Charles Darwin

Shortly after Darwin went to Down he began one long and memorable experiment, which in itself casts a flood of light upon his patient and painstaking method of inquiry. Two years before, he had read at the Geological Society a paper on the 'Formation of Mould,' which more than thirty years later he expanded into his famous treatise on the 'Action of Earthworms.' His uncle and father-in-law, Josiah Wedgwood, suggested to him that the apparent sinking of stones on the surface might really be due to earthworm castings. So, as soon as he had some land of his own to experiment upon, he began, in 1842, to spread broken chalk over a field at Down, in which, twenty-nine years later, in 1871, a trench was dug to test the results. What other naturalist ever waited so long and so patiently to discover the upshot of a single experiment? Is it wonderful that a man who worked like that should succeed, not by faith but by logical power, in removing mountains?

Unfortunately, we do not know the exact date when Darwin first read Malthus. But that the perusal of that remarkable book formed a crisis and turning-point in his mental development we know from his own distinct statement in a letter to Haeckel, prefixed to the brilliant German evolutionist's 'History of Creation.' 'It seemed to me probable,' says Darwin, speaking of his own early development, 'that allied species were descended from a common ancestor. But during several years I could not conceive how each form could have been modified so as to become admirably adapted to its place in nature. I began therefore to study domesticated animals and cultivated plants, and after a time perceived that man's power of selecting and breeding from certain individuals was the most powerful of all means in the production of new races. Having attended to the habits of animals and their relations to the surrounding conditions, I was able to realise the severe struggle for existence to which all organisms are subjected; and my geological observations had allowed me to appreciate to a certain extent the duration of past geological periods. With my mind thus prepared I fortunately happened to read Malthus's "Essay on Population" and the idea of natural selection through the struggle for existence at once occurred to me. Of all the subordinate points in the theory, the last which I understood was the cause of the tendency in the descendants from a common progenitor to diverge in character.'

It is impossible, indeed, to overrate the importance of Malthus, viewed as a schoolmaster to bring men to Darwin, and to bring Darwin himself to the truth. Without the 'Essay on the Principle of Population' it is quite conceivable that we should never have had the 'Origin of Species' or the 'Descent of Man.'

At the same time, Darwin had not been idle in other departments of scientific work. Side by side with his collections for his final effort he had been busy on his valuable treatise upon Coral Reefs, in which he proved, mainly from his own observations on the Keeling archipelago, that atolls owe their origin to a subsidence of the supporting ocean-floor, the rate of upward growth of the reefs keeping pace on the whole with the gradual depression of the sea-bottom. 'No more admirable example of scientific method,' says Professor Geikie forty years later, 'was ever given to the world; and even if he had written nothing else, this treatise alone would have placed Darwin in the very front of investigators of nature.' But, from our present psychological and historical point of view, as a moment in the development of Darwin's influence, and therefore of the evolutionary impulse in general, it possesses a still greater and more profound importance, because the work in which the theory is unfolded forms a perfect masterpiece of thorough and comprehensive inductive method, and gained for its author a well-deserved reputation as a sound and sober scientific inquirer. The acquisition of such a reputation, afterwards increased by the publication of the monograph on the Family Cirripedia (in 1851), proved of immense use to Charles Darwin in the fierce battle which was to rage around the unconscious body of the 'Origin of Species.' To be 'sound' is everywhere of incalculable value; to have approved oneself to the slow and cautious intelligence of the Philistine classes is a mighty spear and shield for a strong man; but in England, and above all in scientific England, it is absolutely indispensable to the thinker who would accomplish any great revolution. Soundness is to the world of science what respectability is to the world of business – the sine qua non for successfully gaining even a hearing from established personages.

To read the book on Coral Reefs is indeed to take a lesson of the deepest value in applied inductive canons. Every fact is duly marshalled: every conclusion is drawn by the truest and most legitimate process from careful observation or crucial experiment. Bit by bit, Darwin shows most admirably that, through gradual submergence, fringing reefs are developed into barrier-reefs, and these again into atolls or lagoon islands; and incidentally he throws a vivid light on the slow secular movements upward or downward for ever taking place in the world's crust. But the value of the work as a geological record, great as it is, is as nothing compared with its value as a training exercise in inductive logic. Darwin was now learning by experience how to use his own immense powers.

