Part 6

Where his great predecessors Buffon and Lamarck had failed, Darwin won through his unparalleled genius as an observer and reasoner, through the absolutely irresistible force of the facts he had assembled and through the simplicity of his presentation. Lacking the literary graces of his grandfather, Erasmus Darwin, and the obscurity of Spencer, Darwin was understood by every one as every one could understand Lincoln. It is true the cause was immediately championed by able men, but victory was gained not by the vehement and radical Haeckel nor yet by the masterly fighter Huxley, but through the resistless power of the truth as Darwin saw it and presented it. It was not a denial, as had been the great sceptical movement of the end of the eighteenth century, but an affirmation. Darwin was not destroying but building; yet at the time good and honest men trembled as if passing through an earthquake, for in the whole history of human thought there had been no such cataclysm.

In what he achieved Darwin is so entirely alone that his place in the history of ideas is next to Aristotle, the great Greek biologist and philosopher who preceded him by over two thousand years.

The biographers of Lincoln are at a loss to explain his greatness through heredity. Darwin belonged to an able family, and his ancestors are singularly prophetic of his career. He was near of kin to Francis Galton, who shares with Weismann the leadership in the study of heredity during the nineteenth century. By a happy combination of all the best traits of the best of his ancestors coupled with the no less happy omission of other traits, Darwin was a far greater man than any of his forebears. Kindliness, truthfulness and love of nature were part of his birthright. From his grandfather Erasmus, Charles may have inherited especially his vividness of imagination and his strong tendency to generalize. Countless hypotheses flitted through his mind. “Without speculation there is no good and original observation,” he wrote to Wallace. Still more interesting is the fact that the inheritance of his grandfather’s tendency toward speculation took the direction of evolution, for before the close of the eighteenth century Erasmus Darwin gave the world in poetical form his belief in a complete evolutionary system as well as the first clear exposition of what is now known as the Lamarckian hypothesis. But in the grandson hypotheses were constantly held in check by the determination to put each to the severe test of observation. Darwin speaks of his father, Robert, as the most acute observer he ever saw, and attributes to him his intense desire to understand the reasons of things; from him came caution and conservatism. He says in his “Autobiography”:

I have steadily endeavored to keep my mind free so as to give up any hypothesis (however much beloved), and I cannot resist forming one on every subject, as soon as facts are shown to be opposed to it.

If the “poet is born not made,” the man of science is surely both born and made. Rare as was Darwin’s genius, it was not more rare than the wonderful succession of outward events which shaped his life. It is true that Darwin believed with his cousin Francis Galton that education and environment produce only a small effect upon the mind of any one, but Darwin underestimated the force of his educational advantages just as he underestimated his own powers, and this because he thought only of his book and classroom life at school, at Edinburgh and at Cambridge, and not of his broader life. It was true in 1817, as today, that few teachers teach and few educators educate. It is true that those were the dull days of classical and mathematical drill. Yet look at the roster of Cambridge and see the men it produced. From Darwin’s regular college work he may have gained but little, yet he was all the while enjoying an exceptional training. Step by step he was made a strong man by a mental guidance which is without parallel, by the precepts and example of his father, for whom he held the greatest reverence, by his reading of the poetry of Shakespeare, Wordsworth, Coleridge and Milton, and the scientific prose of Paley, Herschel and Humboldt, by the subtle scholarly influences of old Cambridge, by the scientific inspiration and advice of Henslow, by the masterful inductive influence of the geologist Lyell, and by the great nature panorama of the voyage of the Beagle.

