The Plurality of Worlds Part 4

29. Astronomy claims a sort of dignity over all other sciences, from her _antiquity_, her _certainty_, and the _vastness_ of her discoveries. But the antiquity of astronomy as a science had no share in such speculations as we are discussing; and if it had had, new truths are better than old conjectures; new discoveries must rectify old errors; new answers must remove old difficulties. The vigorous youth of Geology makes her fearless of the age of Astronomy. And as to the certainty of Astronomy, it has just as little to do with these speculations. The certainty stops, just when these speculations begin. There may, indeed, be some danger of delusion on this subject. Men have been so long accustomed to look upon astronomical science as the mother of certainty, that they may confound astronomical discoveries with cosmological conjectures; though these be slightly and illogically connected with those. And then, as to the vastness of astronomical discoveries,--granting that character, inasmuch as it is to a certain degree, a matter of measurement,--we must observe, that the discoveries of geology are no less vast: they extend through time, as those of astronomy do through s.p.a.ce. They carry us through millions of years, that is, of the earth's revolutions, as those of astronomy do through millions of the earth's diameters, or of diameters of the earth's...o...b..t.

Geology fills the regions of duration with events, as astronomy fills the regions of the universe with objects. She carries us backwards by the relation of cause and effect, as astronomy carries us upwards by the relations of geometry. As astronomy steps on from point to point of the universe by a chain of triangles, so geology steps from epoch to epoch of the earth's history by a chain of mechanical and organical laws. If the one depends on the axioms of geometry, the other depends on the axioms of causation.

30. So far then, Geology has no need to regard Astronomy as her superior; and least of all, when they apply themselves together to speculations like these. But in truth, in such speculations, Geology has an immeasurable superiority. She has the command of an implement, in addition to all that Astronomy can use; and one, for the purpose of such speculations, adapted far beyond any astronomical element of discovery.

She has, for one of her studies,--one of her means of dealing with her problems,--the knowledge of Life, animal and vegetable. Vital organization is a subject of attention which has, in modern times, been forced upon her. It is now one of the main parts of her discipline. The geologist must study the traces of life in every form; must learn to decypher its faintest indications and its fullest development. On the question, then, whether there be in this or that quarter, evidence of life, he can speak with the confidence derived from familiar knowledge; while the astronomer, to whom such studies are utterly foreign, because he has no facts which bear upon them, can offer, on such questions, only the loosest and most arbitrary conjectures; which, as we have had to remark, have been rebuked by eminent men, as being altogether inconsistent with the acknowledged maxims of his science.

31. When, therefore, Geology tells us that the earth, which has been the seat of human life for a few thousand years only, has been the seat of animal life for myriads, it may be, millions of years, she has a right to offer this, as an answer to any difficulty which Astronomy, or the readers of astronomical books, may suggest, derived from the considerations that the Earth, the seat of human life, is but one globe of a few thousand miles in diameter, among millions of other globes, at distances millions of times as great.

32. Let the difficulty be put in any way the objector pleases. Is it that it is unworthy of the greatness and majesty of G.o.d, according to our conceptions of Him, to bestow such peculiar care on so small a part of His creation? But we know, from geology, that He has bestowed upon this small part of His creation, mankind, this special care;--He has made their period, though only a moment in the ages of animal life, the only period of intelligence, morality, religion. If then, to suppose that He has done this, is contrary to our conceptions of His greatness and majesty, it is plain that our conceptions are erroneous; they have taken a wrong direction. G.o.d has not judged, as to what is worthy of Him, as we have judged. He has found it worthy of Him to bestow upon man His special care, though he occupies so small a portion of time; and why not, then, although he occupies so small a portion of s.p.a.ce?

33. Or is the objection this; that if we suppose the earth only to be occupied by inhabitants, all the other globes of the universe are wasted;--turned to no purpose? Is waste of this kind considered as unsuited to the character of the Creator? But here again, we have the like waste, in the occupation of the earth. All its previous ages, its seas and its continents, have been wasted upon mere brute life; often, so far as we can see, for myriads of years, upon the lowest, the least conscious forms of life; upon sh.e.l.l-fish, corals, sponges. Why then should not the seas and continents of other planets be occupied at present with a life no higher than this, or with no life at all? Will it be said that, so far as material objects are occupied by life, they are not wasted; but that they are wasted, if they are entirely barren and blank of life? This is a very arbitrary saying. Why should the life of a sponge, or a coral, or an oyster, be regarded as a good employment of a spot of land and water, so as to save it from being wasted? No doubt, if the coral or the oyster be there, there is a reason why it is so, consistently with the attributes of G.o.d. But then, on the same ground, we may say that if it be not there, there is a reason why it is not so.