Meanwhile, the environment too had been gradually moving. In 1832, the year after young Darwin set out upon his cruise, Lyell published the first edition of his 'Principles of Geology,' establishing once for all the uniformitarian concept of that branch of science. In 1836, the year when he returned, Rafinesque, in his 'New Flora of North America,' had accepted within certain cramping limits the idea that 'all species might once have been varieties, and that many varieties are gradually becoming species by assuming constant and peculiar characters.' Haldeman in Boston, and Grant at University College, London, were teaching from their professorial chairs the self-same novel and revolutionary doctrine. At last, in 1844, Robert Chambers published anonymously his famous and much-debated 'Vestiges of Creation,' which brought down the question of evolution versus creation from the senate of savants to the arena of the mere general public, and set up at once a universal fever of inquiry into the mysterious question of the origin of species. Chambers himself was a man rather of general knowledge and some native philosophical insight than of any marked scientific accuracy or depth. His work in its original form displayed comparatively little acquaintance with the vast groundwork of the question at issue – zoological, botanical, geological, and so forth – and in Charles Darwin's own opinion showed 'a great want of scientific caution.' But its graphic style, its vivid picturesqueness, and to the world at large the startling novelty of its brilliant and piquant suggestions, made it burst at once into an unwonted popularity for a work of so distinctly philosophical a character. In nine years it leaped rapidly through no less than ten successive editions, and remained until the publication of the 'Origin of Species' the chief authoritative exponent in England of the still struggling evolutionary principle.

The 'Vestiges of Creation' may be succinctly described as Lamarck and water, the watery element being due in part to the unnecessary obtrusion (more Scotico) of a metaphysical and theological principle into the physical universe. Chambers himself, in his latest edition (before the book was finally killed by the advent of Darwinism), thus briefly describes his main concepts: 'The several series of animated beings, from the simplest and oldest up to the highest and most recent, are, under the providence of God, the results, first, of an impulse which has been imparted to the forms of life, advancing them, in definite times, by generation, through grades of organisation, terminating in the highest dicotyledons and vertebrata, these grades being few in number, and generally marked by intervals of organic character, which we find to be a practical difficulty in ascertaining affinities; second, of another impulse connected with the vital forces, tending, in the course of generations, to modify organic structures in accordance with external circumstances, as food, the nature of the habitat, and the meteoric agencies.' Now it is clear at once that these two supposed 'impulses' are really quite miraculous in their essence. They do not help us at all to a distinct physical and realisable conception of any natural agency whereby species became differentiated one from the other. They lay the whole burden of species-making upon a single primordial supernatural impetus, imparted to the first living germ by the will of the Creator, and acting ever since continuously it is true, but none the less miraculously for all that. For many creations Chambers substitutes one single long creative nisus: where Darwin saw natural selection, his Scotch predecessor saw a deus ex machina, helping on the course of organic development by a constant but unseen interference from above. He supposed evolution to be predetermined by some intrinsic and externally implanted proclivity. In short, Chambers's theory is Lamarck's theologised, and spoilt in the process.