The college mates of Darwin saw more truly than he himself what the old university was doing for him. Professor Poulton of Oxford believes that the kind of life which so favored Darwin’s mind has largely disappeared in English universities, especially under the sharp system of competitive examinations; yet this is still more truly the atmosphere of old Cambridge today than of any of our American colleges. It would be an interesting subject to debate whether we could nurture such a man; whether a Darwin, were he entered at a Columbia, a Harvard, a Princeton, could develop mentally as Charles Darwin did at Cambridge in 1828. I believe that conditions for the favorable nurture of such a mind are not with us. They are repose, time for continuous thought, respect for the man of brains and of individuality and of such peculiar tastes as Darwin displayed in his avidity for collecting beetles, freedom from mental convention, general sympathy for nature, and, above all, ardor in the world of ideas. If the genial mind cannot find the kindred mind it cannot develop. Many American school and college men are laughed out of the finest promptings of their natures. In short, I believe our intellectual environment would be distinctly against a young Darwin today.

Thus event after event in Darwin’s life was singularly propitious. None but a Darwin would have reflected these events as he did, but grand and rare they certainly were.

At the age of nineteen he entered Christ’s of Cambridge, the small college which two hundred years before had sheltered John Milton, the great poet of “Paradise Lost,” the epic of the special creation theory which it was Darwin’s destiny to destroy. His passion for sport, shooting, hunting, cross-country riding, his genial enjoyment of friends of his own age, did not prevent delightful excursions with older men. He was known as “the man who walks with Henslow”; and close personal intercourse with this learned and genial botanist (Reverend Wm. C. Henslow) affected him more than any other feature of his college life. After graduation this personal association extended through Henslow to the geologist Sedgwick, who prepared him for the next step in his career. It was Henslow who secured for him his place on the exploring ship Beagle and the voyage round the world (1831–1836), by far the most important experience in his life.

No graduate course in any university can compare for a moment with the glorious vision which passed before young Darwin on the Beagle, but here again fortune smiled upon him, for this vision required the very scientific spirit and point of view which came to him through the reading of the “Principles of Geology” of Lyell, the masterly teacher of the uniformitarian doctrine of Hutton. That nature worked slowly in past as in present time and that the interpretation of the past is through observation of the present gave the note of Darwin’s larger and more original interpretation, because the slow evolution which Lyell piously restricted to geology and the surface of the earth Darwin extended to biology and all living beings. If during the voyage Lyell’s arguments convinced Darwin of the permanence of species, Lyell’s way of looking at nature also gave him the means of seeing that species are not permanent. In his own words, he “saw through Lyell’s eyes,” and with the admiration of others always so characteristic of him his tribute to Lyell is without reserve. The second edition of “The Journal” is dedicated:

With grateful pleasure as an acknowledgment that the chief part of whatever scientific merit this Journal and the other works of the author may possess has been derived from studying the well-known and admirable “Principles of Geology.”

The five years of the voyage filled the twenty-second to twenty-seventh years of Darwin’s life, the period now ordinarily given to professional studies. In reading the simple but fascinating “Journal,” which stands quite by itself in literature, we see how Darwin through his own genius and through the methods successively impressed upon him by his father, by Henslow, by Sedgwick and by Lyell was unconsciously preparing his mind for the “Origin of Species” and the “Descent of Man,” the two most influential books of science which have ever appeared. From the islands of the Atlantic and the Pacific we follow his delightful comments on animals and plants of all kinds on sea and land, through forests, pampas and steppes, up the dry slopes of the Andes, along the salt lakes and deserts of Chili and of Australia. The dense forests of Brazil, pendant with orchids and gay with butterflies, contrast with those of Terra del Fuego and of Tahiti, and with the deforested Cape de Verde Islands. On these islands, the first he visits, he is enormously impressed by the superiority of Lyell’s method. He visits other islands of all kinds, inhabited and uninhabited, the non-volcanic St. Paul’s rocks, half-submerged volcanic cones, coral reefs and islands of the south Pacific. He observes live glaciers, as well as the contrasting action of active and of dead volcanoes. Along the rivers of Patagonia he unearths great extinct or fossil mammals; in Peru he studies the extinct races of man; the aborigines of Terra del Fuego and of Patagonia make the most profound impression upon his mind. In brief, he sees the great drama of nature in all its lesser scenes and in all its grander acts. He begins the voyage a firm believer in the fixity of species, but doubts begin to enter his mind when in the sands of the pampas of South America he perceives that the extinct forms are partly ancestral to the living, and when on the isolated Galapagos Islands he finds the life is not that of a special creation but that detached from the continent of South America six hundred miles distant.