Such a mode of regarding the parts of the universe can never give us reasons why they should or should not be inhabited, when we have no other grounds for knowing whether they are. If it be a sufficient employment of a spot of rock or water that it is the seat of organization--of organic powers; why may it not be a sufficient employment of the same spot that it is the seat of attraction, of cohesion, of crystalline powers? All the planets, all parts of the universe, we have good reason to believe, are pervaded by attraction, by forces of aggregation and atomic relation, by light and heat. Why may not these be sufficient to prevent the s.p.a.ce being wasted, in the eyes of the Creator? as, during a great part of the earth's past history, and over large portions of its present ma.s.s, they are actually held by Him sufficient; for they are all that occupy those portions. This notion, then, of the improbability of there being, in the universe, so vast an amount of waste s.p.a.ces, or waste bodies, as is implied in the opinion that the earth alone is the seat of life, or of intelligence, is confuted by the fact, that there are vast s.p.a.ces, waste districts, and especially waste times, to an extent as great as such a notion deems improbable. The avoidance of such waste, according to our notions of waste, is no part of the economy of creation, so far as we can discern that economy, in its most certain exemplifications.

34. Or will the objection be made in this way; that such a peculiar dignity and importance given to the earth is contrary to the a.n.a.logy of creation;--that since there are so many globes, similar to the earth,--like her, revolving round the sun, like her, revolving on her axes, several of them, like her, accompanied by satellites; it is reasonable to suppose that their destination and office is the same as hers;--that since there are so many stars, each like the sun, a source of light, and probably of heat, it is reasonable to suppose that, like the sun, they are the centres of systems of planets, to which their light and heat are imparted, to uphold life:--is it thought that such a resemblance is a strong ground for believing that the planets of our system, and of other systems, are inhabited as the earth is? If such an astronomical a.n.a.logy be insisted on, we must again have recourse to geology, to see what such a.n.a.logy is worth. And then, we are led to reflect, that if we were to follow such a.n.a.logies, we should be led to suppose that all the successive periods of the earth's history were occupied with life of the same order; that as the earth, in its present condition, is the seat of an intelligent population, so must it have been, in all former conditions. The earth, in its former conditions, was able and fitted to support life; even the life of creatures closely resembling man in their bodily structure. Even of monkeys, fossil remains have been found. But yet, in those former conditions, it did not support human life. Even those geologists who have dwelt most on the discovery of fossil monkeys, and other animals nearest to man, have not dreamt that there existed, before man, a race of rational, intelligent, and progressive creatures. As we have seen, geology and history alike refute such a fancy. The notion, then, that one period of time in the history of the earth must resemble another, in the character of its population, because it resembles it in physical circ.u.mstances, is negatived by the facts which we discover in the history of the earth.

And so, the notion that one part of the universe must resemble another in its population, because it resembles it in physical circ.u.mstances, is negatived as a law of creation. a.n.a.logy, further examined, affords no support to such a notion. The a.n.a.logy of time, the events of which we know, corrects all such guesses founded on a supposed a.n.a.logy of s.p.a.ce, the furniture of which, so far as this point is concerned, we have no sufficient means of examining.

35. But in truth, we may go further. Not only does the a.n.a.logy of creation not point to any such entire resemblance of similar parts, as is thus a.s.sumed, but it points in the opposite direction. Not entire resemblance, but universal difference is what we discover; not the repet.i.tion of exactly similar cases, but a series of cases perpetually dissimilar, presents itself; not constancy, but change, perhaps advance; not one permanent and pervading scheme, but preparation and completion of successive schemes; not uniformity and a fixed type of existences, but progression and a climax. This may be said to be the case in the geological aspect of the world; for, without occupying ourselves with the question, how far the monuments of animal life, which we find preserved in the earth's strata, exhibited a gradual progression from ruder and more imperfect forms to the types of the present terrestrial population; from sponges and mollusks, to fish and lizards, from cold-blooded to warm blooded animals, and so on, till we come to the most perfect vertebrates;--a doctrine which many eminent geologists have held, and still hold;--without discussing this question, or a.s.suming that the fact is so; this at least cannot be denied or doubted, that man is incomparably the most perfect and highly-endowed creature which ever has existed on the earth. How far previous periods of animal existence were a necessary preparation of the earth, as the habitation of man, or a gradual progression towards the existence of man, we need not now inquire. But this at least we may say; that man, now that he is here, forms a climax to all that has preceded; a term incomparably exceeding in value all the previous parts of the series; a complex and ornate capital to the subjacent column; a personage of vastly greater dignity and importance than all the preceding line of the procession.

The a.n.a.logy of nature, in this case at least, appears to be, that there should be inferior, as well as superior provinces, in the universe; and that the inferior may occupy an immensely larger portion of time than the superior; why not then of s.p.a.ce? The intelligent part of creation is thrust into the compa.s.s of a few years, in the course of myriads of ages; why not then into the compa.s.s of a few miles, in the expanse of systems? The earth was brute and inert, compared with its present condition, dark and chaotic, so far as the light of reason and intelligence are concerned, for countless centuries before man was created. Why then may not other parts of creation be still in this brute and inert and chaotic state, while the earth is under the influence of a higher exercise of creative power? If the earth was, for ages, a turbid abyss of lava and of mud, why may not Mars or Saturn be so still? If the germs of life were, gradually, and at long intervals, inserted in the terrestrial slime, why may they not be just inserted, or not yet inserted, in Jupiter? Or why should we a.s.sume that the condition of those planets resembles ours, even so far as such suppositions imply?

Why may they not, some or all of them, be barren ma.s.ses of stone and metal, slag and scoriae, dust and cinders? That some of them are composed of such materials, we have better reason to believe, than we have to believe anything else respecting their physical const.i.tution, as we shall hereafter endeavor to show. If then, the earth be the sole inhabited spot in the work of creation, the oasis in the desert of our system, there is nothing in this contrary to the a.n.a.logy of creation.

