As the birthplace of Protestantism, Germany had a tradition of questioning authority and tolerating more liberal interpretations of God, which had an effect upon Central European thinkers. One of the all-time greatest philosophers, Immanuel Kant (1724-1804), was an early believer in the evolution of the solar system, as well as explicitly in biological evolution and progression, as purposively controlled by the Supreme Being, or God. But he did not believe it was our business to investigate:
It is quite certain that we cannot become sufficiently acquainted with organised creatures and their hidden potentialities by aid of purely mechanical natural principles, much less can we explain them; and this is so certain that we may boldly assert that it is absurd for man even to contemplate such an idea, or to hope that a Newton may one day arise to make the production of a blade of grass comprehensible, according to natural laws ordained by no intention; such an insight we must absolutely deny to man.
Another successful, admired philosopher, Friedrich Wilhelm Joseph von Schelling (1775-1854), was also an Evolutionist who maintained that an imperfect universe might be the work of an evolving intelligence. The all-time greatest German writer, Johann Wolfgang von Goethe (1749-1832), who has reached the exalted ranks of being called the German 'Shakespeare', had also been a scientist and definite biological Evolutionist, but no atheist. As early as 1796, Goethe's fertile imagination had composed the following passage:
Thus much then we have gained, that we may assert without hesitation that all the more perfect organic natures, such as fishes, amphibious animals, birds, mammals, and man at the head of the last, were all formed upon one original type, which only varies more or less in parts which are none the less permanent, and still daily changes and modifies its form by propagation.
As a consequence of more liberal ideas of God, belief in the process of evolution was probably far more commonplace in early 19th century Germany than anywhere else. In addition to Kant, Goethe and Schelling, the main exponents were two academic naturalists, Gottfried Reinhold Treviranus (1776-1837) and Lorenz Oken (1779-1851), who were disparagingly referred to as nature-philosophers. Oken can hardly have endeared himself, or his evolutionary views, to people with delusions of grandeur by writing, as early as 1809:
Every organic thing has arisen out of slime, and is nothing but slime in different forms. This primitive slime originated in the sea, from inorganic matter in the course of planetary evolution.
Nonetheless, Oken was a dualist who believed that the Holy Ghost had breathed life and form into that slime. In contrast to Britain, where Mivart's and Butler's views had come after Darwin's, the teleological, dualist view of evolution was well established in Germany long before Darwin's development. Also, in contrast to Britain's Empirical tradition in science of working out the theory on the basis of the evidence, Germany's philosophical leaning to Idealism meant they were more inclined to work out the theory, on the basis of how it should be, and then see if they could find the evidence to support it. It would be a German theory that would change the course of evolutionary thought.
However, the subject of this essay is the German 'Darwin', Ernst Heinrich Haeckel (1834-1919), a Professor of Zoology who became one of the leading figures in the evolution debate. He had been a student of medicine under various eminent teachers, so Haeckel approached evolution theory as a comparative expert in physiology, histology and embryology. His own speciality became what he called Monera, or the many varieties of un-nucleated, unicellular organisms which we now lump together as bacteria, which he believed had been the spontaneously-generated starting point of evolution. (At the time, bacteria were just the parasitic type of micro-organisms.) To Haeckel, those disputed, un-nucleated cells were the vital link between the inorganic world and the world of 'proper' cells. His driving ambition was to defy Kant and demonstrate that the world of life was explicable without recourse to any kind of Creator. Haeckel was the Richard Dawkins of 19th century Germany. To the dualist philosophers and scientists who were prevalent in Germany then, not to mention the Establishment partnership of Church and State, that made him a heretic from the very start.
