10. That when we attempt to extend our sympathies to the inhabitants of other planets and other worlds, and to regard them as living, like us, under a moral government, we are driven to suppose them to be, in all essential respects, human beings like ourselves, we have proof, in all the attempts which have been made, with whatever license of hypothesis and fancy, to present to us descriptions and representations of the inhabitants of other parts of the universe. Such representations, though purposely made as unlike human beings as the imagination of man can frame them, still are merely combinations, slightly varied, of the elements of human being; and thus show us that not only our reason, but even our imagination, cannot conceive creatures subjected to the same government to which man is subjected, without conceiving them as being men of one kind or other. A mere animal life, with no interest but animal enjoyment, we may conceive as a.s.suming forms different from those which appear in existing animal races; though even here, there are, as we shall hereafter attempt to show, certain general principles which run through all animal life. But when in addition to mere animal impulses, we a.s.sume or suppose moral and intellectual interests, we conceive them as the moral and intellectual interests of man. Truth and falsehood, right and wrong, law and transgression, happiness and misery, reward and punishment, are the necessary elements of all that can interest us--of all that we can call _Government_. To transfer these to Jupiter or to Sirius, is merely to imagine those bodies to be a sort of island of Formosa, or new Atlantis, or Utopia, or Platonic Polity, or something of the like kind. The boldest and most resolute attempts to devise some life different from human life, have not produced anything more different than romance-writers and political theorists have devised _as_ a form of human life. And this being so, there is no more wisdom or philosophy in believing such a.s.semblages of beings to exist in Jupiter or Sirius, without evidence, than in believing them to exist in the island of Formosa, with the like absence of evidence.

11. Any examination of what has been written on this subject would show that, in speculating about moral and intellectual beings in other regions of the universe, we merely make them to be men in another place.

With regard to the plants and animals of other planets, fancy has freer play; but man cannot conceive any moral creature who is not man. Thus Fontenelle, in his _Dialogues on the Plurality of Worlds_, makes the inhabitants of Venus possess, in an exaggerated degree, the characteristics of the men of the warm climates of the earth. They are like the Moors of Grenada; or rather, the Moors of Grenada would be to them as cold as Greenlanders and Laplanders to us. And the inhabitants of Mercury have so much vivacity, that they would pa.s.s with us for insane. "Enfin c'est dans Mercure que sont les Pet.i.tes-Maisons de l'Univers." The inhabitants of Jupiter and Saturn are immensely slow and phlegmatic. And though he and other writers attempt to make these inhabitants of remote regions in some respects superior to man, telling us that instead of only five senses, they may have six, or ten, or a hundred, still these are mere words which convey no meaning; and the great astronomer Bessel had reason to say, that those who imagined inhabitants in the Moon and Planets, supposed them, in spite of all their protestations, as like to men as one egg to another.[1]

12. But there is one step more, which we still have to make, in order to bring out this difficulty in its full force. As we have said, the moral law has been, to a certain extent, established, developed, and enforced among men. But, as I have also said, looking carefully at the law, and at the degree of man's obedience to it, and at the operation of the sanctions by which it is supported, we cannot help seeing, that man's knowledge of the law is imperfect, his conviction of its authority feeble, his transgressions habitual, their punishment and consequences obscure. When, therefore, we regard G.o.d, as the Lawgiver and Judge of man, it will not appear strange to us, that he should have taken some mode of promulgating his Law, and announcing his Judgments, in addition to that ordinary operation of the faculties of man, of which we have spoken. Revealed Religion teaches us that he has done so: that from the first placing of the race of man upon the earth, it was his purpose to do so: that by his dealing with the race of man in the earlier times, and at various intervals, he made preparation for the mission of a special Messenger, whom, in the fulness of time, he sent upon the earth in the form of a man; and who both taught men the Law of G.o.d in a purer and clearer form than any in which it had yet been given; and revealed His purpose, of rewards for obedience, and punishments for disobedience, to be executed in a state of being to which this human life is only an introduction; and established the means by which the spirit of man, when alienated from G.o.d by transgression, may be again reconciled to Him. The arrival of this especial Messenger of Holiness, Judgment, and Redemption, forms the great event in the history of the earth, considered in a religious view, as the abode of G.o.d's servants. It was attended with the sufferings and cruel death of the Divine Messenger thus sent; was preceded by prophetic announcements of his coming; and the history of the world, for the two thousand years that have since elapsed, has been in a great measure occupied with the consequences of that advent. Such a proceeding shows, of course, that G.o.d has an especial care for the race of man. The earth, thus selected as the theatre of such a scheme of Teaching and of Redemption, cannot, in the eyes of any one who accepts this Christian faith, be regarded as being on a level with any other domiciles. It is the Stage of the great Drama of G.o.d's Mercy and Man's Salvation; the Sanctuary of the Universe; the Holy Land of Creation; the Royal Abode, for a time at least, of the Eternal King. This being the character which has thus been conferred upon it, how can we a.s.sent to the a.s.sertions of Astronomers, when they tell us that it is only one among millions of similar habitations, not distinguishable from them, except that it is smaller than most of them that we can measure; confused and rude in its materials like them? Or if we believe the Astronomers, will not such a belief lead us to doubt the truth of the great scheme of Christianity, which thus makes the earth the scene of a special dispensation.