But if, in some way which perhaps we cannot discover, the earth obtained, for accompaniments, mere chaotic and barren ma.s.ses, as conditions of coming into its present state; as it may have required, for accompaniments, the brute and imperfect races of former animals, as conditions of coming into its present state, as the habitation of man; the a.n.a.logy is against, and not in favor of, the belief that they too (the other ma.s.ses, the planets, &c.) are habitations. I may hereafter dwell more fully on such speculations; but the possibility that the planets are such rude ma.s.ses, is quite as tenable, on astronomical grounds, as the possibility that the planets resemble the earth, in matters of which astronomy can tell us nothing. We say, therefore, that the example of geology refutes the argument drawn from the supposed a.n.a.logy of one part of the universe with another; and suggests a strong suspicion that the force of a.n.a.logy, better known, may tend in the opposite direction.

36. When such possibilities are presented to the reader, he may naturally ask, if we are thus to regard man as the climax of creation, in s.p.a.ce, as in time, can we point out any characters belonging to him, which may tend to make it conceivable that the Creator should thus distinguish him, and care for him:--should prepare his habitation if it be so, by ages of chaotic and rudimentary life, and by accompanying orbs of brute and barren matter. If Man be, thus, the head, the crowned head of the creation, is he worthy to be thus elevated? Has he any qualities which make it conceivable that, with such an array of preparation and accompaniment, he should be placed upon the earth, his throne? Or rather, if he be thus the chosen subject of G.o.d's care, has he any qualities, which make it conceivable that he should be thus selected; taken under such guardians.h.i.+p; admitted to such a dispensation; graced with such favor. The question with which we began again recurs: What is man that G.o.d should be thus mindful of him? After the views which have been presented to us, does any answer now occur to us?

37. The answer which we have to give, is that which we have already repeatedly stated. Man is an intellectual, moral, religious, and spiritual creature. If we consider these attributes, we shall see that they are such as to give him a special relation to G.o.d, and as we conceive, and must conceive, G.o.d to be; and may therefore be, in G.o.d, the occasion of special guardians.h.i.+p, special regard, a special dispensation towards man.

38. As an intellectual creature, he has not only an intelligence which he can apply to practical uses, to minister to the needs of animal and social life; but also an intellect by which he can speculate about the relations of things, in their most general form; for instance, the properties of s.p.a.ce and time, the relations of finite and infinite. He can discover truths, to which all things, existing in s.p.a.ce and time, must conform. These are conditions of existence to which the creation conforms, that is, to which the Creator conforms; and man, capable of seeing that such conditions are true and necessary, is capable, so far, of understanding some of the conditions of the Creator's workmans.h.i.+p.

In this way, the mind of man has some community with the mind of G.o.d; and however remote and imperfect this community may be, it must be real.

Since, then, man has thus, in his intellect, an element of community with G.o.d, it is so far conceivable that he should be, in a special manner, the object of G.o.d's care and favor. The human mind, with its wonderful and perhaps illimitable powers, is something of which we can believe G.o.d to be "mindful."

39. Again: man is a moral creature. He recognizes, he cannot help recognizing, a distinction of right and wrong in his actions; and in his internal movements which lead to action. This distinction he recognizes as the reason, the highest and ultimate reason, for doing or for not doing. And this law of his own reason, he is, by reflection, led to recognize as a Law of the Supreme Reason; of the Supreme Mind which has made him what he is. The Moral Law, he owns and feels as G.o.d's Law. By the obligation which he feels to obey this Law, he feels himself G.o.d's subject; placed under his government; compelled to expect his judgment, his rewards, and punishments. By being a moral creature, then, he is, in a special manner, the subject of G.o.d; and not only we can believe that, in this capacity, G.o.d cares for him; but we cannot believe that he _does not_ care for him. He cares for him, so as to approve of what he does right, and to condemn what he does wrong. And he has given him, in his own breast, an a.s.surance that he will do this; and thus, G.o.d cares for man, in a peculiar and special manner. As a moral creature, we have no difficulty in conceiving that G.o.d may think him worthy of his regard and government.

40. The development of man's moral nature, as we have just described it, leads to, and involves the development of his religious nature. By looking within himself, and seeing the Moral Law, he learns to look upwards to G.o.d, the Author of the Law, and the Awarder of the rewards and penalties which follow moral good and evil. But the belief of such a dispensation carries us, or makes us long to be carried, beyond the manifestations of this dispensation, as they appear in the ordinary course of human life. By thinking on such things, man is led to ascribe a wider range to the moral Government of G.o.d:--to believe in methods of reward and punishment, which do not appear in the natural course of events: to accept events, out of the order of nature, which announce that G.o.d has provided such methods: to accept them, when duly authenticated, as messages from G.o.d; and thus, when G.o.d provides the means, to allow himself to be placed in intercourse with G.o.d. Since man is capable of this; since, as a religious creature, this is his tendency, his need, the craving of his heart, without which, when his religious nature is fully unfolded, he can feel no comfort nor satisfaction; we cannot be surprised that G.o.d should deem him a proper object of a special fatherly care; a fit subject for a special dispensation of his purposes, as to the consequences of human actions.

