It would be giving a very false idea of the interests which stirred Charles Darwin's mind during his long five years' voyage, however, if we were to dwell exclusively upon the biological side of his numerous observations on that memorable cruise. Ethnology, geology, oceanic phenomena, the height of the snow-line, the climate of the Antarctic islands, the formation of icebergs, the transport of boulders, the habits and manners engendered by slavery, all almost equally aroused in their own way the young naturalist's vivid interest. Nowhere do we get the faintest trace of narrow specialism; nowhere are we cramped within the restricted horizon of the mere vulgar beetle-hunter and butterfly-catcher. The biologist of the 'Beagle' had taken the whole world of science for his special province. Darwin's mind with all its vastness was not, indeed, profoundly analytical. The task of working out the psychological and metaphysical aspects of evolution fell rather to the great organising and systematising intellect of Herbert Spencer. But within the realm of material fact, and of the widest possible inferences based upon such fact, Darwin's keen and comprehensive spirit ranged freely over the whole illimitable field of nature. 'No one,' says Buckle with unwonted felicity, 'can have a firm grasp of any science if, by confining himself to it, he shuts out the light of analogy. He may, no doubt, work at the details of his subject; he may be useful in adding to its facts; he will never be able to enlarge its philosophy. For the philosophy of every department depends on its connection with other departments, and must therefore be sought at their points of contact. It must be looked for in the place where they touch and coalesce: it lies, not in the centre of each science, but on the confines and margin.' This profound truth Darwin fully and instinctively realised. It was the all-embracing catholicity of his manifold interests that raised him into the greatest pure biologist of all time, and that enabled him to co-ordinate with such splendid results the raw data of so many distinct and separate sciences. And even as early as the days of the cruise in the 'Beagle,' that innate catholicity had already asserted itself in full vigour. Now it is a party of Gauchos throwing the bola that engages for the moment his eager attention; and now again it is a group of shivering Fuegians, standing naked with their long hair streaming in the wind on a snowy promontory of their barren coast. Here he examines the tubular lightning-holes melted in the solid rock of Maldonado by the electric energy; and there he observes the moving boulder-streams that course like torrents down the rugged corries of the Falkland Islands. At one time he works upon the unstudied geology of the South American Pampas; at another, he inspects the now classical lagoon and narrow fringing reef of the Keeling archipelago. Everywhere he sees whatever of most noteworthy in animate or inanimate nature is there to be seen; and everywhere he draws from it innumerable lessons, to be applied hereafter to the special field of study upon which his intense and active energies were finally concentrated. It is not too much to say, indeed, that it was the voyage of the 'Beagle' which gave us in the last resort the 'Origin of Species' and its great fellow the 'Descent of Man.'
[1] The full narrative was first given to the world in 1839, some three years after Darwin's return to England, so that much of it evidently represents the results of his maturer thinking and reading on the facts collected during his journey round the world.
CHAPTER V.
THE PERIOD OF INCUBATION.
When Charles Darwin landed in England on his return from the voyage of the 'Beagle' he was nearly twenty-eight. When he published the first edition of the 'Origin of Species' he was over fifty. The intermediate years, though much occupied by many minor works of deep specialist scientific importance, were still mainly devoted to collecting material for the one crowning effort of his life, the chief monument of his great co-ordinating and commanding intellect—the settlement of the question of organic evolution.
'There is one thing,' says Professor Fiske, 'which a man of original scientific or philosophical genius in a rightly ordered world should never be called upon to do. He should never be called upon to earn a living; for that is a wretched waste of energy, in which the highest intellectual power is sure to suffer serious detriment, and runs the risk of being frittered away into hopeless ruin.' From this unhappy necessity Charles Darwin, like his predecessor Lyell, was luckily free. He settled down early in a home of his own, and worked away at his own occupations, with no sordid need for earning the day's bread, but with perfect leisure to carry out the great destiny for which the chances of the universe had singled him out. His subsequent history is the history of his wonderful and unique contributions to natural science.