13. This is the form in which Chalmers has taken up the argument. This is the difficulty which he proposes to solve; or rather, (such being as I have said the mode in which he presents the subject,) the objection which he proposes to refute. It is the bearing of the Astronomical discoveries of modern times, not upon the doctrines of Natural Religion, but upon the scheme of Christianity, which he discusses. And the question which he supposes his opponent to propound, as an objection to the Christian scheme, is:--How is it consistent with the dignity, the impartiality, the comprehensiveness, the a.n.a.logy of G.o.d's proceedings, that he should make so special and pre-eminent a provision for the salvation of the inhabitants of this Earth, where there are such myriads of other worlds, all of which may require the like provision, and all of which have an equal claim to their Creator's care?

14. The answer which Chalmers gives to this objection, is one drawn, in the first instance, from our ignorance. He urges that, when the objector a.s.serts that other worlds may have the like need with our own, of a special provision for the rescue of their inhabitants from the consequences of the transgression of G.o.d's laws, he is really making an a.s.sertion without the slightest foundation. Not only does Science not give us any information on such subjects, but the whole spirit of the scientific procedure, which has led to the knowledge which we possess, concerning other planets and other systems, is utterly opposed to our making such a.s.sumptions, respecting other worlds, as the objection involves. Modern Science, in proportion as she is confident when she has good grounds of proof, however strange may be the doctrines proved, is not only diffident, but is utterly silent, and abstains even from guessing, when she has no grounds of proof. Chalmers takes Newton's reasoning, as offering a special example of this mixed temper, of courage in following the evidence, and temperance in not advancing when there is no evidence. He puts, in opposition to this, the example of the true philosophical temper,--a supposed rash theorist, who should make unwarranted suppositions and a.s.sumptions, concerning matters to which our scientific evidence does not reach;--the animals and plants, for instance, which are to be found in the planet Jupiter. No one, he says, would more utterly reject and condemn such speculations than Newton, who first rightly explained the motion of Jupiter and of his attendant satellites, about which Science _can_ p.r.o.nounce her truths. And thus, nothing can be more opposite to the real spirit of modern science, and astronomy in particular, than arguments, such as we have stated, professing to be drawn from science and from astronomy. Since we know nothing about the inhabitants of Jupiter, true science requires that we say and suppose nothing about them; still more requires that we should not, on the ground of a.s.sumptions made with regard to them, and other supposed groups of living creatures, reject a belief, founded on direct and positive proofs, such as is the belief in the truths of Natural and of Revealed Religion.

15. To this argument of Chalmers, we may not only give our full a.s.sent, but we may venture to suggest, in accordance with what we have already said, that the argument, when so put, is not stated in all its legitimate force. The a.s.sertion that the inhabitants of Jupiter have the same need as we have, of a special dispensation for their preservation from moral ruin, is not only as merely arbitrary an a.s.sumption, as any a.s.sertion could be, founded on a supposed knowledge of an a.n.a.logy between the botany of Jupiter, and the botany of the earth; but it is a great deal more so. There may be circ.u.mstances which may afford some reason to believe that something of the nature of vegetables grows on the surface of Jupiter; for instance, if we find that he is a solid globe surrounded by an atmosphere, vapor, clouds, showers. But, as we have already said, there is an immeasurable distance between the existence of unprogressive tribes of organized creatures, plants, or even animals, and the existence of a progressive creature, which can pa.s.s through the conditions of receiving, discerning, disobeying, and obeying a moral law; which can be estranged from G.o.d, and then reconciled to him. To a.s.sume, without further proof, that there are, in Jupiter, creatures of such a nature that these descriptions apply to them, is a far bolder and more unphilosophical a.s.sumption, than any that the objector could make concerning the botany of Jupiter; and therefore, the objection thus supposed to be drawn from our supposed knowledge, is very properly answered by an appeal to our really utter ignorance, as to the points on which the argument rests.

16. This appeal to our ignorance is the main feature in Chalmers'

reasonings, so far as the argument on the one side or the other has reference to science. Chalmers, indeed, pursues the argument into other fields of speculation. He urges, that not only we have no right to a.s.sume that other worlds require a redemption of the same kind as that provided for man, but that the very reverse maybe the case. Man maybe the only transgressor; and this, the only world that needed so great a provision for its salvation. We read in Scripture, expressions which imply that other beings, besides man, take an interest in the salvation of man. May not this be true of the inhabitants of other worlds, if such inhabitants there be? These speculations he pursues to a considerable length, with great richness of imagination, and great eloquence. But the suppositions on which they proceed are too loosely connected with the results of science, to make it safe for us to dwell upon them here.