Patriot that he was, Haeckel proudly claimed that it was Goethe who first made him aware of evolution, but he did not become a committed Evolutionist till he read the German translation of Darwin's "Origin of Species". He also learned about Lamarckism. Like many contemporary Lamarckists, Haeckel saw no contradiction between the two views; Darwin's Theory of Selection was a complementary development of Lamarck's Theory of Descent. (Seeing selection in broader terms than Darwin, Haeckel usually omitted the word 'natural', as being superfluous.) In his popular 1868 book, "The History of Creation", from which all extracts until further notice are taken, Haeckel threw caution to the wind by expressing evolutionary views more colourfully, uncompromisingly, dogmatically, and readably, than any other 19th century writer. He saw evolution as a battle between the forces of Inheritance, or conservative heredity, and Adaption, or progressive change:
Even long before Darwin had published his Theory of Selection, some naturalists, and especially Goethe, had assumed the interaction of two distinct formative tendencies - a conservative or preserving, and a progressive or changing formative tendency - as the causes of the variety of organic forms. The former was called by Goethe the centripetal or specifying tendency, the latter the centrifugal tendency, or the tendency to metamorphosis. These two tendencies completely correspond with the two processes of Inheritance and Adaption. Inheritance is the centripetal or internal formative tendency which strives to keep the organic form in its species, to form the descendants like the parents, and always to produce identical things from generation to generation. Adaption, on the other hand, which counteracts inheritance, is the centrifugal or external formative tendency, which constantly strives to change the organic forms through the influence of the varying agencies of the outer world, to create new forms out of those existing, and entirely to destroy the constancy or permanency of species. Accordingly as the Inheritance or Adaption predominates in the struggle, the specific form either remains constant or changes into a new species.
Like Darwin, whom he greatly admired, Haeckel believed in the inheritance of acquired characteristics, though Haeckel saw acquired characteristics, through environmental change, nutrition and use or disuse, as the main source of variation, and their inheritability as a proven empirical fact in most cases:
Which of the changes acquired by an organism are transmitted to its descendants, and which are not, cannot be determined a priori, and we are unfortunately not acquainted with the definite conditions under which the transmission takes place. We only know in a general way that certain acquired qualities are much more easily transmitted than others, for example, more easily than the mutilations caused by accidents. These latter are generally not transmitted by inheritance, otherwise the descendants of men who have lost their arms or legs would be born without the corresponding arm or leg; but here, also, exceptions occur, and a race of dogs without tails has been produced by consistently cutting off the tails of both sexes of the dog during several generations. A few years ago a case occurred on an estate near Jena, in which by a careless slamming of a stable door the tail of a bull was wrenched off, and the calves begotten by this bull were all born without a tail. This is certainly an exception; but it is very important to note the fact, that under certain unknown conditions such violent changes are transmitted in the same manner as many diseases.
Well-known to Darwin, disliked by Wallace, and hailed by Huxley, Haeckel was the man who brought biology, as contrasted with natural history, into evolution, not least through his fascination with the processes of reproduction:
It at first appears exceedingly wonderful that in the sexual propagation of man, and of all the higher animals, the small egg, the minute cell, often invisible to the naked eye, is able to transfer to the produced organism all the qualities of the maternal organism, and, no less mysterious, that at the same time the essential qualities of the paternal organism are transferred to the offspring by means of the male sperm, which fructifies the egg-cell by means of a viscid substance in which minute thread-like cells or zoo-sperms move about. But as soon as we compare the connected stages of the different kinds of propagation, in which the produced organism separates itself more and more as a distinct growth from the parental individual, and more or less early enters upon its individual career; as soon as we consider, at the same time, that the growth and development of every higher organism only depends upon the increase of the cells composing it - that is, upon their simple propagation by division - it becomes quite evident that all these remarkable processes belong to one series.
......There can be no doubt as to the purely mechanical material nature of this process. But here we stand full of wonder and astonishment before the infinite and inconceivable delicacy of this albuminous matter. We are amazed at the undeniable fact that the simple egg-cell of the maternal organism, and a single paternal sperm-thread, transfer the molecular individual vital motion of these two individuals to the child so accurately, that afterwards the minutest bodily and mental peculiarities of both parents reappear in it.
