BOOK VII

WHICH TREATS OF COMETS

I

No man is so utterly dull and obtuse, with head so bent on earth, 1 as never to lift himself up and rise with all his soul to the contemplation of the starry heavens, especially when some fresh wonder shows a beacon-light in the sky. As long as the ordinary course of heaven runs on, custom robs it of its real size. Such is our constitution that objects of daily occurrence pass us unnoticed even when most worthy of our admiration. On the other hand, the sight even of trifling things is attractive if their appearance is unusual. So this concourse of stars, which paints with beauty the spacious 2 firmament on high, gathers no concourse of the nation. But when there is any change in the wonted order, then all eyes are turned to the sky. The sun has no observer unless he is in eclipse. No one watches the moon unless she suffer obscuration. But then whole cities cry out, groundless superstition drives every one into panic. And yet how much greater are the ordinary movements of the sun! He takes, so to speak, 3 as many steps as there are days, completing the year in his circuit. From the summer solstice he turns back to the lessening days, from the solstice he slopes his rays,[90] and gives more room to the nights; he occults the planets; though so much larger than the earth he does not burn it up, but cheers it by his heat, which he so regulates as to make it alternately more intense and more subdued. He never fills up with light, nor yet obscures, the moon, except when she is right opposite 4 to him. All this we allow to pass unnoticed as long as the usual order is preserved. But if there is any disturbance or any extraordinary light displayed in the sky, we gaze at it, ask questions, and point it out to our neighbours. So natural is it to admire what is strange rather than what is great.

[90] There is some corruption in the text, but no probable restoration has been suggested. From the Latin words it would appear that this clause is merely an explanation of the previous one, inserted by some officious copyist and therefore spurious.

The same thing holds in regard to comets. If one of these infrequent fires of unusual shape have made its appearance, everybody is eager to know what it is. Blind to all the other celestial bodies, each asks about the newcomer; one is not quite sure whether to admire or to 5 fear it. Persons there are who seek to inspire terror by forecasting its grave import. And so people keep asking and wishing to know whether it is a portent or a star. But, by my honour, no one could embark on a more exalted study, or master a more useful branch of knowledge than that which treats of the nature of the stars and planets. Are they a concentration of flame as our vision avers, and as the very light that streams from them,[91] and the heat that descends from them suggest? 6 Or are their orbs not of flame, but, as it were, solid bodies of earth that glide through tracts of fire, and having no light of their own draw thence their brightness and heat? That is an opinion that has been held by great men who have believed the stars to be compact of hard material, and to be nourished by fire that is not their own. Flame by itself, they argue, would be dissipated and would have nothing to hold or to be held by. If it were merely massed and not attached to a solid body, the universe would assuredly long since have scattered it in its impetuous whirl.

[91] The common reading, _aliis_ = others, seems an error for _illis_ = them.

II

In view of this inquiry it will be well to ask whether comets are 1 wholly analogous to stars and planets. They seem to have certain elements in common with them--for example, rising and setting--as well as their general form, although comets are more scattered, and end in a longer tail. They are alike, too, in their fiery bright appearance. So, if all the stars are earthy bodies, comets must share the same lot. But if the stars are pure fire and nothing else, remaining for 2 six months at a time unbroken by the rapid whirl of the universe, then comets, too, may consist of some rarefied material, which is not broken up by the constant revolution of the sky. It will also tend to clear up this point if we endeavour to ascertain whether the earth stands still while the universe revolves round it, or whether the converse is the truth, the universe standing still while the earth revolves. There have been persons who made bold to say that it is we that all unwitting are borne round by the frame of things, that risings and settings are not produced by a movement of the heavens, but that we ourselves rise and set. The subject well deserves our study, if we are to know where we 3 really stand, whether the abode we have obtained as ours is the most sluggish or the swiftest of motion, whether God causes all things to revolve round us or causes us to revolve. Now, for this it is essential that we have a record of all the appearances of comets in former times. For, on account of their infrequency, their orbit cannot as yet be discovered or examined in detail, to see whether they observe periodic laws, and whether some fixed order causes their reappearance at the appointed day. Such a development of astronomy is recent, having been lately introduced into Greece.

III

Democritus, the most acute of all the ancient philosophers, says he 1 suspects there are several stars whose orbits are erratic. But he has given neither their number nor their names, as the motions of the five planets were not in his time understood. Eudoxus was, in fact, the first to import from Egypt into Greece the knowledge of these motions, though he says nothing about comets. From this it becomes plain that, even among the Egyptians, the people that bestowed most care on observation of the sky, the portion of astronomy that relates to comets had not been worked out. Subsequently Conon, who was himself a 2 careful investigator, made a record of the sun’s eclipses that had been observed by the Egyptians; but he made no mention of comets, though he would certainly not have omitted anything definite on the subject that he had learned in Egypt. So much is certain; two authors, Epigenes and Apollonius of Myndus, the latter highly skilled in casting horoscopes, who say that they studied among the Chaldaeans, are at variance in their accounts. The latter asserts that comets are placed by the 3 Chaldaeans among the number of the wandering stars (_i.e._ planets), and that their orbits have been determined. Epigenes, on the contrary, asserts that the Chaldaeans have ascertained nothing regarding comets, which are thought by them to be fires produced by a kind of eddy of violently rotating air.

IV

In the first place, if it like you, let us set down the views of the 1 last-mentioned author and refute them. He supposes that the planet Saturn has most influence in determining all motions of the heavenly bodies. When it presses upon the constellations next Mars, or crosses to the neighbourhood of the moon, or encounters the rays of the sun, being naturally cold and windy, it contracts and masses the atmosphere at more than one place. By and by, if Saturn absorb all the sun’s rays, there is thunder and lightning. If he has Mars in agreement, the 2 lightning is forked. Moreover, he continues, forked and sheet lightning contain different materials. Evaporation from water or other moisture produces only gleams that threaten but stop short of striking. The hotter and drier exhalation of the earth forges the bolts of forked lightning. Beam meteors and torches, which differ from one another 3 only in size, are produced in this same way. When any ball of air--what we call a whirlwind--encloses moist earthy matter, wherever it rushes it presents the appearance of an extended line of fire, which lasts just so long as the mass of air remains, which carries within it the supply of moist earthy matter.

V

This account of Epigenes is a tissue of falsehoods. To begin with the 1 nearest one, the last, it is not true that torch and beam meteors are due to the violent action of a whirlwind. The whirlwind is formed in the neighbourhood of the earth, and there it runs its course. This is the reason why it tears up trees by the roots, and wherever it swoops down it lays bare the soil, carrying off in the meanwhile woods and roofs of houses; as a rule, it is lower than the clouds, and assuredly never higher. But, on the contrary, it is the more exalted part of heaven that displays beam meteors, and so they never intervene between us and the clouds. Besides, a whirlwind is borne along more swiftly than any cloud, and rotates as on a pivot. And in addition to this, it 2 ceases all of a sudden, bursting by its own force. “Beams,” on the contrary, do not run or fly across, like torches, but remain shining for some time in the same quarter of the sky. Charimander, too, in the book he wrote on comets, asserts that a great and unusual light in the sky of the size of a large beam was once seen by Anaxagoras, and continued to shine for a long period. Callisthenes puts it on record that a similar appearance of a trail of fire was observed before the sea swallowed up Buris and Helice. Aristotle says it was not a “beam,” 3 but a comet; the characteristic dispersion of the fire was not seen at first on account of its excessive brightness, but, in process of time, when the glare began to die down, it recovered the distinctive appearance of a comet. In this fiery phenomenon there were many points worthy of remark, none more so than this, that, immediately it shone in the sky, the sea came over Buris and Helice. Did Aristotle, then, one 4 may ask, believe that not merely that beam but all beams are comets? Surely not, for there is this difference, that beams have their fire continuous, while in the other bodies it is dispersed. Beams have a regular flame, not interrupted or dull at any point, while in the end parts it is condensed, just like what Callisthenes describes the one to have been, to which I referred a moment ago.

