Chapter VII. Critics Of Darwinism.

Chapter VII. Critics Of Darwinism.Let us turn now to the other side. What is opposed to Darwinism in the biological investigations of the experts of to-day is in part simple criticism of the Darwinian position as a whole or in some of its details, and in part constructive individual theories and interpretations of the evolution of organisms.A. Fleischmann's book,“Die Darwinsche Theorie,”39is professedly only critical. He suggests no theory of his own as to the evolution of life in contrast to Darwin's; for, as we have already seen in connection with his earlier book,“Die Deszendenztheorie,”he denies evolution altogether. His agnostic position is maintained, if possible, more resolutely than before. Natural science, according to him, must keep to facts. Drawing conclusions and spinning theories is inexact, and distracts from objective study. The Darwinian theory of selection seems to him a particularly good example of this, for it is built upà priorion theories[pg 161]and hypotheses, it stands apart from experimentation, and it twists facts forcibly to its own ends. It has, however, to be acknowledged that Fleischmann's book is without any“apologetic”intentions. It holds equally aloof from teleology. To seek for purposes and aims in nature he holds to be outside the business of science, as Kant's“Critique of Judgment”suffices to show. After having been more than a decade under the charm of the theory of selection, Fleischmann knows its fascination well, but he now regards it as so erroneous that no one who wishes to do serious work should concern himself about it at all. Point by point he follows all the details of Darwin's work, and seeks to analyse the separate views and theories which go to make up Darwinism as a whole. Darwin's main example of the evolution of the modern races of pigeons from one ancestral form,Columba livia, is, according to Fleischmann, not only unproved but unprovable.40For this itself is not a unified type. The process of“unconscious selection”by man is obscure, and it is not demonstrable, especially in regard to pigeon-breeding. It is a hazy idea which cannot be transferred to the realm of nature. The Malthusian assumption of the necessity of the struggle for existence is erroneous. Malthus was wrong in his law of population as applied[pg 162]to human life, and Darwin was still more mistaken when he transferred it to the organic world in general. It was mere theory. Statistics should have been collected, and observations instead of theories should have been sought for. The alleged superabundance of organisms is not a fact. The marvellously intertwined conditions in the economy of nature make the proportion of supply and demand relatively constant. And even when there is actual struggle for existence, advantages of situation,41which are quite indifferent as far as selection is concerned, are much more decisive than any variational differences. The theory does not explain the first origin of new characters, which can only become advantageous when they have attained to a certain degree of development. As to the illustrations of the influence of selection given by Darwin, from the much discussed fictitious cases, in which the fleet stags select the lithe wolf, to the marvellous mutual adaptations of insects and flowers, Fleischmann objects that there is not even theoretical justification for any one of them. The spade-like foot of the mole is not“more useful”than the form of foot which probably preceded it (cf.Goette), it is merely“different.”For when the mole took to burrowing in the earth and adapting itself to that mode of life, itipso factoforfeited all the advantages of living above ground. The postulated myriads of less well-adapted forms of life are no more to be found to-day than they are in the fauna and flora of[pg 163]palæontological times. The famous giraffe story has already been disposed of by Mivart's objections. As to the whales, it is objected that the earliest stages of their whalebone and their exaggerated nakedness can have been of no use, and a series of other alleged selective effects of“utility”are critically analysed. The refutation of the most brilliant chapter in the Darwinian theory, that on protective coloration and mimicry, is very insufficient. A long concluding chapter sums up the fundamental defects of the Darwinian theory.For the most part, Fleischmann simply brings forward objections which have been urged against the theory of selection from the first, either by naturalists or from other quarters. The chief and the most fatal of these which are still current are the following: The theory of selection does not explain the actually existing discontinuity of species. The real characteristics which distinguish species from species are in innumerable cases quite indifferent from the point of view of“utility”(Nägeli, Bateson).“Selection preserves the good and weeds out the bad.”But where does the good come from? (De Vries). The first beginnings of what may later be useful are almost always useless. The theory of selection might perhaps explain the useful qualities, but not the superfluous, useless, or directly injurious characters which actually exist. Confirmation of the theory of descent may be found in the palæontological record, but it affords none of the theory of selection. Natural selection is continually being neutralised by[pg 164]subsequent inter-crossing and reversion. Natural selection may indeed prevent degeneration within the limits of the species by weeding out what is weak and bad, but it is powerless beyond these limits, and so forth.42These ever-repeated and ever-increasing objections are purely critical. As this is true of Fleischmann's whole book, it is therefore unsatisfactory. It leaves everything in the mist, and puts nothing in place of what it attempts to demolish. But attempts are being made in other quarters, especially among the Lamarckians, to build up an opposition theory.Lamarckism and Neo-Lamarckism.The“Lamarckian”view as opposed to the Darwinian continues to hold its own, and indeed is more ardently supported than ever. On this view, evolution has been accomplished not by a laborious selection of the best which chanced to present itself—a selection in relation to which organisms remained passive, but rather through the exertions of the organisms themselves. It has been especially through the use and exercise of the various[pg 165]organs in response to the requirements of life, through the increased exercise of physical and mental functions, that the organism has adapted itself more diversely and more fully to the conditions of its life. What one generation acquired in differentiation of structure, in capacities and habits, through its own exertions, it handed on to the next. By cumulative inheritance there ultimately arose the fixed specific characters, and the diversity and progressive gradations of organisms have gone hand in hand with an ever increasing activity. And as with the physical so it has been with the mental. Through continual use and exercise of the functions their capacity has been increased and modified. Through the frequent repetition of voluntary actions necessary to life the habitual use of them has come about. Habits that have become fixed are correlated with habitual psychical predispositions. These, gradually handed on by inheritance to the descendants, have resulted in the marvellous instincts of animals. Instinct is inherited habit that has become fixed. Corresponding to this there is on the other hand the recognition—in theory at least—that the disuse of an organ, the non-exercising of a function leads to degeneration of structure and so co-operates in bringing about a gradual but persistent modification of the features and constitution of organisms.These views, which have grown out of Lamarck's fundamental ideas (“Philosophie zoologique,”1809) are now usually associated with the theory advanced chiefly[pg 166]by Etienne Geoffrey St. Hilaire (“Philosophie zoologique,”1830), the opponent of Cuvier, and the ally of Goethe, of the direct influence of themonde ambiant. The“surrounding world,”the influences of climate, of locality, of the weather, of nutrition, of temperature, of the salinity of the water, of the moisture in the air, and all other conditions of existence, influence the living organism. And they do so not indirectly, as is implied in the process of selection, simply playing the part of a sieve, and not themselves moulding and transforming, butdirectlyby necessitating the production of new developments in the living substance, new chemical and physiological activities, new groupings and changes of form, and new organs.Darwin himself did not regard these two theories as opposed to the theory of selection, but utilised them as subsidiary interpretations. It is obvious, however, that at bottom they conceal an essentially different fundamental idea, which, if followed out to its logical consequences, reduces the“struggle for existence”to at most a wholly indifferent accessory circumstance. Weismann felt this, and hence his entirely consistent endeavours to show by great examples, such as the origin of flowers, the mutual adaptations of flowers and insects, the phenomena of mimicry, and many other cases, that neither the Lamarckian nor any other factor in evolution, except only natural, passive selection, suffices as an interpretation. From the Darwinian standpoint he is absolutely right, and must needs speak[pg 167]of the“omnipotence of natural selection,”for it must either be omnipotent, or it must give place to the other two factors, and retain only the significance we attributed to it in another connection (p. 157), which amounts to saying none at all. It is obvious enough why the discussion as to these factors should centre round the question of the“inheritance of acquired characters,”“acquired”either through the use or disuse of organs, the exercise or non-exercise of functions, or through the stimuli of the external world.The neo-Lamarckian conflict with Darwinism has become more and more acute in recent times, and the neo-Lamarckians have sometimes passed from contrasting rival interpretations to excluding the Darwinian factor altogether. As the particular champion of the neo-Lamarckian view, we must name Th. Eimer, the recently deceased Tübingen zoologist. His chief work is in three volumes, entitled“Die Entstehung der Arten auf Grund von Vererbung erworbener Eigenschaften, nach Gesetzen organischen Wachsens.”43It is a polemic against Weismannism in all details, even to the theory of“germinal selection.”Eimer follows in the footsteps of St. Hilaire, and shows what a relatively plastic and sensitive creature the organism is to the surrounding world, the conditions of nutrition and other such influences. There is in this connection a particularly[pg 168]instructive chapter on the physiological and other variations brought about by external influences which act as“stimuli of the nervous system.”The whole theory of Lamarck and St. Hilaire transcends—notwithstanding the protests of Eimer to the contrary—the categories of the mechanical theory of life, and this chapter does so in particular. The array of facts here marshalled as to the spontaneous self-adaptation of organisms to their environment—in relation to colour mainly—forms the most thoroughgoing refutation of Darwinism that it is possible to imagine. It is shown, too, by a wealth of examples from osteology, how use (and the necessities of the case—a consideration which again goes beyond the bounds of mere Lamarckism) may modify, increase or diminish vertebræ, ribs, skull and limbs, in short, the whole skeleton.Kassowitz is equally keen and convinced in his opposition to natural selection, and in his comprehensive“Allgemeine Biologic”44he attacks orthodox Darwinism from the neo-Lamarckian standpoint. The whole of the first volume is almost chapter for chapter a critical analysis, and the polemical element rather outweighs his positive personal contribution. He criticises very severely all attempts to carry the Darwinian principle of explaining adaptations into internal and minute details, arguing against Roux's“Struggle of Parts”and Weismann's“Germinal Selection.”And though he himself maintains very decidedly that the[pg 169]ultimate aim of biology is to find a mechanical solution of the problem of life, he criticises the modern hypotheses in this direction without prejudice, and declares them unsuccessful and insufficient, inclining himself towards the“neo-vitalistic reaction”in its most recent expression. Along with Eimer and Kassowitz, we may name W. Haacke, especially in relation to his views on the acquisition and transmission of functional modifications and his thoroughgoing denial of Darwinism proper. But his work must be dealt with later in a different connection.45These neo-Lamarckian views give us a picture of the evolution of the world that is much more convincing than the strictly Darwinian one. Instead of passive and essentially unintelligent“adaptation”through the sieve of selection, we have here direct self-adaptation of organisms to the conditions of their existence, through their own continual restless activity and exertion, an ascent of their own accord to ever greater heights and perfections. A theory of this kind might easily form part of a religious conception of the world. We might think of the world with primitive tendencies and capacities, in which the potentialities of its evolution were implied, and so ordered that it had to struggle by its own exertions to achieve the full realisation of its[pg 170]possibilities, to attain to ever higher—up to the highest—forms of Being. The process of nature would thus be the direct anticipation of what occurs in the history of man and of mind. And the task set to the freedom of individual men, and to mankind as a whole, namely, to work out their own nature through their own labour and exertion, and to ascend to perfection—this deepest meaning of all individual and collective existence—would have its exact prelude and preparation in the general nature and evolution of all living creatures. The transition from these theories of nature to a teleological outlook from the highest and most human point of view is so obvious as to be almost unavoidable. And although a natural science which keeps to its own business and within its own boundaries has certainly no right to make this transition for itself, it has still less right to prevent its being made outside of its limits.Theory of Definite Variation.But the question now arises, whether both Darwinism and Lamarckism must not be replaced, or at least reduced to the level of accessory theories and factors, by another theory of evolution which was in the field before Darwin, and which since his time has been advanced anew, especially by Nägeli, and has now many adherents who support it in whole or in part. This view affects the very foundations of the Darwinian doctrine. The theory of“indefinite”variation, bringing about easy transitions and affecting every part of[pg 171]the organism separately, which is the necessary correlate of the“struggle for existence,”is rejected altogether. Evolution takes place only along a few definite lines, predetermined through the internal organisation and the laws of growth. It is wholly indifferent to“utility,”and brings forth only what it must according to its own inner laws, not seldom even the monstrous. According to this view, new species arise, not in easy transition, but with a visible leap, by a considerable and far-reaching displacement of the organic equilibrium. What Darwin calls the correlation of parts, and in no way denies, is here maintained in strong opposition to his doctrine of the isolated variation of individual parts; every member or character of the organism depends upon others, and variation of one affects many, and in some way all of the rest.This theory is for the most part intended by its champions to be purely naturalistic. But every one of its points yields support to teleological considerations, most obviously so the concrete instances of correlation. If any one were to attempt to make a theory of evolution from a decidedly teleological standpoint, he would probably construct one very similar to the one we are now considering.It is noteworthy that it has generally been the botanists who have especially supported these views of saltatory evolution in a definite direction and according to internal law, who have therefore tended to react most strongly from Darwinism. We find examples in Nägeli's[pg 172]large and comprehensive work,“Mechanisch-physikalische Theorie der Abstammungslehre”; and, before him, in Wigand's“Darwinismus und die Naturforschung Newton's und Cuvier's”; in von Kölliker's“Heterogenesis”; in von Baer's“Endeavour after an End”; in the chapter added by the translator, Bronn, to the first German edition of the“Origin of Species,”where he urges weighty objections against the theory of selection, and refers to the“innate impulse to development, persistently varying in a definite direction”; in Askenasy's oft-quoted“Beiträge zur Kritik der Darwinschen Lehre,”also referring to“variation in a definite direction,”for instance, in flowers; in Delpino's views, and in the works of many other older writers. But we must leave all these out of account here, since we are concerned only with the present state of the question.De Vries's Mutation-theory.The work that has probably excited most interest in this connection is De Vries'“Die Mutationstheorie: Versuche und Beobachtungen über die Entstehung von Arten im Pflanzenleben.”46In a short preliminary paper he had previously given some account of his leading experiments on a species of evening primrose (Œnothera lamarckiana), and the outlines of his theory. In the work itself he extends this, adding much concrete material, and comparing his views in detail with other[pg 173]theories. Darwin, he says, had already distinguished between variability and mutability; the former manifesting itself in gradual and isolated changes, the latter in saltatory changes on a larger scale. The mistake made by Wallace and by the later Darwinians has been that they regarded this latter form (“single variation”) as unimportant and not affecting evolution, and the former as the real method of evolutionary process. That fluctuating individual variations do occur De Vries admits, but only within narrow limits, never overstepping the type of the species. Here De Vries utilises the recent statistical investigations into the phenomena of individual variation and their laws, as formulated chiefly by Quetelet and Bateson, which were unknown to Darwin and the earlier Darwinians. The actual transition from“species to species”is made suddenly, by mutation, not through variation. And the state of equilibrium thus reached is such a relatively stable one that individual variations can only take place within its limits, but can in no way disturb it.De Vries marshals a series of facts which present insurmountable difficulties to the Darwinian theory, but afford corroboration of the Mutation theory. In particular, he brings forward, from his years of experiment and horticultural observation, comprehensive evidence of the mutational origin of new species from old ones by leaps, and this not in long-past geological times, but in the course of a human life and before our very eyes. The main importance of the book lies in the record of these[pg 174]experiments and observations, rather than in the theory as such, for the way had been paved for it by other workers.In contrast to Darwinism, De Vries states the case for“Halmatogenesis”(saltatory evolution) and“Heterogenesis”(the production of forms unlike the parents), taking his examples from the plant world, but his attitude to Darwinism is conciliatory throughout. Eimer, on the other hand, is sharply antagonistic, especially to Weismann; he takes his proofs from the animal kingdom, and in the second volume of his large work already mentioned, which deals with the“orthogenesis of butterflies,”he attempts to set against the Darwinism“chance theory,”a proof of“definitely directed evolution,”and therefore of the“insufficiency of natural selection in the formation of species.”Eimer's Orthogenesis.Organisation is due to internal causes. Structural characters crystallise out, as it were.