He was characteristically jumping the gun in his conception by means of a single sperm, which may have been news to readers. However, he had put his finger on the realisation, in Germany at least, that the inheritable characteristics of an animal must be somehow contained in the sperm and egg cells. All the information needed to make each sexually-reproducing organism is contained in a single fertilised egg cell. That is the bottle-neck that biology needed to explain. The wonderful facts of life were never far from Haeckel's mind:
A third law of conservative transmission may be called the law of sexual transmission, according to which each sex transmits to the descendants of the same sex peculiarities which are not inherited by the descendants of the other sex. The so-called secondary sexual characters, which in many respects are of extraordinary interest, everywhere furnish numerous examples of this law. Subordinate or secondary sexual characters are those peculiarities of one of the two sexes which are not directly connected with the sexual organs themselves; such characters, which exclusively belong to the male sex, are, for example, the antlers of the stag, the mane of the lion, and the spur of the cock. The human beard, an ornament commonly denied to the female sex, belongs to the same class. Similar characteristics by which the female sex is alone distinguished are, for example, the developed breasts, with the lactatory glands of female mammals, and the pouch of the opossum. The bodily size, also, and complexion, differs in female animals of many species from that of the male. All these secondary sexual qualities, like the sexual organs themselves, are transmitted by the male organism only to the male, not to the female, and vice versa. Contrary facts are rare exceptions to the rule.
A couple of chapters later, after discussing the origin of some male secondary sexual characteristics as weapons in the struggle with other males for the possession of females, which is an issue covered by Natural Selection, we find him canvassing female choice before Darwin even mentioned the idea:
Many male birds carry on a regular musical contest when they contend for the possession of the females. It is known of several singing birds, that in the breeding season the males assemble in numbers round the females, and let their songs resound before them, and that then the females choose the singers who best please them for their mates.....Among many other insects and birds it is not song, or, in fact, any musical accomplishment, but finery or beauty of the one sex which attracts the other. Thus we find that, among most gallinaceous birds, the cocks are distinguished by combs on their heads, or by a beautiful tail, which they can spread out like a fan; as for example, in the case of the peacock and turkey-cock. The magnificent tail of the bird of paradise is also an exclusive ornament of the male sex. In like manner, among very many other birds and very many insects, principally among butterflies, the males are distinguished from the females by special colours or other decorations......As the females do not possess these attractions and decorations, we must come to the conclusion that they have been acquired by degrees by the males in the competition for the females, which takes its origin in the selective discrimination of the females.
More valued in the 20th century, though nonetheless discredited for some of his conclusions (and exaggerated drawings), was his highlighting of the immediate consequences of sex - embryology. He noted, as the father of embryology, Karl Ernst von Baer (1792-1876), had done before, that all mammal embryos, and even non-mammal embryos, follow the same development paths up to a point, after which they diverge in specialist ways. All the different species diverge from the main path at different points, but some species undergo much more embryological development after divergence than others:
Certain very early and low stages in the development of man, and the other vertebrates in general, correspond completely in many points of structure with conditions which last for life in the lower fishes. The next phase which follows upon this presents us with a change of the fish-like being into a kind of amphibious animal. At a later period the mammal, with its special characteristics, develops out of the amphibian, and we can clearly see, in the successive stages of its later development, a series of steps of progressive transformation which evidently correspond with the differences of different mammalian orders and families. Now it is precisely in the same succession that we also see the ancestors of man, and of the higher mammals, appear one after the other in the earth's history; first fishes, then amphibians, later the lower, and at last the higher, mammals. Here, therefore the embryonic development of the individual is completely parallel to the palaeontological development of the whole tribe to which it belongs, and this exceedingly interesting and important phenomenon can be explained only by the interaction of the laws of Inheritance and Adaption.
He hypothesised that the specialist developments were all additions to the original path and that, consequently, the evolution of the embryo mirrored the evolution of the species. In effect, the characteristics that successive organisms had acquired after birth had gradually become incorporated into the later stages of the embryological developments of their descendants. He even accounted for the continued existence of rudimentary organs, diminished but not eliminated by disuse, on the grounds that, at one time in the organism's evolutionary history, those organs had been developed, so the embryo starts to form them and then stops forming them. In case you're interested, in technical terms this theory is known as Recapitulation, which states that ‘ontogeny repeats phylogeny’, both of which words he coined.