VI

There are, Epigenes goes on to say, two classes of comets. One kind 1 sheds its light on all sides without changing its position; the other extends a loose kind of fire in one direction, after the fashion of hair, and passes through among the stars; of the latter kind were the two seen in our own days. The former variety, with hair on all sides, that do not move, are usually low down, and arise from the same causes as beams and torches, that is, from a distempered thick atmosphere that carries in it many of the earth’s exhalations, both dry and moist. Air driven out through narrow apertures is capable of setting on fire 2 the atmosphere situated over it, which is full of elements suitable for feeding a fire; and it is able after that to drive it forward from the clear space, lest from any cause it should fall back and relax its force. After that, it can rise again on the next and following days and set fire to the same spot. As presumptive proof of this, we see winds return during several days at their set time. Rain, too, and storms in other forms recur according to appointment. His opinion may be briefly expressed by saying that he supposes comets to be formed 3 pretty much in the same way as fires excited by whirlwind. There is this one difference, that those whirlwinds are pressed down to earth from a higher region, while these others are raised from earth to the upper regions.

VII

A great deal can be urged against this view. First of all, if wind 1 were responsible, a comet would never make its appearance without wind. As a matter of fact, it appears when the air is perfectly still. In the next place, if it were due to wind, it would fall with the wind; and if it began through wind, would increase with increase of wind, and would be the brighter the more furious the wind was. This point, too, has to be added to the foregoing: while the wind impels many parts of the atmosphere, a comet appears in one spot. The wind does not mount up high, but comets are seen higher up than the winds are permitted to go. Epigenes afterwards goes on to speak of the comets that, he 2 says, have a more definite resemblance to stars, traversing an orbit and passing through the zodiacal signs. He attributes their origin to the same causes as produce those that he called lower comets, the only difference being that the earth’s exhalations in this case contain many dry elements, and therefore seek the higher region, and are driven by the north wind toward the more exalted portions of the heavens. But, surely, if the north wind urged them, they would always be borne toward the south, whither this wind urges its course. And yet, as a fact, they 3 have had different movements, some to east, others to west, all in a curved path, a direction which the wind could not impart. Besides, if the impulse which produced the comet carried up on high those north winds from the earth, comets would not arise when other winds blew; yet they do arise.

VIII

Let us now refute this other explanation of Epigenes, for he employs 1 two. He believes that when all the moist and dry exhalations of the earth unite, the mere discord of the different bodies turns the air into whirlwind. Then the force of that wind as it revolves sets fire by its rapid motion to all that it embraces in itself, and raises it on high. The gleam of the fire that is thus extracted remains as long as there is sufficient nutriment; when the fuel fails, the fire subsides too. Now, one who talks thus pays no attention to the nature of the 2 course of whirlwinds as compared with that of comets. The career of the former is swift and violent, more rapid than the winds themselves. But a comet’s movement is so gradual as to render imperceptible the space traversed during a day and a night. Besides, whirlwinds have an erratic, disorderly, and, to use a word of Sallust’s, eddying, motion. Comets have a regular course, which observes the appointed track. Surely none of us will believe that either the moon or the five planets are carried by the wind or spun round by the whirlwind. I trow not. And why? Just because they have not an irregular and 3 unrestrained motion. Let us apply the principle to comets. They do not move in confusion or irregularity so as to justify the belief that they are impelled by unruly and fickle forces. Besides, even if those eddies could enclose moist earthy elements, and had power to raise them from the depths to the heights, still they could not carry them up higher than the moon. All their force is spent when they reach the region of clouds. But as for the comets, we see them sailing through the upper regions, mingling with the very stars. It is, therefore, improbable that a whirlwind could persist over such a long distance, for the greater it is, the more rapidly is it spent.

IX

Let Epigenes, therefore, make his choice of the two alternatives: 1 if the force is small, it cannot reach so high; if it is great and violent, it will the more quickly break up. But further, according to the opinion of people like Epigenes, these lower comets do not mount higher because they have too much earthiness in them. Their weight keeps them in the neighbourhood of earth. And yet these other comets, which are higher and last longer, must have a more abundant material. For they could not last so long were their supplies not replenished from a larger stock. I said a moment ago that the whirlwind’s eddy 2 could not long endure, nor could it mount higher than the moon, or as far as the place of stars. Of course, the whirlwind is caused by the mutual struggle of several winds, and the contest cannot be kept up for any long time. When the wandering uncertain air assumes a rotatory form, in the last instance the force of all the winds yields to the single strongest one. No hurricane lasts long. The more strength 3 squalls have, the shorter their duration. When winds reach their maximum, they quickly abate all their violence. By that headlong speed they must needs hasten to their own destruction. So no one has ever seen a whirlwind last a whole day, or even an hour. Its velocity is astonishing, its brevity no less astonishing. Moreover, on the earth and near it, its rotation is swifter and more violent; the higher it 4 is, the less condensed and compact is it, and that is the reason of its more rapid dissipation. Add the fact, too, that even if it reached the highest region where the stars’ path lies, it would most certainly be broken up by the motion which causes the universe to revolve. For what can compare in rapidity with the revolution of the world? Thereby the strength of all the winds combined in one would be shattered, aye, and the strong solid chain that binds the earth, not to say a wisp of whirling air.

X

Again, a fire carried along by a whirlwind cannot remain on high 1 unless the whirlwind also remain. But then what is so inconceivable as any prolonged duration in a whirlwind? Above all, the whirlwind motion is neutralised by the opposite motion of the heavens. That region on high to which it is alleged to mount has an eddying motion of its own, which carries onward the sky,

And drags the lofty stars, and turns them in rapid whirl.

And even though one grant some duration to whirlwinds, which is quite contrary to the fact, yet what is to be said of the comets that have continued in sight for six months? Then, as hinted above, there 2 must be two motions in the same spot--one that constant motion of the heaven, accomplishing its task without intermission, the other a strange new motion conveyed by the whirlwind. The one must inevitably obstruct the other. And yet that motion we see of the moon in her orbit, and of the other heavenly bodies that pass above the moon, is irrevocable. It nowhere falters or stops, nor does it convey to us the slightest suggestion of an obstacle being ever placed in its way. It is utterly beyond belief that a whirlwind, the most violent and 3 unruly species of storm, should reach the very centre of the ranks of the stars, and should find a sphere for its boisterous activity in that ordered peace of heaven. Supposing that the revolution of a whirlwind kindles fire, which is shot up to the heights, furnishing apparent ground for the belief that what we see is a trail of fire; yet surely the shape of the fire ought to be something like that which produces it. Now a whirlwind is round in appearance; it remains in the same 4 track, and revolves after the fashion of a rotating pillar. The fire, therefore, that is enclosed ought to resemble it in shape. But in reality it is a trail of scattered fire, and resembles anything rather than fire gathered into a ball.

XI

Let us now say good-bye to Epigenes, and proceed to examine the 1 opinions of other writers. But before beginning to set them forth, I must first, by way of preface, remark that comets are not observed only in one part of the sky, nor merely in the zodiac, but in the east as well as in the west, more frequently, however, toward the north. Nor is 2 their shape uniform. The Greeks, indeed, distinguished three classes of them: those from which the flame hangs down, after the fashion of a beard; those that shoot out what looks like hair round them on all sides; and those which have a scattered kind of fire, which, however, stretches toward an apex.[92] But all the classes have a common characteristic, and are rightly called comets (_i.e._ long-haired). As the different shapes present themselves only at long intervals, it is difficult to compare them with one another. Even at the time of their appearance spectators are not agreed as to their shape. According 3 as one’s eyesight is keener or duller, one asserts that the comet is brighter or redder, and that its hair is compressed toward the interior of the star, or spread out toward its sides. But whether or not there are any differences in comets, they must all be produced by the same method. The one fact about which there ought to be agreement is, that 4 a star of strange unwonted appearance is beheld which drags along with it scattered fire. Some of the ancients are convinced of the truth of this explanation: When one of the planets has come into conjunction with another, the light of the two blends in one, producing the appearance of a more elongated star. This happens not merely when star touches star, but even when one approaches another. The space between the two is in that case lit up by both, and seems aflame, producing the trail of fire.