Man being this, we can believe that G.o.d is not only "mindful of him,"

but "visits him."

41. As we have said, the soul of man, regarded as the subject of G.o.d's religious government, is especially termed his _Spirit_: the course of human being which results from the intercourse with G.o.d, which G.o.d permits, is a _spiritual_ existence. Man is capable, in no small degree, of such an existence, of such an intercourse with G.o.d; and, as we are authorized to term it, of such a life with G.o.d, and in G.o.d, even while he continues in his present human existence. I say _authorized_, because such expressions are used, though reverently, by the most religious men; who are, at any rate, authority as to their own sentiments; which are the basis of our reasoning. Whatever, then, may be the imperfection, in this life, of such a union with G.o.d, yet since man can, when sufficiently a.s.sisted and favored by G.o.d, enter upon such a union, we cannot but think it most credible and most natural, that he should be the object of G.o.d's special care and regard, even of his love and presence.

42. That men are, only in a comparatively small number of cases, intellectual, moral, religious, and spiritual, in the degree which I have described, does not, by any means, deprive our argument of its force. The capacity of man is, that he may become this; and such a capacity may well make him a special object in the eyes of Him under whose guidance and by whose aid, such a development and elevation of his nature is open to him. However imperfect and degraded, however unintellectual, immoral, irreligious, and unspiritual, a great part of mankind may be, still they all have the germs of such an elevation of their nature; and a large portion of them make, we cannot doubt, no small progress in this career of advancement to a spiritual condition.

And with such capacities, and such practical exercise of those capacities, we can have no difficulty in believing, if the evidence directs us to believe, that that part of the creation in which man has his present appointed place, is the special field of G.o.d's care and love; by whatever wastes of s.p.a.ce, and mult.i.tudes of material bodies, it may be surrounded; by whatever races it may have been previously occupied, of brutes that perish, and that, compared with man, can hardly be said to have lived.

FOOTNOTES:

[1] Lyell, II. 420. [6th Ed.]

[2] Cuvier.

[3] By Bishop Berkeley. See Lyell, III. 346.

[4] A recent popular writer, who has a.s.serted the self-civilizing tendency of man, has not been able, it would seem, to adduce any example of the operation of this tendency, except a single tribe of North American Indians, in whom it operated for a short time, and to a small extent.

CHAPTER VII.

THE NEBULae

1. I have attempted to show that, even if we suppose the other bodies of the universe to resemble the Earth, so far as to seem, by their materials, forms, and motions, no less fitted than she is to be the abodes of life; yet that, knowing what we do of man, we can believe that the Earth is tenanted by a race who are the _special_ objects of G.o.d's care. Even if the tendency of the a.n.a.logies of creation were, to incline us to suppose that the other planets are as well suited as our globe, to have inhabitants, still it would require a great amount of evidence, to make us believe that they have such inhabitants as we are; while yet such evidence is altogether wanting. Even if we knew that the stars were the centres of revolving systems, we should have an immense difficulty in believing that an Earth, with such a population as ours, revolves about any of them. If astronomy made a plurality of worlds probable, we have strong reasonings, drawn from other subjects, to think that the other worlds are not like ours.

2. The admirers of astronomical triumphs may perhaps be disposed to say, that when so much has been discovered, we may be allowed to complete the scheme by the exercise of fancy. I have attempted to show that we are not in such a state of ignorance, when we look at other relations of the earth and of man, as to allow us to do this. But now we may go a little onwards in our argument; and may ask, whether Astronomy really does what is here claimed for her:--whether she carries us so securely to the bounds of the visible universe, that our Fancy may take up the task, and people the s.p.a.ce thus explored:--whether the bodies which Astronomy has examined, be really as fitted as our Earth, to sustain a population of living things:--whether the most distant objects in the universe do really seem to be systems, or the beginnings of systems:--whether Astronomy herself may not incline in favor of the condition of man, as being the sole creature of his kind?

3. In making this inquiry, it will of course be understood, that I do so with the highest admiration for the vast discoveries which Astronomy has really made; and for the marvellous skill and invention of the great men who have, in all ages of the world, and not least, in our time, been the authors of such discoveries. From the time when Galileo first discovered the system of Jupiter's satellites, to the last scrutiny of the structure of a nebula by Lord Rosse's gigantic telescope, the history of the telescopic exploration of the sky, has been a history of genius felicitously employed in revealing wonders. In this history, the n.o.ble labors of the first and the second Herschel relative to the distribution of the fixed stars, the forms and cla.s.ses of nebulae, and the phenomena of double stars, especially bear upon our present speculations; to which we may add, the examination of the aspect of each planet, by various observers, as Schroeter, and of the moon by others, from Huyghens to Madler and Beer. The achievements which are most likely to occur to the reader's mind are those of the Earl of Rosse; as being the latest addition to our knowledge, and the result of the greatest instrumental powers. By the energy and ingenuity of that eminent person, an eye is directed to the heavens, having a pupil of six feet diameter, with the most complete optical structure, and the power of ranging about for its objects over a great extent of sky; and thus the quant.i.ty of light which the eye receives from any point of the heavens is augmented, it may be, fifty thousand times. The rising Moon is seen from the Observatory in Ireland with the same increase of size and light, as if her solid globe, two thousand miles in diameter, retaining all its illumination, really rested upon the summits of the Alps, to be gazed at by the naked eye. An object which appears to the naked eye a single star, may, by this telescope, so far as its power of seeing is concerned, be resolved into fifty thousand stars, each of the same brightness as the obvious star.