“Orthogenesis,”or the definitely determined tendency of evolution to advance in a few directions, is a law for the whole of the animate world. In active response to the stimuli and influences of the environment the organism expresses itself in“organic growth”without any relation to utility. Butterflies in particular, and especially their markings and coloration, are taken as illustrations. In the Darwinian theory of“mimicry”these played a brilliant part. The great resemblance[pg 175]to leaves, to dried twigs, or to well-protected species which are secure from enemies, was regarded as the most convincing proof of the operation of natural selection. But Eimer shows that markings, striping, spots, the development of pattern, and the alleged or real resemblances to leaves, are really subject to definite laws of growth, in obedience to which they gradually appear, developing according to their own internal laws, varying and progressing altogether by internal necessity, and without any reference to advantage or disadvantage, In association with this orthogenesis, Eimer recognises halmatogenesis, correlation and“genepistasis”(coming to a standstill at a fixed and definite stage), and these seem to him to make the Darwinian theory utterly impossible. The text and the illustrations of the book show how, in the sequence of evolution (according to Eimer's laws of transformation), the groupings of stripes, bands, and eye-spots must have appeared on the butterfly's wing, how convex or concave curvings of the contour must have come about at certain points, so that the form of a“leaf”and the lines of its venation resulted, how the eye-spots must have been moulded and shunted, so that they produced the effect of rust or other spots on withered leaves. Particular interest attaches to the detailed arguments against the idea that the butterfly must receive some advantage from its“mimicry.”Even the Darwinians have to admit that in a whole series of cases the advantage is not obvious. They talk with some embarrassment of“pseudomimicry.”[pg 176]Some butterflies that are supposed to be protected have the protective markings on the underside, so that these are actually hidden when the insects are flying from pursuing birds. Many of the leaf-like butterflies are not wood-butterflies at all, but meadow species,47and so Eimer's arguments continue.A specially energetic fellow-worker on Eimer's line is W. Haacke, a zoologist of Jena, author of“Gestaltung und Vererbung,”and“Die Schöpfung des Menschen und seiner Ideale.”48In the first of these works Haacke combats, energetically and with much detail, Weismann's“preformation theory,”and defends“epigenesis,”for which he endeavours to construct graphic diagrams, his aim being to make a foundation for the inheritance of acquired characters, definitely directed evolution, saltatory, symmetrical, and correlated variation.The principles of the new school are very widespread to-day, but we cannot here follow their development in the works of individual investigators, such as Reinke, R. Hertwig, O. Hertwig, Wiesner, Hamann, Dreyer, Wolff, Goette, Kassowitz, v. Wettstein, Korschinsky, and others.49[pg 177]The Spontaneous Activity of the Organism.What is particularly luminous in all the theories that express the most recent anti-Darwinian tendency is that they tend to bring into prominence the mysterious powers of living organisms, by means of which, instead of passively waiting for natural selection and the continual accumulation of unceasing variations, they are able spontaneously and of themselves to bring forth what is necessary for self-maintenance, often what is new and different, of course not unlimitedly, but with considerable freedom and often with a surprising range of possibilities. It is, perhaps, partly the fault of the one-sidedness of strict Darwinism that this consideration has been so slowly brought into prominence and subjected to investigation and experiment. It is bound up with the capacity that all forms of life have of reacting spontaneously to“stimuli”and, to a certain extent, of helping themselves if the conditions of existence be unfavourable. They are able, for instance, to produce protective adaptations[pg 178]against cold or heat, to“regenerate”lost parts, often to replace entire organs that have been lost, and, under certain circumstances, to produce new organs altogether. If all this be true, it seems almost like caprice to follow only the roundabout theory of the struggle for existence, and not to take account of these spontaneous capacities of the living organism directly and before all other factors in the attempt to explain evolution. There is no end to the illustrations that are being adduced, that must force investigation to pass from merely superficial considerations of the struggle for existence type to the deeper and more real problems themselves.An effectively modified and adapted type of Alpine flora has not been evolved by a laborious process of selection lasting for many thousand years; the organism may quickly and immediately produce the new characters by its own reaction. Crustaceans gradually transferred from a salt-water to a fresh-water habitat, or conversely, produce in a few generations the type of a new“species”with correlated variations (Schmankewitsch). Birds weaned by careful experiment from a diet of seeds to one of flesh, or conversely, produce changes of effective correlation and adaptation in the characters of their alimentary system. Plants that have been deprived of their normal organs for absorbing water and prevented from growing new ones produce entirely new and effective“hydatodes.”50[pg 179]It is instructive to notice that Darwinism seems likely to be robbed of its stock illustration, namely,“protective coloration.”By its own internal power of reaction, and sometimes within one generation, and even in the lifetime of an individual, an organism may assume the colour of the substratum beneath it (soles, grasshoppers), of its surroundings (Eimer's tree frogs), the colour and spottiness of the granite rock on which it hangs, the colour of the leaves and twigs among which it lives (Poulton's butterfly pupæ), and even that of the brightly coloured sheets of paper amidst which it is kept imprisoned. Certain spiders assume a white, pink, or greenish“protective coloration”corresponding to the tinted blossom of the plants which they frequent, and so on.51Eimer alleged that direct psychical factors co-operated in bringing about these changes. In any case, all this carries us far beyond the domain of mere naturalistic factors into the mystery of life itself. Even what is called the“influence of the external world,”and the“active acquirement of new characters,”have their basis and the reason of their possibility in this domain. And the whole domain is saturated through and through with“teleology.”A recognition of the impressive secret of the organism led Gustav Wolff to become a very pronounced critic of Darwinism, especially in the form of Weismannism.[pg 180]As far back as 1896, in a lecture“On the present position of Darwinism,”in which he dealt only with Weismann, he criticised and analysed that author's last attempt to uphold Darwinism by the construction of his theory of“germinal selection.”He concluded with the wish:“That a spirit of earnestness would once more enter into biological investigation, which would no longer attempt to find in nature just what it wanted to find, but would be ready to follow truth at all costs, and to approach the riddle of life with an open mind.”His“Beiträge zur Kritik der Darwinischen Lehre,”which appeared first as papers in the“Biologisches Centralblatt,”did not see the light in book form until 1898. The doctrine of selection was regarded as so unassailable that no publisher would take the risk of the book. Its appearance is a sure indication of the general modification of opinions that had taken place in the interval. The first and second essays are merely critical objections to the theory of selection, very similar to those frequently urged before, but more precisely stated.52The third is intended to show that there is in the forms of life themselves, as a faculty of adaptation peculiar to them, a primary purposiveness, which is unquestionably active throughout the lifetime and development of every individual, but which is also the deepest cause of“phylogenesis,”or the formation[pg 181]of a race. This doctrine makes both the Darwinian and Lamarckian theories merely secondary. For the phenomena which suggest the Lamarckian interpretation presuppose this most essential factor—the primary adaptiveness. Wolff concludes with a very striking instance—discovered by himself—of this primary adaptiveness of the organism—the regeneration of the lens in the newt's eye.More comprehensively, but from a precisely similar standpoint, Driesch has followed up the discussion of this problem.53He is, of all modern investigators, perhaps the one who has most persistently and thoroughly[pg 182]worked out the problem of causal and teleological interpretation, and he has also thrown much light on the scientific and epistemological aspects of the problem. That he could, in a recent volume of the“Biologisches Zentralblatt,”write a respectful and sympathetic exposition of the Hegelian nature-philosophy—as regards its aims, though not its methods—is as remarkable a symptom as we can instance of the modern trend of views and opinions.54Contrast Between Darwinian and Post-Darwinian Views.The new views that have thus arisen have been definitely summarised and clearly contrasted with Darwinism by the botanist Korschinsky. He died before completing his general work,“Heterogenesis und Evolution,”but he has elsewhere55given an excellent summary of his results, which we append in abstract.Darwin.(1) Everything organic is capable of variation. Variations[pg 183]arise in part from internal, in part from external causes. They are slight, inconspicuous, individual differences.Korschinsky and the Moderns.(1) Everything organic is capable of variation. This capability is a fundamental, inherent character of living forms in general, and is independent of external conditions. It is usually kept latent by“heredity,”but occasionally breaks forth in sudden variations.Darwin.(2) The struggle for existence. This combines, increases, fixes useful variations, and eliminates the useless. All the characters and peculiarities of a finished species are the results of long-continued selection; they must therefore be adapted to the external conditions.Korschinsky and the Moderns.(2) Saltatory variations.—These are, under favourable circumstances, the starting-point of new and constant races. The characters may sometimes be useful, sometimes quite indifferent, neither advantageous nor disadvantageous. Sometimes they are not in harmony with external circumstances.Darwin.(3) The species is subject to constant variation. It is continually subject to selection and augmentation of its characters. Hence again the origin of new species.Korschinsky and the Moderns.(3) All fully developed species persist, but through heterogenesis a splitting up into new forms may take place, and this is accompanied by a disturbance of the vital equilibrium. The new state is at first insecure and fluctuating, and only gradually becomes stable. Thus new forms and races arise with gradual consolidation of their constitution.Darwin.(4) The sharper and more acute the effect of the environment, the keener is the struggle for existence, and the more rapidly and certainly do new forms arise.Korschinsky and the Moderns.(4) Only in specially favourable conditions, only when the struggle for existence is weak, or when there is none, can new forms arise and become fixed. When the conditions are severe no new forms arise, or if they do they are speedily eliminated.Darwin.(5) The chief condition of evolution is therefore the struggle for existence and the selection which this involves.Korschinsky and the Moderns.(5) The struggle for existence simply decimates the overwhelming[pg 184]abundance of possible forms. Where it occurs it prevents the establishment of new variations, and in reality stands in the way of new developments. It is rather an unfavourable than an advantageous factor.Darwin.(6) If there were no struggle for existence there would be no adaptation, no perfecting.Korschinsky and the Moderns.(6) Were there no struggle for existence, there would be no destruction of new forms, or of forms in process of arising. The world of organisms would then be a colossal genealogical tree of enormous luxuriance, and with an incalculable wealth of forms.Darwin.(7) Progress in nature, the“perfecting”of organisms, is only an increasingly complex and ever more perfect adaptation to the external circumstances. It is attained by purely mechanical methods, by an accumulation of the variations most useful at the time.Korschinsky and the Moderns.(7) The adaptation which the struggle for existence brings about has nothing to do with perfecting, for the organisms which are physiologically and morphologically higher are by no means always better adapted to external circumstances than those lower in the scale. Evolution cannot be explained mechanically. The origin of higher forms from lower is only possible if there is a tendency to progress innate in the organism itself. This tendency is nearly related to or identical with the tendency to variation. It compels the organism to perfect itself as far as external circumstances will permit.All this implies an admission of evolution and of descent, but a setting aside of Darwinism proper as an unsuccessful hypothesis, and a positive recognition of[pg 185]an endeavour after an aim, internal causes, and teleology in nature, as against fortuitous and superficial factors. This opens up a vista into the background of things, and thereby yields to the religious conception all that a study of nature can yield—namely, an acknowledgment of the possibility and legitimacy of interpreting the world in a religious sense, and assistance in so doing.The most important point has already been emphasised. Even if the theory of the struggle for existence were correct, it would be possible to subject the world as a whole to a teleological interpretation. But these anti-Darwinian theories now emerging, though they do not directly induce teleological interpretation, suggest it much more strongly than orthodox Darwinism does. A world which in its evolution is not exposed, for good or ill, to the action of chance factors—playing with it and forcing it hither and thither—but which, exposed indeed to the most diverse conditions of existence and their influences, and harmonising with them, nevertheless carries implicitly and infallibly within itself the laws of its own expression, and especially the necessity to develop upwards into higher and higher forms, is expressly suited for teleological consideration, and we can understand how it is that the old physico-teleological evidences of the existence of God are beginning to hold up their heads again. They are wrong when they try to demonstrate God, but quite right when they simply seek to show that nature does not contradict—in[pg 186]fact that it allows room and validity to—belief in the Highest Wisdom as the cause and guide of all things natural.As far as the question of the right to interpret nature teleologically is concerned, it would be entirely indifferent whether what Korschinsky calls“the tendency to progress,”and the system of laws in obedience to which evolution brings forth its forms, can be interpreted“mechanically”or not; that is to say, whether or not evolution depends on conditions and potentialities of living matter, which can be demonstrated and made mechanically commensurable or not. It may be that they can neither be demonstrated nor made mechanically commensurable, but lie in the impenetrable mystery inherent in all life. Whether this mystery really exists, and whether religion has any particular interest in it if it does, must be considered in the following chapter.[pg 187]