[92] _I.e._ are cone-shaped.

XII

Our first answer to this theory is that the number of moving stars 1 (planets) is fixed. It is quite usual for them and comets to appear at the same time; whence it is manifest that the comet is not due to the conjunction of planets, but is a distinctive independent star. Besides, it is a matter of frequent occurrence for a star to come under the orbit of a more elevated star. Saturn, for example, is sometimes above Jupiter; Mars looks down in a straight line on Venus or Mercury. But yet no comet is formed from this movement whereby the one planet 2 approaches the other. Were it otherwise, there would be a comet every year, for every year there are planets in the same constellation. Again, if the approach of star to star produced a comet, the latter would cease to be in a moment. The transit of stars takes place with the utmost rapidity, thence all eclipse of heavenly bodies is of brief duration; by the same motion they are as swiftly separated as they were brought together. The sun and the moon, as we see, part company 3 within a brief space after the eclipse has begun. How much swifter must be the separation of stars, which are so much smaller? Yet comets last for six months at a time, which would not happen if they sprang from the union of two stars. The stars cannot stick to one another for any long time, and the law of their swift motion must ever drive them asunder. Besides, those stars appear to us to be close to one 4 another, but in reality are separated by immense distances. How, then, could the one star transmit fire to the other so that the two should seem in union, when they are thus parted by an immense tract? The light of the two stars, it is replied, mixes, furnishing the appearance of one. I suppose this means that the phenomenon is much the same as when a cloud takes a ruddy colouring from the rays of the sun striking on it, or as when there is the golden glow of evening or morning, or as when the bow is painted in its varied hues, but only in sunshine.

Well, my first criticism is that all the instances mentioned are the 5 result of great force. It is the sun that lights them up. The stars do not possess anything like the same power. My second remark is that none of the phenomena arises except below the moon in the vicinity of the earth. The upper regions are pure and spotless, always retaining their own colour. I remark further, that if anything of the kind did occur, it would not last but would speedily disappear, as halos which surround the sun or moon fade in a very brief space of time. Even the rainbow 6 does not long remain. If there was anything of the kind supposed, to unite the space between the two stars, it would disappear with equal rapidity. In any case it would not remain as long as comets are in the habit of doing. The planets have their orbits within the zodiac, they lie near this circle; but comets are seen in all parts of the sky. Their time of appearance is no more certain than the limits of the space which they may not exceed.

XIII

In reply to arguments like mine it is urged by Artemidorus that the 1 five planets are not the only stars with erratic courses, but merely the only ones of the class that have been observed. But innumerable others revolve in secret, unknown to us either by reason of the faintness of their light, or the situation of their orbit being such that they become visible only when they reach its extremities. It is thus, he says, that certain new stars enter our field of vision, 2 mingling their light with the fixed stars, but displaying a brightness greater than is usual in stars. This is the least serious of his lies: his account of the universe is from end to end a shameless tissue of lies. For instance, if we are to believe him, the upper regions of heaven are perfectly solid--a lofty thick vault, as hard as the roof of a house, formed by the accumulation of masses of atoms. The surface immediately above it is of fire so compact that it cannot be broken up or altered. Nevertheless, it has certain ventilators, and, as 3 it were, windows through which portions of the fire stream from the outer part of the universe, but not so large as to cause commotion in the inner; and again the fires pass from the world back into the outer spaces. These extraordinary appearances, therefore, Artemidorus supposes, have streamed in from that mass of matter which lies outside the world. To set about disproving such a theory is nothing short of beating the air for the sake of exercising the muscles!

XIV

Still, I will descend to the task. Let the man who has placed such a 1 solid roof on the world tell me what reason there is for believing his statement that the heavens have such a thickness. What was it that took all these solid bodies up there and kept them there? Then, a firmament of such thickness must necessarily be of immense weight too. How is it that heavy bodies remain aloft? How is it that the huge mass does not come down and smash itself by its own weight? It is, I imagine, a 2 physical impossibility that such a vast weight as Artemidorus has brought to the support of the heavens should hang suspended, or be supported by a slight foundation. Nor can it be alleged that there are stays[93] of some kind outside by which it is prevented from falling. Nor again can there be any support in the centre[94] to receive and prop up the threatening mass. And again, no one will venture to assert that the universe is being constantly carried down through the immensities of space, falling all the time, though it is not evident that it falls, because its headlong course is to all eternity, having no final obstacle with which to collide. This is indeed a statement people have made about the earth, when they could discover no 3 explanation for a mass standing poised in air. It is borne down, say they, for ever; but it is not evident that it falls because the space into which it falls is endless.

[93] The word is usually applied to a flexible fastening, hawser, cable, or the like.

[94] Or, between the earth and it.

Well, what argument[95] then justifies the assertion that it is not merely the five planets that move, but that there are many such in many quarters of the universe? Or if there is no probable proof of this, one may rejoin: What is there to prevent one from saying either that all the stars move or that none of them does? Besides, your argument 4 is in no way helped by that crowd of stars which you assume to be everywhere roaming about! For the more there are of them, the oftener will they meet with others; whereas comets are rare, and for that reason marvellous. And will not every age give evidence against you by noting and recording for the use of posterity the emergence of such stars?

[95] The argument is resumed from the beginning of XIII. after the digression about the “firmament.”

XV

After the death of Demetrius, king of Syria, whose kingdom was 1 divided by his sons Demetrius and Antiochus, a little before the Achaean War, a comet blazed forth not inferior to the sun in size. Its orb was at first fiery red, and emitted a bright light sufficient to dispel the darkness of night. By and by its size was gradually reduced and its brightness waned. Finally it went completely out. How many stars, suppose you, would require to combine to make up such a huge mass? You might collect in one a thousand of them without ever 2 matching the size of the sun. In the reign of Attalus a comet appeared, moderately small in size to begin with. By and by it mounted up and spread out and moved as far as the equator, equalling in the extent of its immense length the whole quarter of the sky which we call the Milky Way. How many planets must have combined to occupy with an unbroken line of fire such a long tract of the sky?

XVI

I have refuted the argument; I must now discredit its authors. It 1 requires no great effort to strip Ephorus of his authority; he is a mere chronicler. Some of his class seek to recommend their narrative by incredible stories, and by their marvels try to interest the reader, who would probably soon find some other occupation if he were called on to wade through their tedious narrative of ordinary events. Some, again, are too credulous, some too careless, some are deluded, some delighted, by falsehood. The former do not shun it, the latter go in quest of it. The whole clan of them have this in common; they fancy 2 their work cannot merit approval, and become popular unless they freely interlard it with lies. Ephorus is not a person of any scrupulous honour; he is often duped, often he tries to dupe. For example, he asserts that the great comet which, by its rising, sank Helice and Buris, which was carefully watched by the eyes of the whole world since it drew issues of great moment in its train, split up into two stars; but nobody besides him has recorded it. Who, I wonder, could observe the moment at which the comet broke up and was resolved into two 3 parts? And if there is any one who saw it split up into two, how is it that no one saw it first formed out of the two? And why did Ephorus not add the names of the two stars into which it was broken up, since they must have been some of the five planets?

XVII

Apollonius of Myndus differs in his view from Epigenes. He asserts 1 that a comet is not one star made up of many planets, but that many comets are planetary. A comet, he goes on, is not an illusion nor a trail of fire produced on the borders of two stars, but is a distinctive heavenly body, just as the sun or the moon is. Its shape is not limited to the round, but is somewhat extended and produced lengthwise. On the other hand its orbit is not visible. It cuts 2 (‍=‍intersects) the upper part of the universe, but only emerges when at length it reaches the lowest portion of its course. There is no reason to suppose that the same comet reappears; for instance that the one seen in the reign of Claudius was the same as the one we saw in the reign of Augustus; or that the recent one which appeared during the reign of Nero Caesar--which has redeemed comets from their bad character--was similar to the one which burst out after the death of the late Emperor Julius Caesar, about sunset on the day of the games to Venus Genetrix. Comets are as varied as they are numerous. They are 3 unequal in size, unlike in colour. Some are ruddy without any light; others are bright with a pure clear light; others are flame-coloured, but the flame is not a pure thin flame, but is enveloped in a mass of smoky fire. Some are blood-stained and threatening, bringing prognostication of bloodshed to follow in their train. They wax and wane like other planets. They are brighter when they come down toward us, and show larger from a nearer point, smaller when they depart from us, and dimmer when they retire to a greater distance.