17. I conceive, as I have said, that the argument with which Chalmers thus deals admits of answers, also drawn from modern science, which to many persons will seem more complete than that which is thus drawn from our ignorance. But before I proceed to bring forward these answers, which will require several steps of explanation, I have one or two remarks still to make.

18. Undoubtedly they who believe firmly both that the earth has been the scene of a Divine Plan for the benefit of man, and also that other bodies in the universe are inhabited by creatures who may have an interest in such a Plan, are naturally led to conjectures and imaginations as to the nature and extent of that interest. The religious poet, in his Night Thoughts, interrogates the inhabitants of a distant star, whether their race too has, in its history, events resembling the fall of man, and the redemption of man.

Enjoy your happy realms their golden age?

And had your Eden an abstemious Eve?

Or, if your mother fell are you redeemed?

And if redeemed, is your Redeemer scorned?

And such imaginations may be readily allowed to the preacher or the poet, to be employed in order to impress upon man the conviction of his privileges, his thanklessness, his inconsistency, and the like. But every form in which such reflections can be put shows how intimately they depend upon the nature and history of man. And when such reflections are made the source of difficulty or objection in the way of religious thought, and when these difficulties and objections are represented as derived from astronomical discoveries, it cannot be superfluous to inquire whether astronomy has really discovered any ground for such objections. To some persons it may be more grateful to remedy one a.s.sumption by another: the a.s.sumption of moral agents in other worlds, by the a.s.sumption of some operation of the Divine Plan in other worlds. But since many persons find great difficulty in conceiving such an operation of the Divine Plan in a satisfactory way; and many persons also think that to make such unauthorized and fanciful a.s.sumptions with regard to the Divine Plans for the government of G.o.d's creatures is a violation of the humility, submission of mind, and spirit of reverence which religion requires; it may be useful if we can show that such a.s.sumptions, with regard to the Divine Plans, are called forth by a.s.sumptions equally gratuitous on the other side: that Astronomy no more reveals to us extra-terrestrial moral agents, than Religion reveals to us extra-terrestrial Plans of Divine government. Chalmers has spoken of the _rashness_ of making a.s.sumptions on such subjects without proof; leaving it however, to be supposed, that though astronomy does not supply proof of intelligent inhabitants of other parts of the universe, she yet does offer strong a.n.a.logies in favor of such an opinion. But such a procedure is more than rash: when astronomical doctrines are presented in the form in which they have been already laid before the reader, which is the ordinary and popular mode of apprehending them, the a.n.a.logies in favor of "other worlds," are (to say the least) greatly exaggerated. And by taking into account what astronomy really teaches us, and what we learn also from other sciences, I shall attempt to reduce such "a.n.a.logies" to their true value.

14. The privileges of man, which make the difficulty in a.s.signing him his place in the vast scheme of the Universe, we have described as consisting in his being an _intellectual_, _moral_, and _religious_ creature. Perhaps the privileges implied in the last term, and their place in our argument, may justify a word more of explanation. Religion teaches us that there is opened to man, not only a prospect of a life in the presence of G.o.d, after this mortal life, but also the possibility and the duty of spending this life as in the presence of G.o.d. This is properly the highest result and manifestation of the effect of Religion upon man. Precisely because it is this, it is difficult to speak of this effect without seeming to use the language of enthusiasm; and yet again, precisely because it is so, our argument would be incomplete without a reference to it. There is for man, a possibility and a duty of bringing his thoughts, purposes, and affections more and more into continual unison with the will of G.o.d. This, even Natural Religion taught men, was the highest point at which man could aim; and Revealed Religion has still more clearly enjoined the duty of aiming at such a condition. The means of a progress towards such a state belong to the Religion of the heart and mind. They include a constant purification and elevation of the thoughts, affections, and will, wrought by habits of religious reflection and meditation, of prayer and grat.i.tude to G.o.d.

Without entering into further explanation, all religious persons will agree that such a progress is, under happy influences, possible for man, and is the highest condition to which he can attain in this life.

Whatever names may have been applied at different times to the steps of such a progress;--the cultivation of the divine nature in us; resignation; devotion; holiness; union with G.o.d; living in G.o.d, and with G.o.d in us;--religious persons will not doubt that there is a reality of internal state corresponding to these expressions; and that, to be capable of elevation into the condition which these expressions indicate, is one of the especial privileges of man. Man's soul, considered especially as the subject of G.o.d's government, is often called his _Spirit_; and that man is capable of such conformity to the will of G.o.d, and approximation to Him, is sometimes expressed by speaking of him as a _spiritual creature_. And though the privilege of being, or of being capable of becoming, in this sense, a spiritual creature, is a part of man's religious privileges; we may sometimes be allowed to use this additional expression, in order to remind the reader, how great those religious privileges are, and how close is the relation between man and G.o.d, which they imply.

15. We have given a view of the peculiar character of man's condition, which seem to claim for him a nature and place unique and incapable of repet.i.tion, in the scheme of the universe; and to this view astronomy, exhibiting to us the habitation of man as only one among many similar abodes, offers an objection. We are, therefore, now called upon, I conceive, to proceed to exhibit the answer which a somewhat different view of modern science suggests to this difficulty or objection.