Chapter VII. Critics Of Darwinism.Let us turn now to the other side. What is opposed to Darwinism in the biological investigations of the experts of to-day is in part simple criticism of the Darwinian position as a whole or in some of its details, and in part constructive individual theories and interpretations of the evolution of organisms.A. Fleischmann's book,“Die Darwinsche Theorie,”39is professedly only critical. He suggests no theory of his own as to the evolution of life in contrast to Darwin's; for, as we have already seen in connection with his earlier book,“Die Deszendenztheorie,”he denies evolution altogether. His agnostic position is maintained, if possible, more resolutely than before. Natural science, according to him, must keep to facts. Drawing conclusions and spinning theories is inexact, and distracts from objective study. The Darwinian theory of selection seems to him a particularly good example of this, for it is built upà priorion theories[pg 161]and hypotheses, it stands apart from experimentation, and it twists facts forcibly to its own ends. It has, however, to be acknowledged that Fleischmann's book is without any“apologetic”intentions. It holds equally aloof from teleology. To seek for purposes and aims in nature he holds to be outside the business of science, as Kant's“Critique of Judgment”suffices to show. After having been more than a decade under the charm of the theory of selection, Fleischmann knows its fascination well, but he now regards it as so erroneous that no one who wishes to do serious work should concern himself about it at all. Point by point he follows all the details of Darwin's work, and seeks to analyse the separate views and theories which go to make up Darwinism as a whole. Darwin's main example of the evolution of the modern races of pigeons from one ancestral form,Columba livia, is, according to Fleischmann, not only unproved but unprovable.40For this itself is not a unified type. The process of“unconscious selection”by man is obscure, and it is not demonstrable, especially in regard to pigeon-breeding. It is a hazy idea which cannot be transferred to the realm of nature. The Malthusian assumption of the necessity of the struggle for existence is erroneous. Malthus was wrong in his law of population as applied[pg 162]to human life, and Darwin was still more mistaken when he transferred it to the organic world in general. It was mere theory. Statistics should have been collected, and observations instead of theories should have been sought for. The alleged superabundance of organisms is not a fact. The marvellously intertwined conditions in the economy of nature make the proportion of supply and demand relatively constant. And even when there is actual struggle for existence, advantages of situation,41which are quite indifferent as far as selection is concerned, are much more decisive than any variational differences. The theory does not explain the first origin of new characters, which can only become advantageous when they have attained to a certain degree of development. As to the illustrations of the influence of selection given by Darwin, from the much discussed fictitious cases, in which the fleet stags select the lithe wolf, to the marvellous mutual adaptations of insects and flowers, Fleischmann objects that there is not even theoretical justification for any one of them. The spade-like foot of the mole is not“more useful”than the form of foot which probably preceded it (cf.Goette), it is merely“different.”For when the mole took to burrowing in the earth and adapting itself to that mode of life, itipso factoforfeited all the advantages of living above ground. The postulated myriads of less well-adapted forms of life are no more to be found to-day than they are in the fauna and flora of[pg 163]palæontological times. The famous giraffe story has already been disposed of by Mivart's objections. As to the whales, it is objected that the earliest stages of their whalebone and their exaggerated nakedness can have been of no use, and a series of other alleged selective effects of“utility”are critically analysed. The refutation of the most brilliant chapter in the Darwinian theory, that on protective coloration and mimicry, is very insufficient. A long concluding chapter sums up the fundamental defects of the Darwinian theory.For the most part, Fleischmann simply brings forward objections which have been urged against the theory of selection from the first, either by naturalists or from other quarters. The chief and the most fatal of these which are still current are the following: The theory of selection does not explain the actually existing discontinuity of species. The real characteristics which distinguish species from species are in innumerable cases quite indifferent from the point of view of“utility”(Nägeli, Bateson).“Selection preserves the good and weeds out the bad.”But where does the good come from? (De Vries). The first beginnings of what may later be useful are almost always useless. The theory of selection might perhaps explain the useful qualities, but not the superfluous, useless, or directly injurious characters which actually exist. Confirmation of the theory of descent may be found in the palæontological record, but it affords none of the theory of selection. Natural selection is continually being neutralised by[pg 164]subsequent inter-crossing and reversion. Natural selection may indeed prevent degeneration within the limits of the species by weeding out what is weak and bad, but it is powerless beyond these limits, and so forth.42These ever-repeated and ever-increasing objections are purely critical. As this is true of Fleischmann's whole book, it is therefore unsatisfactory. It leaves everything in the mist, and puts nothing in place of what it attempts to demolish. But attempts are being made in other quarters, especially among the Lamarckians, to build up an opposition theory.Lamarckism and Neo-Lamarckism.The“Lamarckian”view as opposed to the Darwinian continues to hold its own, and indeed is more ardently supported than ever. On this view, evolution has been accomplished not by a laborious selection of the best which chanced to present itself—a selection in relation to which organisms remained passive, but rather through the exertions of the organisms themselves. It has been especially through the use and exercise of the various[pg 165]organs in response to the requirements of life, through the increased exercise of physical and mental functions, that the organism has adapted itself more diversely and more fully to the conditions of its life. What one generation acquired in differentiation of structure, in capacities and habits, through its own exertions, it handed on to the next. By cumulative inheritance there ultimately arose the fixed specific characters, and the diversity and progressive gradations of organisms have gone hand in hand with an ever increasing activity. And as with the physical so it has been with the mental. Through continual use and exercise of the functions their capacity has been increased and modified. Through the frequent repetition of voluntary actions necessary to life the habitual use of them has come about. Habits that have become fixed are correlated with habitual psychical predispositions. These, gradually handed on by inheritance to the descendants, have resulted in the marvellous instincts of animals. Instinct is inherited habit that has become fixed. Corresponding to this there is on the other hand the recognition—in theory at least—that the disuse of an organ, the non-exercising of a function leads to degeneration of structure and so co-operates in bringing about a gradual but persistent modification of the features and constitution of organisms.These views, which have grown out of Lamarck's fundamental ideas (“Philosophie zoologique,”1809) are now usually associated with the theory advanced chiefly[pg 166]by Etienne Geoffrey St. Hilaire (“Philosophie zoologique,”1830), the opponent of Cuvier, and the ally of Goethe, of the direct influence of themonde ambiant. The“surrounding world,”the influences of climate, of locality, of the weather, of nutrition, of temperature, of the salinity of the water, of the moisture in the air, and all other conditions of existence, influence the living organism. And they do so not indirectly, as is implied in the process of selection, simply playing the part of a sieve, and not themselves moulding and transforming, butdirectlyby necessitating the production of new developments in the living substance, new chemical and physiological activities, new groupings and changes of form, and new organs.Darwin himself did not regard these two theories as opposed to the theory of selection, but utilised them as subsidiary interpretations. It is obvious, however, that at bottom they conceal an essentially different fundamental idea, which, if followed out to its logical consequences, reduces the“struggle for existence”to at most a wholly indifferent accessory circumstance. Weismann felt this, and hence his entirely consistent endeavours to show by great examples, such as the origin of flowers, the mutual adaptations of flowers and insects, the phenomena of mimicry, and many other cases, that neither the Lamarckian nor any other factor in evolution, except only natural, passive selection, suffices as an interpretation. From the Darwinian standpoint he is absolutely right, and must needs speak[pg 167]of the“omnipotence of natural selection,”for it must either be omnipotent, or it must give place to the other two factors, and retain only the significance we attributed to it in another connection (p. 157), which amounts to saying none at all. It is obvious enough why the discussion as to these factors should centre round the question of the“inheritance of acquired characters,”“acquired”either through the use or disuse of organs, the exercise or non-exercise of functions, or through the stimuli of the external world.The neo-Lamarckian conflict with Darwinism has become more and more acute in recent times, and the neo-Lamarckians have sometimes passed from contrasting rival interpretations to excluding the Darwinian factor altogether. As the particular champion of the neo-Lamarckian view, we must name Th. Eimer, the recently deceased Tübingen zoologist. His chief work is in three volumes, entitled“Die Entstehung der Arten auf Grund von Vererbung erworbener Eigenschaften, nach Gesetzen organischen Wachsens.”43It is a polemic against Weismannism in all details, even to the theory of“germinal selection.”Eimer follows in the footsteps of St. Hilaire, and shows what a relatively plastic and sensitive creature the organism is to the surrounding world, the conditions of nutrition and other such influences. There is in this connection a particularly[pg 168]instructive chapter on the physiological and other variations brought about by external influences which act as“stimuli of the nervous system.”The whole theory of Lamarck and St. Hilaire transcends—notwithstanding the protests of Eimer to the contrary—the categories of the mechanical theory of life, and this chapter does so in particular. The array of facts here marshalled as to the spontaneous self-adaptation of organisms to their environment—in relation to colour mainly—forms the most thoroughgoing refutation of Darwinism that it is possible to imagine. It is shown, too, by a wealth of examples from osteology, how use (and the necessities of the case—a consideration which again goes beyond the bounds of mere Lamarckism) may modify, increase or diminish vertebræ, ribs, skull and limbs, in short, the whole skeleton.Kassowitz is equally keen and convinced in his opposition to natural selection, and in his comprehensive“Allgemeine Biologic”44he attacks orthodox Darwinism from the neo-Lamarckian standpoint. The whole of the first volume is almost chapter for chapter a critical analysis, and the polemical element rather outweighs his positive personal contribution. He criticises very severely all attempts to carry the Darwinian principle of explaining adaptations into internal and minute details, arguing against Roux's“Struggle of Parts”and Weismann's“Germinal Selection.”And though he himself maintains very decidedly that the[pg 169]ultimate aim of biology is to find a mechanical solution of the problem of life, he criticises the modern hypotheses in this direction without prejudice, and declares them unsuccessful and insufficient, inclining himself towards the“neo-vitalistic reaction”in its most recent expression. Along with Eimer and Kassowitz, we may name W. Haacke, especially in relation to his views on the acquisition and transmission of functional modifications and his thoroughgoing denial of Darwinism proper. But his work must be dealt with later in a different connection.45These neo-Lamarckian views give us a picture of the evolution of the world that is much more convincing than the strictly Darwinian one. Instead of passive and essentially unintelligent“adaptation”through the sieve of selection, we have here direct self-adaptation of organisms to the conditions of their existence, through their own continual restless activity and exertion, an ascent of their own accord to ever greater heights and perfections. A theory of this kind might easily form part of a religious conception of the world. We might think of the world with primitive tendencies and capacities, in which the potentialities of its evolution were implied, and so ordered that it had to struggle by its own exertions to achieve the full realisation of its[pg 170]possibilities, to attain to ever higher—up to the highest—forms of Being. The process of nature would thus be the direct anticipation of what occurs in the history of man and of mind. And the task set to the freedom of individual men, and to mankind as a whole, namely, to work out their own nature through their own labour and exertion, and to ascend to perfection—this deepest meaning of all individual and collective existence—would have its exact prelude and preparation in the general nature and evolution of all living creatures. The transition from these theories of nature to a teleological outlook from the highest and most human point of view is so obvious as to be almost unavoidable. And although a natural science which keeps to its own business and within its own boundaries has certainly no right to make this transition for itself, it has still less right to prevent its being made outside of its limits.Theory of Definite Variation.But the question now arises, whether both Darwinism and Lamarckism must not be replaced, or at least reduced to the level of accessory theories and factors, by another theory of evolution which was in the field before Darwin, and which since his time has been advanced anew, especially by Nägeli, and has now many adherents who support it in whole or in part. This view affects the very foundations of the Darwinian doctrine. The theory of“indefinite”variation, bringing about easy transitions and affecting every part of[pg 171]the organism separately, which is the necessary correlate of the“struggle for existence,”is rejected altogether. Evolution takes place only along a few definite lines, predetermined through the internal organisation and the laws of growth. It is wholly indifferent to“utility,”and brings forth only what it must according to its own inner laws, not seldom even the monstrous. According to this view, new species arise, not in easy transition, but with a visible leap, by a considerable and far-reaching displacement of the organic equilibrium. What Darwin calls the correlation of parts, and in no way denies, is here maintained in strong opposition to his doctrine of the isolated variation of individual parts; every member or character of the organism depends upon others, and variation of one affects many, and in some way all of the rest.This theory is for the most part intended by its champions to be purely naturalistic. But every one of its points yields support to teleological considerations, most obviously so the concrete instances of correlation. If any one were to attempt to make a theory of evolution from a decidedly teleological standpoint, he would probably construct one very similar to the one we are now considering.It is noteworthy that it has generally been the botanists who have especially supported these views of saltatory evolution in a definite direction and according to internal law, who have therefore tended to react most strongly from Darwinism. We find examples in Nägeli's[pg 172]large and comprehensive work,“Mechanisch-physikalische Theorie der Abstammungslehre”; and, before him, in Wigand's“Darwinismus und die Naturforschung Newton's und Cuvier's”; in von Kölliker's“Heterogenesis”; in von Baer's“Endeavour after an End”; in the chapter added by the translator, Bronn, to the first German edition of the“Origin of Species,”where he urges weighty objections against the theory of selection, and refers to the“innate impulse to development, persistently varying in a definite direction”; in Askenasy's oft-quoted“Beiträge zur Kritik der Darwinschen Lehre,”also referring to“variation in a definite direction,”for instance, in flowers; in Delpino's views, and in the works of many other older writers. But we must leave all these out of account here, since we are concerned only with the present state of the question.De Vries's Mutation-theory.The work that has probably excited most interest in this connection is De Vries'“Die Mutationstheorie: Versuche und Beobachtungen über die Entstehung von Arten im Pflanzenleben.”46In a short preliminary paper he had previously given some account of his leading experiments on a species of evening primrose (Œnothera lamarckiana), and the outlines of his theory. In the work itself he extends this, adding much concrete material, and comparing his views in detail with other[pg 173]theories. Darwin, he says, had already distinguished between variability and mutability; the former manifesting itself in gradual and isolated changes, the latter in saltatory changes on a larger scale. The mistake made by Wallace and by the later Darwinians has been that they regarded this latter form (“single variation”) as unimportant and not affecting evolution, and the former as the real method of evolutionary process. That fluctuating individual variations do occur De Vries admits, but only within narrow limits, never overstepping the type of the species. Here De Vries utilises the recent statistical investigations into the phenomena of individual variation and their laws, as formulated chiefly by Quetelet and Bateson, which were unknown to Darwin and the earlier Darwinians. The actual transition from“species to species”is made suddenly, by mutation, not through variation. And the state of equilibrium thus reached is such a relatively stable one that individual variations can only take place within its limits, but can in no way disturb it.De Vries marshals a series of facts which present insurmountable difficulties to the Darwinian theory, but afford corroboration of the Mutation theory. In particular, he brings forward, from his years of experiment and horticultural observation, comprehensive evidence of the mutational origin of new species from old ones by leaps, and this not in long-past geological times, but in the course of a human life and before our very eyes. The main importance of the book lies in the record of these[pg 174]experiments and observations, rather than in the theory as such, for the way had been paved for it by other workers.In contrast to Darwinism, De Vries states the case for“Halmatogenesis”(saltatory evolution) and“Heterogenesis”(the production of forms unlike the parents), taking his examples from the plant world, but his attitude to Darwinism is conciliatory throughout. Eimer, on the other hand, is sharply antagonistic, especially to Weismann; he takes his proofs from the animal kingdom, and in the second volume of his large work already mentioned, which deals with the“orthogenesis of butterflies,”he attempts to set against the Darwinism“chance theory,”a proof of“definitely directed evolution,”and therefore of the“insufficiency of natural selection in the formation of species.”Eimer's Orthogenesis.Organisation is due to internal causes. Structural characters crystallise out, as it were.