Though he did succeed in focusing evolutionary attention on embryology, Recapitulation Theory was not very well-received by scientists, especially in England, and he would become seen as "wholly a child of the nineteenth century", and a precocious one to boot. However, in respect of Recapitulation, as well as his beliefs in Lamarckism and the perfectability of humans, which we are about to encounter, Haeckel did have a profound influence upon members of the public, in many countries. Though his books sold very well in Germany, where they were the main source of evolutionary information, he also managed to antagonise a great many people, including many scientists, by straying from strict science into the realms of socio-political commentary and philosophical didacticism. Even many of his evolutionary views would be scorned by later scientists. Quite apart from the implicit requirement of the inheritance of acquired characteristics in Recapitulation, the supposition that different species have undergone different amounts of evolution, as shown by different gestation periods, implies the existence of progression. Unlike Darwin, Haeckel was a self-confessed progressionist, as is well demonstrated by his own contributions to evolution theory, and especially by this passage:
The second great fundamental law which is obvious in the history of nations is the great law of progress or perfecting. Taken as a whole, the history of man is the history of his progressive development. It is true that everywhere and at all times we may notice individual retrogressions, or observe that crooked roads towards progress have been taken, which lead only towards one-sided and external perfecting, and thus deviate more and more from the higher goal of internal and enduring perfecting. However, on the whole, the movement of development of all mankind is and remains a progressive one, inasmuch as man continually removes himself further from his ape-like ancestors, and continually approaches nearer to his own ideal.
It was that belief in evolutionary progression which was to eventually earn Haeckel some discredit, as anti-progressionism became more fashionable. Part of the reason for that was the association that neo-Darwinism was to acquire with racism and supremacism, especially in Germany; it would become necessary for egalitarian Darwinists to emphatically deny that neo-Darwinism implied the existence of distinct superiority. Haeckel has been cited as a forefather of National Socialism on the spurious grounds that Hitler read and admired some of his books, and that the Nazis used some quotes from his books in their propaganda, long after his death. The remaining book extracts in this essay are included as refutation of that suggestion. Though he was anti-Semitic, like most people in 19th century Germany (and many throughout Europe), there is no reason to think that he advocated persecution. Like many of his compatriots, Haeckel believed that Teutons were naturally superior to all other people, though only in a progressive sense rather than distinctly. However, unlike some of his later compatriots, he did not believe that superiority formed the basis for any kind of subjugation, exploitation, discrimination or racial liquidation. Nonetheless, he may have inadvertently contributed in some measure to the scientific authorisation of the enforced 'eugenics programmes' which occurred in Germany, and also in America and Sweden, long after his death. That possibility is exemplified by the following extract, in which Haeckel is shown at his most enlightened, his most scathing, his most dogmatic, and his most controversial:
It appears of interest here to remark that not only natural selection, but also artificial selection exercises its influence in many ways in universal history. A remarkable instance of artificial selection in man, on a great scale, is furnished by the ancient Spartans, among whom, in obedience to a special law, all newly-born children were subject to a careful examination and selection. All those that were weak, sickly, or affected with any bodily infirmity, were killed. Only the perfectly healthy and strong children were allowed to live, and they alone afterwards propagated the race. By this means, the Spartan race was not only continually preserved in excellent strength and vigour, but the perfection of their bodies increased with every generation. No doubt the Spartans owed their rare degree of masculine strength and rough heroic valour (for which they are eminent in ancient history) in a great measure to this artificial selection.
Many tribes also among the Red Indians of North America (who at present are succumbing in the struggle for life to the superior numbers of the white intruders, in spite of a most heroic and courageous resistance) owe their rare degree of bodily strength and warlike bravery to a similar selection of the newly-born children. Among them, also, all children that are weak or affected with any infirmity are immediately killed, and only the perfectly strong individuals remain in life, and propagate the race. That the race becomes greatly strengthened, in the course of very many generations, by this artificial selection cannot in itself be doubted, and is sufficiently proved by many well-known facts.