XVIII

The reply is ready to this last statement, that the same thing does 1 _not_ happen in comets as in the other stars. Some comets attain their maximum on the very first day of their appearance. But, according to the argument, they ought to increase the nearer they approach. As it is, their first aspect remains until they begin to fade. Besides, what has been said in reply to former authorities applies here too: If the comet had an erratic orbit, and were a true planet, it would move within the limits of the zodiac, within which all the planets confine their orbits. Again, a star is never seen through another star. 2 Our sight cannot pierce through the centre of a planet so as to view through it what lies beyond. But through a comet the further regions are discerned as through a cloud. Whence it is evident that it is no planet but an insubstantial, irregular fire.

XIX

The following is the opinion of our Stoic sage Zeno. He is convinced 1 that the stars act in concert, and unite their rays with one another--a partnership in light which creates the image of a more elongated star. Therefore some persons suppose that comets have no real existence, and that it is only the appearance of them that is reproduced through the reflection of neighbouring stars or the union of stars that stick 2 together. Some, again, say that comets are true stars, but with orbits of their own, and that after certain periods they come out into the view of mankind. Some allow their existence but refuse them the title of stars, because they glide out of sight without long duration, and within a brief space are scattered to the winds.

XX

Most of our Stoic brethren entertain another view, which they do not 1 regard as inconsistent with fact. Let me explain it. We observe many species of fire engendered on high, now the heavens ablaze, now

Long glistening trains of flame behind,

now huge torches of fire being hurried along. The lightning itself, whose velocity is so marvellous that it at once blinds, and at the same instant restores, the sight, is fire arising from the friction of air that suffers more violent internal pressure than usual. That is why it does not remain long, but glides off once it issues from 2 the cloud, forthwith perishing. But other fiery appearances remain for a considerable time, and do not break up until all the fuel on which they fed has been used up. Here belong the strange sights recorded by Posidonius--pillars and shields all ablaze, and other flames of marvellous strangeness. They would attract no attention if they ran their course after customary laws; but now the sight of them sends all men agape. They bring down sudden fire from the heights of heaven, 3 sometimes producing a flash which is gone in a moment, sometimes compressing the air, which is forced into a glow; it is a miracle all the same. Yes, and is not sometimes a gulf opened in the ether, which seems to retire on all sides, with a great glare of light in the hollow centre? You are ready to cry out. What is this?

... I see the very centre of heaven open, And the stars wandering in the sky....

These stars sometimes do not wait for night to show their light, but burst out in the full light of day. The reason, however, for the stars showing at a time not their own is different from that alleged; it 4 is well known that they are there all the time, though hidden. Many comets, too, we cannot see because they are obscured by the sun’s rays. Posidonius, in fact, tells us that during an eclipse of the sun a comet once appeared which the sun’s proximity had hitherto concealed. Often, when the sun has just set, straggling fires[96] are seen close to him. No doubt the nucleus of the comet is bathed in sunlight, and therefore cannot be discerned; but the tail escapes the effect of the sun’s rays.

[96] _I.e._ the tail of a comet.

XXI

Our Stoic friends, therefore, are satisfied that, like trumpet meteors 1 and beams, and other portents of the sky, comets are formed by dense air. They appear in greatest number toward the north, because there is most of the sluggish air there. Why, then, you naturally ask, does the comet not remain stationary, but advance in the sky from day to day? Let me explain. The comet, according to this account, pursues its fuel just as fires do. Although its tendency is to rise to the upper regions, still, if material fail it, it retrogrades and sinks. In the air, too, it does not pursue a direct path to right or left. It has no particular route assigned to it; wherever the supply 2 of its fuel leads it, thither it crawls; it does not advance in its orbit as a star, but feeds as a fire. Why, then, does it appear for a long period, and why is it not quickly extinguished? For the recent one which we saw during this joyous reign of Nero displayed itself to view for six months, revolving in the opposite direction to the former one in Claudius’ time. That one rising from the north up toward the zenith made for the east, always growing dimmer. This one began in the same quarter, but making toward the west, turned finally toward the south, where it withdrew from view. No doubt the former found moister elements, more suitable for its fire, and pursued them; the latter 3 in turn chose a richer and more substantial district. So they descend toward the direction in which they are invited by their material, and not by a definite path, which in the two we have seen was different, since the one moved off toward the right and the other toward the left. Now all stars[97] have their orbit in one direction, namely, contrary to the motion of the universe. The latter moves from east to west, the stars go from west to east. For this reason they have a double motion,--one, their own proper motion; the other, which carries them round along with the heavens.

[97] Planets may be specially referred to; the Latin word is the generic one, _stella_.

XXII

I do not agree with my school here, for I cannot think a comet is a 1 sudden fire, but I rank it among Nature’s permanent creations. First of all, everything that the atmosphere creates is short-lived; such things arise in an element that is fugitive and changeable. How can anything continue the same for long in the air, which itself never remains the same? It is always in a state of flux, and its quiet is short-lived. It changes within a brief moment to another condition from that in which it had been. It is now rainy, now clear, now alternates from one to 2 the other. The clouds, so intimately connected with it, into which it collects and from which it is released again, now gather, now disperse, but never remain at rest. Fire cannot possibly abide securely in a volatile body, nor can it keep its place so persistently as does a fire that Nature has fixed never to be dislodged. Further, if the fire stuck close to its fuel, it would always sink. For the air is the thicker, 3 the nearer it is to the earth. But a comet is never depressed to the lowest strata of the atmosphere, nor does it ever approach the ground. Besides, fire either goes in the direction its nature prompts, that is, upwards, or else in the direction in which it is drawn by the material on which it has fastened, and on which it feeds.

XXIII

In none of the ordinary fires in the sky is the route curved; it 1 is distinctive of a star (planet) that it describes a curve in its orbit. Whether other comets had this circular orbit I cannot say. The two in our own age at any rate had. Again, everything kindled by a temporary cause quickly gives out. Thus torches gleam only while they flit across the sky; thus lightning has strength for just one stroke; thus so-called shooting and falling stars fly past, cutting through the air. No fires have any considerable duration unless 2 their strength is inherent. I mean the divine fires which the universe maintains eternally, because they are its parts and works. These, I say, are always active; they have an orbit the even tenor of which they preserve, and they are uniform. They would on alternate days be larger or smaller if the fire was merely casual, the sudden outcome of some accidental cause. Such a fire would be greater or less according as it was fed more abundantly or more scantily. I said a moment ago that no fire could be lasting which arose from some defect in the atmosphere. I have now to add further, that it can by no means be fixed and steady. 3 Both torch and lightning and shooting star, and any other kind of fire forced out of the air by pressure, are in flight; none of them is visible save in the course of its fall. But a comet has its own settled position. For that reason it is not expelled in haste, but steadily traverses its course; it is not snuffed out, but takes its departure. If it were a wandering star (_i.e._ planet), says some one, it would be in the zodiac. Who, say I, ever thinks of placing a single bound to the stars? or of cooping up the divine into narrow space? These very 4 stars, which you suppose to be the only ones that move, have, as every one knows, orbits differing one from another. Why, then, should there not be some stars that have a separate distinctive orbit far removed from them? What reason is there why there should not be passages into the heavens at some part of them?[98] But if you are convinced that every star (planet) cannot but touch the zodiac, then I say the comet might have such a wide orbit that at some point it may coincide with the zodiac. This is not necessary, but it is possible.

[98] The meaning seems to be, there may be passages--inlets and outlets--by which occasional visitants like comets may temporarily enter the heavens as we know them, and subsequently pass out of them. The text is doubtful.