For this purpose, we must begin by regarding the Earth in another point of view, different from that hitherto considered by us.

FOOTNOTES:

[1] Populare Vorlesungen uber Wissenschaftliche Gegenstande, p. 31.

CHAPTER V.

GEOLOGY.

1. Man, as I trust has been made apparent to the consciousness and conviction of the reader, is an intelligent, moral, religious, and spiritual creature; and we have to discuss the difficulty, or perplexity, or objection, which arises in our minds, when we consider such a creature as occupying an habitation, which is but one among many globes apparently equally fitted to be the dwelling-places of living things--a mere speck in the immensity of creation--an atom among such a vast array of material structures--a world, as we needs must deem it, among millions of other objects which appear to have an equal claim to be regarded as worlds.

2. The difficulty appears to be great, either way. Can the earth alone be the theatre of such intelligent, moral, religious, and spiritual action? On the other hand, can we conceive such action to go on in the other bodies of the universe? If we take the latter alternative, we must people other planets and other systems with men such as we are, even as to their history. For the intellectual and moral condition of man implies a _history_ of the species; and the view of man's condition which religion presents, not only involves a scheme of which the history of the human race is a part, but also a.s.serts a peculiar reference had, in the provisions of G.o.d, to the nature of man; and even a peculiar relation and connection between the human and the divine nature. To extend such suppositions to other worlds would be a proceeding so arbitrary and fanciful, that we are led to consider whether the alternative supposition may not be more admissible. The alternative supposition is, that man is, in an especial and eminent manner, the object of G.o.d's care; that his place in the creation is, not that he merely occupies one among millions of similar domiciles provided in boundless profusion by the Creator of the Universe, but that he is the servant, subject, and child of G.o.d, in a way unique and peculiar; that his being a spiritual creature, (including his other attributes in the highest for the sake of brevity,) makes him belong to a spiritual world, which is not to be judged of merely by a.n.a.logies belonging to the material universe.

3. Between these two difficulties the choice is embarra.s.sing, and the decision must be unsatisfactory, except we can find some further ground of judgment. But perhaps this is not hopeless. We have hitherto referred to the evidence and a.n.a.logies supplied by one science, namely, astronomy. But there are other sciences which give us information concerning the nature and history of the earth. From some of these, perhaps, we may obtain some knowledge of the place of the earth in the scheme of creation--how far it is, in its present condition, a thing unique, or only one thing among many like it. Any science which supplies us with evidence or information on this head, will give us aid in forming a judgment upon the question under our consideration. To such sciences, then, we will turn our attention.

One science has employed itself in investigating the nature and history of the earth by an examination of the materials of which it is composed; namely, Geology. Let us call to mind some of the results at which this science has arrived.

4. A very little attention to what is going on among the materials of which the earth's surface is composed, suffices to show us that there are causes of change constantly and effectually at work. The earth's surface is composed of land and water, hills and valleys, rocks and rivers. But these features undergo change, and produce change in each other. The mountain-rivers cut deeper and deeper into the ravines in which they run; they break up the rocks over which they rush, use the fragments as implements of further destruction, pile them up in sloping mounds where the streams issue from the mountains, spread them over the plains, fill up lakes with sediment, push into the sea great deltas. The sea batters the cliffs and eats away the land, and again, forms banks and islands where there had been deep water. Volcanoes pour out streams of lava, which destroy the vegetation over which they flow, and which again, after a series of years, are themselves clothed with vegetation.

Earthquakes throw down tracts of land beneath the sea, and elevate other tracts from the bottom of the ocean. These agencies are everywhere manifest; and though at a given moment, at a given spot, their effect may seem to us almost imperceptible, too insignificant to be taken account of, yet in a long course of years almost every place has undergone considerable changes. Rivers have altered their courses, lakes have become plains, coasts have been swept away or have become inland districts, rich valleys have been ravaged by watery or fiery deluges, the country has in some way or other a.s.sumed a new face. The present aspect of the earth is in some degree different from what it was a few thousand years ago.

5. But yet, in truth, the changes of which we thus speak have not been very considerable. The forms of countries, the lines of coasts, the ranges of mountains, the groups of valleys, the courses of rivers, are much the same now as they were in ancient times. The face of the earth, since man has had any knowledge of it, may have undergone some change, but the changeable has borne a small proportion to the permanent.

Changes have taken place, and are taking place, but they do not take place rapidly. The ancient earth and the modern earth are, in all their main physical features, identical; and we must go backwards through a considerably larger interval than that which carries us back to what we usually term _antiquity_, before we are led, by the operation of causes now at work, to an aspect of the earth's surface very different from that which it now presents.

6. For instance, rivers do, no doubt, more or less alter, in the course of years, by natural causes. The Rhine, the Rhone, the Po, the Danube, have, certainly, during the last four thousand years, silted up their beds in level places, expanded the deltas at their mouths, changed the channels by which they enter the sea; and very probably, in their upper parts, altered the forms of their waterfalls and of their shingle beds.