Darwin says:

I owe to the voyage the first real training and education of my mind. That my mind had developed is rendered probable by my father’s first exclamation on my return, “why the shape of his head is quite altered.”

III

Soon after Darwin’s return he moved to London for the two most active years of his life, to care for his collections and to write up his observations. At this moment came the third of the great turning-points in his life, which as a mysteriously disguised blessing was brought about through ill health. In London he was entering official duties and public scientific service which would undoubtedly have increased and interfered more and more seriously with his work. We can only count it as one of the most fortunate circumstances in the history of science that Darwin at the age of thirty-three was forced to leave London and to move to Down. Here for forty years he never knew for one day the health of an ordinary man; his life was one long struggle against the strain of sickness. But unrealized by him there was the compensation of a mind undisturbed by the constant interruption of outside affairs, such interruption as killed Huxley and is killing so many fine and ambitious men today. When I saw Huxley and Darwin side by side in 1879, the one only fifty-four, the other seventy, the younger man looked by far the more careworn of the two. Huxley, the strong man, broke down mentally at fifty-six; Darwin, the invalid, was vigorous mentally at seventy-two.

Darwin’s writings fall into three grand series. In the nine years after he returned from the voyage, or between his twenty-seventh and thirty-sixth years, Darwin wrote the first series, including his pre-evolutionary geological and zoological works, his “Coral Reefs” (1842), his “Zoology and Geology of the Voyage of the Beagle” (1844–1846), his “Journal of Researches,” the popular narrative of his voyage (1845). Darwin’s ill health thereafter shut him off from geology, although his last volume, “The Earthworm,” was in a sense geological.

It is characteristic of the life of every great man that his genius and his own self-analysis instinctively guide him to discover his mental needs.

Until the age of forty-five Darwin in his own opinion had not completed his education, in the sense that education is a broad and exact training. He now proceeded to fill the one gap in his training by devoting the eight years of his life between thirty-seven and forty-five to a most laborious research upon the barnacles, or Cirripedia. This gave him the key to the principles of the natural or adaptively branching and divergent arrangement of animals through the laws of descent as set forth in the “Origin,” which he certainly could not have secured in any other way. The value he placed on his work on the barnacles is of especial import today when systematic work is so lightly esteemed by many biologists, young and old. Darwin subsequently, in the words of Hooker, “recognized three stages in his career as a biologist, the mere collector at Cambridge, the collector and observer on the Beagle and for some years afterwards, and the trained naturalist after, and only after, the Cirripede work.”

Long before this, however, at the age of twenty-eight, Darwin had begun his career as a Darwinian. In July, 1837, he began his notes on the transmutation of species, based on purely Baconian principles, on the rigid collection of facts which would bear in any way on the variations of animals and plants under domestication and in nature. Rare as was his reasoning power, his powers of observation were of a still more distinct order. He persistently and doggedly followed every clew; he noticed little things which escaped others; he always noted exceptions and at once jotted down facts opposed to his theories. On the voyage the marvellous adaptations of animals and plants had been his greatest puzzle. Fifteen months later, in October, 1838, in reading the work of Malthus, on “Population,” there flashed across his mind the threefold clew of the struggle for existence, of constant variability, and of the selection of variations which happen to be adaptive.