What seems to the una.s.sisted vision a nebula, a patch of diluted light, in which no distinct luminous point can be detected, may, by such an instrument, be discriminated or resolved into a number of bright dots; as the stippled shades of an engraving are resolved into dots by the application of a powerful magnifying gla.s.s. Similar results of the application of great telescopic power had of course been attained long previously; but, as the nature of scientific research is, each step adds something to our means of knowledge; and the last addition a.s.sumes, includes, and augments the knowledge which we possessed before. The discussions in which we are engaged, belong to the very boundary region of science;--to the frontier where knowledge, at least astronomical knowledge, ends, and ignorance begins. Such discoveries, therefore, as those made by Lord Rosse's telescope, require our special notice here.

4. We may begin, at what appears to us the outskirts of creation, the Nebulae. At one time it was conceived by astronomers in general, that these patches of diffused light, which are seen by them in such profusion in the sky, are not luminous bodies of regular terms and definite boundaries, apparently solid, as the stars are supposed to be; but really, as even to good telescopes many of them seem, ma.s.ses of luminous cloud or vapor, loosely held together, as clouds and vapors are, and not capable by any powers of vision of being resolved into distinct visible elements. This opinion was for a time so confidentially entertained, that there was founded upon it an hypothesis, that these were gaseous ma.s.ses, out of which suns and systems might afterwards be formed, by the concentration of these luminous vapors into a solid central sun, more intensely luminous; while detached portions of the ma.s.s, flying off, and cooling down so as to be no longer self-luminous, might revolve round the central body, as planets and satellites. This is the _Nebular Hypothesis_, suggested by the elder Herschel, and adopted by the great mathematician Laplace.

5. But the result of the optical scrutiny of the nebulae by more modern observers, especially by Lord Rosse in Ireland, and Mr. Bond in America, has been, that many celestial objects which were regarded before as truly nebulous, have been resolved into stars; and this resolution has been extended to so many cases of nebulae, of such various kinds, as to have produced a strong suspicion in the minds of astronomers that _all_ the nebulae, however different in their appearance, may really be resolved into stars, if they be attacked with optical powers sufficiently great.

6. If this were to be a.s.sumed as done, and if each of the separate points, into which the nebulae are thus resolved, were conceived to be a star, which looks so small only because it is so distant, and which really is as likely to have a system of planets revolving about it, as is a star of the first magnitude:--we should then have a view of the immensity of the visible universe, such as I presented to the reader in the beginning of this essay. All the distant nebulae appear as nebulae, only because they are so distant; if truly seen, they are groups of stars, of which each may be as important as our sun, being, like it, the centre of a planetary system. And thus, a patch of the heavens, one hundredth or one thousandth part of the visible breadth of our sun, may contain in it more life, not only than exists in the solar system, but in as many such systems as the una.s.sisted eye can see stars in the heavens, on the clearest winter night.

7. This is a stupendous view of the greatness of the creation; and, to many persons, its very majesty, derived from magnitude and number, will make it so striking and acceptable, that, once apprehended, they will feel as if there were a kind of irreverence in disturbing it. But if this view be really not tenable when more closely examined, it is, after all, not wise to connect our feelings of religious reverence with it, so that they shall suffer a shock when we are obliged to reject it. I may add, that we may entertain an undoubting trust that any view of the creation which is found to be true, will also be found to supply material for reverential contemplation. I venture to hope that we may, by further examination, be led to a reverence of a deeper and more solemn character than a mere wonder at the immensity of s.p.a.ce and number.

8. But whatever the result may be, let us consider the evidence for this view. It a.s.sumes that all the Nebulae are resolvable into stars, and that they appear as nebulae only because they are more distant than the region in which they can appear as stars. Are there any facts, any phenomena in the heavens, which may help us to determine whether this is a probable opinion?

9. It is most satisfactory for us, when we can, in such inquiries, know the thoughts which have suggested themselves to the minds of those who have examined the phenomena with the most complete knowledge, the greatest care, and the best advantages; and have speculated upon these phenomena in a way both profound and unprejudiced. Some remarks of Sir John Herschel, recommended by these precious characters, seem to me to bear strongly upon the question which I have just had to ask:--Do all the nebulae owe their nebulous appearance to their being too distant to be seen as groups of distinct stars, though they really are such groups?

