The Lancelet (Amphioxus), the supposed earliest type of vertebrate animal, and, according to Haeckel, the ancestor of man. The figure is a section enlarged to twice the natural size.
a, mouth;
b, anus;
c, gill-opening;
d, gill;
e, stomach;
f, liver;
g, intestine;
h, gill-cavity;
i, notochord, or rudimentary back-bone;
k, l, m, n, o, arteries and veins.
In like manner, the ascidians, or sea-squirts—mollusks of low grade, or, as Haeckel prefers to regard them, allied to worms—are most remote in almost every respect from the vertebrates. But in the young state of some of these creatures, and in the adult condition of one animal referred to this group (Appendicularia), they have a sort of swimming tail, which is stiffened by a rod of cartilage to enable it to perform its function, and which for a time gives them a certain resemblance to the lancelet or to embryo fishes; and this usually temporary contrivance—curious as an imitative adaptation, but of no other significance—becomes, by the art of "appearing and disappearing," a rudimentary backbone, and enables us at once to recognize in the young ascidian an embryo man.
A second method characteristic of the book, and furnishing, indeed, the main basis of its argument, is that of considering analogous processes as identical, without regard to the difference of the conditions under which they may be carried on. The great leading use of this argument is in inducing us to regard the development of the individual animal as the precise equivalent of the series of changes by which the species was developed in the course of geological time. These two kinds of development are distinguished by appropriate names. Ontogenesis is the embryonic development of the individual animal, and is, of course, a short process, depending on the production of a germ by a parent animal or parent pair, and the further growth of this germ in connection more or less with the parent or with provision made by it. This is, of course, a fact open to observation and study, though some of its processes are mysterious and yet involved in doubt and uncertainty. Phylogenesis is the supposed development of a species in the course of geological time and by the intervention of long series of species, each in its time distinct and composed of individuals each going regularly through a genetic circle of its own.
The latter is a process not open to observation within the time at our command—purely hypothetical, therefore, and of which the possibility remains to be proved; while the causes on which it must depend are necessarily altogether different from those at work in ontogenesis, and the conditions of a long series of different kinds of animals, each perfect in its kind, are equally dissimilar from those of an animal passing through the regular stages from infancy to maturity. The similarity, in some important respects, of ontogenesis to phylogenesis was inevitable, provided that animals were to be of different grades of complexity, since the development of the individual must necessarily be from a more simple to a more complex condition. On any hypothesis, the parallelism between embryological facts and the history of animals in geological time affords many interesting and important coincidences. Yet it is perfectly obvious that the causes and the conditions of these two successions cannot have been the same. Further, when we consider that the embryo-cell which develops into one animal must necessarily be originally distinct in its properties from that which develops into another kind of animal, even though no obvious difference appears to us, we have no ground for supposing that the early stages of all animals are alike; and when we rigorously compare the development of any animal whatever with the successive appearance of animals of the same or similar groups in geological time, we find many things which do not correspond—not merely in the want of links which we might expect to find, but in the more significant appearance, prematurely or inopportunely, of forms which we would not anticipate. Yet the main argument of Haeckel's book is the quiet assumption that anything found to occur in ontogenetic development must also have occurred in phylogenesis, while manifest difficulties are got rid of by assuming atavisms and abnormalities.
A third characteristic of the method of the book is the use of certain terms in peculiar senses, and as implying certain causes which are taken for granted, though their efficacy and their mode of operation are unknown. The chief of the terms so employed are "heredity" and "adaptation." "Heredity" is usually understood as expressing the power of permanent transmission of characters from parents to offspring, and in this aspect it expresses the constancy of specific forms; but, as used by Haeckel, it means the transmission by a parent of any exceptional characters which the individual may have accidentally assumed. "Adaptation" has usually been supposed to mean the fitting of animals for their place in nature, however that came about; as used by Haeckel, it imports the power of the individual animal to adapt itself to changed conditions and to transmit these changes to its offspring. Thus in this philosophy the rule is made the exception and the exception the rule by a skilful use of familiar terms in new senses; and heredity and adaptation are constantly paraded as if they were two potent divinities employed in constantly changing and improving the face of nature.
It is scarcely too much to say that the conclusions of the book are reached almost solely by the application of the above-mentioned peculiar modes of reasoning to the vast store of facts at command of the author, and that the reader who would test these conclusions by the ordinary methods of judgment must be constantly on his guard. Still, it is not necessary to believe that Haeckel is an intentional deceiver. Such fallacies are those which are especially fitted to mislead enthusiastic specialists, to be identified by them with proved results of science, and to be held in an intolerant and dogmatic spirit.