XXIV

Consider whether it is not more in keeping with the size of the 1 universe that it be supposed to be divided into many routes, and do not keep this one beaten track while every other portion is a waste. Do you suppose that in this great and fair creation, among the countless stars that adorn the night with varied beauty, never suffering the atmosphere to become empty and sluggish, there are only five stars that are allowed to move freely, while all the rest stand still, a fixed, immovable crowd? Should any one here ask me: Why, then, has their 2 course not been observed like that of the five planets? my answer to him shall be: There are many things whose existence we allow, but whose character we are still in ignorance of. We shall all admit that we have a mind, by whose behest we are urged forward and called back; but what that mind is which directs and rules us, no one can explain any more than he can tell where it resides. One will say that it is breath; another, a kind of harmony; another, a divine force and part of God; another, subtlest air; another, disembodied power. Some will even be found to call it blood, or heat. So far is the mind from being clear on all other subjects that it is still in search of itself.

XXV

Why should we be surprised, then, that comets, so rare a sight in the 1 universe, are not embraced under definite laws, or that their beginning and end are not known, seeing that their return is at long intervals? It is not yet fifteen hundred years since Greece

Counted the number of the stars and named them every one.

And there are many nations at the present hour who merely know the 2 face of the sky and do not yet understand why the moon is obscured in an eclipse. It is but recently indeed that science brought home to ourselves certain knowledge on the subject. The day will yet come when the progress of research through long ages will reveal to sight the mysteries of nature that are now concealed. A single lifetime, though it were wholly devoted to the study of the sky, does not suffice for the investigation of problems of such complexity. And then we never make a fair division of the few brief years of life as between study and vice. It must, therefore, require long successive ages to unfold all. The day will yet come when posterity will be amazed that we 3 remained ignorant of things that will to them seem so plain. The five planets are constantly thrusting themselves on our notice; they meet us in all the different quarters of the sky with a positive challenge to our curiosity. Yet it is but lately we have begun to understand their motions, to realise what their morning and evening settings mean, what their turnings when they move straight toward us, why they are driven back from us. We have learned but a few years ago whether Jupiter would rise or set, or whether he would retrograde--the term that has been applied to his retirement from us. People have been found bold enough 4 to say to us: You are mistaken in thinking that any star ever stops or wheels in its course. The heavenly bodies may not stand or turn away. All advance; once the signal is given they start on their race. Their career will end only with their existence. This eternal creation has motions that suffer no recall. Should they once be arrested, they will encounter obstacles in front which are meantime held in place by the ordered, regular march of the universe.

XXVI

What then is the reason, you may ask, for the apparent retrogression 1 of some heavenly bodies? The appearance of slowness in their motion is caused by their encountering the sun, as well as by the character of their paths and the position of their orbits, which are at certain periods calculated to deceive the eye. Ships in the same way moving under full sail seem withal to be stationary. Men will some day be able to demonstrate in what regions comets have their paths, why their course is so far removed from the other stars, what is their size and constitution. Let us be satisfied with what we have discovered, and leave a little truth for our descendants to find out.

We cannot, Apollonius says, see through the stars what is beyond, but sight passes easily through the comets. Well, in the first place, if 2 that is the case, it is not so in the part of the body which consists of dense solid fire, but only where the dispersed glow extends as it breaks up into the appearance of hair. One can see through the gaps in the fire and not through the fire itself. Stars again, it is said, are all round, comets extended; whence it is plain that they are not true stars. But who, pray, will allow that comets are long? Their tendency like that of other stars is to a globe shape, only the light from them is prolonged. The sun shoots out his rays far and wide, but has himself a shape different from that of the light that streams from him. So in comets, the body is rounded, but the glow from them presents the appearance of being longer than that of the other stars.

XXVII

Why is this so, you ask. Do you tell me first why the light the 1 moon receives is wholly unlike the sun although she receives it from the sun. Why is it now ruddy, now pale? why is her colour ashen or black when she is cut off from the sun’s view? Or tell me why all the stars have aspects to some extent dissimilar to one another and all as different as possible from the sun. It is no hindrance to their being true stars that they are not all alike; so there is nothing to prevent comets from being permanent through all time, sharing the same destiny as the other stars, even though they have not an appearance like theirs. Besides, is not the universe, if you will only examine it 2 carefully, made up of contrarieties? Why is it that the sun should be always blazing hot in Leo, scorching the ground with his fierce glow, while in Aquarius he brings winter’s chain and closes the rivers with ice? The one constellation is subject to the same law as the other, though its characteristics and influence are so different. Aries again rises in a moment, Libra lifts its scales very slowly; yet the one sign is of the same nature as the other, though that one mounts in a brief space, this comes forth very deliberately. Do you not see, too, how contrary the elements are to one another? They are heavy and 3 light, cold and hot, moist and dry. The whole concord of the universe is a harmony of discords. You say a comet is not a star, because its form does not correspond to the type, but is unlike other stars. You can see, no doubt, how very like that star that returns to its place after thirty years is to this which revisits its haunt within the year! Nature does not turn out her work according to a single pattern; she prides herself upon her power of variation. She has made some 4 things larger, some swifter than others; some stronger, some more limited in power; some she has separated from the crowd, that their splendid isolation might render their progress conspicuous; some she has consigned to a place in the common herd. He has little conception of nature’s power who thinks that she may not do exceptionally what she does not do repeatedly. She does not often display comets; she has assigned them a different place, different periods from the other stars, and motions unlike theirs. She wished to enhance the greatness of her work by these strange visitants whose form is too beautiful to be thought accidental, whether you consider their vastness or their brightness that surpasses in size and brilliance all other stars. Their appearance has, in truth, an exceptional distinction; they are not cribbed and cabined within narrow bonds, but let loose to roam freely, to range over the region of many stars.

XXVIII

According to Aristotle, comets give indications of storm and disturb- 1 ances that bring wind and rain. Well, then, are you of opinion it is not a star because it foretells what is coming? True the comet is not a sign of storm in the same way as it is a sign of coming rain when

The oil splutters, and rotten fungus covers the wick;

or in the same way as it is a forecast of a raging sea--if

the sea Coots[99] sport on land; her haunts in the marshes Are deserted by the heron, and she soars above the heights of cloud:

[99] Perhaps cormorants: the identity of the bird is difficult to determine.

but in the same way as the equinox is a sign of the turn of the year 2 toward cold or heat, or as the predictions of the Chaldaean soothsayers who tell what sorrow or joy is determined at birth by the natal star, are indications of coming events. To convince you of the truth of this, I must warn you that the rising of a comet does not convey a threat of wind and rain in the immediate future, as Aristotle says, but casts suspicion over the whole year. Hence it is plain that the comet has not derived prognostications from its immediate surroundings to reveal for the immediate future, but that it has them stored up and buried deep within by the laws of the universe. The comet which appeared in the consulship of Paterculus and Vopiscus fulfilled the anticipations of this kind entertained by Aristotle, and for that matter by

Theophrastus; for there were everywhere severe and prolonged storms, 3 while in Achaia and Macedonia cities were overturned by earthquakes. The slowness of the comets’ motion, Aristotle says, is a proof that they are rather heavy, containing much earthy matter. So are their orbits too, for they are usually confined to the neighbourhood of the poles.

XXIX

Both statements are false. Let me take them in their order. Well, it 1 is asserted, is it, that all bodies are heavy that move more slowly? What! is the planet Saturn, which accomplishes its circuit most slowly of all the planets, heavy? It has, in fact, a proof of lightness in being higher than all the rest. But, you say, it takes a wider sweep, and does not go more slowly than the others, but only a longer distance. Let me suggest that I can make the same statement of the comets; even if their course is more sluggish, they have farther to go. But it is a falsehood to assert that they move more slowly. For this 2 last comet traversed within six months half the span of heaven; the previous one withdrew from sight in a shorter period. But again, it is urged, on account of their weight, they are borne down lower. Well, in the first place, a comet is not borne down, but round. In the second, this recent one began its motion in the north, and passing by way of the west, reached the southern quarters, and was elevating its orbit when it faded from sight. That other one, in Claudius’ reign, also 3 first appeared in the north, and continued without intermission to rise straight up to a higher elevation until it disappeared. Such are the matters relating to comets which have had weight with others and with myself. Whether they are true or not, those who attain knowledge of the truth must decide. We are permitted only to conjecture and grope in the dark, with no assurance of discovery, and yet not without hope.