10. Herschel, in the visit which he made to the Cape of Good Hope, for the purpose of erecting to his father the most splendid monument that son ever erected,--the completed survey of the vault of heaven,--had full opportunity of studying a certain pair of remarkable bright s.p.a.ces of the skies, filled with a cloudy light, which lie near the southern pole; and which, having been unavoidably noticed by the first Antarctic voyagers, are called the _Magellanic Clouds_. When the larger of these two clouds is examined through powerful telescopes, it presents, we are told, a const.i.tution of uncommon complexity: "large patches and tracts of nebulosity in every stage of resolution, from light, irresolvable with eighteen inches of reflecting aperture, up to perfectly separated stars like the Milky Way, and cl.u.s.tering groups sufficiently insulated and condensed to come under the designation of irregular, and in some cases pretty rich cl.u.s.ters. But besides these, there are also nebulae in abundance, both regular and irregular; globular cl.u.s.ters in every stage of condensation, and objects of a nebulous character quite peculiar, and which have no a.n.a.logies in any other region of the heavens."[1] He goes on to say, that these nebulae and cl.u.s.ters are far more crowded in this s.p.a.ce than they are in any other, even the most crowded parts, of the nebulous heavens. This _Nubecula Major_, as it is termed, is of a round or oval form, and its diameter is about six degrees, so that it is about twelve times the apparent diameter of the moon. The _Nubecula Minor_ is a smaller patch of the same kind. If we suppose the s.p.a.ce occupied by the various objects which the nubecula major includes, to be, in a general way, spherical, its nearest and most remote parts must (as its angular size proves) differ in their distance from us by little more than a tenth part of our distance from its centre. That the two nubeculae are thus approximately spherical s.p.a.ces, is in the highest degree probable; not only from the peculiarity of their contents, which suggests the notion of a peculiar group of objects, collected into a limited s.p.a.ce; but from the barrenness, as to such objects, of the sky in the neighborhood of these Magellanic Clouds. To suppose (the only other possible supposition) that they are two columns of s.p.a.ce, with their ends turned towards us, and their lengths hundreds and thousands of times their breadths, would be too fantastical a proceeding to be tolerated; and would, after all, not explain the facts without further altogether arbitrary a.s.sumptions.

11. It appears, then, that, in these groups, there are stars of various magnitudes, cl.u.s.ters of various forms, nebulae regular and irregular, nebulous tracts and patches of peculiar character; and all so disposed, that the most distant of them, whichever these may be, are not more than one-tenth more distant than the nearest. If the nearest star in this s.p.a.ce be at nine times the distance of Sirius, the farthest nebulae, contained in the same s.p.a.ce, will not be at more than ten times the distance of Sirius. Of course, the doctrine that nebulae are seen as nebulae, merely because they are so distant, requires us to a.s.sume all nebulae to be hundreds and thousands of times more distant than the smallest stars. If stars of the eighth magnitude (which are hardly visible to the naked eye) be eight times as remote as Sirius, a nebula containing a thousand stars, which is invisible to the naked eye, must be more than eight thousand times as remote as Sirius. And thus if, in the whole galaxy, we reckon only the stars as far as the eighth magnitude, and suppose all the stars of the galaxy to form a nebula, which is visible to the spectators in a distant nebula, only as their nebula is visible to us; we must place them at eight thousand times two hundred thousand times the distance of the Sun; and, even so, we are obviously vastly understating the calculation. These are the gigantic estimates with which some astronomical speculators have been in the habit of overwhelming the minds of their listeners; and these views have given a kind of majesty to the aspect of the nebulae; and have led some persons to speak of the discovery of every new streak of nebulous light in the starry heavens, as a discovery of new worlds, and still new worlds. But the Magellanic Clouds show us very clearly that all these calculations are entirely baseless. In those regions of s.p.a.ce, there coexists, in a limited compa.s.s, and in indiscriminate position, stars, cl.u.s.ters of stars, nebulae, regular and irregular, and nebulous streaks and patches. These, then, are different kinds of things in themselves, not merely different to us. There are such things as nebulae side by side with stars, and with cl.u.s.ters of stars. Nebulous matter resolvable occurs close to nebulous matter irresolvable. The last and widest step by which the dimensions of the universe have been expanded in the notions of eager speculators, is checked by a completer knowledge and a sager spirit of speculation. Whatever inference we may draw from the resolvability of some of the nebulae, we may not draw this inference;--that they are more distant, and contain a larger array of systems and of worlds, in proportion as they are difficult to resolve.

12. But indeed, if we consider this process, of the resolution of nebulae into luminous points, on its own ground, without looking to such facts as I have just adduced, it will be difficult, or impossible, to a.s.sign any reason why it should lead to such inferences as have been drawn from it. Let us look at this matter more clearly. An astronomer, armed with a powerful telescope, _resolves_ a nebula, discerns that a luminous cloud is composed of s.h.i.+ning dots:--but what are these dots? Into _what_ does he resolve the nebula? Into _Stars_, it is commonly said. Let us not wrangle about words. By all means let these dots be Stars, if we know about what we are speaking: if a _Star_ merely mean a luminous dot in the sky. But that these stars shall resemble, in their nature, stars of the first magnitude, and that such stars shall resemble our Sun, are surely very bold structures of a.s.sumption to build on such a basis. Some nebulae are resolvable; are resolvable into distinct points; certainly a very curious, probably an important discovery. We may hereafter learn that _all_ nebulae are resolvable into distinct points: that would be a still more curious discovery. But what would it amount to? What would be the simple way of expressing it, without hypothesis, and without a.s.sumption? Plainly this: that the substance of all nebulae is not continuous, but discrete;--separable, and separate into distinct luminous elements;--nebulae are, it would then seem, as it were, of a curdled or granulated texture; they have run into _lumps_ of light, or have been formed originally of such lumps. Highly curious. But what are these lumps? How large are they? At what distances? Of what structure?