Having thus noticed Haeckel's assumptions and his methods, we may next shortly consider the manner in which he proceeds to work out the phylogeny of man. Here he pursues a purely physiological method, only occasionally and slightly referring to geological facts. He takes as a first principle the law long ago formulated by Hunter, Omne vivum ex ovo—a law which modern research has amply confirmed, showing that every animal, however complex, can be traced back to an egg, which in its simplest state is no more than a single cell, though this cell requires to be fertilized by the addition of the contents of another dissimilar cell, produced either in another organ of the same individual or in a distinct individual. This process of fertilization Haeckel seems to regard as unnecessary in the lowest forms of life; but, though there are some simple animals in which it has not been recognized, analogy would lead us to believe that in some form it is necessary in all. Haekel's monistic view, however, requires that in the lowest forms it should be absent and should have originated spontaneously, though how does not seem to be very clear, as the explanation given of it by him amounts to little more than the statement that it must have occurred. Still, as a "dualistic" process it is very significant with reference to the monistic theory.
Much space is, of course, devoted to the tracing of the special development or ontogenesis of man, and to the illustration of the fact that in the earlier stages of this development the human embryo is scarcely distinguishable from that of lower animals. We may, indeed, affirm that all animals start from cells which, in so far as we can see, are similar to each other, yet which must include potentially the various properties of the animals which spring from them. As we trace them onward in their development, we see these differences manifesting themselves. At first all pass, according to Haeckel, through a stage which he calls the "gastrula," in which the whole body is represented by a sort of sac, the cavity of which is the stomach and the walls of which consist of two layers of cells. It should be stated, however, that many eminent naturalists dissent from this view, and maintain that even in the earliest stages material differences can be observed. In this they are probably right, as even Haeckel has to admit some degree of divergence from this all-embracing "gastræa" theory. Admitting, however, that such early similarity exists within certain limits, we find that, as the embryo advances, it speedily begins to indicate whether it is to be a coral-animal, a snail, a worm, or a fish. Consequently, the physiologist who wishes to trace the resemblances leading to mammals and to man has to lop off one by one the several branches which lead in other directions, and to follow that which conducts by the most direct course to the type which he has in view. In this way Haeckel can show that the embryo Homo sapiens is in successive stages so like to the young of the fish, the reptile, the bird, and the ordinary quadruped that he can produce for comparison figures in which the cursory observer can detect scarcely any difference.
All this has long been known, and has been regarded as a wonderful evidence of the homology or unity of plan which pervades nature, and as constituting man the archetype of the animal kingdom—the highest realization of a plan previously sketched by the Creator in many ruder and humbler forms. It also teaches that it is not so much in the mere bodily organism that we are to look for the distinguishing characters of humanity as in the higher rational and moral nature.
But Haeckel, like other evolutionists of the monistic and agnostic schools, goes far beyond this. The ontogeny, on the evidence of analogy, as already explained, is nothing less than a miniature representation of the phylogeny. Man must in the long ages of geological time have arisen from a monad, just as the individual man has in his life-history arisen from an embryo-cell, and the several stages through which the individual passes must be parallel to those in the history of the race. True, the supposed monad must have been wanting in all the conditions of origin, sexual fertilization, parental influence, and surroundings. There is no perceptible relation of cause and effect, any more than between the rotation of a carriage-wheel and that of the earth on its axis. The analogy might prompt to inquiries as to common laws and similarities of operation, but it proves nothing as to causation.
In default of such proof, Haeckel favors us with another analogy, derived from the science of language. All the Indo-European languages are believed to be descended from a common ancestral tongue, and this is analogous to the descent of all animals from one primitive species. But unfortunately the languages in question are the expressions of the voice and the thought of one and the same species. The individuals using them are known historically to have descended by ordinary generation from a common source, and the connecting-links of the various dialects are unbroken. The analogy fails altogether in the case of species succeeding each other in geological time, unless the very thing to be proved is taken for granted in the outset.