XXX

Aristotle has finely said that we should never be more reverent 1 than when we are treating of the gods. We enter a temple with all due gravity, we lower our eyes, draw up our toga, and assume every token of modesty when we approach the sacrifice. How much more is all this due when we discuss the heavenly bodies, the stars, the nature of the gods, lest in ignorance we make any assertion regarding them that is hasty, or disrespectful; or lest we wittingly lie. Let us not 2 be surprised that what is buried so deeply should be unearthed so slowly. Panaetius and others, who will have it that a comet is not an ordinary star but the mere counterfeit of a star, have bestowed careful treatment on the question whether all seasons of the year are equally fitted to produce comets, and whether all quarters of the sky are equally suitable for their creation. They have inquired, too, whether they can be formed in all regions through which they can pass, and have discussed other points of a like kind. But all these questions are foreclosed by my statement that they are not accidental fires, but inwoven in the texture of the universe, directed by it in secret, but not often revealed. And how many bodies besides revolve in secret, 3 never dawning upon human eyes? Nor is it for man that God has made all things.[100] How small a portion of His mighty work is entrusted to us? But He who directs them all, who established and laid the foundations of all this world, who has clothed Himself with creation, and is the greater and better part of His work, He is hidden from our eyes, He can be perceived only by thought.

[100] Another reading runs: Nor has God revealed all things to man.

XXXI

Many things, moreover, akin to highest deity or holding power near 1 it, are still obscure. Or, perhaps, one may be still more surprised to find that they at once fill and elude our sight. Either their subtlety is too great for human vision to grasp, or such exalted majesty conceals itself in the holier sanctuary, and rules its kingdom, which is itself, without permitting access to any power except the spirit. What that is, without which nothing is, we cannot know: and when God, the greatest part of the universe, is an unknown God, we are surprised, are we, that there are some specks of fire we do not fully understand? How many animals we have come to know for the first time in our own 2 days! Many, too, that are unknown to us, the people of a coming day will know. Many discoveries are reserved for the ages still to be, when our memory shall have perished. The world is a poor affair if it do not contain matter for investigation for the whole world in every age. Some of the sacred rites are not revealed to worshippers all at once. Eleusis retains some of its mysteries to show to votaries on their second visit. Nature does not reveal all _her_ secrets at once. We imagine we are initiated in her mysteries: we are, as yet, but hanging around her outer courts. Those secrets of hers are not opened 3 to all indiscriminately. They are withdrawn and shut up in the inner shrine. Of one of them this age will catch a glimpse, of another, the age that will come after.

When, then, it may be asked, will all these things come to our full knowledge? Great schemes mature slowly, especially if effort is relaxed. There is one object we are bent on, heart and soul,--to be as wicked as possible--and we have not yet attained perfection. Vice is still making progress. Luxury is constantly discovering some new 4 outlet for its madness, indecency some new form of insult on itself. Dissolute effeminacy and corruption are constantly discovering some more refined and delicate means of self-destruction. We have not yet wholly cast off our vigour. We are still doing our best to extinguish any spark of virtue that is left. By the smoothness and polish of our bodies we men have outdone the refinements of women; we have adopted the colours of harlots, that even an honest woman would not put on. With delicate mincing step we check our gait; we do not walk, with 5 measured pace we go. We adorn our fingers with rings. A precious stone sparkles on every joint. Day by day we devise means of wronging and degrading our manhood, vexed that we cannot strip it off. One becomes a eunuch, another assumes the scandalous part of a gladiator, and, hired for death, arms for disgrace. The very pauper selects a victim on whom to sate his morbid lust.

XXXII

Do you wonder that wisdom has not yet attained her perfect work? Why, 1 vice has not wholly revealed itself. It is still in its infancy, and yet on it we bestow all our efforts; our eyes and our hands are its slaves. Who attends the school of wisdom now? Who thinks it worth while to have more than a bowing acquaintance with her? Who has regard for philosophy or any liberal pursuit, except when a rainy day comes round to interrupt the games, and it may be wasted without loss? And so the many sects of philosophers are all dying out for lack of successors. 2 The Academy, both old and new, has left no disciple. Who is there to hand down the precepts of Pyrrho? That famous school of Pythagoras, despised of the rabble, can find no master. The new sect of the Sextii, which contained the vigour of Rome, started with great enthusiasm, but on the very threshold of its career is also dead.

But what anxious care we bestow that the name of no actor may be 3 lost! The house of Pylades and Bathyllus stands in a long line of successors. For arts of that kind there are plenty of pupils and plenty of teachers. The actor’s platform resounds in every private house in the whole city. On it men and women alike practise the ballet step. Husbands and wives vie in paying court to actors. By and by, when the brow is rubbed smooth by long wearing of the mask, the transition to the brothel is easy and natural. Philosophy gets never 4 a thought. And so it comes to pass that, far from advance being made toward the discovery of what the older generations left insufficiently investigated, many of their discoveries are being lost. But yet, on my soul of honour, if we urged on this task with all our powers, if our youth in sobriety braced themselves to it, if the elder taught it and the younger learned it, even then scarce should we reach the bottom of the well in which truth lies. As it is, we search for her on the surface, and with a slack hand.

NOTES ON SENECA’S “QUAESTIONES NATURALES”

By Sir ARCHIBALD GEIKIE, K.C.B., Pres.R.S.

The treatise of which the present volume is a translation possesses a twofold interest. In the first place, it is probably the last literary work of a man who filled a large space in the Roman world of his day. After a varied career as philosopher, barrister, politician, statesman, courtier, and man of letters, he at last incurred the implacable enmity of Nero, to whom he had been tutor. Having in his youth paid some attention to physical inquiries, he had then been led to prepare and publish a book on earthquakes. But in subsequent years the absorbing cares of State probably left him little leisure to continue these studies, for which, however, he had retained his taste. Hence, when in his last days he sought in retirement to devote himself to philosophical pursuits, he naturally turned to some of the physical problems that had interested him in earlier life. The earthquake which on 5th February A.D. 63 had done much damage to the towns of Campania, revived his youthful enthusiasm for the investigation of such phenomena, and may possibly have suggested to him the preparation of another volume dealing with this and other scientific matter. We know at least from the book itself that he wrote a part, if not the whole, of it after that date (221, 230),[101] and that he took pains to collect information about the catastrophe. As he was in the habit of sojourning on the shores of the Bay of Naples, he probably visited the scene of destruction himself for the purpose of his book. We learn from Tacitus that it was immediately after his return from Campania to his villa near Rome, bringing with him, we may suppose, his nearly completed manuscript, that Seneca received the Emperor’s order to commit suicide.

[101] The numbers within parentheses throughout these Notes refer to the pages of the Translation.

In the second place, Seneca’s work on _Natural Questions_ stands out as one of the few treatises on physical science which have come down to us from antiquity. It is interesting alike for the quotations it contains from the works of previous authors, some of which have not survived, and for the criticisms and opinions which he himself expresses on the various subjects of which he treats. It can hardly, however, be regarded as an original contribution to science. Its author’s life had been spent in other and widely different pursuits, which led him far away from scientific inquiry. But as a summary of the general state of knowledge in his day, made by a man of strong intellect, who had been trained in the legal and philosophical schools of the time, and had read widely and reflected much on these matters, the book may be taken to afford a fair presentation of the manner in which a number of questions in astronomy, meteorology, and physical geography were regarded by thoughtful minds in the first century of our era.