The book had nevertheless a most prodigious and perfectly unprecedented success. The secret of its authorship was keenly debated and jealously kept. The most ridiculous surmises as to its anonymous origin were everywhere afloat. Some attributed it to Thackeray, and some to Prince Albert, some to Lyell, some to Sir John Herschel, and some to Charles Darwin himself. Obscurantists thought it a wicked book; 'intellectual' people thought it an advanced book. As a matter of fact it was neither the one nor the other. It was just a pale and colourless transcript of the old familiar teleological Lamarckism. Yet it did good in its generation. The public at large were induced by its ephemeral vogue to interest themselves in a question to which they had never previously given even a passing thought, though more practised biologists of evolutionary tendencies were grieved at heart that evolution should first have been popularly presented to the English world under so unscientific, garbled, and mutilated a form. From the philosophic side, Herbert Spencer found 'this ascription of organic evolution to some aptitude naturally possessed by organisms or miraculously imposed upon them' to be 'one of those explanations which explain nothing – a shaping of ignorance into the semblance of knowledge. The cause assigned,' he says, 'is not a true cause – not a cause assimilable to known causes – not a cause that can be anywhere shown to produce analogous effects. It is a cause unrepresentable in thought: one of those illegitimate symbolic conceptions which cannot by any mental process be elaborated into a real conception.' From the scientific side, on the other hand, Darwin felt sadly the inaccuracy and want of profound technical knowledge everywhere displayed by the anonymous author. These things might naturally cause the enemy to blaspheme. No worse calamity, indeed, can happen to a great truth than for its defence to be intrusted to inefficient hands. Nevertheless, long after, in the 'Origin of Species,' the great naturalist wrote with generous appreciation of the 'Vestiges of Creation,' 'In my own opinion it has done excellent service in this country in calling attention to the subject, in removing prejudice, and in thus preparing the ground for the reception of analogous views.'

Still Darwin gave no sign. A flaccid, cartilaginous, unphilosophic evolutionism had full possession of the field for the moment, and claimed, as it were, to be the genuine representative of the young and vigorous biological creed, while he himself was in truth the real heir to all the honours of the situation. He was in possession of the master-key which alone could unlock the bars that opposed the progress of evolution, and still he waited. He could afford to wait. He was diligently collecting, amassing, investigating; eagerly reading every new systematic work, every book of travels, every scientific journal, every record of sport, or exploration, or discovery, to extract from the dead mass of undigested fact whatever item of implicit value might swell the definite co-ordinated series of notes in his own commonplace books for the now distinctly contemplated 'Origin of Species.' His way was to make all sure behind him, to summon up all his facts in irresistible array, and never to set out upon a public progress until he was secure against all possible attacks of the ever-watchful and alert enemy in the rear. Few men would have had strength of mind enough to resist the temptation offered by the publication of the 'Vestiges of Creation,' and the extraordinary success attained by so flabby a presentation of the evolutionary case: Darwin resisted it, and he did wisely.

We may, however, take it for granted, I doubt not, that it was the appearance and success of Chambers's invertebrate book which induced Darwin, in 1844 (the year of its publication), to enlarge his short notes 'into a sketch of the conclusions which then seemed to him probable.' This sketch he showed to Dr. (now Sir Joseph) Hooker, no doubt as a precaution to ensure his own claim of priority against any future possible competitor. And having thus eased his mind for the moment, he continued to observe, to read, to devour 'Transactions,' to collate instances, with indefatigable persistence for fifteen years longer. If any man mentally measures out fifteen years of his own life, and bethinks him of how long a space it seems when thus deliberately pictured, he will be able to realise a little more definitely – but only a little – how profound was the patience, the self-denial, the single-mindedness of Darwin's intense search after the ultimate truths of natural science.

What was the sketch that he thus committed to paper in 1844, and submitted to the judgment of his friend Hooker? It was the germ of the theory of natural selection. According to that theory, organic development is due to the survival of the fittest among innumerable variations, good, bad, and indifferent, from one or more parent stocks. Darwin's reading of Malthus had suggested to him (apparently as early as the date of publication of the 'Naturalist's Journal') the idea that every species of plant and animal must always be producing a far greater number of seeds, eggs, germs, or young offspring than could possibly be needed for the maintenance of the average number of the species. Of these young, by far the greater number must always perish from generation to generation, for want of space, of food, of air, of raw material. The survivors in each brood must be those naturally best adapted for survival. The many would be eaten, starved, overrun, or crowded out; the few that survive would be those that possessed any special means of defence against aggressors, any special advantage for escaping starvation, any special protection against overrunning or overcrowding foes. Animals and plants, Darwin found on inquiry and investigation, tended to vary under diverse circumstances from the parent or parents that originally produced them. These variations were usually infinitesimal in amount, but sometimes more considerable or even striking. If any particular variation tended in any way to preserve the life of the creatures that exhibited it, beyond the average of their like competitors, that variation would in the long run survive, and the individuals that possessed it, being thus favoured in the struggle for existence, would replace the less adapted form from which they sprang. Darwinism is Malthusianism on the large scale: it is the application of the calculus of population to the wide facts of universal life.