The actual proof that a basis exists in nature for the doctrine of evolution founded on these analogies, might be threefold. First. There might be changes of the nature of phylogenesis going on under our own observation, and even a very few of these would be sufficient to give some show of probability. Elaborate attempts have been made to show that variations, as existing in the more variable of our domesticated species, lead in the direction of such changes; but the results have been unsatisfactory, and our author scarcely condescends to notice this line of proof. He evidently regards the time over which human history has extended as too short to admit of this kind of demonstration. Secondly. There might be in the existing system of nature such a close connection or continuous chain of species as might at least strengthen the argument from analogy; and undoubtedly there are many groups of closely allied species, or of races confounded with true specific types, which it might not be unreasonable to suppose of common origin. These are, however, scattered widely apart; and the contrary fact of extensive gaps in the series is so frequent, that Haeckel is constantly under the necessity of supposing that multitudes of species, and even of larger groups, have perished just where it is most important to his conclusion that they should have remained. This is, of course, unfortunate for the theory; but then, as Haeckel often remarks, "we must suppose" that the missing links once existed. But, thirdly, these gaps which now unhappily exist may be filled up by fossil animals; and if in the successive geological periods we could trace the actual phylogeny of even a few groups of living creatures, we might have the demonstration desired. But here again the gaps are so frequent and so serious that Haeckel scarcely attempts to use this argument further than by giving a short and somewhat imperfect summary of the geological succession in the beginning of his second volume. In this he attempts to give a continuous series of the ancestors of man as developed in geological time; but, of twenty-one groups which he arranges in order from the beginning of the Laurentian to the modern period, at least ten are not known at all as fossils, and others do not belong, so far as known, to the ages to which he assigns them. This necessity of manufacturing facts does not speak well for the testimony of geology to the supposed phylogeny of man.
In point of fact, it cannot be disguised that, though it is possible to pick out some series of animal forms, like the horses and camels referred to by some palæontologists, which simulate a genetic order, the general testimony of palæontology is, on the whole, adverse to the ordinary theories of evolution, whether applied to the vegetable or to the animal kingdom. This the writer has elsewhere endeavored to show; but he may refer here to the labors of Barrande, perhaps unrivalled in extent and accuracy, which show that in the leading forms of life in the older geological formations the succession is not such as to correspond with any of the received theories of derivation.[2] Even evolutionists, when sufficiently candid, admit their case not proven by geological evidence. Gaudry, one of the best authorities on the Tertiary mammalia, admits the impossibility of suggesting any possible derivation for some of the leading groups, and Saporta, Mivart, and Le Conte fall back on periods of rapid or paroxysmal evolution scarcely differing from the idea of creation by law, or mediate creation, as it has been termed.
Thus the utmost value which can be attached to Haeckel's argument from analogy would be that it suggests a possibility that the processes which we see carried on in the evolution of the individual may, in the laws which regulate them, be connected in some way more or less close with those creative processes which on the wider field of geological time have been concerned in the production of the multitudinous forms of animal life. That Haeckel's philosophy goes but a very little way toward any understanding of such relations, and that our present information, even within the more limited scope of biological science, is too meagre to permit of safe generalization, will appear from the consideration of a few facts taken here and there from the multitude employed by him to illustrate the monistic theory.
When we are told that a moner or an embryo-cell is the early stage of all animals alike, we naturally ask, Is it meant that all these cells are really similar, or is it only that they appear similar to us, and may actually be as profoundly unlike as the animals which they are destined to produce? To make this question more plain, let us take the case as formally stated: "From the weighty fact that the egg of the human being, like the egg of all other animals, is a simple cell, it may be quite certainly inferred that a one-celled parent-form once existed, from which all the many-celled animals, man included, developed."
Now, let us suppose that we have under our microscope a one-celled animalcule quite as simple in structure as our supposed ancestor. Along with this we may have on the same slide another cell, which is the embryo of a worm, and a third, which is the embryo of a man. All these, according to the hypothesis, are similar in appearance; so that we can by no means guess which is destined to continue always an animalcule, or which will become a worm or may develop into a poet or a philosopher. Is it meant that the things are actually alike or only apparently so? If they are really alike, then their destinies must depend on external circumstances. Put either of them into a pond, and it will remain a monad. Put either of them into the ovary of a complex animal, and it will develop into the likeness of that animal. But such similarity is altogether improbable, and it would destroy the argument of the evolutionist. In this case he would be hopelessly shut up to the conclusion that "hens were before eggs;" and Haeckel elsewhere informs us that the exactly opposite view is necessarily that of the monistic evolutionist. Thus, though it may often be convenient to speak of these three kinds of cells as if they were perfectly similar, the method of "disappearance" has immediately to be resorted to, and they are shown to be, in fact, quite dissimilar. There is, indeed, the best ground to suppose that the one-celled animals and the embryo-cells referred to, have little in common except their general form. We know that the most minute cell must include a sufficient number of molecules of protoplasm to admit of great varieties of possible arrangement, and that these may be connected with most varied possibilities as to the action of forces. Further, the embryo-cell which is produced by a particular kind of animal, and whose development results in the reproduction of a similar animal, must contain potentially the parts and structures which are evolved from it; and fact shows that this may be affirmed of both the embryo and the sperm-cells where there are two sexes. Therefore it is in the highest degree probable that the eggs of a worm and those of man, though possibly alike to our coarse methods of investigation, are as dissimilar as the animals that result from them. If so, the "egg may be before the hen;" but it is as difficult to imagine the spontaneous production of the egg which is potentially the hen as of the hen itself. Thus the similarity of the eggs and early embryos of animals of different grades is apparent only; and this fact, which embodies a great, and perhaps insoluble, mystery, invalidates the whole of Haeckel's reasoning on the alleged resemblances of different kinds of animals in their early stages.