The first thing to be done, of course, was the arrangement and classification of the natural history spoils gathered during the cruise, and the preparation of his own journal of the voyage for publication. The strict scientific results of the trip were described in the 'Zoology of the Voyage of the "Beagle,"' the different parts of which were undertaken by rising men of science of the highest distinction, under Charles Darwin's own editorship. Sir Richard Owen took in hand the fossil mammals; Waterhouse arranged their living allies; Gould discussed the birds, Jenyns the fish, and Bell the amphibians and reptiles. In this vast co-operative publication Darwin thus obtained the assistance of many among the most competent specialists in the England of his day, and learned to understand his own collections by the light thrown upon them from the focussed lamps of the most minute technical learning. As for the journal, it was originally published with the general account of the cruise by Captain Fitzroy in 1839, but was afterwards set forth in a separate form under the title of 'A Naturalist's Voyage Round the World.'
But while Darwin was thus engaged in arranging and classifying the animals and plants he had brought home with him, the germs of those inquiring ideas about the origin of species which we have already observed in his account of the voyage were quickening into fresh life within him. As he ruminated at his leisure over the results of his accumulations, he was beginning to work upon the great problem with the definite and conscious resolution of solving it. 'On my return home, it occurred to me,' he says, 'in 1837, that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it. After five years' work, I allowed myself to speculate on the subject, and drew up some short notes; these I enlarged in 1844 into a sketch of the conclusions that then seemed to me probable; from that period to the present day [1859] I have steadily pursued the same object. I hope that I may be excused for entering on these personal details, as I give them to show that I have not been hasty in coming to a decision.'
So Darwin wrote at fifty. The words are weighty and well worthy of consideration. They give us in a nutshell the true secret of Darwin's success in compelling the attention and assent of his contemporaries to his completed theory. For speculations and hypotheses like those of Lamarck and Erasmus Darwin, however brilliant and luminous they may be, the hard, dry, scientific mind cares as a rule less than nothing. Men of genius and insight like Goethe and Oken may, indeed, seize greedily upon the pregnant suggestion; their intellects are already attuned by nature to its due reception and assimilation; but the mere butterfly-catchers and plant-hunters of the world, with whom after all rests ultimately the practical acceptance or rejection of such a theory, can only be convinced by long and patient accumulations of facts, by infinite instances and endless examples, by exhaustive surveys of the whole field of nature in a thousand petty details piecemeal. They have to be driven by repeated beating into the right path. Everywhere they fancy they see the loophole of an objection, which must be carefully closed beforehand against them with anticipatory argument, as we close hedges by the wayside against the obtrusive donkey with a cautious bunch of thorny brambles. Even if Charles Darwin had hit upon the fundamental idea of natural selection, and had published it, as Wallace did, in the form of a mere splendid aperçu, he would never have revolutionised the world of biology. When the great discovery was actually promulgated, it was easy enough to win the assent of philosophical thinkers like Herbert Spencer; easy enough, even, to gain the ready adhesion of non-biological but kindred minds, like Leslie Stephen's and John Morley's; those might all, perhaps, have been readily convinced by far less heavy and crushing artillery than that so triumphantly marshalled together in the 'Origin of Species.' But in order to command the slow and grudging adhesion of the rank and file of scientific workers, the 'hodmen of science,' as Professor Huxley calls them, it was needful to bring together an imposing array of closely serried facts, to secure every post in the rear before taking a single step onward, and to bring to bear upon every antagonist the exact form of argument with which he was already thoroughly familiar. It was by carefully pursuing these safe and cautious philosophical tactics that Charles Darwin gained his great victory. Where others were pregnant, he was cogent. He met the Dryasdusts of science on their own ground, and he put them fairly to flight with their own weapons. More than that, he brought them all over in the long run as deserters into his own camp, and converted them from doubtful and suspicious foes into warm adherents of the evolutionary banner.