In one sense, indeed, it may be said that, given Malthus on the one hand and the Lamarckian evolutionism on the other, some great man somewhere must sooner or later, almost of necessity, have combined the two, and hit out the doctrine of natural selection as we actually know it. Quite so; but then the point is just this: Darwin was the great man in question; he did the work which in the very essence of things some such great man was naturally and inevitably predestined to do. You can always easily manage to get on without any particular great man, provided, of course, you have ready to hand another equally able great man by whom to replace him in the scheme of existence. But how many ordinary naturalists possess the width of mind and universality of interest which would prompt them to read, mark, learn, and inwardly digest a politico-economical treatise of the calibre of Malthus? How many, having done so, have the keenness of vision to perceive the ensuing biological implications? How many, having seen them, have the skill and the patience to work up the infinite chaos of botanical and zoological detail into the far-reaching generalisations of the 'Origin of Species'? Merely to have caught at the grand idea is in itself no small achievement; others did so and deserve all honour for their insight; but to flesh it out with all the minute care and conclusive force of Darwin's masterpiece is a thousand times a greater and nobler monument of human endeavour.

During the fifteen years from 1844 to 1859, however, Darwin's pen was by no means idle. In the first-named year he published his 'Geological Observations on Volcanic Islands' – part of the 'Beagle' exploration series; in 1846 he followed this up by his 'Geological Observations on South America;' in 1851 he gave to the world his monograph on 'Recent Barnacles;' and in 1853, his treatise on the fossil species of the same family. But all these works of restricted interest remained always subsidiary to the one great central task of his entire lifetime, the preparation of his projected volume on the Origin of Species.

All through the middle decades of the century Darwin continued to labour at his vast accumulation of illustrative facts; and side by side with his continuous toil, outside opinion kept paving the way for the final acceptance of his lucid ideas. The public was buying and reading all the time its ten editions of the 'Vestiges of Creation.' It was slowly digesting Lyell's 'Principles of Geology,' in which the old cataclysmic theories were featly demolished, and the uniformitarian conception of a past gradually and insensibly merging into the present was conclusively established. It was getting accustomed to statements like those of the younger St. Hilaire, in 1850, that specific characters may be modified by changes in the environing conditions, and that the modifications thus produced may often be of generic value – may make a difference so great that we must regard the product not merely as belonging to a distinct species, but even to a distinct genus or higher kind. In 1852 Herbert Spencer published in the 'Leader' his remarkable essay, contrasting the theories of creation and evolution, as applied to organic beings, with all the biting force of his profound intelligence; and in 1855, the same encyclopædic philosopher put forth the first rough sketch of his 'Principles of Psychology,' in which he took the lead in treating the phenomena of mind from the point of view of gradual development. In that extraordinary work, the philosopher of evolution traced the origin of all mental powers and faculties by slow gradations from the very simplest subjective elements. The 'Principles of Psychology' preceded the 'Origin of Species' by nearly five years; the first collected volume of Mr. Spencer's essays preceded Darwin's work by some twelve months. Baden-Powell's essay on the 'Philosophy of Creation' (much debated and condemned in ecclesiastical circles), and Professor Owen's somewhat contradictory utterances on the nature of types and archetypal ideas, also helped to keep alive interest in the problem of origins up to the very moment of the final appearance of Darwin's great and splendid solution.