The opposite of this artificial selection of the wild Redskins and the ancient Spartans is seen in the individual selection which is universally practised in our modern military states, for the purpose of maintaining standing armies, and which, under the name of military selection, we may conveniently consider as a special form of selection. Unfortunately, in our day, militarism is more than ever prominent in our so-called "civilisation"; all the strength and all the wealth of flourishing civilised states are squandered on its development; whereas the education of the young, and public instruction, which are the foundations of the true welfare of nations and the ennobling of humanity, are neglected and mismanaged in a most pitiable manner. And this is done in states which believe themselves to be the privileged leaders of the highest human intelligence, and to stand at the head of civilisation. As is well known, in order to increase the standing army as much as possible, all healthy and strong young men are annually selected by a strict system of recruiting. The stronger, healthier, and more spirited a youth is, the greater is his prospect of being killed by needle-guns, cannons, and other similar instruments of civilisation. All youths that are unhealthy, weak, or affected with infirmities, on the other hand, are spared by the "military selection," and remain at home during the war, marry, and propagate themselves. The more useless, the weaker, or infirmer the youth is, the greater is his prospect of escaping the recruiting officer, and of founding a family. While the healthy flower of youth dies on the battle-field, the feeble remainder enjoy the satisfaction of reproduction and of transmitting all their weaknesses and infirmities to their descendants. According to the laws of transmission by inheritance, there must necessarily follow in each succeeding generation, not only a further extension, but also a more deeply-seated development of weakness of body, and what is inseparable from it, a condition of mental weakness also. This and other forms of artificial selection practised in our civilised states sufficiently explain the sad fact that, in reality, weakness of the body and weakness of character are on the perpetual increase among civilised nations, and that, together with strong, healthy bodies, free and independent spirits are becoming more and more scarce.
To the increasing enervation of modern civilised nations, which is the necessary consequence of military selection, there is further added another evil. The progress of modern medical science, although still little able really to cure diseases, yet possesses and practises more than it used to do in the art of prolonging life during lingering, chronic diseases for many years. Such ravaging evils as consumption, scrofula, syphilis, and many forms of mental disorders, are transmitted by inheritance to a great extent, and transferred by sickly parents to some of their children, or even to the whole of their descendants. Now, the longer the diseased parents, with medical assistance, can drag on their sickly existence, the more numerous are the descendants who will inherit incurable evils, and the greater will be the number of individuals, again, in succeeding generations, thanks to that artificial "medical selection," who will be infected by their parents with lingering, hereditary disease.
If any one were to venture the proposal, after the examples of the Spartans and Redskins, to kill, immediately upon their birth, all miserable, crippled children to whom with certainty a sickly life could be prophesied, instead of keeping them in life injurious to them and to the race, our so-called "humane civilisation" would utter a cry of indignation. But the same "humane civilisation" thinks it quite as it should be, and accepts without a murmur, that at the outbreak of every war (and in the present state of civilised life, and in the continual development of standing armies, wars must naturally become more frequent) hundreds and thousands of the finest men, full of youthful vigour, are sacrificed in the hazardous game of battles.
Despite some aspects of that passage, which represents views which were commonplace in many countries, Haeckel had amazingly enlightened views, especially with regard to euthanasia, a woman's right to choose about abortion, and animal rights. As a vehemently anti-religious, monist Materialist, who obviously had no option but to deny the existence of Free Will, he saw no abrupt distinction between people and other animals:
The activity of the will, which is the organ of habit, of practice, of the use or non-use of organs among animals, is, like every other activity of the animal soul, dependent upon material processes in the central nervous system.... The will, as well as the other mental activities, in higher animals, in this respect is different from that of man only in quantity, not in quality. The will of the animal, as well as that of man, is never free. The widely spread dogma of the freedom of the will is, from a scientific point of view, altogether untenable. Every physiologist who scientifically investigates the activity of the will in man and animals, must of necessity arrive at the conviction that in reality the will is never free, but is always determined by external or internal influences.
Incidentally, though I accurately describe him as a monist Materialist, Haeckel preferred to describe himself merely as a monist, due to the association that materialism had, and still has, with people who live life for personal gain and pleasure:
We therefore look in vain for such materialism among naturalists and philosophers, whose highest happiness is the intellectual enjoyment of Nature, and whose highest aim is the knowledge of her laws. We find it in the palaces of ecclesiastical princes, and in those hypocrites who, under the outward mask of a pious worship of God, solely aim at hierarchical tyranny over, and material spoilation of, their fellow-men. Blind to the grandeur of the so-called "raw material," and the glorious world of phenomena arising from it - insensible to the inexhaustible charms of Nature, and without a knowledge of her laws - they stigmatise all natural science, and the culture arising from it, as sinful "materialism," while really it is this which they themselves exhibit in a most shocking form. Satisfactory proofs of this are furnished, not only by the whole history of the Catholic Popes, with their long series of crimes, but also by the history of the morals of orthodoxy in every form of religion.
