Haeckel

We still celebrate, at a distance of centuries, the return of the birthday of great men. In reality it is a mistake. We ought to celebrate the hour when not merely life, but the idea of their life, quickened them. That is the really important birth that calls for commemoration. Luther’s real birthday was when he nailed his theses to the church door. Then was born the Luther that belongs to the world. Over the world-cradle of Columbus shines, not the trivial and evanescent planet given in his horoscope, but the little red flickering star of Guanahani, the light that he saw from the shore on the night before he landed on an island of the New World.

Life is a voyage of discovery to the man who passes through it. He looks out with his child-eyes and discovers the world—at the bottom, discovers only himself. But one day a greater veil is torn from before his self. Genius, the greater I, stirs within him like the butterfly in its narrow pupa-case. For the world at large that is the hour when the great man is born who will leave his mark on it.

Haeckel’s biography only begins on a certain day, if we look at it rightly and broadly. Until that day he is merely a young man, an outgrowth from a rich old civilisation: a young man who has felt in him a struggle between artistic and scientific tendencies, like so many: who has vacillated between the choice of a “paying profession” and research for its own sake, and has decided for the former, like so many: who has chosen zoology, and begun to work hard on professional lines at his science: and who has been told prophetically that he will one day do something, though along a line where much has been done already. In the whole of this development we have as yet no indication of the real tenor of his life.

It comes first with the name of Darwin. The arabesque of a very different life begins to blend with that of his own.

In the February of the year in which Haeckel was born (1834), twenty-eight years before the point we have arrived at, Charles Darwin was on a scientific expedition to South America. There is a romantic element in the earlier story of this journey. The naked Fuegians had stolen a boat from an English Government ship that was engaged in making geographical measurements, towards the close of the twenties, on the wild coast of Tierra del Fuego. FitzRoy, the captain, arrested a few of the natives, brought them on board as hostages, and in the end took them with him to England. They were to be instructed in morality and Christianity and then taken back to their people, in order to introduce these elements of civilisation, for the advantage of shipwrecked sailors or distressed travellers who might fall in with them. We feel a breath of the spirit of Rousseau in it. As a fact nothing came of the device. The good Fuegians were clothed and improved by civilised folk for a year or two, returned home, immediately abandoned their trousers and their Christianity, and remained naked savages. But the bringing home of these hostages led, in the early thirties, to a new expedition of FitzRoy to Tierra del Fuego. The Government directed him to draw up further charts, and he looked about for a man of science to accompany him.

The man proved to be Charles Darwin, then in his twenty-second year.

The son of a prosperous provincial physician, he had begun to study medicine without much success, and was transferred to theology, only to find after three years of study that he was as little fitted to become a country clergyman as a country doctor. He had an unconquerable love of scientific investigation. He collected all kinds of things, and desired to travel, without any very clear idea of his destiny. A chance introduction came to the young man as a godsend, and he joined FitzRoy’s expedition to South America. Once more, it was this journey that made him “Darwin,” the mighty intellectual force in the nineteenth century.

Darwin found an idea in South America. You have to examine it very closely to appreciate it clearly. Let us recapitulate very briefly the hundred years of zoology and botany that had gone before.

In the eighteenth century Linné drew up, for the first time, a great catalogue of plant and animal species. Each species had a solid Latin name, and was provided with its particular label, by which every representative of the species could be recognised at once. Then the species were bracketed together in larger groups, and a general system was formed. It was an immense scientific advance, and is still generally appreciated as such. But we have to make one reserve. It is not man that separates things; nature, or rather God who created nature, has already distinguished them. In this respect zoology and botany are of God. The various species of plants and animals are something firmly established by God. Take the polar bear, the hippopotamus, the giraffe, or a particular species of palm, or vine, or rose. There they are, and all that man has to do is to learn their specific characters in order to determine and name them.

Behind all this we really have the ancient idea of the Mosaic story of creation. God made the animals and plants, species by species, put them in their places, and said to man, “Name them as you think fit, classify them, putting the like together and separating the unlike.” So God spake to Adam when he stood before him, naked as a Fuegian. Linné comes on the scene some six thousand years afterwards to set about this naming and arranging in earnest. But that does not make much difference. There are the species created by God. They have ceaselessly reproduced themselves since the days of Paradise according to the command to increase and multiply, each one in its own kind, so that the polar bear has only begotten polar bears, the giraffe giraffes, the hippopotamus hippopotami. Thus, in spite of death, the primitive Paradise is still there, and Linné, the official professor at Upsala, with his venerable wig and embroidered coat, can take up the work of the naked Adam with a good conscience, and finish what the patriarch had not been able to do.

Linné died in 1778 (about the time when Goethe was beginning the Iphigenia and Wilhelm Meister) in the full fame of all these achievements and all his hypotheses from the giraffe to God. Fifty years elapsed between this and Darwin’s voyage; but in those fifty years the following process is accomplished:—

An increasing number of bones and other relics of animal species, that exist no longer, were dug out of the earth. In South America the skeleton was found of a giant-sloth, the megatherium, the remains of a kind of animal, larger than the elephant, that no traveller could find living in the country. The famous mammoth-corpse came to light in the ice of Siberia; an entirely strange elephant with curved tusks and a red woolly coat. Ichthyosauri were found in the rocks in England, and so on. All these “extinct” species had to be named and arranged in the system. A special scientific indication was put on them, which means “extinct.” But this was not enough for thought—which cannot be “entirely dispensed with,” as some one well said, even in exact science.