“Orthogenesis,”or the definitely determined tendency of evolution to advance in a few directions, is a law for the whole of the animate world. In active response to the stimuli and influences of the environment the organism expresses itself in“organic growth”without any relation to utility. Butterflies in particular, and especially their markings and coloration, are taken as illustrations. In the Darwinian theory of“mimicry”these played a brilliant part. The great resemblance[pg 175]to leaves, to dried twigs, or to well-protected species which are secure from enemies, was regarded as the most convincing proof of the operation of natural selection. But Eimer shows that markings, striping, spots, the development of pattern, and the alleged or real resemblances to leaves, are really subject to definite laws of growth, in obedience to which they gradually appear, developing according to their own internal laws, varying and progressing altogether by internal necessity, and without any reference to advantage or disadvantage, In association with this orthogenesis, Eimer recognises halmatogenesis, correlation and“genepistasis”(coming to a standstill at a fixed and definite stage), and these seem to him to make the Darwinian theory utterly impossible. The text and the illustrations of the book show how, in the sequence of evolution (according to Eimer's laws of transformation), the groupings of stripes, bands, and eye-spots must have appeared on the butterfly's wing, how convex or concave curvings of the contour must have come about at certain points, so that the form of a“leaf”and the lines of its venation resulted, how the eye-spots must have been moulded and shunted, so that they produced the effect of rust or other spots on withered leaves. Particular interest attaches to the detailed arguments against the idea that the butterfly must receive some advantage from its“mimicry.”Even the Darwinians have to admit that in a whole series of cases the advantage is not obvious. They talk with some embarrassment of“pseudomimicry.”[pg 176]Some butterflies that are supposed to be protected have the protective markings on the underside, so that these are actually hidden when the insects are flying from pursuing birds. Many of the leaf-like butterflies are not wood-butterflies at all, but meadow species,47and so Eimer's arguments continue.A specially energetic fellow-worker on Eimer's line is W. Haacke, a zoologist of Jena, author of“Gestaltung und Vererbung,”and“Die Schöpfung des Menschen und seiner Ideale.”48In the first of these works Haacke combats, energetically and with much detail, Weismann's“preformation theory,”and defends“epigenesis,”for which he endeavours to construct graphic diagrams, his aim being to make a foundation for the inheritance of acquired characters, definitely directed evolution, saltatory, symmetrical, and correlated variation.The principles of the new school are very widespread to-day, but we cannot here follow their development in the works of individual investigators, such as Reinke, R. Hertwig, O. Hertwig, Wiesner, Hamann, Dreyer, Wolff, Goette, Kassowitz, v. Wettstein, Korschinsky, and others.49[pg 177]The Spontaneous Activity of the Organism.What is particularly luminous in all the theories that express the most recent anti-Darwinian tendency is that they tend to bring into prominence the mysterious powers of living organisms, by means of which, instead of passively waiting for natural selection and the continual accumulation of unceasing variations, they are able spontaneously and of themselves to bring forth what is necessary for self-maintenance, often what is new and different, of course not unlimitedly, but with considerable freedom and often with a surprising range of possibilities. It is, perhaps, partly the fault of the one-sidedness of strict Darwinism that this consideration has been so slowly brought into prominence and subjected to investigation and experiment. It is bound up with the capacity that all forms of life have of reacting spontaneously to“stimuli”and, to a certain extent, of helping themselves if the conditions of existence be unfavourable. They are able, for instance, to produce protective adaptations[pg 178]against cold or heat, to“regenerate”lost parts, often to replace entire organs that have been lost, and, under certain circumstances, to produce new organs altogether. If all this be true, it seems almost like caprice to follow only the roundabout theory of the struggle for existence, and not to take account of these spontaneous capacities of the living organism directly and before all other factors in the attempt to explain evolution. There is no end to the illustrations that are being adduced, that must force investigation to pass from merely superficial considerations of the struggle for existence type to the deeper and more real problems themselves.An effectively modified and adapted type of Alpine flora has not been evolved by a laborious process of selection lasting for many thousand years; the organism may quickly and immediately produce the new characters by its own reaction. Crustaceans gradually transferred from a salt-water to a fresh-water habitat, or conversely, produce in a few generations the type of a new“species”with correlated variations (Schmankewitsch). Birds weaned by careful experiment from a diet of seeds to one of flesh, or conversely, produce changes of effective correlation and adaptation in the characters of their alimentary system. Plants that have been deprived of their normal organs for absorbing water and prevented from growing new ones produce entirely new and effective“hydatodes.”50[pg 179]It is instructive to notice that Darwinism seems likely to be robbed of its stock illustration, namely,“protective coloration.”By its own internal power of reaction, and sometimes within one generation, and even in the lifetime of an individual, an organism may assume the colour of the substratum beneath it (soles, grasshoppers), of its surroundings (Eimer's tree frogs), the colour and spottiness of the granite rock on which it hangs, the colour of the leaves and twigs among which it lives (Poulton's butterfly pupæ), and even that of the brightly coloured sheets of paper amidst which it is kept imprisoned. Certain spiders assume a white, pink, or greenish“protective coloration”corresponding to the tinted blossom of the plants which they frequent, and so on.51Eimer alleged that direct psychical factors co-operated in bringing about these changes. In any case, all this carries us far beyond the domain of mere naturalistic factors into the mystery of life itself. Even what is called the“influence of the external world,”and the“active acquirement of new characters,”have their basis and the reason of their possibility in this domain. And the whole domain is saturated through and through with“teleology.”A recognition of the impressive secret of the organism led Gustav Wolff to become a very pronounced critic of Darwinism, especially in the form of Weismannism.[pg 180]As far back as 1896, in a lecture“On the present position of Darwinism,”in which he dealt only with Weismann, he criticised and analysed that author's last attempt to uphold Darwinism by the construction of his theory of“germinal selection.”He concluded with the wish:“That a spirit of earnestness would once more enter into biological investigation, which would no longer attempt to find in nature just what it wanted to find, but would be ready to follow truth at all costs, and to approach the riddle of life with an open mind.”His“Beiträge zur Kritik der Darwinischen Lehre,”which appeared first as papers in the“Biologisches Centralblatt,”did not see the light in book form until 1898. The doctrine of selection was regarded as so unassailable that no publisher would take the risk of the book. Its appearance is a sure indication of the general modification of opinions that had taken place in the interval. The first and second essays are merely critical objections to the theory of selection, very similar to those frequently urged before, but more precisely stated.52The third is intended to show that there is in the forms of life themselves, as a faculty of adaptation peculiar to them, a primary purposiveness, which is unquestionably active throughout the lifetime and development of every individual, but which is also the deepest cause of“phylogenesis,”or the formation[pg 181]of a race. This doctrine makes both the Darwinian and Lamarckian theories merely secondary. For the phenomena which suggest the Lamarckian interpretation presuppose this most essential factor—the primary adaptiveness. Wolff concludes with a very striking instance—discovered by himself—of this primary adaptiveness of the organism—the regeneration of the lens in the newt's eye.More comprehensively, but from a precisely similar standpoint, Driesch has followed up the discussion of this problem.53He is, of all modern investigators, perhaps the one who has most persistently and thoroughly[pg 182]worked out the problem of causal and teleological interpretation, and he has also thrown much light on the scientific and epistemological aspects of the problem. That he could, in a recent volume of the“Biologisches Zentralblatt,”write a respectful and sympathetic exposition of the Hegelian nature-philosophy—as regards its aims, though not its methods—is as remarkable a symptom as we can instance of the modern trend of views and opinions.54Contrast Between Darwinian and Post-Darwinian Views.The new views that have thus arisen have been definitely summarised and clearly contrasted with Darwinism by the botanist Korschinsky. He died before completing his general work,“Heterogenesis und Evolution,”but he has elsewhere55given an excellent summary of his results, which we append in abstract.Darwin.(1) Everything organic is capable of variation. Variations[pg 183]arise in part from internal, in part from external causes. They are slight, inconspicuous, individual differences.Korschinsky and the Moderns.(1) Everything organic is capable of variation. This capability is a fundamental, inherent character of living forms in general, and is independent of external conditions. It is usually kept latent by“heredity,”but occasionally breaks forth in sudden variations.Darwin.(2) The struggle for existence. This combines, increases, fixes useful variations, and eliminates the useless. All the characters and peculiarities of a finished species are the results of long-continued selection; they must therefore be adapted to the external conditions.Korschinsky and the Moderns.(2) Saltatory variations.—These are, under favourable circumstances, the starting-point of new and constant races. The characters may sometimes be useful, sometimes quite indifferent, neither advantageous nor disadvantageous. Sometimes they are not in harmony with external circumstances.Darwin.(3) The species is subject to constant variation. It is continually subject to selection and augmentation of its characters. Hence again the origin of new species.Korschinsky and the Moderns.(3) All fully developed species persist, but through heterogenesis a splitting up into new forms may take place, and this is accompanied by a disturbance of the vital equilibrium. The new state is at first insecure and fluctuating, and only gradually becomes stable. Thus new forms and races arise with gradual consolidation of their constitution.Darwin.(4) The sharper and more acute the effect of the environment, the keener is the struggle for existence, and the more rapidly and certainly do new forms arise.Korschinsky and the Moderns.(4) Only in specially favourable conditions, only when the struggle for existence is weak, or when there is none, can new forms arise and become fixed. When the conditions are severe no new forms arise, or if they do they are speedily eliminated.Darwin.(5) The chief condition of evolution is therefore the struggle for existence and the selection which this involves.Korschinsky and the Moderns.(5) The struggle for existence simply decimates the overwhelming[pg 184]abundance of possible forms. Where it occurs it prevents the establishment of new variations, and in reality stands in the way of new developments. It is rather an unfavourable than an advantageous factor.Darwin.(6) If there were no struggle for existence there would be no adaptation, no perfecting.Korschinsky and the Moderns.(6) Were there no struggle for existence, there would be no destruction of new forms, or of forms in process of arising. The world of organisms would then be a colossal genealogical tree of enormous luxuriance, and with an incalculable wealth of forms.Darwin.(7) Progress in nature, the“perfecting”of organisms, is only an increasingly complex and ever more perfect adaptation to the external circumstances. It is attained by purely mechanical methods, by an accumulation of the variations most useful at the time.Korschinsky and the Moderns.(7) The adaptation which the struggle for existence brings about has nothing to do with perfecting, for the organisms which are physiologically and morphologically higher are by no means always better adapted to external circumstances than those lower in the scale. Evolution cannot be explained mechanically. The origin of higher forms from lower is only possible if there is a tendency to progress innate in the organism itself. This tendency is nearly related to or identical with the tendency to variation. It compels the organism to perfect itself as far as external circumstances will permit.All this implies an admission of evolution and of descent, but a setting aside of Darwinism proper as an unsuccessful hypothesis, and a positive recognition of[pg 185]an endeavour after an aim, internal causes, and teleology in nature, as against fortuitous and superficial factors. This opens up a vista into the background of things, and thereby yields to the religious conception all that a study of nature can yield—namely, an acknowledgment of the possibility and legitimacy of interpreting the world in a religious sense, and assistance in so doing.The most important point has already been emphasised. Even if the theory of the struggle for existence were correct, it would be possible to subject the world as a whole to a teleological interpretation. But these anti-Darwinian theories now emerging, though they do not directly induce teleological interpretation, suggest it much more strongly than orthodox Darwinism does. A world which in its evolution is not exposed, for good or ill, to the action of chance factors—playing with it and forcing it hither and thither—but which, exposed indeed to the most diverse conditions of existence and their influences, and harmonising with them, nevertheless carries implicitly and infallibly within itself the laws of its own expression, and especially the necessity to develop upwards into higher and higher forms, is expressly suited for teleological consideration, and we can understand how it is that the old physico-teleological evidences of the existence of God are beginning to hold up their heads again. They are wrong when they try to demonstrate God, but quite right when they simply seek to show that nature does not contradict—in[pg 186]fact that it allows room and validity to—belief in the Highest Wisdom as the cause and guide of all things natural.As far as the question of the right to interpret nature teleologically is concerned, it would be entirely indifferent whether what Korschinsky calls“the tendency to progress,”and the system of laws in obedience to which evolution brings forth its forms, can be interpreted“mechanically”or not; that is to say, whether or not evolution depends on conditions and potentialities of living matter, which can be demonstrated and made mechanically commensurable or not. It may be that they can neither be demonstrated nor made mechanically commensurable, but lie in the impenetrable mystery inherent in all life. Whether this mystery really exists, and whether religion has any particular interest in it if it does, must be considered in the following chapter.[pg 187]