Yet even if we were thus to go backwards ten thousand, or twenty, or thirty thousand years, (setting aside great and violent causes of change, as earthquakes, volcanic eruptions, and the like,) the general form and course of these rivers, and of the ranges of mountains in which they flow, would not be different from what it is now. And the same may be said of coasts and islands, seas and bays. The present geography of the earth may be, and from all the evidence which we have, must be, very ancient, according to any measures of antiquity which can apply to human affairs.

7. But yet the further examination of the materials of the earth carries us to a view beyond this. Though the general forms of the land and the waters of continents and seas, were, several thousand years ago, much the same as they now are; yet it was not always so. We have clear evidence that large tracts which are now dry ground, were formerly the bed of the ocean; and these, not tracts of the sh.o.r.e, where the varying warfare of sea and land is still going on, but the very central parts of great continents; the Alps, the Pyrenees, the Himalayas. For not only are the rocks of which these great mountain-chains consist, of such structure that they appear to have been formed as layers of sediment at the bottom of water; but also, these layers contain vast acc.u.mulations of sh.e.l.ls, or impressions of sh.e.l.ls, and other remains of marine animals. And these appearances are not few, limited, or partial. The existence of such marine remains, in the solid substance of continents and mountains, is a general, predominant, and almost universal fact, in every part of the earth. Nor is any other way of accounting for this fact admissible, than that those materials really have, at some time, formed bottoms of seas. The various other conjectures and hypotheses, which were put forward on this subject, when the amount, extent, multiplicity, and coherence of the phenomena were not yet ascertained, and when their natural history was not yet studied, cannot now be considered as worthy of the smallest regard. That many of our highest hills are formed of materials raised from the depths of ocean, is a proposition which cannot be doubted, by any one, who fairly examines the evidence which nature offers.

8. If we take this proposition only, we cannot immediately connect it with our knowledge respecting the surface of the earth in its present form. We learn that what is now land, has been sea; and we may suppose (since it is natural to a.s.sume that the bulk of the sea has not much changed) that what is now sea was formerly land. But, except we can learn something of the manner in which this change took place, we cannot make any use of our knowledge. Was the change sudden, or gradual; abrupt, or successive; brief, or long-continuing?

9. To these questions, the further study of the facts enables us to return answers with great confidence. The change or changes which produced the effects of which we have spoken--the conversion of the bottom of the ocean into the centre of our greatest continents and highest mountains,--were undoubtedly gradual, successive, and long continued. We must state very briefly the grounds on which we make this a.s.sertion.

10. The ma.s.ses which form our mountain-chains, offer evidence, as I have said, that they were deposited as sediment at the bottom of a sea, and then hardened. They consist of successive layers of such sediment, making up the whole ma.s.s of the mountain. These layers are, of course, to a certain extent, a measure of the time during which the deposition of sediment took place. The thicker the ma.s.s of sediment, the more numerous and varied its beds, and the longer period must we suppose to have been requisite for its formation. Without making any attempt at accurate or definite estimation, which would be to no purpose, it is plain that a ma.s.s of sedimentary strata five thousand or ten thousand feet thick, must have required, for its deposit, a long course of years, or rather, a long course of ages.

11. But again: on further examination it is found, that we have not merely one series of sedimentary deposits, thus forming our mountains.

There are a number of different series of such layers or strata, to be found in different ranges of hills, and in the same range, one series resting upon another. These different series of strata are distinguishable from one another by their general structure and appearance, besides more intimate characters, of which we shall shortly have to speak. Each such series appears to have a certain consistency of structure within itself; the layers of which it is composed being more or less parallel, but the successive series are not thus always parallel, the lower ones being often highly inclined and irregular, while the upper ones are more level and continuous: as if the lower strata had been broken up and thrown into disorder, and then a new series of strata had been deposited horizontally on their fragments. But in whatever way these different sedimentary series succeeded each other, each series must have required, as we have seen, a long period for its formation; and to estimate the length of the interval between the two series, we have, at the present stage of our exposition, no evidence.

12. But the mechanical structure of the strata, the result, as it seems, of aqueous sedimentary deposit, is not the only, nor the most important evidence, with regard to the length of time occupied by the formation of the rocky layers which now compose our mountains. As we have said, they contain sh.e.l.ls, and other remains of creatures which live in the sea.

These they contain, not in small numbers, scattered and detached, but in vast abundance, as they are found in those parts of the ocean which is most alive with them. There are the remains of oysters and other sh.e.l.l-fish in layers, as they live at present in the seas near our sh.o.r.es; of corals, in vast patches and beds, as they now occur in the waters of the Pacific; of shoals of fishes, of many different kinds, in immense abundance. Each of these beds of sh.e.l.ls, of corals, and of fishes, must have required many years, perhaps many centuries, for the growth of the successive individuals and successive generations of which it consists: as long a time, perhaps, as the present inhabitants of the sea have lived therein: or many times longer, if there have been many such successive changes. And thus, while the present condition of the earth extends backwards to a period of vast but unknown antiquity; we have, offered to our notice, the evidence of a series of other periods, each of which, so far as we can judge, may have been as long or longer than that during which the dry land has had its present form.