Where did these extinct species come from? What is their relation to the Creator? Were they created long ago in Paradise with the others, and afterwards conveyed in the ark, only to disappear in the course of time? And what was the cause of their disappearance? Must we conclude that part of what Adam saw was not available for Linné and his pupils? These four remains, a few bones here and there, do not tell us much about them.

Therefore, species may perish: many of them have perished.

There was something new in this, something that obscured the clear lines of earlier science. However, a way of escape was found. It was claimed that these grotesque monsters—ichthyosauri, megatheria, mammoths, &c.—represent an earlier creation, with which Adam had nothing to do. Cuvier developed the theory in his grandiose way in 1812. Before the creation of the animal and plant species that Adam found in Paradise there was a long series of periods in the history of the earth, each of which had its own animal and plant population. It was in one of these periods that the forests grew which we find fossilised in our coal. In another the ichthyosauri, gigantic lizards, filled the ocean. In a third the hideous megatherium dragged along its huge frame, and so on. It is true that there is nothing in the Bible about these ancient and extinct periods; but the Mosaic verses move quickly—they press on to come to man. The repeated creations of the animal and plant worlds are summed up in a single one. We must read something between the lines.

Apart from that, everything is clear. Hence the ancient species were made fixed, solid, and unchangeable by God just like the later species that Adam found in Paradise, and that still exist. Without the will of God they could no more have died out than the actual ones; and there were no human beings there to destroy them. But the divine action intervened. At the end of each of these old-world periods a terrible spectacle was witnessed. The heavens poured out their punishing floods; the seas were heated to steam by fiery masses of rock that were summoned by the divine power from the bowels of the earth. In the course of a single day the carboniferous forests were swallowed up; the megatheria disappeared, legs uppermost, like flies in butter, in the sand dunes of the terrible floods.

The might of the creative act was equalled by the might of the destruction. The science of these vast new creations and divine revolutions before Adam’s birth was called geology. It lived in peace with Linné’s theory of fixed species. Its parent, Cuvier, was so great a genius that it seemed quite impossible that he had made a mistake. Before twenty years were out he was, in the opinion of a contemporary and equally able geologist, declared to be certainly wrong on one point.

Lyell wrote a magnificent work in which he proved, from the point of view of scientific geology, that the whole story of these terrible revolutions was a fiction. There are no such sharp sections in the early history of the earth. Everything goes to show that throughout the whole period of the earth’s development the same natural laws have been at work as we find to-day. It is true that the relative positions of sea and land, hill and valley, forest and desert, have often changed; but very, very slowly, in the course of millions of years. A single drop of water, constantly falling, will hollow out a stone. In these millions of years the water has swept away rocks here, and formed new land by the accumulation of sand there. In these millions of years the sand has been compressed into the gigantic masses that tower above us to-day as sandstone mountains; they are formed of sand that was originally laid like mud, layer by layer, on the floor of the ocean.

It was all very plausible; it seemed to picture an eternal flow of things in which there was no room for God. The changes in the earth’s surface were easily brought about without catastrophes, in the course of incalculable ages. God was excluded from geological discussions of the formation of hill and dale. And when it was fully realised, it brought the question of species to the front once more.

It was impossible to retreat simply to Linné’s position. Lyell by no means denied Cuvier’s various periods in the earth’s development as such. He believed, moreover, that the plant and animal populations were different in these epochs. When the forests flourished which have formed the mass of our coal-measures there were no ichthyosauri; when the ichthyosauri came there were no longer any carboniferous forests; with the ichthyosauri there were no megatheria, and the last ichthyosaurus was extinct before the megatheria arrived. All that Lyell rejected was the great divine catastrophes. But when these were abandoned, it was no longer possible to attribute the “end” of the extinct species to a divine act. We were faced with the slow and natural conversion of terrestrial things in the course of endless ages.

Species must have been liable to be destroyed by purely natural causes. The catastrophes were abandoned, yet species had been destroyed. And when that was granted—it was the devil’s little finger—a further conclusion was inevitable. If species have died out slowly and naturally in the history of the earth, and new species have made their appearance at the same time, may not these new species have arisen slowly and naturally? Suppose these simple and purely natural causes, that had brought about the extinction of certain species, had been for others the very starting-point of development? In one word: if the extinction was not due to a mighty divine interference, was it not conceivable that the origin also may not have needed such?

One more deduction, and the demon of knowledge had hold of the entire hand. May not this natural extinction and natural new-birth have been directly connected in many cases? As a fact, some of the species had been wholly extirpated. But others had provided the living material of the new arrivals; they had been transformed into these apparently new species. That was the decisive deduction. It did away with the need of any sudden creation. It merely made a claim that was appalling to the Linnean principles: namely, that species may change. In the course of time and at a favourable spot one species may be transformed into another.