A second difficulty arises from the fact that the simple embryo-cell of any of the higher animals rapidly produces various kinds of specialized cells different in structure and appearance and capable of performing different functions, whereas in the lower forms of life such cells may remain simple or may merely produce several similar cells little or not at all differentiated. This objection, whenever it occurs, Haeckel endeavors to turn by the assertion that a complex animal is merely an aggregate of independent cells, each of which is a sort of individual. He thus tries to break up the integrity of the complex organism and to reduce it to a mere swarm of monads. He compares the cells of an organism to the "individuals of a savage community," who, at first separate and all alike in their habits and occupations, at length organize themselves into a community and assume different avocations. Single cells, he says, at first were alike, and each performed the same simple offices of all the others. "At a later period isolated cells gathered into communities; groups of simple cells which had arisen from the continued division of a single cell remained together, and now began gradually to perform different offices of life."
But this is a mere vague analogy. It does not represent anything actually occurring in nature, except in the case of an embryo produced by some animal which already shows all the tissues which its embryo is destined to reproduce. Thus it establishes no probability of the evolution of complex tissues from simple cells, and leaves altogether unexplained that wonderful process by which the embryo-cell not only divides into many cells, but becomes developed into all the variety of dissimilar tissues evolved from the homogeneous egg; but evolved from it, as we naturally suppose, because of the fact that the egg represents potentially all these tissues as existing previously in the parent organism.
But if we are content to waive these objections or to accept the solutions given of them by the "appearance-and-disappearance" argument, we still find that the phylogeny, unlike the ontogenesis, is full of wide gaps only to be passed per saltum or to be accounted for by the disappearance of a vast number of connecting-links. Of course, it is easy to suppose that these intermediate forms have been lost through time and accident, but why this has happened to some rather than to others cannot be explained. In the phylogeny of man, for example, what a vast hiatus yawns between the ascidian and the lancelet, and another between the lancelet and the lamprey! It is true that the missing links may have consisted of animals little likely to be preserved as fossils; but why, if they ever existed, do not some of them remain in the modern seas? Again, when we have so many species of apes and so many races of men, why can we find no trace, recent or fossil, of that "missing link" which we are told must have existed, the "ape-like men," known to Haeckel as the "Alali," or speechless men?
A further question which should receive consideration from the monist school is that very serious one, Why, if all is "mechanical" in the development and actions of living beings, should there be any progress whatever? Ordinary people fail to understand why a world of mere dead matter should not go on to all eternity obeying physical and chemical laws without developing life; or why, if some low form of life were introduced capable of reproducing simple one-celled organisms, it should not go on doing so.
Further, even if some chance deviations should occur, we fail to perceive why these should go on in a definite manner producing not only the most complex machines, but many kinds of such machines—on different plans, but each perfect in its way. Haeckel is never weary of telling us that to monists organisms are mere machines. Even his own mental work is merely the grinding of a cerebral machine. But he seems not to perceive that to such a philosophy the homely argument which Paley derived from the structure of a watch would be fatal: "The question is whether machines (which monists consider all animals to be, including themselves) infinitely more complicated than watches could come into existence without design somewhere"[3] —that is, by mere chance. Common sense is not likely to admit that this is possible.
Impression of five fingers and five toes of an Amphibian of the Lower Carboniferous Age, from the lowest Carboniferous beds in Nova Scotia—an evidence of the fact that the number five was already selected for the hands and feet of the earliest known land vertebrates, and that the decimal system of notation, with all that it involves to man, was determined in the Palæozoic Age. The upper figure natural size, the lower reduced.
