To prove the original igneous fluidity of the globe, we might have adopted another course of argument. All will admit that the present temperature of the interior of the earth is far more elevated than that of the surrounding planetary spaces. The inevitable result is, from the known laws of heat, that its radiation into the celestial spaces is constantly going on, and consequently the earth’s temperature is being constantly lowered. Who can tell us now when this process of refrigeration commenced? If no one, then there must have been a time when the heat was great enough to fuse the whole globe. And the facts already stated confirm such an inference. For all the efforts hitherto made to show that the earth may be passing through regions of various temperatures, in its march around the centre of centres, amount to nothing more than dreamy conjecture.
In order to feel the force of the argument, sustained by so many facts in geology, just picture to yourselves this vast globe as a mass of liquid fire. From such a world every thing organic must have been excluded, and every thing combustible consumed, and only such combinations of matter have existed as incandescent heat could not decompose. Compare such a world with that now teeming with life, and beauty, and glory, which we inhabit; and say, must not the transition to its present condition have demanded the exercise of infinite power, infinite wisdom, and infinite benevolence? You can, indeed, conceive how a solid crust might have formed over the vast fiery ocean, by the simple radiation of heat; and then, too, by natural laws, might the vapors have been condensed into oceans and clouds, while volcanic force within might have lifted up our continents and mountains above the flood. But what a picture of desolation and ruin would such a world present, while unadorned with vegetation, and with no voice of life to break the stillness of universal death! Here is, then, the precise point where we need the interference of a Deity. Admit, if you please, that atheism, with its eternal matter and the laws of nature at command, might form a world without inhabitants. Who does not see, that to bestow organization, and life, and instinct, to say nothing of intellect, upon brute matter, is the loftiest prerogative of Jehovah? especially to fill so vast a world as ours with its teeming millions, exhibiting ten thousand diversities of size, form, and structure.
Let the atheist then exult in the belief of an eternal world. Geology shows him that it must have been without inhabitants; and that, therefore, the most wonderful part of the creation still remains to be accounted for; while physiology teaches that the interference of an infinite Deity can alone solve the enigma.
My second example from geology to disprove the notion of an eternal series of animals and plants on the globe, is derived from the history of organic remains. That history shows us clearly, that the earth, since its creation, has been the seat of several distinct economies of life, each occupying long periods, and successively passing away. During each of these periods, distinct groups of animals and plants have occupied the earth, the air, and the waters. Each successive group has been entirely distinct from that which preceded it, though each group was exactly adapted to the existing state of the climate and the food provided; so that, had the different groups changed places with one another, they must have perished, because their constitutions were adapted only to the state of things during the period in which they actually lived. A distinguished naturalist has recently declared that “he has discovered, in surveying the entire series of fossil animal remains, five great groups, so completely independent that no species whatever is found in more than one of them.”—Deshayes.
Including the existing races, this would give us six entirely distinct groups of organic beings that have lived in succession upon this globe since it became a habitable world. But even if it should be found that a few species are common to adjoining groups, the great truth would still remain, that the different groups were too much unlike to be contemporaries, and that consequently a new creation must have taken place whenever each new group commenced its course.
It is probable the earth has changed its inhabitants more than the six times that have been mentioned; some think as many as twelve times. But a larger number cannot yet be proved so clearly; and could they be, they would add nothing to this argument; for it rests mainly on the fact that this change of organic life has even once been complete. We may, however, very safely assume that the present animals and plants are the sixth group that have occupied the globe.[12]
These facts being admitted, and who does not see the necessity of divine interference, whenever one race of animals and plants passed from the earth in order to repeople it? It is not difficult to conceive how volcanic fires, or aqueous inundations, may have carried universal destruction over the globe, and bereft it of inhabitants. But where, save in the fiat of an infinite Deity, is the power that can make this universe of death teem again with life and beauty? In the powerful language of Dr. Chalmers, we may inquire, “Is there aught in the rude and boisterous play of a great physical catastrophe that can germinate those exquisite structures, which, during our yet undisturbed economy, have been transmitted in pacific succession to the present day? What is there in the rush, and turbulence, and mighty clamor of such great elements, of ocean heaved from its old resting-place, and lifting its billows above the Alps and the Andes of a former continent,—what is there in this to charm into being the embryo of an infant family, wherewith to stock and to repeople a now desolate world? We see in the sweeping energy and uproar of this elemental war enough to account for the disappearance of all the old generations, but nothing that might cradle any new generations into existence, so as to have effloresced on ocean’s deserted bed the life and loveliness which are now before our eyes. At no juncture, we apprehend, in the history of the world, is the interposition of the Deity more manifest than at this; nor can we better account for so goodly a creation emerging again into new forms of animation and beauty from the wreck of the old one, than that the spirit of God moved on the face of chaos, and that nature, turned by the last catastrophe into a wilderness, was again repeopled at the utterance of his word.”
Sir Isaac Newton has said, that “the growth of new systems out of old ones, without the mediation of a divine power, seems to me apparently absurd.” He seems in this passage to have referred only to the arrangements of matter, “with respect to size, figure, proportions, and properties,” and not to the principle of life, of instinct, or of intellect. But when the latter are taken into the account, it must be superlatively absurd to suppose new systems can grow out of old ones by merely natural operations. He, indeed, who can bring himself to believe, with a certain writer, that “the instincts of animals are nothing more than inert and passive attractions, derived from the power of sensation, and the instinctive operations of animals nothing more than crystallizations produced through the agency of that power,”—such a man could probably easily persuade himself that, by the help of galvanism, animals and plants might be the result of natural operations. Such doctrines, however, we shall examine in another lecture.
My third example from geology, showing the non-eternity of the present condition of the globe, is the fact of the disappearance of several large species of animals since the commencement of the most recent or alluvial geological period. Certain large pachydermatous and other animals, such as the fossil elephant, the mastodon, the megatherium, the mylodon, the megalonyx, the glyptodon, the fossil horse, ox, deer, &c., also nine or ten species of huge birds—the dinornis, the palapteryx, aptornis, notornis, and nestor of New Zealand, the dodo of Mauritius and Bourbon, and the pezohaps or solitaire of Rodriguez,—have ceased to exist since the tertiary period; some of them—the birds, for instance—since man’s creation. Now, if any important species of animals from time to time disappear from any system of organic life, it shows a tendency to ruin in that system; for such is the intimate dependence of different beings upon one another, that you cannot blot out one, certainly not a large number, without disturbing the healthy balance between the whole, and probably bringing the whole to ultimate ruin. At any rate, if several species die out by natural processes, no reason can be given why others should not, in like manner, disappear. And to prove that any organic system shows a tendency to ruin is to show that it had a beginning.
My third example from geology, demonstrating the special interference of the Deity in the affairs of this world, is the fact of the comparatively recent commencement of the human race. That man was among the very last of the animals created is made certain by the fact that his remains are found only in the highest part of alluvium. This is rarely more than one hundred feet in thickness, while the other fossiliferous strata, lying beneath the alluvium, are six miles thick.