It is interesting during these intermediate years to watch from time to time the occasional side-hints of Darwin's activity and of the interest it aroused among his scientific contemporaries. In 1854, for example, Sir Charles Lyell notes, after an evening at Darwin's, how Sir Joseph Hooker astonished him with an account of that strange orchid, Catasetum, which bears three totally distinct kinds of flowers on the same plant; 'It will figure,' he says, 'in C. Darwin's book on species, with many other "ugly facts," as Hooker, clinging like me to the orthodox faith, calls these and other abnormal vagaries.' On a similar occasion, a little later, Lyell asks, after meeting 'Huxley, Hooker, and Wollaston at Darwin's,' 'After all, did we not come from an ourang?' Last of all, in 1857, Darwin himself writes an anticipatory letter to his American friend, Asa Gray, in which he mentions 'six points' – the cardinal conceptions of the 'Origin of Species.' His book is now fairly under weigh; he speaks of it himself to acquaintance and correspondents as an acknowledged project.

Events were growing ripe for the birth. A lucky accident precipitated its parturition in the course of the year 1858.

CHAPTER VI

'THE ORIGIN OF SPECIES.'

The accident came in this wise.

Alfred Russel Wallace, a young Welsh biologist, went out at twenty-four, in 1848, to the Amazons River, in company with Bates (the author of 'The Naturalist on the Amazons'), to collect birds and butterflies, and to study tropical life in the richest region of equatorial America. Like all other higher zoologists of their time, the two young explorers were deeply interested in the profound questions of origin and metamorphosis, and of geographical distribution, and in the letters that passed between them before they started they avowed to one another that the object of their quest was a solution of the pressing biological enigma of creation or evolution. Starting with fresh hopes and a few pounds in pocket, on an old, worn-out, and unseaworthy slave-trader, they often discussed these deep problems of life and nature together upon the Sargasso sea, or among the palms and lianas of the Brazilian woodlands. The air was thick with whiffs and foretastes of evolutionism, and the two budding naturalists of the Amazons expedition had inhaled them eagerly with every breath. They saw among the mimicking organisms of that equatorial zone strange puzzles to engage their deepest attention; they recognised in the veins and spots that diversified the filmy membranes of insects' wings the hieroglyphs of nature, writing as on a tablet for them to decipher the story of the slow modification of species. In 1852 – the year when Herbert Spencer in England published his essay on the 'Development Hypothesis,' and when Naudin in France put forth his bold and able paper on the 'Origin of Species' – Wallace once more returned to Europe, and gave to the world his interesting 'Travels on the Amazons and the Rio Negro.' Two years later the indefatigable traveller set out a second time on a voyage of tropical exploration, among the islands of the Malay archipelago, and for eight years he wandered about in Malay huts and remote islets, gathering in solitude and isolation the enormous store of minute facts which he afterwards lavished with so prodigal a hand upon 'Tropical Nature,' and the 'Geographical Distribution of Animals.'

While Wallace was still at Amboyna, he sent home in 1858 a striking memoir, addressed to Darwin, with a request that he would forward it to Sir Charles Lyell, for presentation to the Linnean Society. Darwin opened and read his brother naturalist's paper, and found to his surprise that it contained his own theory of natural selection, not worked out in detail, as he himself was working it out, but still complete in spirit and essence, with no important portion of the central idea lacking to its full rotundity of conception. A jealous man would have thrown obstacles in the way of publication; but both Darwin and Wallace were born superior to the meannesses of jealousy. The elder naturalist commended his young rival's paper at once to Sir Charles Lyell, who sent it on immediately to the Linnean Society.

But Sir Charles Lyell and Sir Joseph Hooker, both of whom knew of Darwin's work, thought it advisable that he should publish, in the 'Journal' of the Society, a few extracts from his own manuscripts, side by side with Wallace's paper. Darwin, therefore, selected some essential passages for the purpose from his own long-gathered and voluminous notes, and the two contributions were read together before the Society on July the 1st, 1858. That double communication marks the date of birth of modern evolutionism. It is to the eternal credit of both thinkers that each accepted his own true position with regard to the great discovery in perfect sincerity. The elder naturalist never strove for a moment to press his own claim to priority against the younger: the younger, with singular generosity and courtesy, waived his own claim to divide the honours of discovery in favour of the elder. Not one word save words of fraternal admiration and cordial appreciation ever passed the lips of either with regard to the other.