The difficulties above referred to relate to the introduction of life and of new species on the monistic view. Others might be referred to in connection with the production of new organs. An illustration is afforded, among others, by the discussion of the introduction of the five fingers and toes of man, which appear to descend to us unchanged from the amphibians or batrachians of the Carboniferous period. In this ancient age of the earth's geological history, feet with five toes appear in numerous species of reptilians of various grades (Fig. 2). They are preceded by no other vertebrates than fishes, and these have numerous fin-rays instead of toes. There are no properly transitional forms either fossil or recent. How were the five-fingered limbs acquired in this abrupt way? Why were they five rather than any other number? Why, when once introduced, have they continued unchanged up to the present day? Haeckel's answer is a curious example of his method: "The great significance of the five digits depends on the fact that this number has been transmitted from the Amphibia to all higher vertebrates. It would be impossible to discover any reason why in the lowest Amphibia, as well as in reptiles and in higher vertebrates up to man, there should always originally be five digits on each of the anterior and posterior limbs, if we denied that heredity from a common five-fingered parent-form is the efficient cause of this phenomenon; heredity can alone account for it. In many Amphibia certainly, as well as in many higher vertebrates, we find less than five digits. But in all these cases it can be shown that separate digits have retrograded, and have finally been completely lost. The causes which affected the development of the five-fingered foot of the higher vertebrates in this amphibian form from the many-fingered foot (or properly fin), must certainly be found in the adaptation to the totally altered functions which the limbs had to discharge during the transition from an exclusively aquatic life to one which was partially terrestrial. While the many-fingered fins of the fish had previously served almost exclusively to propel the body through the water, they had now also to afford support to the animal when creeping on the land. This effected a modification both of the skeleton and of the muscles of the limbs. The number of fin-rays was gradually lessened, and was finally reduced to five. These five remaining rays were, however, developed more vigorously. The soft cartilaginous rays became hard bones. The rest of the skeleton also became considerably more firm. The movements of the body became not only more vigorous, but also more varied;" and the paragraph proceeds to state other ameliorations of muscular and nervous system supposed to be related to or caused by the improvement of the limbs.
It will be observed that in the above extract, under the formula "the causes which affected the development of the five-fingered foot ... must certainly be found," all that other men would regard as demanding proof is quietly assumed, and the animal grows before our eyes from a fish to a reptile as under the wand of a conjurer. Further, the transmission of the five toes is attributed to heredity or unchanged reproduction, but this, of course, gives no explanation of the original formation of the structure, nor of the causes which prevented heredity from applying to the fishes which became amphibians and acquired five toes, or to the amphibians which faithfully transmitted their five toes, but not their other characteristics.
It is perhaps scarcely profitable to follow further the criticism of this extraordinary book. It may be necessary, however, to repeat that it contains clear, and in the main accurate, sketches of the embryology of a number of animals, only slightly colored by the tendency to minimize differences. It may also be necessary to say that in criticising Haeckel we take him on his own ground—that of a monist—and have no special reference to those many phases which the philosophy of evolution assumes in the minds of other naturalists, many of whom accept it only partially or as a form of mediate creation more or less reconcilable with theism. To these more moderate views no reference has been made, though there can be no doubt that many of them are quite as assailable as the position of Haeckel in point of argument. It may also be observed that Haeckel's argument is almost exclusively biological and confined to the animal kingdom, and to the special line of descent attributed to man. The monistic hypothesis becomes, as already stated, still less tenable when tested by the facts of palæontology. Hence most of the palæontologists who favor evolution appear to shrink from the extreme position of Haeckel. Gaudry, one of the ablest of this school, in his recent work on the development of the Mammalia, candidly admits the multitude of facts for which derivation will not account, and perceives in the grand succession of animals in time the evidence of a wise and far-reaching creative plan, concluding with the words: "We may still leave out of the question the processes by which the Author of the world has produced the changes of which palæontology presents the picture." In like manner, the Count de Saporta in his World of Plants closes his summary of the periods of vegetation with the words: "But if we ascend from one phenomenon to another, beyond the sphere of contingent and changeable appearance, we find ourselves arrested by a Being unchangeable and supreme, the first expression and absolute cause of all existence, in whom diversity unites with unity, an eternal problem, insoluble to science, but ever present to the human consciousness. Here we reach the true source of the idea of religion, and there presents itself distinctly to the mind that conception to which we apply instinctively the name of God."