Another fairly obvious deduction could be made. Who brought about the transformation? Lyell proved that, without any catastrophes, terrestrial things are constantly changing—the water and the land, the mountains and the valleys, and even the climate. In this gradual change the environments of living things were at length altered to such an extent that they were bound to cause a change in the organisms. However, different species reacted in different ways. Some gradually died out. Others adapted themselves to the new conditions; just as, in human affairs, one race breaks down under changed conditions while another rises to a higher and richer and new stage on that very account. No creation! Merely transformations of species, development of new forms from older ones by adaptation to new, naturally modified conditions. Even zoology and botany were without the finger of God from the earliest days.

Of course there was no trace of these latter deductions in Lyell. But they pressed themselves with an irresistible and decisive force on the mind of one of his first readers, Darwin.

He took Lyell’s book with him to South America. Step by step the logic of it forced him to admit that this was what must have taken place somewhere. First the idea of “extinct species” became a concrete picture to him there, a sort of diabolic vision. The whole substratum of the pampas is one colossal tomb of strange monsters. The bones lie bare at every outcrop. Megatheria, or giant-sloths, as large as elephants, and with thighbones three times as thick as that of the elephant, able to break off branches in the primitive forests with their paws: armadilloes as big as rhinoceroses, with coats as hard as stone and curved like barrels; gigantic llamas, the macrouchenias, compared with which the modern specimens are Liliputians; mastodons and wild horses, of which America was entirely free even in the days of Columbus, and lion-like carnivores with terrible sabre-teeth. There they all are to-day—extinct, lost, buried in the deserted cemetery of the pampas-loam.

When the young Darwin stood by these groves, like Hamlet, he did not know how closely this ghost-world came to our own day. At that time the armour of the gigantic armadillo, the glyptodon, that had formed shelters over the heads of the human dwellers in the pampas, like Esquimaux huts, had not yet been discovered. The cave of Ultima Esperanza in Patagonia had not been searched, and no one had seen the red-haired coat of the sloth as large as an ox, the gryptotherium (a relative of the real megatherium), cut by some prehistoric human hand, amongst a heap, several yards deep, of the animal’s manure—in such peculiar circumstances as to prompt the suggestion that the giant-sloths had been kept tame in the cavern, as in a cyclopean stable, by prehistoric Indians. Darwin thought the remains were very old, though this by no means lessened the inspiration.

As our geological Hamlet speculated over these bones of extinct monsters, the ideas of Linné and Cuvier struggled fiercely in his mind with the new, heretical ideas inspired by Lyell. How was it that these ancient, extinct animal forms of America resembled in every detail and in the most marked characteristics certain living American animals? Before him were the relics of past sloths, armadilloes, and giant-llamas. In the actual America, also, there were sloths, armadilloes, and llamas, though with some difference. And nowhere else on earth, either in past or present time, were there sloths, armadilloes, and llamas. Cuvier had replied, God had pleased to create those ancient megatheria, glyptodons, and macrouchenias of America. Then, one day, he sent his destructive catastrophe, and swept them all away, as a sponge goes over the table. Then, in the empty land, he created afresh the sloths, armadilloes, and llamas of to-day. But why had God made the new animals so like the old that the modern zoologist has to class the megatherium in the same narrow group as the actual sloth, the ancient glyptodon with the modern armadillo, and so on?

Darwin, who had studied theology, was unshaken with regard to God himself. However, something occurred that occurs so often and with such good result in the history of thought. It appeared to him that the notion of a direct creation is by no means the simplest way of explaining things, but the most puzzling and complicated. Darwin believed in Lyell. There had been no destructive catastrophe at all to sweep away the megatherium and its companions. They had disappeared gradually, by natural means. Was it not much more rational to suppose that the actual sloths and armadilloes came into being gradually, by natural means? Part of the old animal population had not perished, but been transformed into the actual species. There was a bond of relationship between the past and the present. One or other grotesque and perhaps helpless giant form may have completely disappeared in the course of time. But the golden thread of life was never entirely broken. Other and more fortunate species had preserved the type of the sloth, the armadillo, and the llama; they had developed naturally into the living animals of America. God might remain at the groundwork of things. He had launched matter into space, and impressed natural laws on it. But these sufficed for the further work. They created America. They developed the mammal into the sloth and the armadillo in the days of the megatherium and the glyptodon. They maintained these types in the country, in a straight line of development; the progressive principle of life bringing about the extinction of certain forms, and transforming others by a more fitting adaptation to their environment.

Darwin always looked back on this first conflict of his ideas in presence of the dead shells and bones of the ancient pampas animals as an hour of awakening. It was the birth of his humanity in the higher sense. It is of interest to us because it coincides exactly with the date of Haeckel’s birth in the ordinary sense.