Not content with just antagonising the military state, dualist philosophers, the bourgeoisie, and the Church, incessantly, he also attacked anti-Evolutionists and the class system:
....Ignorance and superstition are the foundations upon which most men construct their conception of their own organisation and its relation to the totality of things; and these palpable facts of the history of development, which might throw the light of truth upon them, are ignored. It is true these facts are not calculated to excite approval among those who assume a thorough difference between man and the rest of nature, and who will not acknowledge the animal origin of the human race. That origin must be a very unpleasant truth to members of the ruling and privileged castes in those nations among which there exists an hereditary division of social classes, in consequence of false ideas about the laws of inheritance. It is well known that, even in our day, in many civilised countries the idea of hereditary grades of rank goes so far that, for example, the aristocracy imagine themselves to be of a nature totally different from that of ordinary citizens, and nobles who commit a disgraceful offence are punished by being expelled from the caste of nobles and thrust down among the pariahs of "vulgar citizens." What are these nobles to think of the noble blood which flows in their privileged veins, when they learn that all human embryos, those of nobles as well as commoners, during the first two months of development, are scarcely distinguishable from the tailed embryos of dogs and other mammals?
In respect of his love of mother Nature, it is quite appropriate that it was Haeckel who coined the word 'ecology', of which the following passage, which also shows the great emphasis he placed on the role of nutrition in evolution, is a beautiful example:
The infinitely complicated correlations which exist between the organisms of every district, and which must be looked upon as the real conditions of the struggle for life, are mostly unknown to us, and are very difficult to discover. We have hitherto been able to trace them only to a certain point in individual cases, as in the example given by Darwin of the relations between cats and red clover in England. The red clover, which in England is among the best fodder for cattle, requires the visit of humming-bees in order to attain the formation of seeds. These insects, while sucking the honey from the bottom of the flower, bring the pollen in contact with the stigma, and thus cause fructification of the flower, which never takes place without it. Darwin has shown by experiment, that red clover which is not visited by humming-bees does not yield a single seed. The number of bees is determined by the number of their enemies, the most destructive of which are the field-mice. The more field-mice predominate, the less the clover is fructified. The number of the field-mice, again, is dependent upon the number of their enemies, principally cats. A great number of cats, therefore, is evidently of great advantage for the fructification of clover. This example may be followed still further, as has been done by Carl Vogt, if we consider the cattle which feed on red clover are one of the most important foundations of the wealth of England. Englishmen preserve their bodily and mental powers by making excellent meat - roast beef and beefsteak - their principal food. The English owe the superiority of their brains and minds over those of other nations in a great measure to their excellent meat. But this is clearly indirectly dependent upon the cats, which pursue the mice. We may, with Huxley, even trace the chain of causes to those old maids who cherish and keep cats, and, consequently, are of great importance to the fructification of clover and to the prosperity of England.
Notwithstanding all of the above, Haeckel is now most famous for having drawn the evolutionary trees which were used to illustrate the descent of different species. With hindsight, they are still remarkably accurate but he unerringly placed man at the very top of his trees. Actually, that is not strictly accurate since, on at least one tree, he placed a naked Germanic woman on top, as the representation of evolutionary perfection. (On the basis of Recapitulation, you might well think that it should have been an elephant, with a gestation period of 22 months, that inhabited the top branch.) On the subject of Germanic women, in his best-selling 1899 exposition of his monistic philosophy, "The Riddle of the Universe", Haeckel showed himself to be decades ahead of his time, not least with the following passage:
"The intimate sexual union, on which the preservation of the human race depends, is just as important on that account as the spiritual penetration of the two sexes, or the mutual complement which they bring to each other in the practical wants of daily life as well as in the highest ideal functions of the soul. For man and woman are two different organisms, equal in worth, each having its characteristic virtues and defects. As civilisation advanced, this ideal value of sexual love was more appreciated, and woman held in higher honour, especially among the Teutonic races; she is the inspiring source of the highest achievements of art and poetry."