Thus these evolutionists, like many others in this country and in England, find a modus vivendi between evolution and theism. They have committed themselves to an interpretation of nature which may prove fanciful and evanescent, and which certainly up to this time remains an hypothesis, ingenious and captivating, but not fortified by the evidence of facts. But in doing so they are not prepared to accept the purely mechanical creed of the monist, or to separate themselves from those ideas of morality, of religion, and of sonship to God which have hitherto been the brightest gems in the crown of man as the lord of this lower world. Whether they can maintain this position against the monists, and whether they will be able in the end to retain any practical form of religion along with the doctrine of the derivation of man from the lower animals, remains to be seen. Possibly before these questions come to a final issue the philosophy of evolution may itself have been "modified" or have given place to some new phase of thought.
One curious point in this connection, to which little attention has been given by evolutionists, is that to which Herbert Spencer has given the name of "direct equilibration," though he is sufficiently wise not to invite too much attention to it. This is the balance of parts and forces within the organism itself. The organism is a complex machine; and if its parts have been put together by chance and are drifting onward in the path of evolution, there must of necessity be a continual struggle going on between the different organs and functions, each tending to swallow up the others and each struggling for its own existence. This resolution of the body of each animal into a house divided against itself is at first sight so revolting to common sense and right feeling that few like to contemplate it. Roux and other recent writers, however, especially in Germany, have brought it into prominence, and it is no doubt a necessary consequence of the evolutionary idea, though altogether at variance with the theory of intelligent design, which supposes the animal machine put together with care and for a purpose, and properly adjusted in all its parts. On the hypothesis of evolution, the animal thus ceases to be, in the proper sense of the term, even a machine, and becomes a mere mass of conflicting parts depending for any constancy they may have on a chance balancing of hostile forces, without any compelling power to bring them together at first, or any means to bind them to joint action in the system. The more such a doctrine is considered, the more difficult does it seem to believe in the possibility of its truth. Evolution has already reduced the cosmos into chaos, the harmony of the universe into discord; but it seems past belief to introduce this into the microcosm itself, and to see nothing in its exquisite adjustments except the momentary equilibrium of a well-balanced fight. Geological history also adds to the absurdity of such a view by showing the marvellous permanence of many forms of life which have continued to perpetuate themselves through almost immeasurable ages without material changes, thus proving unanswerably the perfect adjustment of their parts.
Viewed rightly, this direct equilibration of the parts of the animal seems to throw the greatest possible doubt on the capacity of any form of evolution to produce new species. It is certain, from the facts collected by Mr. Darwin himself in his work on animals under domestication, that when man disturbs the balance of any organism by changing in any way the relations of its parts, he introduces elements of instability and weakness, which, despite the efforts of nature to correct the evils resulting, speedily lead to degeneracy, infertility, and extinction. Mr. T. Warren O'Neil of Philadelphia has recently argued this point with much ability,[4] and has shown, on the testimony of Darwin's facts, that unless "natural selection" is a much more skilful breeder than man, and possesses some secrets not yet discovered by us, the effects of this imaginary power would lead, not to the production of new species, but merely to the extinction of those already existing. In short, all the evidence goes to show that—so beautifully balanced are the parts of the organism—any excess or deficiency in any of them, when artificially or accidentally introduced, brings in elements not only of instability, but of decay and destruction. This subject is deserving of a more full treatment than it can receive here, but enough has been said to show that in this evolutionists have unwittingly furnished us with a new confirmation of the theory of intelligent design.
In some places there are in Haeckel's book touches of a grim humor which are not without interest, as showing the subjective side of the monistic theory and illustrating the attitude of its professors to things held sacred by other men. For example, the following is the introduction to the chapter headed "From the Primitive Worm to the Skulled Animal," and which has for its motto the lines of Goethe beginning:
But like the worms which in the dust must go."
"Both in prose and poetry man is very often compared to a worm; 'a miserable worm,' 'a poor worm,' are common and almost compassionate phrases. If we cannot detect any deep phylogenetic reference in this zoological metaphor, we might at least safely assert that it contains an unconscious comparison with a low condition of animal development which is interesting in its bearing on the pedigree of the human race."
If Haeckel were well read in Scripture, he might have quoted here the melancholy confession of the man of Uz: "I have said to the worm, Thou art my mother and my sister." But, though Job, like the German professor, could humbly say to the worm, "Thou art my mother," he could still hold fast his integrity and believe in the fatherhood of God.