In Darwin’s fine account of his voyage, which is mostly arranged in the form of a diary, we find a passage written on the east coast of Patagonia on January 9, 1834, and the next on April 13th. In the meantime the ship had made a short zigzag course, which is spoken of in another connection. But the interval between the two dates is taken up with a passage on these gigantic animals, the reasons for their extinction and the striking fact of their bodily resemblance to the living animals of South America. “This remarkable resemblance,” we read, “between the dead and the living animals of one and the same continent will yet, I doubt not, throw more light on the appearance of organic beings on the earth than any other class of facts.” This is clearly a summary of Darwin’s deepest thoughts at the time. Haeckel was born on February 16th of the same year, 1834. Thus the bodily birth of one of the two men whom we conceive to-day as Dioscuri coincides with the spiritual rebirth of the other. But it would be nearly thirty years before they would meet in spirit never to part again. At the very beginning of their acquaintance Darwin wrote a letter to Haeckel (October 8, 1864) in which he speaks of the earliest suggestions of his theory. The Hamlet-hour comes back vividly to his memory. “I shall never forget my astonishment when I dug out a gigantic piece of armour, like that of a living armadillo. As I reflected on these facts and compared others of a like nature, it seemed to me probable that closely related species may have descended from a common ancestor.”

However we take it, Darwin then saw for the first time that his difficulty about the mutability of species was from the first, in his own mind, a difficulty about God. He began his doubts with the ancient armadillo; he ended with God.

On the return journey from South America, which amounted to a circumnavigation of the globe, the struggle was renewed at the Galapagos islands. Volcanic forces had raised these islands from the bed of the ocean in comparatively recent times. They were, therefore, bound to be a virgin province at the time. Now, however, the walls of the crater were clothed with vegetation, birds flew after insects, and gigantic turtles and lizards lived on the shores. Whence did these plants and animals come? Darwin examines them. They have an unusual appearance, and seem to point to America. Yet not a single species is now wholly American; each has its peculiarities. An historical controversy arises over the islands, and men range themselves in parties once more. Empty islands emerge from the blue waters. How are they to be populated? There are two possibilities. One is that God has created the animals and plants—Galapagos animals and plants. But in that case why has he created them entirely on the American model, while diverging from it in small details? The second possibility is that the animals and plants were brought by the current or the wind from the neighbouring American coast; they are American plants and animals. After landing on the islands, they adapted themselves to their new surroundings, and were altered. Hence both the resemblance and the difference. The theory assumes, of course, that species are mutable. If that is so, we can explain everything—without God.

But the greatest and tensest struggle began when Darwin returned home. He approached the most audacious, but most striking fact, for his purpose. Up to this the question had been whether new species were produced by God or by natural necessity. Now a third element was introduced, man himself. He also alters species, as a breeder of pigeons, rabbits, sheep. He has done it with success for ages—only the Linnés and Cuviers had not noticed the fact. How does he accomplish it?

A breeder desires to give his sheep finer wool. He examines the wool of a thousand sheep. The difference between them is so slight that it is of no practical consequence. But the farmer selects the male sheep out of the thousand that has the best quality of wool, and the corresponding female. He crosses the two. Their young have wool of a slightly improved quality, and he picks out the best amongst them once more for crossing. He continues this through several generations. At last, with his continuous selection and crossing, the quality of the wool increases so much that any one can recognise it at once, and it has a distinct cultural value. In this way improved races of animals and large numbers of fine flowers have been produced by breeders: by artificial selection of the fittest to reproduce in each generation. This was done by man—not by God, not by nature in remote times, but under our very eyes, by man.

Now for an analogous process without man. Let our sheep live wild in any country. No human breeder has any interest in them: God does not seem to interfere with them. They live on and on, for thousands of years, generation after generation. Here again, in the wild state, we find the same slight variations in the quality of the wool. One sheep has a thicker coat than another. For thousands of years the fact is without significance. Then occurs a slow change of the environment. The climate becomes colder. Perhaps an ice-age sets in, such as our earth seems to have passed through many times. There are two alternatives. A very hard winter may set in at once and all the sheep perish, because their woolly coat is too thin in all cases. That would mean the extinction of a whole species. But the severe cold may come on gradually. The winters are more trying. So many sheep perish in the first winters; but so many others survive. Which will survive? Naturally, those that happened to have the thicker coats. Those alone live on to the spring, and reproduce. The following year the coat is thicker all round, as the lambs all came from relatively thick-coated parents. The winter decimates them again, and the thickest coated survive once more, and so on. The pressure of external conditions, the “struggle for life,” selects just as man does. Only the best adapted individuals survive and reproduce.

The whole earth is a vast field of splendid adaptations. The tree-frogs are green because only green frogs are preserved; all the others are destroyed. The arctic hare is white on the snow, the desert-fox yellow. For a thousand reasons in the course of the earth’s development these backgrounds—white, yellow, green; snow, desert, forest, &c.—have themselves been constantly changing under the action of Lyell’s changes in the crust of the earth. Hence constantly fresh adaptations, with a certain percentage of complete extinctions. In these ceaseless new adaptations we see a picture of an eternal progressive development. Always a finer selection: always better material: natural things always selecting and being selected. Man is superfluous in this world-old, eternal process. And God, too, is superfluous.

That was Darwin’s last and decisive thought. Divine action was excluded from the whole province of animal and plant species. It does not matter whether or no the shrewd idea of natural selection solves the whole problem. Why speak of “whole,” when all problems are really unfathomable? He left open the question of the origin of the first slight variations, the first increase in the fineness or thickness of the sheep’s wool, for instance. He left open the question of the inner nature of the process—and a good deal more. But these things did not affect the great issue.

