The General Morphology of Organisms[[2]] was published in 1866, with the sub-title: “General elements of the science of organic forms, mechanically grounded on the theory of descent as reformed by Charles Darwin.” It consists of two thick volumes of small print, containing more than 1,200 pages. The preface is dated September 14, 1866. It is now one of the most important works in the whole mental output of the second half of the nineteenth century. In respect of method of scientific research it is a landmark by which we may characterise and appraise the whole half-century. For general biological classification it inaugurates a new epoch, as had been done fifty years before by Cuvier, and again fifty years earlier by Linné. What it did for zoology in the narrow sense was thirty years afterwards summed up in one phrase by a writer of acknowledged competence, Richard Hertwig: “Few works have done as much towards raising the intellectual level of zoology.” Among Haeckel’s own achievements, great and varied as they are, this work occupies the highest place. Setting aside certain special pieces of research, and regarding him mainly as a man of great ideas, we find his whole programme in this work. The History of Creation, that has taken his name far and wide over the globe beyond the frontiers of zoology, is only an extract from this work. He put his heart in it. The others are only the improved blood-vessels of his system of ideas, partly duplications, partly simplifications. I do not say this either in blind admiration or in criticism, but as the expression of a plain fact. Posterity will turn to this work when, either in hostility or in sympathy, it wishes to appreciate Haeckel.[[3]]

[2]. This work of Professor Haeckel’s has not been translated into English. [Trans.]

[3]. Professor Huxley described the General Morphology as “one of the greatest scientific works ever published.” [Trans.]

His contemporaries did not accept the work without difficulty. It came out without noise, exerted a tremendous influence in a quiet way, and at last disappeared altogether from the bookshops. It is still attacked, but has never been refuted. At libraries one finds, as I know from experience, that it is always “out,” and therefore must be read continually. It is found occasionally at second-hand booksellers; an antiquarian price running to five pounds and more is put on it, after forty years’ active production on the part of its author. At present you could count on your fingers the German works that have this distinction of being highly priced and out of print. One such is Vischer’s Æsthetics, and another is the first edition of Gottfried Keller’s Green Henry. Keller had threatened any one who ever attempted to republish this first edition (afterwards modified but not improved by him) that their hand would not rest quietly in the grave. But the price of the work went up amongst antiquarians. I feel, in speaking of Haeckel’s General Morphology, that I am describing a book which has become so rare that one must treat it as something new, a codex that is only accessible to a few. It is certainly not known to the general reader.

Let me endeavour in a few words to give a general idea of the chief contents of the work.

All the intellectual forces that had had any influence upon Haeckel now concentrated for a supreme achievement. First of these was Goethe, who supplied the title, “Morphology.” In its simplest signification morphology is merely “the science of forms.” If I take houses, furniture, statues, fishes, flowers, crystals, &c., and only regard and describe their forms, I am a morphologist in the literal sense of the word. But when Goethe invented the term he sought to give it a more restricted application, writing in the style of earlier days, but clearly enough, at Jena in 1807. We have, he says, natural objects before us, especially living objects. We try to penetrate the secrets of their nature and their action. We are not merely observers, but philosophers. It is from this point of view that we approach the subject. It appears to us that the best way to proceed is to separate the various parts. Such a procedure seems calculated to take us very far. Chemistry and anatomy are instances of this analytic kind of research, and both are greatly esteemed and successful. But this method has its limitations. “We can easily break up the living thing into its elements, but we cannot put these together again and restore them to life. We cannot do this in the case of many inorganic, to say nothing of organic, bodies.” What are we to do? “Hence,” Goethe continues, “even scientific men have at all times had an impulse to recognise living things as such, to grasp connectedly their external visible and tangible parts, and take these as indications of the inner life, and thus in a sense to compass the whole in one glance.” “Hence we find at the threshold of art and knowledge and science a number of attempts to establish and elaborate a science that we may call morphology.”

Perhaps Goethe’s meaning can be realised best if one takes a great work of art—say, the Venus of Milo—and imagines how these different kinds of knowledge would deal with it. Purely analytic anatomy would dissolve the superb artistic form into a rubbish-heap of bits of marble. Chemistry would still further break up these bits of marble into the chemical elements of which every block of marble is ultimately composed. The “form” would disappear altogether. But in this case the form means—the Venus of Milo. We see at once that we need another branch of science and investigation besides anatomy and chemistry: we need a morphology, or science of the complete form in which the block of marble is moulded into the Venus of Milo. In the case of our work of art, morphology would be identical with æsthetics, or at least with a branch of it. There can be no doubt that the first and most imperative need for the establishment of a special science of morphology arises from artistic and æsthetic feelings. It is not without significance that it was founded by the poet Goethe, and elaborated with such great success in the nineteenth century by the born artist Haeckel. However, that does not prevent the analogy of the Venus of Milo, which happens to be a creation of human art, being applied equally to every individualised form in nature, to every crystal, plant, and animal. Goethe himself immediately transferred his morphology into the province of botany with such vigour that the term is still regarded, in its narrower sense, as a technical botanical expression. It extends, however, to the whole world in so far as its contents come before us in “forms.” When Haeckel adopted the term he deliberately restricted it, in harmony with the general definition, by calling his work the “Morphology of Organisms,” or the science of the forms of animals and plants.

But there was one danger in the conception of a morphology of animals and plants, namely, the danger of taking it to mean a purely external description: so many thousand species of plants, soberly described, labelled, and numbered, a huge cabinet of stuffed skins, a herbarium of hay. A whole scientific school had really taken it in this sense since Goethe’s time; much as if one were to think æsthetics consisted simply in forming an illustrated catalogue of all the art-treasures in the world, a realistic catalogue in which the marble statues from the Parthenon and the Moses of Michael Angelo would simply be given as number so-and-so in class so-and-so.

Haeckel was preserved from this school by his more immediate masters, as well as by Goethe himself; firstly by Johannes Müller, then by the botanist Schleiden, finally by the influence of Gegenbaur. There was at the time enough, and more than enough, of this external museum-morphology. It was far from Haeckel’s intention to produce a new compendium, in several volumes, of this kind of science of plants and animals. His morphology was to be “general,” to have a broader range, be a programme. As Richard Hertwig said very happily at a later date, he saw his science, not as it then was, but as it ought to be, in his opinion.

The science of forms was to be in the fullest sense a “philosophy of forms.” “Zoological philosophy” was the name given by the hapless Lamarck, in France a century ago, to a work that appeared in the year that Darwin was born, and anticipated his most advanced thoughts. Haeckel, also, gave a new “philosophy of zoology and botany.” The title embodies the magic formula that gave him courage to take up resolutely once more the proscribed word, that seemed to have been scalded and spoiled for ever in the witches’ cauldron of “natural philosophy”; it spoke of the “theory of descent as reformed by Charles Darwin.” Two sub-titles divided the work into two sections from the start. The first part was, the critical elements of the mechanical science of the developed forms of organisms (animal and plant); the second part was, the same elements of the mechanical science of the developing forms of organisms.