The moral bearing of monism is further illustrated by the following extract, which refers to a more advanced step of the evolution—that from the ape to man—and which shows the honest pride of the worthy professor in his humble parentage: "Just as most people prefer to trace their pedigree from a decayed baron, or if possible from a celebrated prince, rather than from an unknown humble peasant, so they prefer seeing the progenitor of the human race in an Adam degraded by the fall, rather than in an ape capable of higher development and progress. It is a matter of taste, and such genealogical preferences do not, therefore, admit of discussion. It is more to my individual taste to be the more highly-developed descendant of an ape, who in the struggle for existence had developed progressively from lower mammals as they from still lower vertebrates, than the degraded descendant of an Adam, Godlike but debased by the fall, who was formed from a clod of earth, and of an Eve created from a rib of Adam. As regards the celebrated 'rib,' I must here expressly add, as a supplement to the history of the development of the skeleton, that the number of ribs is the same in man and in woman.[5] In the latter as well as in the former the ribs originate from the skin-fibrous layer, and are to be regarded phylogenetically as lower or ventral vertebræ."[6]
There is no accounting for tastes, yet we may be pardoned for retaining some preference for the first link of the old Jewish genealogical table: "Which was the son of Adam, which was the son of God." As to the "debasement" of the fall, it is to be feared that the aboriginal ape would object to bearing the blame of existing human iniquities as having arisen from any improvement in his nature and habits; and it is scarcely fair to speak of Adam as "formed from a clod of earth," which is not precisely in accordance with the record. As to the "rib," which seems so offensive to Haeckel, one would have thought that he would, as an evolutionist, have had some fellow-feeling in this with the writer of Genesis. The origin of sexes is one of the acknowledged difficulties of the hypothesis, and, using his method, we might surely "assume," or even "confidently assert," the possibility that, in some early stage of the development, the unfinished vertebral arches of the "skin-fibrous layer" might have produced a new individual by a process of budding or gemmation. Quite as remarkable suppositions are contained in some parts of his own volumes, without any special divine power for rendering them practicable. Further, if only an individual man originated in the first instance, and if he were not provided with a suitable spouse, he might have intermarried with the unimproved anthropoids, and the results of the evolution would have been lost. Such considerations should have weighed with Haeckel in inducing him to speak more respectfully of Adam's rib, especially in view of the fact that in dealing with the hard question of human origin the author of Genesis had not the benefit of the researches of Baer and Haeckel. He had, no doubt, the advantage of a firm faith in the reality of that Creative Will which the monistic prophets of the nineteenth century have banished from their calculations. Were Haeckel not a monist, he might also be reminded of that grand doctrine of the lordship and superiority of man based on the fact that there was no "help meet for him;" and the foundation of the most sacred bond of human society on the saying of the first man: "This is now bone of my bones, and flesh of my flesh." But monists probably attach little value to such ideas.
It may be proper to add here that in his references to Adam, Haeckel betrays a weakness not unusual with his school, in putting a false gloss on the old record of Genesis. The statement that man was formed from the dust of the ground implies no more than the production of his body from the common materials employed in the construction of other animals; this also in contradistinction from the higher nature derived from the inbreathing or inspiration of God. The precise nature of the method by which man was made or created is not stated by the author of Genesis. Further, it would have been as easy for Divine Power to create a pair as an individual. If this was not done, and if after the lesson of superiority taught by the inspection of lower animals, and the lesson of language taught by naming them, the first man in his "deep sleep" is conscious of the removal of a portion of his own flesh, and then on awaking has the woman "brought" to him, all this is to teach a lesson not to be otherwise learned. The Mosaic record is thus perfectly consistent with itself and with its own doctrine of creation by Almighty Power.
I have quoted the above passages as examples of the more jocose vein of the Jena physiologist; but they constitute also a serious revelation of the influence of his philosophy on his own mind and heart, in lowering both to a cold, mechanical, and unsympathetic view of man and nature. This is especially serious when we remember how earnestly in a recent address he advocated the teaching of the methods and results of this book, as those which, in the present state of knowledge, should supersede the Bible in our schools. We may well say, with his great opponent on that occasion, that if such doctrines should be proved to be true, the teaching of them might become a necessity, but one that would bring us face to face with the darkest and most dangerous moral problem that has ever beset humanity; and that so long as they remain unproved it is both unwise and criminal to propagate them among the mass of men as conclusions which have been demonstrated by science.