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.

However, we find a curious confession a few paragraphs before the theistic conclusion of the book. It runs: “Light will be thrown on the origin and history of humanity.” Light, that is to say, from the theory of the transformation of species by natural selection. The words contained the promise of a new twilight of the gods. In the innocent days, when the Creator stood in person behind each species of animal and plant, Linné had seen no great innovation in his defining man as a definite species, the highest species of mammal. God had created the polar bear and the hippopotamus, Genesis said, as well as man. That man had transgressed the command in Paradise, fallen into sin, needed salvation, and so on, was another matter altogether. With Darwin the innovation was incalculably important.

On his theory the various species of animals had been developed from each other, without a new creative act. If man was an animal species in this sense, he also must have originated from other animals; and that would be bitter. The phrase shows that Darwin already saw clearly, and had abandoned his belief in a special creation of man. But this point was bound to make more bad blood than all the rest put together. God, now restricted to the direct production of the first living things, had lost man as well as the animals. Moreover, whatever interpretation was put upon the Mosaic narrative, the very source of theistic belief, the Bible, was called into question. How had we come to know of this story of divine creations? By the Bible, the vehicle of revelation. But this Bible was the work of man, and man was now well within the bounds of nature, from which God had been excluded. How could he learn anything from revelation? The biblical writers had clearly only made conjectures. Some of them—with regard to Adam, for instance—were certainly incorrect. There was nothing in the Bible about evolution by means of selection. Indeed, was not the whole picture of a creating Deity an error? These thoughts were bound to press upon the religious mind with all their logical force. When they did so, the very foundations of theology became insecure, to a far more serious extent than Darwin’s moderate conclusion suggested. When the book fell on this contentious ground, it was bound, even if it were only read in the last two pages, to provoke vast waves of hostility against its heretical zoology and botany, especially in England.

Haeckel was in Italy when the work—the work of his life, too, as the sequel shows—was published. We have seen where he was: in sight of the blue sea, penetrating for the first time into a special section of zoology, the radiolaria, and making it his own. He was far from theorising, for the first years of reality were upon him. He returned to Berlin at the beginning of May, 1860, bringing his study of the radiolaria, and resolved to publish it in comprehensive form. Here he learned for the first time that a “mad” work by Darwin had appeared, that denied the venerable Linnean dogma of the immutability of species.

German official science was now invaded from two sides at once. Haeckel had returned like a new man from the freshness of Italy; and Darwin’s work, translated by Bronn, was bringing some slight extract of the English student’s thoughts, like a draught of old golden wine. They were bound to meet this time.

The aged Bronn, a German naturalist of distinction and merit, had found the Origin of Species interesting enough, at least, to deserve the trouble of translation. But his interest in it was very restricted. He was one of the thoughtful students of the days following Cuvier, and was not of the kind to pin his faith to one man. The appearance of the plant and animal species in the various terrestrial periods, so sharply separated by Cuvier himself, showed unmistakably an ascent from lower to higher forms. The fish is placed lower in the system than the mammal. At a certain period there were fishes living, but no mammals as yet. At another period the only plants on the earth were of the decidedly lower group of the cryptogams (ferns, shore-grasses, club-mosses), and these were succeeded by pines and palm-ferns, and finally by the true palms and foliage-trees. Cuvier’s theory of creation had to take account of this. Agassiz, who held firmly to the fresh creation of species in each new epoch, conceived the Creator as an artist who improved in his work in the course of time. Each new achievement was better than the preceding. It was rather a curious idea of the Creator!

Others, who did not venture to use the idea of Deity quite so naïvely as Agassiz in zoology and botany, conceived a “law of development” within life itself. It was a time when belief in a “vital force” was universal. Living things had their peculiar force, which was not found in lifeless things. The life-principle might be at work in the law of development. It would raise living things higher and higher in the succeeding geological epochs. It was a vague theory, though it purported to cover not only the fact but the machinery of development. In the course of ages it brought about the appearance of new species. Those who held this idea of an immanent law of evolution rejected the older notion of a personal Deity, putting in an appearance suddenly at the beginning of the secondary period and creating the ichthyosauri “out of nothing.” They looked upon Cuvier’s catastrophes, to which Agassiz still clung, with a touch of Lyell’s scepticism. The “law of evolution” had been the deus ex machina of the long procession of life-forms. One day a fish ceased to give birth to little fishes in the manner of its parents. The “law of evolution” was at work in its ova, and suddenly little ichthyosauri were developed from them. Thus, again, a lizard was believed to have engendered young mammals one day. One student would hold that the transition was quite abrupt in this sense. Another would think it more gradual, and approach the idea of a slow transformation of a fish into a lizard, and a lizard into a mammal, or a tree-fern into a palm-fern, and this into a true palm. At the bottom they were all agreed that the whole inner law of evolution had nothing whatever in common with the other laws of nature and was not subordinate to them. They did not hold an evolution in harmony with the great mechanism of natural laws. Their principle got astride of natural laws at certain points, like a little man, and turned them in this or that direction.

