What Darwin did was to show for the first time how we might conceive the natural evolution of species; to suggest that the miracle of the purposive adaptation of organisms to their environment could be explained by purely natural causes without introducing teleological and supernatural agencies to bring the disharmony into harmony. The older mind and logic had seen the action of God everywhere; the new thought and logic were gradually restricting his sphere. Darwin took away a whole province from the teleologist when he merely set up the idea of selection. He towered above himself in that moment. Natural philosophy wrested zoology and botany from the hands of Linné and Cuvier. It destroyed the old idea of a design in the interest of natural law and the general unity of nature. “Allah need create no more.” We cannot emphasise it too much: it was the conceivability that settled the question. Darwin had shown that “it might have been so,” and this possibility stood for the first time in zoology and botany opposed, with all the weight of logic, to the other theory, which was no more understood, but was supplied by imagination to fill a gap—the idea of a special creation of each animal species, the idea that the green tree-frog, had been created amongst the foliage just as he was. The feebler fancy gave way to the better. In this concession lay whole sciences that would have to be entirely transformed on the strength of Darwin’s achievement.
Narrow-minded folk have tried to make light of the mere “possibility,” creating a distinction between truth and logical theory. As if all truth were not solely in the human mind! What an age can conceive is true to that age. There is nothing higher in the bounds of time and the development in which we are involved. All truth and science began for humanity in the form of possibilities. Copernicus’s theory was only a possibility when it first came. All that we call human culture has come of the putting together of thousands upon thousands of these possibilities, like so many stones. It is no use raising up against it the figment of “absolute truth.” The main point was that Darwin raised the conceivability of a natural origin of species by the modification of older forms, which were driven ceaselessly to new adaptations under the stress of the struggle for life, to such a pitch that the older possibility of a creation of each species and its deliberate adaptation by supernatural action sank lower and lower. It was a pure conflict of ideas; the greater overcame the smaller—now smaller.
Darwin’s work, the Origin of Species, was published on November 24, 1859, after twenty-five years of study. He kept the theory of selection to himself for more than twenty years. The whole of the young generation from the beginning of the thirties, to which Haeckel belonged, grew up without any suspicion of it. Apart from the constant ill-health that hindered his work, Darwin was tortured with anxiety lest he should be treated as an imaginative dilettante with his heretical ideas. In the scientific circles of the middle of the century one was apt to be disdainfully put down as a windy “natural philosopher” if one spoke of “the evolution of animal and plant species” and the like. The word had become the scarecrow of the exact, professional scientific workers; much as when commercial men exclaim, “Dear me, the man’s a poet.” Hence Darwin wanted to provide a most solid foundation of research for his work, and then to smuggle it into the house like a goblin in a jar.
He took his task so seriously that, as Lyell afterwards wrote to him, he might have worked on until his hundredth year without ever being ready in the sense he wished. Chance had to intervene, and bring forward one of the younger men, who almost robbed him of the title of discoverer. Wallace arrived independently at the idea of selection, and he was within a hair’s breadth of being the first to publish it. The aged scholar at Down had to come forward. Then the great book was published, and Wallace disappeared in its shadow.
In Darwin’s opinion it was only a preliminary extract, and he added many supplementary volumes as time went on. As a fact it was so severely elaborated that even the thoughtful layman, possibly with a sympathy for the idea, was almost, if not wholly, unable to digest the proofs. It had to be “translated” for the majority of Darwin’s educated countrymen. On the other hand, this mass of facts was partly strange and new to the professional biologists. What did so many of the museum-zoologists know, for instance, of the results and problems of the practical breeder? “That belongs to the province of my colleague who teaches agriculture, not to mine.” His proofs were taken indiscriminately from zoology, botany, and geology. But at that time it was woe to the man that mixed up the various branches of research. The professor of zoology could not control the botanical material, and vice versâ. There was, in addition, the general dislike of the natural-philosophical nucleus. It was impossible to suppose that this very individual book, transgressing every rule, should at once meet with wide encouragement, or even ordinary appreciation.
In England Darwin’s repute as a traveller and geologist, and the personal respect felt for him, had some effect. Then came a small circle of friends, Hooker, Huxley, even, to some extent, the aged Lyell, who had seen the manuscript before publication, and had at once started a more or less brisk propaganda. In the first six months three editions of the work were sold, so that it was read by a few thousand men. As a rule there was at that time less dread of “natural philosophy” in England than elsewhere. But pious minds were alarmed at the “struggle against God” that was based on the exact data of zoology, botany, and geology.
Darwin had made that the salient point, as a glance at the work shows, since he closes with a reference to the Deity. He said it was a “grand” view of the Creator to suppose that he had created only the first forms of life on the earth, and then left it to natural laws to develop these germs into the various species of animals and plants. It was prudent to restrict the theistic conflict. God was merely excluded from the origin of species. Natural selection did not apply to the further problem of the origin of the primitive life-forms and of life itself. Theism could retain them. There was something soothing psychologically in the phrase, which was often attacked subsequently, and did not represent Darwin’s later views. It was characteristic of Darwin’s gentle disposition.
He did not start out from the position that God does not exist, and that we must, at all costs, seek natural causes for the origin of things. He had not abandoned the idea of the clerical profession because he had lost belief in God, but because he had more attraction for catching butterflies and shooting birds. Still a firm theist, he had been convinced, as a candid geologist, by Lyell’s demonstration that God had had nothing to do with the moulding of hill and valley or the distribution of land and water. As a candid zoologist and botanist he had then convinced himself that the analogous changes in the animal and plant worlds had needed no divine intervention.
As yet, however, he saw no reason to draw more radical conclusions. He sought, as far as honour permitted, a certain peace of thought by asking whether this indirect action of the personal Ruler over such vast provinces did not enhance the idea of him instead of detracting from it.
Goethe would have been prepared, on his principles, to recognise the step taken in the direction of natural law as a victory for our increasing knowledge of and reverence for the Deity. For him a natural law was the will of God; if natural selection created species, he would have seen merely the will of God in selection. But Darwin had not yet advanced so far, and still less could this be expected in his pious readers.