13. But the most remarkable feature in the evidence is yet to come. We have spoken in general of the oysters, and corals, and fishes, which occur in the strata of our hills; as if they were creatures of the same kinds which we now designate by those names. But a more exact examination of these remains of organized beings, shows that this is not so. The tribes of animals which are found petrified in our rocks are almost all different, so far as our best natural historians can determine, from those which now live in our existing seas. They are different species; different genera. The creatures which we find thus embedded in our mountains, are not only dead as individuals, but extinct as species. They belonged, not only to a terrestrial period, but to an animal creation, which is now past away. The earth is, it seems, a domicile which has outlasted more than one race of tenants.

14. It may seem rash and presumptuous in the natural historian to p.r.o.nounce thus peremptorily that certain forms of life are nowhere to be found at present, even in the unfathomable and inaccessible depths of the ocean. But even if this were so, the proposition that the earth has changed its inhabitants, since the rocks were formed, of which our hills consist, does not depend for its proof on this a.s.sumption. For in the organic bodies which our strata contain, we find remains, not only of marine animals, but of animals which inhabit the fresh waters, and the land, and of plants. And the examination of such remains having been pursued with great zeal, and with all the aids which natural history can supply, the result has been, the proofs of a vast series of different tribes of animals and plants, which have successively occupied the earth and the seas; and of which the number, variety, multiplicity, and strangeness, exceed, by far, everything which could have been previously imagined. Thus Cuvier found, in the limestone strata on which Paris stands, animals of the most curious forms, combining in the most wonderful manner the qualities of different species of existing quadrupeds. In another series of strata, the Lias, which runs as a band across England from N. E. to S. W., we have the remains of lizards, or lacertine animals, different from those which now exist, of immense size and of extraordinary structure, some approaching to the form of fishes (_ichthyosaurus_); others, with the neck of a serpent; others with wings, like the fabled forms of dragons. Then beyond these, that is, anterior to them in the series of time, we have the immense collection of fossil plants, which occur in the Coal Strata; the sh.e.l.ls and corals of the Mountain Limestone; the peculiar fishes, different altogether from existing fishes, of the Old Red Sandstone; and though, as we descend lower and lower, the traces of organic life appear to be more rare and more limited in kind, yet still we have, beneath these, in slates and in beds of limestone, many fossil remains, still differing from those which occur in the higher, and therefore, newer strata.

15. We have no intention of inst.i.tuting any definite calculation with regard to the periods of time which this succession of forms of organic life may have occupied. This, indeed, the boldest geological speculators have not ventured to do. But the scientific discoveries thus made, have a bearing upon the a.n.a.logies of creation, quite as important as the discoveries of astronomy. And therefore we may state briefly some of the divisions of the series of terrestrial strata which have suggested themselves to geological inquirers. At the outset of such speculations, it was conceived that the lower rocks, composed of granite, slate, and the like, had existed before the earth was peopled with living things; and that these, being broken up into inclined positions, there were deposited upon them, as the sediment of superinc.u.mbent waters, strata more horizontal, containing organic remains. The former were then called _Primitive_ or _Primary_, the latter, _Secondary_ rocks. But it was soon found that this was too sweeping and peremptory a division. Rocks which had been cla.s.sed as Primary, were found to contain traces of life; and hence, an intermediate cla.s.s of _Transition_ strata was spoken of. But this too was soon seen to be too narrow a scheme of arrangement, to take in the rapidly-acc.u.mulating ma.s.s of facts, organic and others, which the geological record of the earth's history disclosed. It appeared that among the fossil-bearing strata there might be discerned a long series of Formations: the term _Formation_ being used to imply a collection of successive strata, which, taking into account all the evidence, of materials, position, relations, and organic remains, appears to have been deposited during some one epoch or period; so as to form a natural group, chronologically and physiologically distinct from the others. In this way it appeared that, taking as the highest part of the Secondary series, the beds of chalk, which, marked by characteristic fossils, run through great tracts of Europe, with other beds, of sand and clay, which generally accompany these; there was, below this _Cretaceous Formation_, an _Oolitic Formation_, still more largely diffused, and still more abundant in its peculiar organic remains. Below this, we have, in England, the _New Red Sandstone Formation_, which, in other countries, is accompanied by beds abundant in fossils, as the _Muschelkalk_ of Germany. Below this again we have the _Coal Formation_, and the _Mountain Limestone_, with their peculiar fossils. Below these, we have the Old Red Sandstone or Devonian System, with its peculiar fishes and other fossils. Beneath these, occur still numerous series of distinguishable strata; which have been arranged by Sir Roderick Murchison as the members of the _Silurian_ formation; the researches by which it was established having been carried on, in the first place, in South Wales, the ancient country of the Silures. Including the lower part of this formation, and descending still lower in order, is the _Cambrian_ formation of Professor Sedgwick. And since the races of organic beings, as we thus descend through successive strata, seem to be fewer and fewer in their general types, till at last they disappear; these lower members of the geological series have been termed, according to their succession, _Palaeozoic_, _Protozoic_, and _Hypozoic_ or _Azoic_. The general impression on the minds of geologists has been, that, as we descend in this long staircase of natural steps, we are brought in view of a state of the earth in which life was scantily manifested, so as to appear to be near its earliest stages.