In conclusion, we may notice shortly a few of the consequences of the monistic evolution as held by Haeckel and others. Doctrines are perhaps not to be judged by the consequences—at least, by the immediate consequences—of their acceptance. Yet if their logical consequences are such as to introduce confusion into our higher ideas and sentiments, we have reason to hesitate as to their adoption—if on no other ground, because we ourselves are a part of nature and should be in harmony with any true explanation of it.
We may affirm in this connection that agnostic evolution reduces all our science to mere evanescent anthropomorphic fancies; so that, like a parasite, it first supports itself on the strength and substance of science, and then strangles it to death. Physical science is a product of our thinking as to external things. If, therefore, the thinking brain and the external nature which it studies are both of them the fortuitous products of blind tendencies in a process of continuous flux and vicissitude, our science can embody no elements of eternal truth nor any conceptions as to the plans of a higher creative reason. In that case it is absolutely worthless, and a pure waste of time and energy, except in so far as it may yield any temporary material advantages.
Further, the agnostic evolution thus leaves us as orphans in the midst of a cold and insensate nature. We are no longer dwellers in our Father's house, beautiful and fitted for us, but are thrown into the midst of a hideous conflict of dead forces, in which we must finally perish and be annihilated. In a struggle so hopeless it is a mere mockery to tell us that in millions of years something better may come out of it, for we know that this will be of no avail to us, and we feel that it is impossible. Thus the agnostic philosophy, if it be once accepted as true, seriously raises the question whether life is worth living.
But if worth living, then it must be for the immediate and selfish gratification of our desires and passions; and since we are deprived of God and conscience, and right and wrong, and future reward or punishment, and all men are alike in this position, there can be nothing left for us but to rend and fight with our fellows for such share of good as may fall to us in the deadly struggle, that we may reach such happiness as may be possible for us in such an existence, ere we drift into nonentity. Here, again, we are told that the struggle will some time lead to the survival of the fittest, and that the fittest may inaugurate a new and better reign of peace. But the world has already lasted countless ages without arriving at this result. It cannot concern me individually, any more than what happens to-day concerns the extinct ichthyosaur or the megatherium. All that is left for me is to "eat and drink, for to-morrow I die."
If any one thinks that this is an exaggerated picture of the effects of agnostic evolution as applied to man, I may refer him to the study of Herbert Spencer's recent work The Data of Ethics, which has contributed very much to open the eyes of thoughtful men to the depth of spiritual, moral, and even social and political, ruin into which we shall drift under the guidance of this philosophy. In this work the data of ethics are reduced to the one consideration of what is "pleasurable" to ourselves and others, and it is admitted that our ideas of conscience, duty, and even of social obligation, are merely fictions of temporary use until the time shall come when what is pleasurable to ourselves shall coincide with what is pleasurable to others; and this is to come, not out of the love of God and the influence of his Spirit, but out of the blind struggle of opposing interests. It has been well said that this system of morals—if it can be dignified with such a name—is inferior, logically and practically, not only to the "supernatural ethics" which it boastfully professes to replace, but to the ethics of Aristotle and Cicero, and that "it will not supersede revelation, nor is it likely to displace the old data of ethics, whether Greek, Roman, or English." Independently of its antagonism to theism and Christianity, it is foredoomed by the common sense and the right feeling of even imperfect human nature.
LECTURE III.
EVOLUTION AS TESTED BY THE RECORDS OF THE
ROCKS.
Having discussed those vague analogies and fanciful pedigrees by which it has been attempted to drag the science of Biology into the service of Agnostic Evolution, we may now turn to another science—that of the earth—and inquire how far it justifies us in affirming the spontaneous evolution of plants and animals in the progress of geological time. This subject is one which would require a lengthy treatise for its full development, and it cannot be pursued in the most satisfactory way without much previous knowledge of geological facts and principles, and of the classification of animals and plants. On the present occasion it must therefore be treated in the most general possible manner, and with reference merely to the results which have been reached. There is the more excuse for this mode of treatment that, in works already published and widely circulated,[7] I have endeavored to present its details in a popular form to general readers.
Geological investigation has disclosed a great series of stratified rocks composing the crust of the earth, and formed at successive times, chiefly by the agency of water. These can be arranged in chronological order; and, so arranged, they constitute the physical monuments of the earth's history. We must here take for granted, on the testimony of geology, that the accumulation of this series of deposits has extended over a vast lapse of time, and that the successive formations contain remains of animals and plants from which we can learn much as to the succession of life on the earth. Without entering into geological details, it may be sufficient to present in tabular form (see p. 107) the grand series of formations, with the general history of life as ascertained from them.
Tabular View of Geological Periods and of Life-Epochs.