Very little philosophic reflection was needed to show that they had merely replaced the Creator with a word. The older Dualism remained. On one side was the raw material of the world with the ordinary natural laws; on the other side a lord and master, the law of evolution, playing with the laws as it pleased, and moulding the material into new life-forms in an advancing series. It is true that they no longer pictured to themselves a venerable being with a white beard creating the ichthyosauri, but the finger of God remained in the law of evolution, attenuated into a special and spectral form. The God that acted from without was banished, but the “impulse from within,” reduced to a mere skeleton in substance, was put upon the throne.

The advocates of the law of evolution had assuredly done much in preparing the way for Darwin, as they had insisted that certain advances in detail were undeniable and built up theories from the chaotic material provided by special research—especially seeing that some of the ablest naturalists of the time were amongst them, who determined to retain speculation in zoology and botany. But, on the other hand, it cannot be questioned that the confused nature of their fundamental idea, which, in fact, was not far removed from the theological notion of the vital force, gave the rigid and “exact” academic workers an apparent right to reject all speculation on the possibility of an evolution of species as an unscientific dream. The aged Bronn was in 1860 one of the most prudent and sober of the advocates of the inner principle of evolution. He candidly acknowledged that Darwin had struck a severe blow at the great idea of his life, on one side at least. Darwin’s work not merely dismissed God to the wings as a personality, but even left no room for the finger of God, for his spiritual writing on the walls of the living world. It found evidence of natural laws alone. From them came, if not life itself, at all events selection, adaptation, and evolution by virtue of this increasing adaptation—the higher advance that converted the fish into a lizard and the lizard into a mammal. The fine old worker, with an age of indefatigable labour behind him, though he had not got beyond the idea of a “law of evolution,” looked on Darwin with a mixture of fear and admiration as he cut into the very heart of these problems. He added amiable notes to the work to the effect that one would like to go so far, but the distance was intimidating. In fact, he omitted altogether from his translation the very important phrase that “light would be thrown on the origin of man.” It would be a terrible affair, he thought, if the discussion were at once turned on this. Man himself owing his origin neither to God nor the finger of God, but to natural selection in the ordinary course of natural laws! It was not to be thought of. Hence the phrase was struck out, as quite too extravagant, in his otherwise admirable work.

Bronn had himself become something of a revolutionary amongst his colleagues by the translation. The rigidly “exact” workers crossed themselves before the Germanised work. Most of the “evolutionists” in the older sense had by no means the bonhomie to speak even of a “possibility” like the patriarch Bronn. From the first Darwin was—Haeckel was the first to experience it—branded with the anathemas of the two opposite schools of science in Germany. On the one hand the rigorous and exact workers declared that his teaching was pure metaphysics, because it sought to prove evolution and contemplated vast ideal connections. On the other hand the Dualist metaphysicians denounced him as an empiric of the worst character, who sought to replace the great ideal elements in the world by a few miserable natural necessities. It is significant to find that Schopenhauer, the brilliant thinker, regarded the Origin of Species as one of the empirical soapsud or barber books produced by exact investigation, which he thoroughly despised from his metaphysical point of view. And there were already (there are more to-day) whole schools of zoology and botany that looked upon Darwin’s theoretical explanations as unscientific “mysticism,” “metaphysics,” and “philosophy in the worst sense of the word.”

Haeckel read the dangerous book at Berlin in May, 1860. “It profoundly moved me,” he writes to me, “at the first reading. But as all the Berlin magnates (with the single exception of Alexander Braun) were against it, I could make no headway in my defence of it. I did not breathe freely until I visited Gegenbaur at Jena (June, 1860); my long conversations with him finally confirmed my conviction of the truth of Darwinism or transformism.”

It was, therefore, in the critical days immediately before or during the negotiations with Gegenbaur which led to his setting up as a private teacher at Jena. The names of Darwin and Jena unite chronologically in Haeckel’s life—two great names that were to bear him into the very depths of his career, and that have their roots in the same hour.

We may ask what it was in the book that “profoundly moved” the young student of the radiolaria. The name of Braun only partly explains the matter, as Braun was an evolutionist of the same type as Bronn. He was amiably disposed to meet it, but did not openly enter on the new path. We must go deeper. We then understand it clearly enough, if we recollect Haeckel’s bent in the last few years.

He had no longer any scruples with regard to religion. The God of tradition had been entirely replaced in him by Goethe’s God, who did not stand outside of, but was one with, nature. “There is nothing within, nothing without: for what is within is without.” There was not a kernel, God, and a shell, Nature. “Nature has neither kernel nor shell: it is both together.”