Of what use? It would seem that he must be a bold man who undertakes to answer these questions. Certainly he must appear to ordinary thinkers to be _very_ bold, who, in reply, says, gravely and confidently, as if he had unquestionable authority for his teaching:--"These lumps, O man, are Suns; they are distant from each other as far as the Dog-star is from us; each has its system of Planets, which revolve around it; and each of these Planets is the seat of an animal and vegetable creation. Among these Planets, some, we do not yet know how many, are occupied by rational and responsible creatures, like Man; and the only matter which perplexes us, holding this belief on astronomical grounds, is, that we do not quite see how to put our theology into its due place and form in our system."

13. In discussing such matters as these, where our knowledge and our ignorance are so curiously blended together, and where it is so difficult to make men feel that so much ignorance can lie so close to so much knowledge;--to make them believe that they have been allowed to discover so much, and yet are not allowed to discover more:--we may be permitted to ill.u.s.trate our meaning, by supposing a case of blended knowledge and ignorance, of real and imaginary discovery. Suppose that there were carried from a scientific to a more ignorant nation, excellent maps of the world, finely engraved; the mountain-ranges shaded in the most delicate manner, and the sheet crowded with information of all kinds, in writing large, small, and microscopic. Suppose also, that when these maps had been studied with the naked eye, so as to establish a profound respect for the knowledge and skill of the author of them, some of those who perused them should be furnished with good microscopes, so as to carry their examination further than before. They might then find that, in several parts, what before appeared to be merely crooked lines, was really writing, stating, it may be, the amount of population of a province, or the date of foundation of a town. To exhaust all the information thus contained on the maps, might be a work of considerable time and labor. But suppose that, when this was done, a body of resolute microscopists should insist that the information which the map contained was not exhausted: that they should continue peering perseveringly at the lines which formed the shading of the mountains, maintaining that these lines also were writing, if only it might be deciphered; and should go on increasing, with immense labor and ingenuity, the powers of their microscopes, in order to discover the legend contained in these unmeaning lines. We should, perhaps, have here an image of the employment of these astronomers, who now go on looking in nebulae for worlds. And we may notice in pa.s.sing, that several of the arguments which are used by such astronomers, might be used, and would be used, by our microscopists:--how improbable it was that a person so full of knowledge, and so able to convey it, as the author of the maps was known to be, should not have a design and purpose in every line that he drew: what a waste of s.p.a.ce it would be to leave any part of the sheet blank of information; and the like. To which the reply is to us obvious; that the design of shading the mountains was design enough; and that the information conveyed was all that was necessary or convenient.

Nor does this ill.u.s.tration at all tend to show that such astronomical scrutiny, directed intelligently, with a right selection of the points examined, may not be highly interesting and important. If the microscopists had examined the map with a view to determine the best way in which mountains can be indicated by shading, they would have employed themselves upon a question which has been the subject of multiplied and instructive discussion in our own day.

14. But to return to the subject of Nebulae, we may further say, with the most complete confidence, that whether or not nebulous matter be generally resolvable into s.h.i.+ning dots, it cannot possibly be true that its being, or not being so resolvable by our telescopes, depends merely upon its smaller or greater distance from the observer. For, in the first place, that there is matter, to the best a.s.sisted eye not distinguishable from nebulous matter, which is not so resolvable, is proved by several facts. The tails of Comets often resemble nebulae; so much so that there are several known nebulae, which are, by the less experienced explorers of the sky, perpetually mistaken for comets, till they are proved not to be so, by their having no cometary motion. Such is the nebula in Andromeda, which is visible to the naked eye.[2] But the tails and nebulous appendages of comets, though they alter their appearance very greatly, according to the power of the telescope with which they are examined, have never been resolved into stars, or any kind of dots; and seem, by all investigations, to be sheets or cylinders or cones of luminous vapor, changing their form as they approach to or recede from the sun, and perhaps by the influence of other causes. Yet some of them approach very near the earth; all of them come within the limits of our system. Here, then, we have (probably, at least,) nebulous matter, which when brought close to the eye, compared with the stellar nebulae, still appears as nebulous.

15. Again, as another phenomenon, bearing upon the same question, we have the Zodiacal Light. This is a faint cone of light[3] which, at certain seasons, may be seen extending from the horizon obliquely upwards, and following the course of the ecliptic, or rather, of the sun's equator. It appears to be a lens-shaped envelope of the sun, extending beyond the orbits of Mercury and Venus, and nearly attaining that of the earth; and in Sir John Herschel's view, may be regarded as placing the sun in the list of nebulous stars. No one has ever thought that this nebulous appearance was resolvable into luminous points; but if it were, probably not even the most sanguine of speculators on the mult.i.tude of suns would call these points _suns_.