Chapter VII. Critics Of Darwinism.Let us turn now to the other side. What is opposed to Darwinism in the biological investigations of the experts of to-day is in part simple criticism of the Darwinian position as a whole or in some of its details, and in part constructive individual theories and interpretations of the evolution of organisms.A. Fleischmann's book,“Die Darwinsche Theorie,”39is professedly only critical. He suggests no theory of his own as to the evolution of life in contrast to Darwin's; for, as we have already seen in connection with his earlier book,“Die Deszendenztheorie,”he denies evolution altogether. His agnostic position is maintained, if possible, more resolutely than before. Natural science, according to him, must keep to facts. Drawing conclusions and spinning theories is inexact, and distracts from objective study. The Darwinian theory of selection seems to him a particularly good example of this, for it is built upà priorion theories[pg 161]and hypotheses, it stands apart from experimentation, and it twists facts forcibly to its own ends. It has, however, to be acknowledged that Fleischmann's book is without any“apologetic”intentions. It holds equally aloof from teleology. To seek for purposes and aims in nature he holds to be outside the business of science, as Kant's“Critique of Judgment”suffices to show. After having been more than a decade under the charm of the theory of selection, Fleischmann knows its fascination well, but he now regards it as so erroneous that no one who wishes to do serious work should concern himself about it at all. Point by point he follows all the details of Darwin's work, and seeks to analyse the separate views and theories which go to make up Darwinism as a whole. Darwin's main example of the evolution of the modern races of pigeons from one ancestral form,Columba livia, is, according to Fleischmann, not only unproved but unprovable.40For this itself is not a unified type. The process of“unconscious selection”by man is obscure, and it is not demonstrable, especially in regard to pigeon-breeding. It is a hazy idea which cannot be transferred to the realm of nature. The Malthusian assumption of the necessity of the struggle for existence is erroneous. Malthus was wrong in his law of population as applied[pg 162]to human life, and Darwin was still more mistaken when he transferred it to the organic world in general. It was mere theory. Statistics should have been collected, and observations instead of theories should have been sought for. The alleged superabundance of organisms is not a fact. The marvellously intertwined conditions in the economy of nature make the proportion of supply and demand relatively constant. And even when there is actual struggle for existence, advantages of situation,41which are quite indifferent as far as selection is concerned, are much more decisive than any variational differences. The theory does not explain the first origin of new characters, which can only become advantageous when they have attained to a certain degree of development. As to the illustrations of the influence of selection given by Darwin, from the much discussed fictitious cases, in which the fleet stags select the lithe wolf, to the marvellous mutual adaptations of insects and flowers, Fleischmann objects that there is not even theoretical justification for any one of them. The spade-like foot of the mole is not“more useful”than the form of foot which probably preceded it (cf.Goette), it is merely“different.”For when the mole took to burrowing in the earth and adapting itself to that mode of life, itipso factoforfeited all the advantages of living above ground. The postulated myriads of less well-adapted forms of life are no more to be found to-day than they are in the fauna and flora of[pg 163]palæontological times. The famous giraffe story has already been disposed of by Mivart's objections. As to the whales, it is objected that the earliest stages of their whalebone and their exaggerated nakedness can have been of no use, and a series of other alleged selective effects of“utility”are critically analysed. The refutation of the most brilliant chapter in the Darwinian theory, that on protective coloration and mimicry, is very insufficient. A long concluding chapter sums up the fundamental defects of the Darwinian theory.For the most part, Fleischmann simply brings forward objections which have been urged against the theory of selection from the first, either by naturalists or from other quarters. The chief and the most fatal of these which are still current are the following: The theory of selection does not explain the actually existing discontinuity of species. The real characteristics which distinguish species from species are in innumerable cases quite indifferent from the point of view of“utility”(Nägeli, Bateson).“Selection preserves the good and weeds out the bad.”But where does the good come from? (De Vries). The first beginnings of what may later be useful are almost always useless. The theory of selection might perhaps explain the useful qualities, but not the superfluous, useless, or directly injurious characters which actually exist. Confirmation of the theory of descent may be found in the palæontological record, but it affords none of the theory of selection. Natural selection is continually being neutralised by[pg 164]subsequent inter-crossing and reversion. Natural selection may indeed prevent degeneration within the limits of the species by weeding out what is weak and bad, but it is powerless beyond these limits, and so forth.42These ever-repeated and ever-increasing objections are purely critical. As this is true of Fleischmann's whole book, it is therefore unsatisfactory. It leaves everything in the mist, and puts nothing in place of what it attempts to demolish. But attempts are being made in other quarters, especially among the Lamarckians, to build up an opposition theory.Lamarckism and Neo-Lamarckism.The“Lamarckian”view as opposed to the Darwinian continues to hold its own, and indeed is more ardently supported than ever. On this view, evolution has been accomplished not by a laborious selection of the best which chanced to present itself—a selection in relation to which organisms remained passive, but rather through the exertions of the organisms themselves. It has been especially through the use and exercise of the various[pg 165]organs in response to the requirements of life, through the increased exercise of physical and mental functions, that the organism has adapted itself more diversely and more fully to the conditions of its life. What one generation acquired in differentiation of structure, in capacities and habits, through its own exertions, it handed on to the next. By cumulative inheritance there ultimately arose the fixed specific characters, and the diversity and progressive gradations of organisms have gone hand in hand with an ever increasing activity. And as with the physical so it has been with the mental. Through continual use and exercise of the functions their capacity has been increased and modified. Through the frequent repetition of voluntary actions necessary to life the habitual use of them has come about. Habits that have become fixed are correlated with habitual psychical predispositions. These, gradually handed on by inheritance to the descendants, have resulted in the marvellous instincts of animals. Instinct is inherited habit that has become fixed. Corresponding to this there is on the other hand the recognition—in theory at least—that the disuse of an organ, the non-exercising of a function leads to degeneration of structure and so co-operates in bringing about a gradual but persistent modification of the features and constitution of organisms.These views, which have grown out of Lamarck's fundamental ideas (“Philosophie zoologique,”1809) are now usually associated with the theory advanced chiefly[pg 166]by Etienne Geoffrey St. Hilaire (“Philosophie zoologique,”1830), the opponent of Cuvier, and the ally of Goethe, of the direct influence of themonde ambiant. The“surrounding world,”the influences of climate, of locality, of the weather, of nutrition, of temperature, of the salinity of the water, of the moisture in the air, and all other conditions of existence, influence the living organism. And they do so not indirectly, as is implied in the process of selection, simply playing the part of a sieve, and not themselves moulding and transforming, butdirectlyby necessitating the production of new developments in the living substance, new chemical and physiological activities, new groupings and changes of form, and new organs.Darwin himself did not regard these two theories as opposed to the theory of selection, but utilised them as subsidiary interpretations. It is obvious, however, that at bottom they conceal an essentially different fundamental idea, which, if followed out to its logical consequences, reduces the“struggle for existence”to at most a wholly indifferent accessory circumstance. Weismann felt this, and hence his entirely consistent endeavours to show by great examples, such as the origin of flowers, the mutual adaptations of flowers and insects, the phenomena of mimicry, and many other cases, that neither the Lamarckian nor any other factor in evolution, except only natural, passive selection, suffices as an interpretation. From the Darwinian standpoint he is absolutely right, and must needs speak[pg 167]of the“omnipotence of natural selection,”for it must either be omnipotent, or it must give place to the other two factors, and retain only the significance we attributed to it in another connection (p. 157), which amounts to saying none at all. It is obvious enough why the discussion as to these factors should centre round the question of the“inheritance of acquired characters,”“acquired”either through the use or disuse of organs, the exercise or non-exercise of functions, or through the stimuli of the external world.The neo-Lamarckian conflict with Darwinism has become more and more acute in recent times, and the neo-Lamarckians have sometimes passed from contrasting rival interpretations to excluding the Darwinian factor altogether. As the particular champion of the neo-Lamarckian view, we must name Th. Eimer, the recently deceased Tübingen zoologist. His chief work is in three volumes, entitled“Die Entstehung der Arten auf Grund von Vererbung erworbener Eigenschaften, nach Gesetzen organischen Wachsens.”43It is a polemic against Weismannism in all details, even to the theory of“germinal selection.”Eimer follows in the footsteps of St. Hilaire, and shows what a relatively plastic and sensitive creature the organism is to the surrounding world, the conditions of nutrition and other such influences. There is in this connection a particularly[pg 168]instructive chapter on the physiological and other variations brought about by external influences which act as“stimuli of the nervous system.”The whole theory of Lamarck and St. Hilaire transcends—notwithstanding the protests of Eimer to the contrary—the categories of the mechanical theory of life, and this chapter does so in particular. The array of facts here marshalled as to the spontaneous self-adaptation of organisms to their environment—in relation to colour mainly—forms the most thoroughgoing refutation of Darwinism that it is possible to imagine. It is shown, too, by a wealth of examples from osteology, how use (and the necessities of the case—a consideration which again goes beyond the bounds of mere Lamarckism) may modify, increase or diminish vertebræ, ribs, skull and limbs, in short, the whole skeleton.Kassowitz is equally keen and convinced in his opposition to natural selection, and in his comprehensive“Allgemeine Biologic”44he attacks orthodox Darwinism from the neo-Lamarckian standpoint. The whole of the first volume is almost chapter for chapter a critical analysis, and the polemical element rather outweighs his positive personal contribution. He criticises very severely all attempts to carry the Darwinian principle of explaining adaptations into internal and minute details, arguing against Roux's“Struggle of Parts”and Weismann's“Germinal Selection.”And though he himself maintains very decidedly that the[pg 169]ultimate aim of biology is to find a mechanical solution of the problem of life, he criticises the modern hypotheses in this direction without prejudice, and declares them unsuccessful and insufficient, inclining himself towards the“neo-vitalistic reaction”in its most recent expression. Along with Eimer and Kassowitz, we may name W. Haacke, especially in relation to his views on the acquisition and transmission of functional modifications and his thoroughgoing denial of Darwinism proper. But his work must be dealt with later in a different connection.45These neo-Lamarckian views give us a picture of the evolution of the world that is much more convincing than the strictly Darwinian one. Instead of passive and essentially unintelligent“adaptation”through the sieve of selection, we have here direct self-adaptation of organisms to the conditions of their existence, through their own continual restless activity and exertion, an ascent of their own accord to ever greater heights and perfections. A theory of this kind might easily form part of a religious conception of the world. We might think of the world with primitive tendencies and capacities, in which the potentialities of its evolution were implied, and so ordered that it had to struggle by its own exertions to achieve the full realisation of its[pg 170]possibilities, to attain to ever higher—up to the highest—forms of Being. The process of nature would thus be the direct anticipation of what occurs in the history of man and of mind. And the task set to the freedom of individual men, and to mankind as a whole, namely, to work out their own nature through their own labour and exertion, and to ascend to perfection—this deepest meaning of all individual and collective existence—would have its exact prelude and preparation in the general nature and evolution of all living creatures. The transition from these theories of nature to a teleological outlook from the highest and most human point of view is so obvious as to be almost unavoidable. And although a natural science which keeps to its own business and within its own boundaries has certainly no right to make this transition for itself, it has still less right to prevent its being made outside of its limits.Theory of Definite Variation.But the question now arises, whether both Darwinism and Lamarckism must not be replaced, or at least reduced to the level of accessory theories and factors, by another theory of evolution which was in the field before Darwin, and which since his time has been advanced anew, especially by Nägeli, and has now many adherents who support it in whole or in part. This view affects the very foundations of the Darwinian doctrine. The theory of“indefinite”variation, bringing about easy transitions and affecting every part of[pg 171]the organism separately, which is the necessary correlate of the“struggle for existence,”is rejected altogether. Evolution takes place only along a few definite lines, predetermined through the internal organisation and the laws of growth. It is wholly indifferent to“utility,”and brings forth only what it must according to its own inner laws, not seldom even the monstrous. According to this view, new species arise, not in easy transition, but with a visible leap, by a considerable and far-reaching displacement of the organic equilibrium. What Darwin calls the correlation of parts, and in no way denies, is here maintained in strong opposition to his doctrine of the isolated variation of individual parts; every member or character of the organism depends upon others, and variation of one affects many, and in some way all of the rest.This theory is for the most part intended by its champions to be purely naturalistic. But every one of its points yields support to teleological considerations, most obviously so the concrete instances of correlation. If any one were to attempt to make a theory of evolution from a decidedly teleological standpoint, he would probably construct one very similar to the one we are now considering.It is noteworthy that it has generally been the botanists who have especially supported these views of saltatory evolution in a definite direction and according to internal law, who have therefore tended to react most strongly from Darwinism. We find examples in Nägeli's[pg 172]large and comprehensive work,“Mechanisch-physikalische Theorie der Abstammungslehre”; and, before him, in Wigand's“Darwinismus und die Naturforschung Newton's und Cuvier's”; in von Kölliker's“Heterogenesis”; in von Baer's“Endeavour after an End”; in the chapter added by the translator, Bronn, to the first German edition of the“Origin of Species,”where he urges weighty objections against the theory of selection, and refers to the“innate impulse to development, persistently varying in a definite direction”; in Askenasy's oft-quoted“Beiträge zur Kritik der Darwinschen Lehre,”also referring to“variation in a definite direction,”for instance, in flowers; in Delpino's views, and in the works of many other older writers. But we must leave all these out of account here, since we are concerned only with the present state of the question.De Vries's Mutation-theory.The work that has probably excited most interest in this connection is De Vries'“Die Mutationstheorie: Versuche und Beobachtungen über die Entstehung von Arten im Pflanzenleben.”46In a short preliminary paper he had previously given some account of his leading experiments on a species of evening primrose (Œnothera lamarckiana), and the outlines of his theory. In the work itself he extends this, adding much concrete material, and comparing his views in detail with other[pg 173]theories. Darwin, he says, had already distinguished between variability and mutability; the former manifesting itself in gradual and isolated changes, the latter in saltatory changes on a larger scale. The mistake made by Wallace and by the later Darwinians has been that they regarded this latter form (“single variation”) as unimportant and not affecting evolution, and the former as the real method of evolutionary process. That fluctuating individual variations do occur De Vries admits, but only within narrow limits, never overstepping the type of the species. Here De Vries utilises the recent statistical investigations into the phenomena of individual variation and their laws, as formulated chiefly by Quetelet and Bateson, which were unknown to Darwin and the earlier Darwinians. The actual transition from“species to species”is made suddenly, by mutation, not through variation. And the state of equilibrium thus reached is such a relatively stable one that individual variations can only take place within its limits, but can in no way disturb it.De Vries marshals a series of facts which present insurmountable difficulties to the Darwinian theory, but afford corroboration of the Mutation theory. In particular, he brings forward, from his years of experiment and horticultural observation, comprehensive evidence of the mutational origin of new species from old ones by leaps, and this not in long-past geological times, but in the course of a human life and before our very eyes. The main importance of the book lies in the record of these[pg 174]experiments and observations, rather than in the theory as such, for the way had been paved for it by other workers.In contrast to Darwinism, De Vries states the case for“Halmatogenesis”(saltatory evolution) and“Heterogenesis”(the production of forms unlike the parents), taking his examples from the plant world, but his attitude to Darwinism is conciliatory throughout. Eimer, on the other hand, is sharply antagonistic, especially to Weismann; he takes his proofs from the animal kingdom, and in the second volume of his large work already mentioned, which deals with the“orthogenesis of butterflies,”he attempts to set against the Darwinism“chance theory,”a proof of“definitely directed evolution,”and therefore of the“insufficiency of natural selection in the formation of species.”Eimer's Orthogenesis.Organisation is due to internal causes. Structural characters crystallise out, as it were.