The years spent in southern Italy had certainly helped to bring out as strongly as possible the contrast between Goethe’s conception and the conventional idea of God as an extramundane Creator. No surroundings are more apt to do this than the Romance peoples of the Mediterranean. In the northern, Protestant countries the ecclesiastical tradition of Deity has always a spiritual element, a kind of vague resolution into moral laws, that in some measure approach natural law, though one made by man. There is no trace of this in Naples and Sicily. The supernatural there is the saint, the madonna; they penetrate unceasingly into the natural reality, in every little detail of life and conduct. The antithesis of the poor cosmic machinery and the ever-present heavenly help and supersession of it is raised to a supreme height in the popular belief. Miracles are not relegated to earlier days and ancient books. They are expected, affirmed, and believed every day. The saint fills the net of the fisherman as he chases the edible cuttle-fishes by torchlight. The saint makes the storm that threatens the boat—makes it suddenly out of nothing. The madonna can arrest in a second the glowing stream of lava that rolls towards the village from Vesuvius, and if hundreds of them unite in ardent prayer and the making of vows, she will be appeased and do it. Every hair on a man’s head is twofold; there is the natural hair and a hair that can at any moment be changed, transformed, annihilated, or created afresh from nothing, by divine power. The man who has lived in this atmosphere of practical Dualism for years must be saturated to his innermost being with a feeling of the absolute contradiction between this conception of God and nature and Goethe’s philosophy. If he is to follow Goethe, this ancient extramundane, ever-interfering Deity must be given up without the least attempt at compromise.

Thus Haeckel’s position was incomparably more radical than Darwin’s from the very first. He no longer believed in a Creator, either in whole or part.

He asked himself, therefore, how he could now explain certain things in nature. He had learned from the great Johannes Müller that species were unchangeable, and it was impossible to conceive the spontaneous generation of the living from the dead. The essence, the predominant element of the living thing was the mysterious, purposive “vital force.” The first of these three ideas of the master’s to be surrendered entirely by him was the vital force. Even in Müller’s lifetime, and in his own laboratory, so to say, his pupil, Du Bois-Reymond, made the first great breach in the doctrine with his famous study of animal electricity, a really pioneer piece of work, especially as regards method, at that time. It was now more than ever probable that there was no more a special vital force besides the simple natural forces than there was a God distinct from nature. The animal or the plant was a wonderful outcome of the same laws that had built the crystal or the globe. The sharp distinction between living and dead matter fell into the waste-basket, where so many other Dualistic tags lay, cut off by the shears of science.

But if one of Müller’s theses was abandoned, another was retained as a real blessing with all the more tenacity by his pupils—the thesis that even the scientific investigator shall always “think”—nay, even “philosophise.” Müller called it “using one’s imagination,” in his desire to emphasise it. Now it was certainly a fair philosophic deduction from Du Bois-Reymond’s discoveries that one ought no longer to be so rigid as regards the possibility of spontaneous generation. If the same natural forces are at work in the organic and the inorganic, the living and the dead, it is no longer inconceivable theoretically that life and inorganic matter only differ in degree, not in kind. The distinction might become so slender—either now, or at least in past times—that an apparent “spontaneous generation” might really take place.

Here again, it is plain, Haeckel had a greater freedom than Darwin. Working gradually from above, Darwin desisted when he came to spontaneous generation, and left room for God. Haeckel came into an open field, believing that there was no eternal Deity and that spontaneous generation itself was by no means a forbidding conception. The problem for him was merely, how he could work upward through the plants and animals of all geological periods until he reached man. He was bound to seek to dispense even here with the historical vital force, and explain everything by the great natural laws of the cosmos.

It was in this frame of mind that he received Darwin’s book. Can it be in the least surprising that it “profoundly moved” him. It opened out to him the whole way, just as he desired it. Müller’s third thesis, the immutability of species, broke down. But what did it matter? It was now possible for the first time to construct a philosophical zoology and botany in Müller’s sense, without any vital force and without God.

At the same time this rapid and impulsive acceptance of Darwin’s theory was not merely a decisive moment in Haeckel’s intellectual development; it was bound to be, even externally, a most important step in his career. The theistic controversy was forced on his attention. It passed out of the province of his inmost life, that had hitherto only been discussed in conversation with intimate friends, into the professional work of his most serious and public occupation—into zoology, into the radiolaria at which he had been working for years.

We must realise clearly what it must have meant at that time for a young zoologist, who wanted to do rigorous professional work and had quickly decided to settle at Jena in order to begin his career as an official teacher, to become “a Darwinian” in conviction and open confession. It might cost him both his official position and his scientific future; and this at the very moment when he had just secured them, or was in a better position to secure them. We have here for the first time the open manifestation of a principle in Haeckel’s life that he had hitherto only used inwardly, in application to himself. The truth must be told, whatever it cost. Shoot me dead, morally, materially, or bodily, as you will: but you will have to shoot the law first.

Darwin’s ominous book had been available in Bronn’s translation for two years. The German professional zoologists, botanists, and geologists almost all regarded it as absolute nonsense. Agassiz, Giebel, Keferstein, and so many others, laughed until they were red in the face, like a riotous first-night public that has made up its mind as to the absurdity of the play from the first act, and torment the author as the cat torments a mouse. Then Haeckel gave to the world his long-prepared Monograph on the Radiolaria (1862), the work with which he endeavours to establish—in fact, must establish—his position as an exact investigator, even amongst the academic scholars of the opposite camp. All goes very smoothly for many pages of the work. A few traces of heresy may be detected about page 100. The passage deals with the relation of organ to individual, in connection with the social species of radiolaria that live in communities. It is a subject that Haeckel took up with great vigour later on, as we shall see. Here it affords him an opportunity to say a word about the general fusion of things in the world of life, in opposition to our rigid divisions in classification. Organ and individual pass into each other without any fixed limit. That, he says, is only a repetition of the relation of the plant to the animal. We cannot establish any fixed limitations between them. What we set up as such are only man’s abstractions. In nature itself we never find these subjective abstract ideas of limitation “incorporated purely, but always fading away in gradual transitions; here, again, the scale of organisation rises gradually from the simplest to the most complex, in a continuous development.” However, these are words that might have been written by Schleiden or Unger or Bronn before Darwin’s time.