16. But indeed the nebulae themselves, and especially the most remote of the nebulae, or at least those which most especially require the most powerful telescopes, offer far more decisive proofs that their resolvability or non-resolvability,--their apparent const.i.tution as diffused and vaporous ma.s.ses,--does not depend upon their distance. A remarkable fact in the irregular, and in some of the regular nebulae[4]

is, that they consist of long patches and streaks, which stretch out in various directions, and of which the form[5] and extent vary according to the visual power which is applied to them. Many of the nebulae and especially of the fainter ones, entirely change their form with the optical power of the instrument by which they are scrutinized; so that, as seen in the mightier telescopes of modern times, the astronomer scarcely recognizes the figures in which the earlier observers have recorded what they saw in the same place. Parts which, before, were separate, are connected by thin bridges of light which are now detected; and where the nebulous s.p.a.ce appeared to be bounded, it sends off long tails of faint light into the surrounding s.p.a.ce. Now, no one can suppose that these newly-seen portions of the nebula are immensely further off than the other parts. However little we know of the nature of the object, we must suppose it to be one connected object, with all its parts, as to sense, at the same distance from us. Whether therefore it be resolvable or no, there must be some other reason, besides the difference of distance, why the brighter parts were seen, while the fainter parts were not. The obvious reason is, that the latter were not seen because they were thin films which required more light to see them.

We are led, irresistibly as it seems, to regard the whole ma.s.s of such a nebula, as an aggregation of vaporous rolls and streaks, a.s.suming such forms as thin volumes of smoke or vapor often a.s.sume in our atmosphere, and a.s.suming, like them, different shapes according to the quant.i.ty of light which comes to us from them. If, as soon as one of these new filaments or webs of a nebula comes into view, we should say, Here we have a new array of suns and of worlds, we should judge as fantastically, as any one who should combine the like imaginations with the varying cloud-work of a summer-sky. To suppose that all the varied streaks by which the patch of nebulous light shades off into the surrounding darkness, and which change their form and extent with every additional polish which we can give to a reflecting or refracting surface, disclose, with every new streak, new worlds, is a wanton indulgence of fancy, to which astronomy gives us no countenance.[6]

17. Undoubtedly all true astronomers, taught caution and temperance of thought by the discipline of their magnificent science, abstain from founding such a.s.sumptions upon their discoveries. They know how necessary it is to be upon their guard against the tricks which fancy plays with the senses; and if they see appearances of which they cannot interpret the meaning, they are content that they should have no meaning for them, till the due explanation comes. We have innumerable examples of this wise and cautious temper, in all periods of astronomy. One has occurred lately. Several careful astronomers, observing the stars by day, had been surprised to see globes of light glide across the field of view of their telescopes, often in rapid succession and in great numbers. They did not, as may be supposed, rush to the a.s.sumption that these globes were celestial bodies of a new kind, before unseen; and that from the peculiarity of their appearance and movement, they were probably inhabited by beings of a peculiar kind. They proceeded very differently; they altered the focus of their telescopes, looked with other gla.s.ses, made various changes and trials, and finally discovered that these globes of light were the winged seeds of certain plants which were wafted through the air; and which, illuminated by the sun, were made globular by being at distances unsuited to the focus of the telescope.[7]

18. But perhaps something more may be founded on the ramified and straggling form which belongs to many of the nebulae. Under the powers of Lord Rosse's telescope, a considerable number of them a.s.sume a shape consisting of several spiral films diverging from one centre, and growing broader and fainter as they diverge, so as to resemble a curled feather, or whirlpool of light.[8] This form, though generally deformed by irregularities, more or less, is traceable in so many of the nebulae, that we cannot easily divest ourselves of the persuasion that there is some general reason for such a form;--that something, in the mechanical causes which have produced the nebulae, has tended to give them this shape. Now, when this thought has occurred to us, since mathematicians have written a great deal concerning the mechanics of the universe, it is natural to ask, whether any of the problems which they have solved give a result like that thus presented to our eyes. Do such spirals as we here see, occur in any of the diagrams which ill.u.s.trate the possible motions of celestial bodies? And to this, a person acquainted with mathematical literature might reply, that in the second Book of Newton's _Principia_, in the part which has especial reference to the Vortices of Descartes, such spirals appear upon the page. They represent the path which a body would describe if, acted upon by a central force, it had to move in a medium of which the resistance was considerable;--considerable, that is, in comparison with the other forces which act; as for example, the forces which deflect the motion from a straight line. Indeed, that in such a case a body would describe a spiral, of which the general form would be more or less oval, is evident on a little consideration. And in this way, for instance, Encke's comet, which, if the resistance to its motion were insensible, would go on describing an ellipse about the sun, always returning upon the same path after every revolution; does really describe a path which, at each revolution, falls a little within the preceding revolution, and thus gradually converges to the centre. And if we suppose the comet to consist of a luminous ma.s.s, or a string of ma.s.ses, which should occupy a considerable arc of such an orbit, the orbit would be marked by a track of light, as an oval spiral. Or if such a comet were to separate into two portions, as we have, with our own eyes, recently seen Biela's comet do; or into a greater number; then these portions would be distributed along such a spiral. And if we suppose a large ma.s.s of cometic matter thus to move in a highly resisting medium, and to consist of patches of different densities, then some would move faster and some more slowly; but all, in spirals such as have been spoken of; and the general aspect produced would be, that of the spiral nebulae which I have endeavored to describe. The luminous matter would be more diffused in the outer and more condensed in the central parts, because to the centre of attraction all the spirals converge.