“Orthogenesis,”or the definitely determined tendency of evolution to advance in a few directions, is a law for the whole of the animate world. In active response to the stimuli and influences of the environment the organism expresses itself in“organic growth”without any relation to utility. Butterflies in particular, and especially their markings and coloration, are taken as illustrations. In the Darwinian theory of“mimicry”these played a brilliant part. The great resemblance[pg 175]to leaves, to dried twigs, or to well-protected species which are secure from enemies, was regarded as the most convincing proof of the operation of natural selection. But Eimer shows that markings, striping, spots, the development of pattern, and the alleged or real resemblances to leaves, are really subject to definite laws of growth, in obedience to which they gradually appear, developing according to their own internal laws, varying and progressing altogether by internal necessity, and without any reference to advantage or disadvantage, In association with this orthogenesis, Eimer recognises halmatogenesis, correlation and“genepistasis”(coming to a standstill at a fixed and definite stage), and these seem to him to make the Darwinian theory utterly impossible. The text and the illustrations of the book show how, in the sequence of evolution (according to Eimer's laws of transformation), the groupings of stripes, bands, and eye-spots must have appeared on the butterfly's wing, how convex or concave curvings of the contour must have come about at certain points, so that the form of a“leaf”and the lines of its venation resulted, how the eye-spots must have been moulded and shunted, so that they produced the effect of rust or other spots on withered leaves. Particular interest attaches to the detailed arguments against the idea that the butterfly must receive some advantage from its“mimicry.”Even the Darwinians have to admit that in a whole series of cases the advantage is not obvious. They talk with some embarrassment of“pseudomimicry.”[pg 176]Some butterflies that are supposed to be protected have the protective markings on the underside, so that these are actually hidden when the insects are flying from pursuing birds. Many of the leaf-like butterflies are not wood-butterflies at all, but meadow species,47and so Eimer's arguments continue.A specially energetic fellow-worker on Eimer's line is W. Haacke, a zoologist of Jena, author of“Gestaltung und Vererbung,”and“Die Schöpfung des Menschen und seiner Ideale.”48In the first of these works Haacke combats, energetically and with much detail, Weismann's“preformation theory,”and defends“epigenesis,”for which he endeavours to construct graphic diagrams, his aim being to make a foundation for the inheritance of acquired characters, definitely directed evolution, saltatory, symmetrical, and correlated variation.The principles of the new school are very widespread to-day, but we cannot here follow their development in the works of individual investigators, such as Reinke, R. Hertwig, O. Hertwig, Wiesner, Hamann, Dreyer, Wolff, Goette, Kassowitz, v. Wettstein, Korschinsky, and others.49[pg 177]The Spontaneous Activity of the Organism.What is particularly luminous in all the theories that express the most recent anti-Darwinian tendency is that they tend to bring into prominence the mysterious powers of living organisms, by means of which, instead of passively waiting for natural selection and the continual accumulation of unceasing variations, they are able spontaneously and of themselves to bring forth what is necessary for self-maintenance, often what is new and different, of course not unlimitedly, but with considerable freedom and often with a surprising range of possibilities. It is, perhaps, partly the fault of the one-sidedness of strict Darwinism that this consideration has been so slowly brought into prominence and subjected to investigation and experiment. It is bound up with the capacity that all forms of life have of reacting spontaneously to“stimuli”and, to a certain extent, of helping themselves if the conditions of existence be unfavourable. They are able, for instance, to produce protective adaptations[pg 178]against cold or heat, to“regenerate”lost parts, often to replace entire organs that have been lost, and, under certain circumstances, to produce new organs altogether. If all this be true, it seems almost like caprice to follow only the roundabout theory of the struggle for existence, and not to take account of these spontaneous capacities of the living organism directly and before all other factors in the attempt to explain evolution. There is no end to the illustrations that are being adduced, that must force investigation to pass from merely superficial considerations of the struggle for existence type to the deeper and more real problems themselves.An effectively modified and adapted type of Alpine flora has not been evolved by a laborious process of selection lasting for many thousand years; the organism may quickly and immediately produce the new characters by its own reaction. Crustaceans gradually transferred from a salt-water to a fresh-water habitat, or conversely, produce in a few generations the type of a new“species”with correlated variations (Schmankewitsch). Birds weaned by careful experiment from a diet of seeds to one of flesh, or conversely, produce changes of effective correlation and adaptation in the characters of their alimentary system. Plants that have been deprived of their normal organs for absorbing water and prevented from growing new ones produce entirely new and effective“hydatodes.”50[pg 179]It is instructive to notice that Darwinism seems likely to be robbed of its stock illustration, namely,“protective coloration.”By its own internal power of reaction, and sometimes within one generation, and even in the lifetime of an individual, an organism may assume the colour of the substratum beneath it (soles, grasshoppers), of its surroundings (Eimer's tree frogs), the colour and spottiness of the granite rock on which it hangs, the colour of the leaves and twigs among which it lives (Poulton's butterfly pupæ), and even that of the brightly coloured sheets of paper amidst which it is kept imprisoned. Certain spiders assume a white, pink, or greenish“protective coloration”corresponding to the tinted blossom of the plants which they frequent, and so on.51Eimer alleged that direct psychical factors co-operated in bringing about these changes. In any case, all this carries us far beyond the domain of mere naturalistic factors into the mystery of life itself. Even what is called the“influence of the external world,”and the“active acquirement of new characters,”have their basis and the reason of their possibility in this domain. And the whole domain is saturated through and through with“teleology.”A recognition of the impressive secret of the organism led Gustav Wolff to become a very pronounced critic of Darwinism, especially in the form of Weismannism.[pg 180]As far back as 1896, in a lecture“On the present position of Darwinism,”in which he dealt only with Weismann, he criticised and analysed that author's last attempt to uphold Darwinism by the construction of his theory of“germinal selection.”He concluded with the wish:“That a spirit of earnestness would once more enter into biological investigation, which would no longer attempt to find in nature just what it wanted to find, but would be ready to follow truth at all costs, and to approach the riddle of life with an open mind.”His“Beiträge zur Kritik der Darwinischen Lehre,”which appeared first as papers in the“Biologisches Centralblatt,”did not see the light in book form until 1898. The doctrine of selection was regarded as so unassailable that no publisher would take the risk of the book. Its appearance is a sure indication of the general modification of opinions that had taken place in the interval. The first and second essays are merely critical objections to the theory of selection, very similar to those frequently urged before, but more precisely stated.52The third is intended to show that there is in the forms of life themselves, as a faculty of adaptation peculiar to them, a primary purposiveness, which is unquestionably active throughout the lifetime and development of every individual, but which is also the deepest cause of“phylogenesis,”or the formation[pg 181]of a race. This doctrine makes both the Darwinian and Lamarckian theories merely secondary. For the phenomena which suggest the Lamarckian interpretation presuppose this most essential factor—the primary adaptiveness. Wolff concludes with a very striking instance—discovered by himself—of this primary adaptiveness of the organism—the regeneration of the lens in the newt's eye.More comprehensively, but from a precisely similar standpoint, Driesch has followed up the discussion of this problem.53He is, of all modern investigators, perhaps the one who has most persistently and thoroughly[pg 182]worked out the problem of causal and teleological interpretation, and he has also thrown much light on the scientific and epistemological aspects of the problem. That he could, in a recent volume of the“Biologisches Zentralblatt,”write a respectful and sympathetic exposition of the Hegelian nature-philosophy—as regards its aims, though not its methods—is as remarkable a symptom as we can instance of the modern trend of views and opinions.54Contrast Between Darwinian and Post-Darwinian Views.The new views that have thus arisen have been definitely summarised and clearly contrasted with Darwinism by the botanist Korschinsky. He died before completing his general work,“Heterogenesis und Evolution,”but he has elsewhere55given an excellent summary of his results, which we append in abstract.Darwin.(1) Everything organic is capable of variation. Variations[pg 183]arise in part from internal, in part from external causes. They are slight, inconspicuous, individual differences.Korschinsky and the Moderns.(1) Everything organic is capable of variation. This capability is a fundamental, inherent character of living forms in general, and is independent of external conditions. It is usually kept latent by“heredity,”but occasionally breaks forth in sudden variations.Darwin.(2) The struggle for existence. This combines, increases, fixes useful variations, and eliminates the useless. All the characters and peculiarities of a finished species are the results of long-continued selection; they must therefore be adapted to the external conditions.Korschinsky and the Moderns.(2) Saltatory variations.—These are, under favourable circumstances, the starting-point of new and constant races. The characters may sometimes be useful, sometimes quite indifferent, neither advantageous nor disadvantageous. Sometimes they are not in harmony with external circumstances.Darwin.(3) The species is subject to constant variation. It is continually subject to selection and augmentation of its characters. Hence again the origin of new species.Korschinsky and the Moderns.(3) All fully developed species persist, but through heterogenesis a splitting up into new forms may take place, and this is accompanied by a disturbance of the vital equilibrium. The new state is at first insecure and fluctuating, and only gradually becomes stable. Thus new forms and races arise with gradual consolidation of their constitution.Darwin.(4) The sharper and more acute the effect of the environment, the keener is the struggle for existence, and the more rapidly and certainly do new forms arise.Korschinsky and the Moderns.(4) Only in specially favourable conditions, only when the struggle for existence is weak, or when there is none, can new forms arise and become fixed. When the conditions are severe no new forms arise, or if they do they are speedily eliminated.Darwin.(5) The chief condition of evolution is therefore the struggle for existence and the selection which this involves.Korschinsky and the Moderns.(5) The struggle for existence simply decimates the overwhelming[pg 184]abundance of possible forms. Where it occurs it prevents the establishment of new variations, and in reality stands in the way of new developments. It is rather an unfavourable than an advantageous factor.Darwin.(6) If there were no struggle for existence there would be no adaptation, no perfecting.Korschinsky and the Moderns.(6) Were there no struggle for existence, there would be no destruction of new forms, or of forms in process of arising. The world of organisms would then be a colossal genealogical tree of enormous luxuriance, and with an incalculable wealth of forms.Darwin.(7) Progress in nature, the“perfecting”of organisms, is only an increasingly complex and ever more perfect adaptation to the external circumstances. It is attained by purely mechanical methods, by an accumulation of the variations most useful at the time.Korschinsky and the Moderns.(7) The adaptation which the struggle for existence brings about has nothing to do with perfecting, for the organisms which are physiologically and morphologically higher are by no means always better adapted to external circumstances than those lower in the scale. Evolution cannot be explained mechanically. The origin of higher forms from lower is only possible if there is a tendency to progress innate in the organism itself. This tendency is nearly related to or identical with the tendency to variation. It compels the organism to perfect itself as far as external circumstances will permit.All this implies an admission of evolution and of descent, but a setting aside of Darwinism proper as an unsuccessful hypothesis, and a positive recognition of[pg 185]an endeavour after an aim, internal causes, and teleology in nature, as against fortuitous and superficial factors. This opens up a vista into the background of things, and thereby yields to the religious conception all that a study of nature can yield—namely, an acknowledgment of the possibility and legitimacy of interpreting the world in a religious sense, and assistance in so doing.The most important point has already been emphasised. Even if the theory of the struggle for existence were correct, it would be possible to subject the world as a whole to a teleological interpretation. But these anti-Darwinian theories now emerging, though they do not directly induce teleological interpretation, suggest it much more strongly than orthodox Darwinism does. A world which in its evolution is not exposed, for good or ill, to the action of chance factors—playing with it and forcing it hither and thither—but which, exposed indeed to the most diverse conditions of existence and their influences, and harmonising with them, nevertheless carries implicitly and infallibly within itself the laws of its own expression, and especially the necessity to develop upwards into higher and higher forms, is expressly suited for teleological consideration, and we can understand how it is that the old physico-teleological evidences of the existence of God are beginning to hold up their heads again. They are wrong when they try to demonstrate God, but quite right when they simply seek to show that nature does not contradict—in[pg 186]fact that it allows room and validity to—belief in the Highest Wisdom as the cause and guide of all things natural.As far as the question of the right to interpret nature teleologically is concerned, it would be entirely indifferent whether what Korschinsky calls“the tendency to progress,”and the system of laws in obedience to which evolution brings forth its forms, can be interpreted“mechanically”or not; that is to say, whether or not evolution depends on conditions and potentialities of living matter, which can be demonstrated and made mechanically commensurable or not. It may be that they can neither be demonstrated nor made mechanically commensurable, but lie in the impenetrable mystery inherent in all life. Whether this mystery really exists, and whether religion has any particular interest in it if it does, must be considered in the following chapter.