16. Each of these formations is of great thickness. Several of the members of each formation are hundreds, many of them thousands of feet thick. Taken altogether, they afford an astounding record of the time during which they must have been acc.u.mulating, and during which these successive groups of animals must have been brought into being, lived, and continued their kinds.

17. We must add, that over the Secondary strata there are found, in patches, generally of more limited extent, another, and of course, newer ma.s.s of strata, which have been termed _Tertiary Formations_. Of these, the strata, near and under Paris, lying in a hollow of the subjacent strata, and hence termed the _Paris Basin_, attracted prominent notice in the first place. And these are found to contain an immense quant.i.ty of remains of animals, which, being well preserved, and being subjected to a careful and scientific scrutiny by the great naturalist George Cuvier, had an eminent share in establishing in the minds of Geologists the belief of the extinct character of fossil species, and of the possibility of reconstructing, from such remains, the animals, different from those which now live, which had formerly tenanted the earth.

18. We have, in this enumeration, a series of groups of strata, each of which, speaking in a general way, has its own population of animals and plants, and is separated, by the peculiarities of these, from the groups below and above it. Each group may, in a general manner, be considered as a separate creation of animal and vegetable forms--creatures which have lived and died, as the races now existing upon the earth live and die; and of which the living existence may, and according to all appearance must, have occupied ages, and series of ages, such as have been occupied by the present living generations of the earth. This series of creations, or of successive periods of life, is, no doubt, a very striking and startling fact, very different from anything which the imagination of man, in previous stages of investigation of the earth's condition, had conceived; but still, is established by evidence so complete, drawn from an examination and knowledge of the structures of living things so exact and careful, as to leave no doubt whatever of the reality of the fact, on the minds of those who have attended to the evidence; founded, as it is, upon the a.n.a.logies, offices, anatomy, and combinations of organic structures. The progress of human knowledge on this subject has been carried on and established by the same alternations of bold conjectures and felicitous confirmations of them,--of minute researches and large generalizations,--which have given reality and solidity to the other most certain portions of human knowledge. That the strata of the earth, as we descend from the highest to the lowest, are distinguished in general by characteristic or organic fossils, and that these forms of organization are different from those which now live on the earth, are truths as clearly and indisputably established in the minds of those who have the requisite knowledge of geology and natural history, as that the planets revolve round the sun, and satellites round the planets. That these epochs of creation are something quite different from anything which we now see taking place on the earth, no more disturbs the belief of those facts, which scientific explorers entertain, than the seemingly obvious difference between the nebulae which are regarded as yet unformed planetary systems, and the solar system to which our earth belongs, disturbs the belief of astronomers, that such nebulae, as well as our system, really exist.

Indeed we may say, as we shall hereafter see, that the fact of our earth having pa.s.sed through the series of periods of organic life which geologists recognize, is, hitherto, incomparably better established, than the fact that the nebulae, or any of them, are pa.s.sing through a series of changes, such as may lead to a system like ours; as some eminent astronomers in modern times have held. In this respect, the history of the world, and its place in the universe, are far more clearly learnt from geology than from astronomy.