Yet there is something in the work that would have been a jet of ice-cold water to the Agassizs and Giebels. This brilliant new “Extraordinary Professor of Zoology and Director of the Zoological Museum at Jena University,” as it says on the title-page, accepts Darwin in a certain unambiguous passage late in the text.

It is necessary to bring to light once more this passage, buried in a work that is not easily accessible, an expensive technical work separated from us by four decades now. It is worth doing so, not only on account of the courage it displayed at the time, but also as a document relating to the great controversy of the nineteenth century. It is found on pages 231 and 232, partly in the text, but for the most part in a note. Immediately after giving the table of classification Haeckel goes on to say: “I cannot leave this general account of the relationship of the various families of the radiolaria without drawing special attention to the numerous transitional forms that most intimately connect the different groups and make it difficult to separate them in classification, to some extent.” It is interesting to note that in spite of our very defective knowledge of the radiolaria it is nevertheless possible to arrange “a fairly continuous chain of related forms.” He would like to draw particular attention to this, because “the great theories that Charles Darwin has lately put forward, in his Origin of Species in the Plant and Animal World by Natural Selection, or The Preservation of the Improved Races in the Struggle for Life, and which have opened out a new epoch for systematic biology, have given such importance to the question of the affinities of organisms and to proofs of continuous concatenation that even the smallest contribution towards the further solution of these problems must be welcome.” He then endeavours in the text, without any more theoretical observations, practically to construct a “genealogical tree of the radiolaria,” the first of a large number of such trees in the future. He takes as the primitive radiolarian a simple trellis-worked globule with centrifugal radiating needles, embodied in the Heliosphæra. “At the same time,” he says, characteristically, “this does not imply in the least that all the radiolaria must have descended from this primitive form; I merely show that, as a matter of fact, all these very varied forms may be derived from such a common fundamental type.” In other words, once more, it is conceivable—a golden word even long afterwards. The first “genealogical tree,” a “table of the related families, sub-families, and genera of the radiolaria,” arranged in order from the higher forms down, and connected with lines and brackets, comes next. The text deals thoroughly with the possibility of descent. This closes the first and general part of the monograph. But there is a long note at this point in the text, where Darwin’s title is cited, that gives us his first appreciation of Darwin in detail. It begins: “I cannot refrain from expressing here the great admiration with which Darwin’s able theory of the origin of species has inspired me. Especially as this epoch-making work has for the most part been unfavourably received by our German professors of science, and seems in some cases to have been entirely misunderstood. Darwin himself desires his theory to be submitted to every possible test, and ‘looks confidently to the young workers who will be prepared to examine both sides of the question impartially. Whoever leans to the view that species are changeable will do a service to science by a conscientious statement of his conviction; only in that way can we get rid of the mountain of prejudice that at present covers the subject.’ I share this view entirely,” Haeckel continues, “and on that account feel that I must express here my belief in the mutability of species and the real genealogical relation of all organisms. Although I hesitate to accept Darwin’s views and hypotheses to the full and to endorse the whole of his argument, I cannot but admire the earnest, scientific attempt made in his work to explain all the phenomena of organic nature on broad and consistent principles and to substitute an intelligible natural law for unintelligible miracles. There may be more error than truth in Darwin’s theory in its present form, as the first attempt to deal with the subject. Undeniably important as are the principles of natural selection, the struggle for life, the relation of organisms to each other, the divergence of characters, and all the other principles employed by Darwin in support of his theory, it is, nevertheless, quite possible that there are just as many and important principles still quite unknown to us that have an equal or even greater influence on the phenomena of organic nature. This is the first great attempt to construct a scientific, physiological theory of the development of organic life and to prove that the physiological laws and the chemical and physical forces that rule in nature to-day must also have been at work in the world of yesterday.” Haeckel then refers to Bronn, the translator of the book. With Bronn he calls Darwin’s theory the fertilised egg from which the truth will gradually develop; the pupa from which the long-sought natural law will emerge. And he concludes: “The chief defect of the Darwinian theory is that it throws no light on the origin of the primitive organism—probably a simple cell—from which all the others have descended. When Darwin assumes a special creative act for this first species, he is not consistent and, I think, not quite sincere. However, apart from these and other defects, Darwin’s theory has the undying merit of bringing sense and reason into the whole subject of the relations of living things. When we remember how every great reform, every important advance, meets with a resistance in proportion to the depth of the prejudices and dogmas it assails, we shall not be surprised that Darwin’s able theory has as yet met with little but hostility instead of its well-merited appreciation and test.” There is yet no question of man and his origin. But what he says is very bold for the time; and before a year is out we shall find him drawing the most dangerous conclusion of all. And it is found, not in a late page and note in a stout technical volume, but in the pitiless glare of the sunlight, in the most prominent position that could then be given to it in German scientific culture.