Let us turn now to the other side. What is opposed to Darwinism in the biological investigations of the experts of to-day is in part simple criticism of the Darwinian position as a whole or in some of its details, and in part constructive individual theories and interpretations of the evolution of organisms.

A. Fleischmann's book,“Die Darwinsche Theorie,”39is professedly only critical. He suggests no theory of his own as to the evolution of life in contrast to Darwin's; for, as we have already seen in connection with his earlier book,“Die Deszendenztheorie,”he denies evolution altogether. His agnostic position is maintained, if possible, more resolutely than before. Natural science, according to him, must keep to facts. Drawing conclusions and spinning theories is inexact, and distracts from objective study. The Darwinian theory of selection seems to him a particularly good example of this, for it is built upà priorion theories[pg 161]and hypotheses, it stands apart from experimentation, and it twists facts forcibly to its own ends. It has, however, to be acknowledged that Fleischmann's book is without any“apologetic”intentions. It holds equally aloof from teleology. To seek for purposes and aims in nature he holds to be outside the business of science, as Kant's“Critique of Judgment”suffices to show. After having been more than a decade under the charm of the theory of selection, Fleischmann knows its fascination well, but he now regards it as so erroneous that no one who wishes to do serious work should concern himself about it at all. Point by point he follows all the details of Darwin's work, and seeks to analyse the separate views and theories which go to make up Darwinism as a whole. Darwin's main example of the evolution of the modern races of pigeons from one ancestral form,Columba livia, is, according to Fleischmann, not only unproved but unprovable.40For this itself is not a unified type. The process of“unconscious selection”by man is obscure, and it is not demonstrable, especially in regard to pigeon-breeding. It is a hazy idea which cannot be transferred to the realm of nature. The Malthusian assumption of the necessity of the struggle for existence is erroneous. Malthus was wrong in his law of population as applied[pg 162]to human life, and Darwin was still more mistaken when he transferred it to the organic world in general. It was mere theory. Statistics should have been collected, and observations instead of theories should have been sought for. The alleged superabundance of organisms is not a fact. The marvellously intertwined conditions in the economy of nature make the proportion of supply and demand relatively constant. And even when there is actual struggle for existence, advantages of situation,41which are quite indifferent as far as selection is concerned, are much more decisive than any variational differences. The theory does not explain the first origin of new characters, which can only become advantageous when they have attained to a certain degree of development. As to the illustrations of the influence of selection given by Darwin, from the much discussed fictitious cases, in which the fleet stags select the lithe wolf, to the marvellous mutual adaptations of insects and flowers, Fleischmann objects that there is not even theoretical justification for any one of them. The spade-like foot of the mole is not“more useful”than the form of foot which probably preceded it (cf.Goette), it is merely“different.”For when the mole took to burrowing in the earth and adapting itself to that mode of life, itipso factoforfeited all the advantages of living above ground. The postulated myriads of less well-adapted forms of life are no more to be found to-day than they are in the fauna and flora of[pg 163]palæontological times. The famous giraffe story has already been disposed of by Mivart's objections. As to the whales, it is objected that the earliest stages of their whalebone and their exaggerated nakedness can have been of no use, and a series of other alleged selective effects of“utility”are critically analysed. The refutation of the most brilliant chapter in the Darwinian theory, that on protective coloration and mimicry, is very insufficient. A long concluding chapter sums up the fundamental defects of the Darwinian theory.