In judging of the intrinsic merit of such a work as the present, the modern reader finds a difficulty in realising from the broad platform of natural knowledge which, after the labours of the intervening centuries, has now been laid, how exceedingly narrow was the circle of ascertained fact available to the student two thousand years ago. The spirit of scientific observation and experiment had not then been developed, yet the familiar phenomena of everyday life pressed, as they still do, for explanation. Man’s knowledge of nature was then too limited to furnish a basis for distinguishing what was fact from what was mere guesswork. In the infancy of our race, as in the childhood of the individual, the tendency of the human mind is to perceive resemblances rather than differences. Analogies are readily observed and, in default of knowledge of the facts involved, are mistaken for identical sequences of cause and effect. Throughout the interpretations of natural phenomena given by the philosophers of antiquity, it is remarkable to what a large extent the meaning of one appearance is explained by comparing it with another to which in reality it may bear no resemblance. Seneca’s volume abounds in examples of this use of analogy.

The authority of great names exercised a wonderful fascination on the minds of the early investigators of nature. Generation after generation of writers were led to accept with little or no modification the dicta of eminent philosophers who had preceded them. An observer might sometimes recognise the erroneousness of the opinion of a predecessor, and yet lack the means of detecting the falsity of his own, which nevertheless he propounded with full assurance of its truth. In such circumstances criticism had no secure foundation, while credulity, rampant in the world outside, could hardly fail to show itself in philosophic circles. Even the most cautious and truth-seeking inquirer might easily and almost inevitably be led to accept statements which did not seem to him unreasonable, and which no previous experience of his own or others warranted him to disbelieve or even to suspect.

It behoves us, therefore, to be on our guard lest, from our much higher standard of knowledge, we may be tempted to look with amused contempt on the puerile conceptions of nature to be met with in the writings of the ancients--the grave assertion of absurdities as actual facts, the inept analogies, the confident explanations which are no explanations at all, and the complete absence of any attempt to test by examination or experiment the validity of statements which with but little trouble could have been disproved.

These evidences of the exceedingly imperfect knowledge of his time are fully illustrated in Seneca’s chapters. He quotes some two dozen of previous writers who had dealt with the same or cognate subjects. It is needless to say that they were Greeks, no place having yet been found in Latin literature for treatises on Science. The author most frequently cited by him is Aristotle, whose _Meteorologica_ he had evidently studied with care. He gives frequent quotations from that work, but even where he does not specifically quote, his views generally accord with those of the great philosopher and naturalist.[102] Almost the only quotations from the works of his own countrymen are verses from some of the poets, especially from Virgil and Ovid. It is remarkable that he makes only one quotation from Lucretius, although he would have found in that poet’s noble work many passages more apposite to his subject than those which he has taken from the _Aeneid_, the _Georgics_, and the _Metamorphoses_. We may suppose that these works were favourites with him, and that he knew much of them by heart, but that he was less familiar with the _De Rerum Natura_.

[102] Seneca’s indebtedness to Aristotle is emphatically expressed by Barthélemy Saint-Hilaire in the Dissertation prefixed to his translation of the _Meteorologica_ (_Météorologie d’Aristote_, 1863, pp. lxix-lxx).

It is manifest from the present volume that its author, like Lucretius before him, had a lofty conception of the dignity and moral influence of the study of nature. This pursuit seemed to him to raise us above the sordid things of life and to withdraw the mind from the body--a dissociation so eminently beneficial to our higher aspirations. He believed that in the study of the hidden phenomena of the universe a mental alacrity is developed which will be found to be not without practical utility in the conduct of affairs that lie nearer the surface (113).

With this clear recognition of the importance of his theme he resolved in his old age to enter upon a task which other less worthy pursuits had hindered him from pursuing. He would now attempt to survey the universe, unravel its secrets, and give the results of his studies to the world (109). It was not, however, his aim to compose a systematic treatise on Natural Philosophy, but rather to take up some special subjects and deal with them in the light of what had already been written upon them, and of what his own reflections suggested. His undertaking assumed the form of a series of epistolary essays addressed to his friend Lucilius Junior, procurator of Sicily. The literary shape thus selected allowed the use of an unconstrained, almost colloquial, style which would not have been suitable to a more ambitious work.

Had Seneca designed to prepare a formal or methodical treatise, he would doubtless have planned it to include the three sections which he regarded as comprising every inquiry that can arise as to the nature and constitution of the Universe (_Universum_)--celestial, atmospheric, and terrestrial (_Caelestia, Sublimia, Terrena_, 51). The world (_Mundus_) in his view comprehends all things that come or can come within our cognisance (54). Instead of entering upon a full discussion of any one of his three sections, he selected from them a few topics which had probably more particularly engaged his attention. Most of these belong to the second or atmospheric division of his scheme of arrangement, to which he devotes six of his seven books, the remaining one being given to the discussion of some celestial phenomena. Certain subjects which we should naturally range in the terrestrial series, such as the source and flow of rivers and the nature and origin of earthquakes, he explicitly includes among his atmospheric phenomena (51).

It appears to be probable that Seneca had neither finished nor revised his manuscript at the time of his death. Parts of the work are obviously incomplete, though some of these gaps may be due to defects of transcription or to the subsequent loss of parts of the text. The obscurities of language, which are not infrequent, may likewise have partly arisen from lack of the author’s revision of his original copy. His discussion of the problem of the rise of the Nile suddenly breaks off in such an abrupt manner as to suggest the loss of a portion of the original volume. One of the most important omissions is the absence of any account of the phenomena of volcanoes. The author does indeed refer in several places to this subject, but with Aetna before him, of which so many Greek and Latin poets had sung, and which had so often been referred to in the writings of the philosophers, he could hardly have meant to offer no commentary on so notable a feature in the geography and history of his own country. We know indeed that he was keenly interested in this mountain, and that he wrote to Lucilius to ascend the volcano and send him particulars about it. In the letter conveying this request he alludes to some of the Roman poets who had sung of its wonders, and urges that a description of Aetna should form part of a poem on which his correspondent appears to have been then engaged.[103] Another important subject in physical geography finds no place in Seneca’s volume--the Sea. Of the outer ocean it was not to be expected that he could have had much to say, but we can hardly suppose that he would have considered his essay complete without some discussion of the various phenomena presented by the Mediterranean Sea.

[103] Seneca, _Epist._ lxxix.

A century before Seneca’s prime, the immortal _De Rerum Natura_ of Lucretius had appeared at Rome, wherein the origin and constitution of the world were sung with the intense earnestness, brilliant imagination, and resounding cadence of a great poet and with the grasp and penetration of a great philosopher. In this splendid work some of the problems discussed by Seneca were considered, and explanations were given of them with the usual undoubting confidence of olden time. In literary quality the two writers stand far apart, yet it is not uninteresting to compare their respective views of nature. The vivid and often majestic diction of the one is not more diverse from the somewhat familiar and conversational tone of the other than are their respective creeds. Lucretius was a convinced and enthusiastic Epicurean, and in accordance with the teachings of his master denied the existence of any divine co-operation in the plan and government of the Universe,

nequaquam nobis divinitus esse paratam naturam rerum,[104]

[104] _De Rerum Natura_, v. 198.

although no writer either of ancient or modern time has had a more overpowering sense of the beauty, majesty, and order of this world. It was his earnest purpose to show men how, by a contemplation of the face and ordered scheme of nature, they could free themselves from the bond of religious superstition and the fear of death.[105]

[105]

rursus in antiquas referuntur religiones et dominos acres adsciscunt, omnia posse quos miseri credunt, ignari quid queat esse, quid nequeat, finita potestas denique cuique quanam sit ratione atque alte terminus haerens.--_Op. cit._ v. 86.

hunc igitur terrorem animi tenebrasque necessest non radii solis neque lucida tela diei discutiant, sed naturae species ratioque.--i. 146.

Seneca, on the other hand, held the Stoic belief in an all-wise and omnipotent Creator. In an eloquent exordium to his volume, and in a peroration near its end, he affirms his conviction that this Divine Being is all in all, at once within and without his works; He has clothed himself with creation, but is hidden from our eyes and can be perceived only by thought (3, 7, 305). Our philosopher could not conceive of anything more beautiful, more orderly, and more consistent everywhere in plan than the world around us. That such a world should have resulted from the tumult of chaos, by the mere chance collocation of atoms, appeared to him the madness of vulgar error. Yet it was only too true, though it might be thought hardly credible, that even philosophers had been tainted with this pernicious doctrine. Hence it would be in the author’s judgment a profitable task to inquire into the truth concerning these matters. To explore this world, he remarks, is far more than enough for a single lifetime. Whether what we may be led to believe regarding it shall be true must be decided by those who may attain the knowledge of the truth; we can but examine and conjecture, with no certain assurance of discovery, yet not without hope (304). It behoves us to be ever watchful against forming conclusions rashly, disrespectfully, or ignorantly, and of being knowingly untrue. In this quest after knowledge, while much may be found out which will be of practical usefulness, we are encouraged to advance, not by any hope of gain, but by the wonder with which the inquiry fills the soul. To obtain a knowledge of Nature is the highest reward to which the mind of man can aspire (230, 304). Seneca’s practical conclusion was thus much the same as that of Lucretius. He does not, however, attempt in this volume to enforce it with the solemn earnestness shown by the poet, though he loses no opportunity of inveighing against the follies and vices of his time. In discussing natural phenomena his first desire is to explain them, and in so doing to animadvert on the explanations of previous writers, with perhaps a not unnatural wish to show his own ability as a critic and expositor.

It was in due accordance with the principles of his school, as well as with his own natural temperament, that Seneca should continually be led to draw ethical lessons from the physical phenomena which he discussed. The interpolation of some of these reflections may occasionally seem to a modern reader rather irrelevant and far-fetched, but there can be no question as to the spirit of reverence with which he approached his subject. Like other philosophers who had preceded him, he maintained this spirit, while at the same time he had discarded the crowded and confused polytheism of the prevalent mythology. But he here keeps this antagonism in due restraint, only occasionally expressing his dissent from the popular creed. He would not admit that even the old philosophers could have been so foolish as to credit the gods with some of the acts which had been popularly attributed to them. He refused to believe that the guardian and ruler of the Universe hurled thunderbolts with his own hand. Still less could he suppose that the gods had lighter bolts with which they amused themselves in play. His expression (fulminibus lusoriis, 91) recalls the bitter irony of Lucretius and the sarcasm of his question whether, when the gods aim at lonely places or at the sea, they are only at practice to strengthen their arms.[106] But Seneca held with Lucretius that in the contemplation of nature we obtain the courage and elevation of mind which fit us for the trials of life and the coming of death (113).

[106] an tum bracchia consuescunt firmantque lacertos?--vi. 397.

In the treatment of scientific problems Seneca displays the same unhesitating assurance of the truth of his opinions, which was characteristic of the philosophers of antiquity. These writers had hardly a glimmering conception of nature’s infinite complexity, of the extreme diversity and intricacy of natural processes, of the unbroken and endlessly ramifying relations of cause and effect, of the long and patient investigation by which alone these relations could be unravelled, and of the caution and diffidence with which conclusions regarding them should at least for a time be formulated. Seneca frequently passes caustic criticisms on the views expressed by his predecessors. He styles the philosophers, as a body, “a credulous folk.” Some of them he even goes so far as to accuse of perpetrating deliberate falsehoods (276, 286, 289). Nor does he hesitate to banter his brethren of the Stoic School, whose “absurdities,” as he calls them, he cannot refrain from quoting.

Yet when his own opinions are examined in the light of the present day, they are found to be in many cases no nearer the truth than those which he rejected with contempt. It is, indeed, sometimes difficult to realise the mental position of a man who could adopt and propound them. In many cases he accounts for a phenomenon by the analogy of another to which it has no real affinity, as where he explains halos by the circular undulations produced on a surface of water into which a stone is thrown (13). He sometimes suggests an experiment to prove the truth of his assertion, but if he had made the experiment he would have found how completely it failed to support him, as, for instance, when he states that a large pond of water reflects only one image of the sun, but that, if it is divided into several smaller ponds by the insertion of partitions, it will show as many images as there are divisions (18). Striking also and numerous are the examples of his credulous acceptance of statements which, had it occurred to him to test them by actual examination, he could easily have found to be erroneous. He affirms, for instance, more than once, that while lightning melts metals, it freezes wine, and he gravely alleges that when the wine is thawed and imbibed, it either kills or drives mad those who partake of it (79, 97). He asserts that the waters of certain rivers have the power of dyeing whole flocks of sheep, black fleeces being changed into white, and white into black (137), that some waters are so dense that even the heaviest objects will not sink in them (138); that the heat of the sun in the Nile valley is so great as to melt silver and the joints of statues (173). When he proceeds to explain the reason of such abnormalities he expresses no hesitation, but delivers his opinion with the assurance of a professor who has obtained the experimental demonstration in his laboratory.

It is remarkable that although some progress had been made in astronomy, especially by Greek philosophers, before the beginning of the Christian era, the conclusions arrived at by these observers regarding the relations of the earth to the other heavenly bodies met with but little acceptance for many centuries, even among reflecting minds. Lucretius, for example, still believed the earth to be the centre of the Universe to which all the heavier materials had converged, while the fire-laden ether escaped to the outer boundaries of space, sun, moon, and stars occupying an intermediate place. He did not think that the sun can be much larger than it looks to be to our senses, nor was he quite sure whether it is the same sun which, passing under the earth, reappears in the morning, or if at the close of each day the sun is extinguished and a new collection of fires makes a fresh sun in the morning. He was quite aware of the different views of Chaldaean sages and astronomers, but in such questions he could see no reason why one theory should be better than another.[107]

[107] _De Rer. Nat._ v. 564, 650, 680, 727.

Seneca, however, had, on the whole, a more advanced appreciation of the relations of the earth to the heavenly bodies. He believed the sun to be larger than our globe, and that a thousand stars might be put together without equalling his mass (284, 288). He thought the heavens to be so vast as to afford space for the swiftest of the planets to rush along with uninterrupted speed during full thirty years (7). He showed his enlightened outlook upon astronomical possibilities when he surmised that comets may have orbits that carry them far beyond the Zodiac, and when he conjectured that other planets than those then known remained to be discovered (296–299). And yet, sharing these more enlarged conceptions, he clung with curious pertinacity to some of the old childish faith which was natural in the infancy of mankind. He knew that some philosophers held that it is the earth which revolves and not the heavens, and though he does not deliberately reject this opinion, it is evident that he still held that the heavens circle round the earth.[108] Again and again he expresses his conviction that the force which sustains the energy of the sun and the stars consists of the exhalations that arise from the surface of the earth. These exhalations, he says, are the pasturage of the heavenly bodies, the breath of the world. It would be impossible, he asserts, for the earth to furnish so ample a store of nourishment to bodies larger than itself unless it were full of breath which is passing off from every part of its surface both by day and night. To the obvious objection that the supply of this energy would soon become exhausted, he has the reply that this exhaustion would certainly take place were it not that the elements are in a condition of continual transformation, issuing in one form, passing into each other, and returning to their original positions, thence to begin their cycle anew (55, 198, 244–5). In this universal transmutation water passes into air, air into water; air likewise is changed into fire, fire into air, while earth is formed from water, and water from earth (120).

[108] See _postea_, Notes on Book VII.

In his general conception of the universe, Seneca, as a Stoic philosopher, recognised a principle of evolution. He believed that the world embraces in its constitution everything that it is destined to experience from its beginning to its end. As a human embryo contains the germ of the future man, so at the first creation of the universe, sun and moon, the changes of the stars, and the birth of living things were all embraced. And there were likewise included the forces whereby the earth is affected, and which will ultimately lead to the final destruction of the globe (151).[109]

[109] Lucretius, too, had his views on evolution, which are well expressed in four lines of verse:

mutat enim mundi naturam totius aetas, ex alioque alius status excipere omnia debet, nec manet ulla sui similis res: omnia migrant, omnia commutat natura et vertere cogit. --_De Rer. Nat._ v. 828.

With regard to the earth itself, whether it is to be regarded as a soul or as an organised body, Seneca announced his conviction that it has been constructed much after the plan of our human bodies. As in these bodies, veins and arteries are provided for the reception of blood and breath, so in the earth there are passages, some for the transport of water, others for the flow of air (126). He was sure, also, that everything on the surface of the earth has its counterpart beneath--caves, mountains, lakes, and rivers.