The three memorable features of Darwin’s greatest work, “The Origin of Species,” are, that he was twenty-one years in preparing it, that, although by 1844 he was a strongly convinced evolutionist and natural selectionist, he kept on with his observations for fifteen years, and the volume even then would have been still longer postponed but for a wonderful coincidence, which constitutes the third and not the least memorable feature. This coincidence was that Wallace had also become an evolutionist and had also discovered the principle of natural selection through the reading of the same essay of Malthus. It is further remarkable that of all persons Wallace selected Darwin as the one to whom to send his paper. It was then through the persuasion of the great botanist Hooker, who had known Darwin’s views for thirteen years, that these independent discoveries were published jointly on July 1, 1858. All the finest points of Darwin’s personal character were displayed at this time; in fact, the entire Darwin-Wallace history up to and including Wallace’s noble and self-depreciatory tribute to Darwin on July 1 of last summer, is one of the brightest chapters in the history of science. Wallace himself pointed out the very important distinction that while the theories contained in the two papers published fifty years ago were nearly identical, Wallace had deliberated only three days after coming across the passage in Malthus, while Darwin had deliberated for fifteen years. He modestly declared that the respective credit should be in the ratio of fifteen years to three days.

Several months past the age of fifty Darwin published his epoch-making work (November, 1859), and despite ill health, between fifty and seventy-three he produced the nine great volumes which expand and illustrate the views expressed in “The Origin of Species.”

A parallel to this remarkable late productiveness is that of Kant, who also put forth his greatest work after fifty. Let those past the five decades take heart, for it appears that while there are inborn differences between men in this regard, imagination, observation, reasoning and production do not necessarily dim with age. Darwin’s mind remained young and plastic to the end; his latest and one of his most characteristic works, “The Formation of Vegetable Mould through the Action of Earth Worms,” was published at the age of seventy-two, after forty-four years of observation. It contained another and perhaps the most extreme demonstration of Lyell’s principle that vast changes in nature are brought about by the slow operation of infinitesimal causes.

Three of Darwin’s succeeding volumes are a filling out of the “Origin.” “The Variation of Animals and Plants under Domestication” (two volumes, 1868) presents the entire fabric of the notes begun twenty-one years before on the transmutation of species. “The Descent of Man” (1871) was another logical outcome of the “Origin,” yet it was only faintly adumbrated by a single allusion in that work to the fact that the transmutation of species necessarily led to the evolution of man. The “Descent” marks the third of the great dates in the history of thought, as the “Origin” marks the second, because it is the final step in the development of ideas which began with Copernicus in 1543. The world-wide sensation, the mighty storm produced by this bold climax of Darwin’s work, is so fresh in the memory of all that a mere allusion suffices. The evolutionary or genetic basis for modern psychology as stated in “The Descent of Man” was given still more concrete form in Darwin’s succeeding and most delightful volume, “The Expression of the Emotions” (1872).

The knowledge of zoology and anatomy displayed in these four evolutionary volumes came from direct observation, vast and systematic reading and note-taking from the simple materials which Darwin could collect at Down. Always penetrating as these observations are, they are still, in my opinion, surpassed in beauty and ingenuity by his marvellous work on plants, published between 1862 and 1880. Here the principles of co-adaptation of plants and insects in cross- and self-fertilization, in climbing plants and insectivorous plants, in forms of flowers, in movements of plants, are all brought forth in support of the theory of natural selection and the operation of unknown laws. Darwin’s most precise observations and some of his most brilliant discoveries recorded in these volumes laid the foundations of modern experimental botany.

Of his method Darwin writes:

From my early youth I had the strongest desire to understand or explain whatever I observed, that is, to group facts under some general laws. My mind seems to have become a kind of machine for grinding general laws out of large collections of facts.

The only work which Darwin wrote deductively was his “Coral Reefs.” Every other volume came through the inductive-deductive process, that is, through an early assemblage of facts followed by a series of trial hypotheses, each of which was rigidly tested by additional facts. The most central of these trial hypotheses was that of the building up of adaptations through the selection of the single adaptive variation out of the many fortuitous variations, and this Darwin was unable to rigidly test by facts but was obliged to leave for verification or disproof by work after him.

On December 8, 1879, when Darwin was in his seventieth year and I in my twenty-second, I had the rare privilege of meeting him and looking steadily in his face during a few moments’ conversation. It was in Huxley’s laboratory, and I was at the time working upon the anatomy of the Crustacea. The entry in my journal is as follows: