III.—The History of the Earth's Life
Mixed up, however, with the geological changes, and apparently as final object connected with the formation of the globe itself, there is another set of phenomena presented in the course of our history—the coming into existence, namely, of a long suite of living things, vegetable and animal, terminating in the families which we still see occupying the surface. The question arises: In what manner has this set of phenomena originated? Can we touch at and rest for a moment on the possibility of plants and animals having likewise been produced in a natural way, thus assigning immediate causes of but one character for everything revealed to our sensual observation; or are we at once to reject this idea, and remain content, either to suppose that creative power here acted in a different way, or to believe unexaminingly that the inquiry is one beyond our powers? Taking the last question first, I would reply that I am extremely loth to imagine that there is anything in Nature which we should, for any reason, refrain from examining. If we can infer aught from the past history of science, it is that the whole of Nature is a legitimate field for the exercise of our intellectual faculties; that there is a connection between this knowledge and our well-being; and that, if we may judge from things once despaired of by our inquiring reason, but now made clear and simple, there is none of Nature's mysteries which we may not hopefully attempt to penetrate. To remain idly content to presume a various class of immediate causes for organic Nature seems to me, on this ground, equally objectionable.
With respect to the other question the idea has several times arisen that some natural course was observed in the production of organic things, and this even before we were permitted to attain clear conclusions regarding inorganic nature. It was always set quickly aside as unworthy of serious consideration. The case is different now, when we have admitted law in the whole domain of the inorganic.
Otherwise, the absurdities into which we should be led must strike every reflecting mind. The Eternal Sovereign arranges a solar or an astral system, by dispositions imparted primordially to matter; he causes, by the same means, vast oceans to join and continents to rise, and all the grand meteoric agencies to proceed in ceaseless alternation, so as to fit the earth for a residence of organic beings. But when, in the course of these operations, fuci and corals are to be, for the first time, placed in these oceans, a change in his plan of administration is required. It is not easy to say what is presumed to be the mode of his operations. The ignorant believe the very hand of Deity to be at work. Amongst the learned, we hear of "creative fiats," "interferences," "interpositions of the creative energy," all of them very obscure phrases, apparently not susceptible of a scientific explanation, but all tending simply to this: that the work was done in a marvellous way, and not in the way of Nature.
But we need not assume two totally distinct modes of the exercise of the divine power—one in the course of inorganic nature and the other in intimately connected course of organic nature.
Indeed, when all the evidence is surveyed, it seems difficult to resist the impression that vestiges, at least, are seen of the manner and method of the Creator in this part of His work. It appears to be a case in which rigid proof is hardly to be looked for. But such evidences as exist are remarkably consistent and harmonious. The theory pointed to consorts with everything else which we have learned accurately regarding the history of the universe. Science has not one positive affirmation on the other side. Indeed, the view opposed to it is not one in which science is concerned; it appears as merely one of the prejudices formed in the non-age of our race.
For the history, then, of organic nature, I embrace, not as a proved fact, but as a rational interpretation of things as far as science has revealed them, the idea of progressive development. We contemplate the simplest and most primitive types of being as giving birth to a type superior to it; this again producing the next higher, and so on to the highest. We contemplate, in short, a universal gestation of Nature, like that of the individual being, and attended as little by circumstances of a miraculous kind as the silent advance of an ordinary mother from one week to another of her pregnancy.
Thus simple—after ages of marvelling—appears organic creation, while yet the whole phenomena are, in another point of view, wonders of the highest kind, being the undoubted results of ordinances arguing the highest attributes of foresight, skill and goodness on the part of their Divine Author.
If, finally, we study the mind of man, we find that its Almighty Author has destined it, like everything else, to be developed from inherent qualities.
Thus the whole appears complete on one principle. The masses of space are formed by law; law makes them in due time theatres of existence for plants and animals; sensation, disposition, intellect, are all in like manner sustained in action by law.