within the shadow of the earth? Or shall I take for the subject of a declamation the making a demonstration of it, by rehearsing to you all the arguments, one after another?

Nay, by Jove, said Theon, let this be the argument of your discourse. For I indeed stand in need of some persuasion,

having only heard that when these three bodies, the earth, the moon, and the sun, are in a direct line, then eclipses happen; for that either the earth takes the sun from the moon, or the moon takes him from the earth. For the sun suffers an eclipse when the moon, and the moon when the earth, is in the midst of the three; of which the one happens in the conjunction or new moon, and the other in the opposition or when the moon is full.

Then said Lucius: These are the principal points, and the summary of what is said. But in the first place, if you please, take the argument drawn from the form and figure of the shadow. For this is a cone, as it must be when a great fire or light that is spherical encompasses a mass that is also globular but less; whence it comes that, in the eclipses of the moon, the circumscriptions of the black and dark from the clear and luminous have their sections always round. For the sections given or received by one round body applied to another, which way soever they go, do by reason of the similitude always keep a circular form. Now as for the second argument, I suppose you understand that the first part which is eclipsed in the moon is always that which looks towards the east, and in the sun that which regards the west. Now the shadow of the earth moves from the east to the west, but the sun and moon from the west eastward. The experience of the appearances gives us a visible knowledge of this, nor is there need of many words to make us fully understand it; and from these suppositions the cause of the eclipse is confirmed. For, inasmuch as the sun is eclipsed by being overtaken, and the moon by meeting that which makes the eclipse, it probably or rather necessarily follows that the one is surprised behind, and the other before. For the obstruction begins on that side whence that which causes it first approaches. Now the moon comes upon the sun from the west, as striving in course with

him and hastening after him; but the shadow of the earth comes from the east, as that which has a contrary motion.

The third argument is taken from the time and greatness of the eclipses. For the moon, if she is eclipsed when she is on high in her apogee (or at her farthest distance from the earth), continues but a little while in her defect or want of light; but when she suffers the same accident being low and in her perigee (or near the earth), she is very much oppressed, and slowly gets out of the shadow; and yet, when she is low, she moves swifter, and when high, slower. But the cause of the difference is in the shadow, which is, like pyramids, broadest at the bottom or basis; and, growing still narrower by little and little, terminates in a sharp point at the top. Whence it comes, that when she is low, she is embarrassed within greater circles, traversing the bottom of the shadow and what is most obscure and dark; but when she is high, being through the narrowness of the shadow (as it were) but in a shallow puddle, by which she is sullied, she immediately gets out again. I omit what was said particularly about the bases and disposition of parts, for these admit of a rational explanation, so far as this is possible; but I return to the subject properly before us, which has its foundation in our senses. For we see that fire shines forth and appears brighter out of a dark and shady place, through the thickness of the caliginous air, which admits no effluxions or diffusions of the fire’s virtue, but keeps in and contains its substance within itself. Or rather,—if this is a passion of the senses,—as hot things, when near to cold ones, are felt to be hotter, and pleasures immediately after pains are found more vehement, so things that are bright appear better when they are near to such as are obscure, the imagination being more strained and extended by means of different passions. But there seems to be a greater appearance of probability in the first reason.

For in the sun, all the nature of fire not only loses its faculty of illuminating, but is also rendered duller and more unapt to burn, because the heat of the sun dissipates and scatters all its force.

If it were then true that the moon, being, as the Stoics say, a muddy and troubled star, has a weak and duskish fire, it would be meet that she should suffer none of these accidents which she is now seen to suffer, but altogether the contrary; to wit, that she should be seen when she is hidden, and absconded when she appears; that is, she should be concealed all the rest of the time, being obscured by the environing air, and again shine forth and become apparent and manifest for six months together, and afterwards disappear again five months, entering into the shadow of the earth. For of four hundred and sixty-five revolutions of ecliptic full moons, four hundred and four are of six months’ duration, and the rest of five. The moon then should all this time appear shining in the shadow; but on the contrary we see, that in the shadow she is eclipsed and loses her light, and recovers it again after she is escaped and got forth of the shadow. Nay, she appears often in the daytime, so that she is rather any thing else than a fiery and starry body.