19. But with regard to this series of Organic _Creations_, if, for the sake of brevity, we may call them so; we may naturally ask, in what manner, by what agencies, at what intervals, they succeeded each other on the earth? Now, do the researches of geologists give us any information on these points, which may be brought to bear upon our present speculations? If we ask these questions, we receive, from different cla.s.ses of geologists, different answers. A little while ago, most geologists held, probably the greater number still hold, that the transitions from one of these periods of organic life to another, were accompanied generally by seasons of violent disruption and mutation of the surface of the earth, exceeding anything which has taken place since the surface a.s.sumed its present general form; in the same proportion as the changes of its organic population go beyond any such changes which we can discern to be at present in operation. And there were found to be changes of other kinds, which seemed to show that these epochs of organic transition had also been epochs of mechanical violence, upon a vast and wonderful scale. It appeared that, at some of these epochs at least, the strata previously deposited, as if in comparative tranquillity, had been broken, thrust up from below, or drawn or cast downwards; so that strata which must at first have been nearly level, were thrown into positions highly inclined, fractured, set on edge, contorted, even inverted. Over the broken edges of these strata, thus disturbed and fractured, were found vast acc.u.mulations of the fragments which such rude treatment might naturally produce; these fragmentary ruins being spread in beds comparatively level, over the bristling edges of the subjacent rocks, as if deposited in the fluid which had overwhelmed the previous structure; and with few or no traces of life appearing in this ma.s.s of ruins; while, in the strata which lay over them, and which appeared to have been the result of quieter times, new forms of organic life made their appearance in vast abundance. Such is, for example, the relation of the coal strata in a great part of England; broken into innumerable basins, ridges, valleys, strips, and shreds, lying in all positions; and then filled into a sort of level, by the conglomerate of the magnesian limestone, and the superinc.u.mbent red sandstone and oolites. In other cases it appeared as if there were the means of tracing, in these dislocations, the agency of igneous stony matter, which had been injected from below, so as to form mountain-chains, or the cores of such; and in which the period of the convulsion could be traced, by the strata to which the disturbance extended; _those_ strata being supposed to have been deposited before the eruption, which were thrust upwards by it into highly-inclined positions; while those strata which, though near to these scenes of mechanical violence, were still comparatively horizontal, as they had been originally deposited, were naturally inferred to have been formed in the waters, after the catastrophe had pa.s.sed away. By such reasonings as these, M. Elie de Beaumont has conceived that he can ascertain the relative ages (according to the vast and loose measurements of age which belong to this subject) of the princ.i.p.al ranges of mountains of the earth's surface.

20. Such estimations of age can, indeed, as we have intimated, be only of the widest and loosest kind; yet they all concur in a.s.signing very great and gigantic periods of time, as having been occupied by the events which have formed the earth's strata, and brought them into their present position. For not only must there have been long ages employed, as we have said, while the successive generations of each group of animals lived, and died, and were entombed in the abraded fragments of the then existing earth; but the other operations which intervened between these apparently more tranquil processes, must also have occupied, it would seem, long ages at each interval. The dislocation, disruption, and contortion of the vast ma.s.ses of previously existing mountains, by which their framework was broken up, and its ruins covered with beds of its own rubbish, many thousand feet thick, and gradually becoming less coa.r.s.e and smoother, as the higher beds were deposited upon the lower, could hardly take place, it would seem, except in hundreds and thousands of years. And then again, all these processes of deposition, thus arranging loose ma.s.ses of material into level beds, must have taken place in the bottom of deep oceans; and the beds of these oceans must have been elevated into the position of mountain ridges which they now occupy, by some mighty operation of nature, which must have been comparatively tranquil, since it has not much disturbed those more level beds; and which, therefore, must have been comparatively long continued. If we accept, as so many eminent geologists have done, this evidence of a vast series of successive periods of alternate violence and repose, we must a.s.sign to each such period a duration which cannot but be immense, compared with the periods of time with which we are commonly conversant. In the periods of comparative quiet, such as now exist on the earth's surface, and such as seem to be alone consistent with continued life and successive generation, deposits at the bottom of lakes and seas take place, it would seem, only at the rate of a few feet in a year, or perhaps, in a century. When, therefore, we find strata, bearing evidence of such a mode of deposit, and piled up to the amount of thousands and tens of thousands of feet, we are naturally led to regard them as the production of myriads of years; and to add new myriads, as often as, in the prosecution of geological research, we are brought to new ma.s.ses of strata of the like kind; and again, to interpolate new periods of the same order, to allow for the transition from one such group to another.

21. Nor is there anything which need startle us, in the necessity of a.s.suming such vast intervals of time, when we have once brought ourselves to deal with the question of the antiquity of the earth upon scientific evidence alone. For if geology thus carries us far backwards through thousands, it may be, millions of years, astronomy does not offer the smallest argument to check this regressive supposition. On the contrary, all the most subtle and profound investigations of astronomers have led them to the conviction, that the motions of the earth may have gone on, as they now go on, for an indefinite period of past time. There is no tendency to derangement in the mechanism of the solar system, so for as science has explored it. Minute inequalities in the movements exist, too small to produce any perceptible effect on the condition of the earth's surface; and even these inequalities, after growing up through long cycles of ages, to an amount barely capable of being detected by astronomical scrutiny, reach a maximum; and, diminishing by the same slow degrees by which they increased, correct themselves, and disappear. The solar system, and the earth as part of it, const.i.tute, so for as we can discover, a Perpetual Motion.

22. There is therefore nothing, in what we know of the Cosmical conditions of our globe, to contradict the Terrestrial evidence for its vast antiquity, as the seat of organic life. If for the sake of giving definiteness to our notions, we were to a.s.sume that the numbers which express the antiquity of these four Periods;--the Present organic condition of the earth; the Tertiary Period of geologists, which preceded that; the Secondary Period, which was anterior to that; and the Primary Period which preceded the Secondary; were on the same scale as the numbers which express these four magnitudes:--the magnitude of the Earth; that of the Solar System compared with the Earth; the distance of the nearest Fixed Stars compared with the solar system; and the distance of the most remote Nebulae compared with the nearest fixed stars; there is, in the evidence which geological science offers, nothing to contradict such an a.s.sumption.