For the most part, Fleischmann simply brings forward objections which have been urged against the theory of selection from the first, either by naturalists or from other quarters. The chief and the most fatal of these which are still current are the following: The theory of selection does not explain the actually existing discontinuity of species. The real characteristics which distinguish species from species are in innumerable cases quite indifferent from the point of view of“utility”(Nägeli, Bateson).“Selection preserves the good and weeds out the bad.”But where does the good come from? (De Vries). The first beginnings of what may later be useful are almost always useless. The theory of selection might perhaps explain the useful qualities, but not the superfluous, useless, or directly injurious characters which actually exist. Confirmation of the theory of descent may be found in the palæontological record, but it affords none of the theory of selection. Natural selection is continually being neutralised by[pg 164]subsequent inter-crossing and reversion. Natural selection may indeed prevent degeneration within the limits of the species by weeding out what is weak and bad, but it is powerless beyond these limits, and so forth.42

These ever-repeated and ever-increasing objections are purely critical. As this is true of Fleischmann's whole book, it is therefore unsatisfactory. It leaves everything in the mist, and puts nothing in place of what it attempts to demolish. But attempts are being made in other quarters, especially among the Lamarckians, to build up an opposition theory.

Lamarckism and Neo-Lamarckism.The“Lamarckian”view as opposed to the Darwinian continues to hold its own, and indeed is more ardently supported than ever. On this view, evolution has been accomplished not by a laborious selection of the best which chanced to present itself—a selection in relation to which organisms remained passive, but rather through the exertions of the organisms themselves. It has been especially through the use and exercise of the various[pg 165]organs in response to the requirements of life, through the increased exercise of physical and mental functions, that the organism has adapted itself more diversely and more fully to the conditions of its life. What one generation acquired in differentiation of structure, in capacities and habits, through its own exertions, it handed on to the next. By cumulative inheritance there ultimately arose the fixed specific characters, and the diversity and progressive gradations of organisms have gone hand in hand with an ever increasing activity. And as with the physical so it has been with the mental. Through continual use and exercise of the functions their capacity has been increased and modified. Through the frequent repetition of voluntary actions necessary to life the habitual use of them has come about. Habits that have become fixed are correlated with habitual psychical predispositions. These, gradually handed on by inheritance to the descendants, have resulted in the marvellous instincts of animals. Instinct is inherited habit that has become fixed. Corresponding to this there is on the other hand the recognition—in theory at least—that the disuse of an organ, the non-exercising of a function leads to degeneration of structure and so co-operates in bringing about a gradual but persistent modification of the features and constitution of organisms.These views, which have grown out of Lamarck's fundamental ideas (“Philosophie zoologique,”1809) are now usually associated with the theory advanced chiefly[pg 166]by Etienne Geoffrey St. Hilaire (“Philosophie zoologique,”1830), the opponent of Cuvier, and the ally of Goethe, of the direct influence of themonde ambiant. The“surrounding world,”the influences of climate, of locality, of the weather, of nutrition, of temperature, of the salinity of the water, of the moisture in the air, and all other conditions of existence, influence the living organism. And they do so not indirectly, as is implied in the process of selection, simply playing the part of a sieve, and not themselves moulding and transforming, butdirectlyby necessitating the production of new developments in the living substance, new chemical and physiological activities, new groupings and changes of form, and new organs.Darwin himself did not regard these two theories as opposed to the theory of selection, but utilised them as subsidiary interpretations. It is obvious, however, that at bottom they conceal an essentially different fundamental idea, which, if followed out to its logical consequences, reduces the“struggle for existence”to at most a wholly indifferent accessory circumstance. Weismann felt this, and hence his entirely consistent endeavours to show by great examples, such as the origin of flowers, the mutual adaptations of flowers and insects, the phenomena of mimicry, and many other cases, that neither the Lamarckian nor any other factor in evolution, except only natural, passive selection, suffices as an interpretation. From the Darwinian standpoint he is absolutely right, and must needs speak[pg 167]of the“omnipotence of natural selection,”for it must either be omnipotent, or it must give place to the other two factors, and retain only the significance we attributed to it in another connection (p. 157), which amounts to saying none at all. It is obvious enough why the discussion as to these factors should centre round the question of the“inheritance of acquired characters,”“acquired”either through the use or disuse of organs, the exercise or non-exercise of functions, or through the stimuli of the external world.The neo-Lamarckian conflict with Darwinism has become more and more acute in recent times, and the neo-Lamarckians have sometimes passed from contrasting rival interpretations to excluding the Darwinian factor altogether. As the particular champion of the neo-Lamarckian view, we must name Th. Eimer, the recently deceased Tübingen zoologist. His chief work is in three volumes, entitled“Die Entstehung der Arten auf Grund von Vererbung erworbener Eigenschaften, nach Gesetzen organischen Wachsens.”43It is a polemic against Weismannism in all details, even to the theory of“germinal selection.”Eimer follows in the footsteps of St. Hilaire, and shows what a relatively plastic and sensitive creature the organism is to the surrounding world, the conditions of nutrition and other such influences. There is in this connection a particularly[pg 168]instructive chapter on the physiological and other variations brought about by external influences which act as“stimuli of the nervous system.”The whole theory of Lamarck and St. Hilaire transcends—notwithstanding the protests of Eimer to the contrary—the categories of the mechanical theory of life, and this chapter does so in particular. The array of facts here marshalled as to the spontaneous self-adaptation of organisms to their environment—in relation to colour mainly—forms the most thoroughgoing refutation of Darwinism that it is possible to imagine. It is shown, too, by a wealth of examples from osteology, how use (and the necessities of the case—a consideration which again goes beyond the bounds of mere Lamarckism) may modify, increase or diminish vertebræ, ribs, skull and limbs, in short, the whole skeleton.Kassowitz is equally keen and convinced in his opposition to natural selection, and in his comprehensive“Allgemeine Biologic”44he attacks orthodox Darwinism from the neo-Lamarckian standpoint. The whole of the first volume is almost chapter for chapter a critical analysis, and the polemical element rather outweighs his positive personal contribution. He criticises very severely all attempts to carry the Darwinian principle of explaining adaptations into internal and minute details, arguing against Roux's“Struggle of Parts”and Weismann's“Germinal Selection.”And though he himself maintains very decidedly that the[pg 169]ultimate aim of biology is to find a mechanical solution of the problem of life, he criticises the modern hypotheses in this direction without prejudice, and declares them unsuccessful and insufficient, inclining himself towards the“neo-vitalistic reaction”in its most recent expression. Along with Eimer and Kassowitz, we may name W. Haacke, especially in relation to his views on the acquisition and transmission of functional modifications and his thoroughgoing denial of Darwinism proper. But his work must be dealt with later in a different connection.45These neo-Lamarckian views give us a picture of the evolution of the world that is much more convincing than the strictly Darwinian one. Instead of passive and essentially unintelligent“adaptation”through the sieve of selection, we have here direct self-adaptation of organisms to the conditions of their existence, through their own continual restless activity and exertion, an ascent of their own accord to ever greater heights and perfections. A theory of this kind might easily form part of a religious conception of the world. We might think of the world with primitive tendencies and capacities, in which the potentialities of its evolution were implied, and so ordered that it had to struggle by its own exertions to achieve the full realisation of its[pg 170]possibilities, to attain to ever higher—up to the highest—forms of Being. The process of nature would thus be the direct anticipation of what occurs in the history of man and of mind. And the task set to the freedom of individual men, and to mankind as a whole, namely, to work out their own nature through their own labour and exertion, and to ascend to perfection—this deepest meaning of all individual and collective existence—would have its exact prelude and preparation in the general nature and evolution of all living creatures. The transition from these theories of nature to a teleological outlook from the highest and most human point of view is so obvious as to be almost unavoidable. And although a natural science which keeps to its own business and within its own boundaries has certainly no right to make this transition for itself, it has still less right to prevent its being made outside of its limits.

The“Lamarckian”view as opposed to the Darwinian continues to hold its own, and indeed is more ardently supported than ever. On this view, evolution has been accomplished not by a laborious selection of the best which chanced to present itself—a selection in relation to which organisms remained passive, but rather through the exertions of the organisms themselves. It has been especially through the use and exercise of the various[pg 165]organs in response to the requirements of life, through the increased exercise of physical and mental functions, that the organism has adapted itself more diversely and more fully to the conditions of its life. What one generation acquired in differentiation of structure, in capacities and habits, through its own exertions, it handed on to the next. By cumulative inheritance there ultimately arose the fixed specific characters, and the diversity and progressive gradations of organisms have gone hand in hand with an ever increasing activity. And as with the physical so it has been with the mental. Through continual use and exercise of the functions their capacity has been increased and modified. Through the frequent repetition of voluntary actions necessary to life the habitual use of them has come about. Habits that have become fixed are correlated with habitual psychical predispositions. These, gradually handed on by inheritance to the descendants, have resulted in the marvellous instincts of animals. Instinct is inherited habit that has become fixed. Corresponding to this there is on the other hand the recognition—in theory at least—that the disuse of an organ, the non-exercising of a function leads to degeneration of structure and so co-operates in bringing about a gradual but persistent modification of the features and constitution of organisms.

These views, which have grown out of Lamarck's fundamental ideas (“Philosophie zoologique,”1809) are now usually associated with the theory advanced chiefly[pg 166]by Etienne Geoffrey St. Hilaire (“Philosophie zoologique,”1830), the opponent of Cuvier, and the ally of Goethe, of the direct influence of themonde ambiant. The“surrounding world,”the influences of climate, of locality, of the weather, of nutrition, of temperature, of the salinity of the water, of the moisture in the air, and all other conditions of existence, influence the living organism. And they do so not indirectly, as is implied in the process of selection, simply playing the part of a sieve, and not themselves moulding and transforming, butdirectlyby necessitating the production of new developments in the living substance, new chemical and physiological activities, new groupings and changes of form, and new organs.

Darwin himself did not regard these two theories as opposed to the theory of selection, but utilised them as subsidiary interpretations. It is obvious, however, that at bottom they conceal an essentially different fundamental idea, which, if followed out to its logical consequences, reduces the“struggle for existence”to at most a wholly indifferent accessory circumstance. Weismann felt this, and hence his entirely consistent endeavours to show by great examples, such as the origin of flowers, the mutual adaptations of flowers and insects, the phenomena of mimicry, and many other cases, that neither the Lamarckian nor any other factor in evolution, except only natural, passive selection, suffices as an interpretation. From the Darwinian standpoint he is absolutely right, and must needs speak[pg 167]of the“omnipotence of natural selection,”for it must either be omnipotent, or it must give place to the other two factors, and retain only the significance we attributed to it in another connection (p. 157), which amounts to saying none at all. It is obvious enough why the discussion as to these factors should centre round the question of the“inheritance of acquired characters,”“acquired”either through the use or disuse of organs, the exercise or non-exercise of functions, or through the stimuli of the external world.

The neo-Lamarckian conflict with Darwinism has become more and more acute in recent times, and the neo-Lamarckians have sometimes passed from contrasting rival interpretations to excluding the Darwinian factor altogether. As the particular champion of the neo-Lamarckian view, we must name Th. Eimer, the recently deceased Tübingen zoologist. His chief work is in three volumes, entitled“Die Entstehung der Arten auf Grund von Vererbung erworbener Eigenschaften, nach Gesetzen organischen Wachsens.”43It is a polemic against Weismannism in all details, even to the theory of“germinal selection.”Eimer follows in the footsteps of St. Hilaire, and shows what a relatively plastic and sensitive creature the organism is to the surrounding world, the conditions of nutrition and other such influences. There is in this connection a particularly[pg 168]instructive chapter on the physiological and other variations brought about by external influences which act as“stimuli of the nervous system.”The whole theory of Lamarck and St. Hilaire transcends—notwithstanding the protests of Eimer to the contrary—the categories of the mechanical theory of life, and this chapter does so in particular. The array of facts here marshalled as to the spontaneous self-adaptation of organisms to their environment—in relation to colour mainly—forms the most thoroughgoing refutation of Darwinism that it is possible to imagine. It is shown, too, by a wealth of examples from osteology, how use (and the necessities of the case—a consideration which again goes beyond the bounds of mere Lamarckism) may modify, increase or diminish vertebræ, ribs, skull and limbs, in short, the whole skeleton.

Kassowitz is equally keen and convinced in his opposition to natural selection, and in his comprehensive“Allgemeine Biologic”44he attacks orthodox Darwinism from the neo-Lamarckian standpoint. The whole of the first volume is almost chapter for chapter a critical analysis, and the polemical element rather outweighs his positive personal contribution. He criticises very severely all attempts to carry the Darwinian principle of explaining adaptations into internal and minute details, arguing against Roux's“Struggle of Parts”and Weismann's“Germinal Selection.”And though he himself maintains very decidedly that the[pg 169]ultimate aim of biology is to find a mechanical solution of the problem of life, he criticises the modern hypotheses in this direction without prejudice, and declares them unsuccessful and insufficient, inclining himself towards the“neo-vitalistic reaction”in its most recent expression. Along with Eimer and Kassowitz, we may name W. Haacke, especially in relation to his views on the acquisition and transmission of functional modifications and his thoroughgoing denial of Darwinism proper. But his work must be dealt with later in a different connection.45

These neo-Lamarckian views give us a picture of the evolution of the world that is much more convincing than the strictly Darwinian one. Instead of passive and essentially unintelligent“adaptation”through the sieve of selection, we have here direct self-adaptation of organisms to the conditions of their existence, through their own continual restless activity and exertion, an ascent of their own accord to ever greater heights and perfections. A theory of this kind might easily form part of a religious conception of the world. We might think of the world with primitive tendencies and capacities, in which the potentialities of its evolution were implied, and so ordered that it had to struggle by its own exertions to achieve the full realisation of its[pg 170]possibilities, to attain to ever higher—up to the highest—forms of Being. The process of nature would thus be the direct anticipation of what occurs in the history of man and of mind. And the task set to the freedom of individual men, and to mankind as a whole, namely, to work out their own nature through their own labour and exertion, and to ascend to perfection—this deepest meaning of all individual and collective existence—would have its exact prelude and preparation in the general nature and evolution of all living creatures. The transition from these theories of nature to a teleological outlook from the highest and most human point of view is so obvious as to be almost unavoidable. And although a natural science which keeps to its own business and within its own boundaries has certainly no right to make this transition for itself, it has still less right to prevent its being made outside of its limits.

Theory of Definite Variation.But the question now arises, whether both Darwinism and Lamarckism must not be replaced, or at least reduced to the level of accessory theories and factors, by another theory of evolution which was in the field before Darwin, and which since his time has been advanced anew, especially by Nägeli, and has now many adherents who support it in whole or in part. This view affects the very foundations of the Darwinian doctrine. The theory of“indefinite”variation, bringing about easy transitions and affecting every part of[pg 171]the organism separately, which is the necessary correlate of the“struggle for existence,”is rejected altogether. Evolution takes place only along a few definite lines, predetermined through the internal organisation and the laws of growth. It is wholly indifferent to“utility,”and brings forth only what it must according to its own inner laws, not seldom even the monstrous. According to this view, new species arise, not in easy transition, but with a visible leap, by a considerable and far-reaching displacement of the organic equilibrium. What Darwin calls the correlation of parts, and in no way denies, is here maintained in strong opposition to his doctrine of the isolated variation of individual parts; every member or character of the organism depends upon others, and variation of one affects many, and in some way all of the rest.This theory is for the most part intended by its champions to be purely naturalistic. But every one of its points yields support to teleological considerations, most obviously so the concrete instances of correlation. If any one were to attempt to make a theory of evolution from a decidedly teleological standpoint, he would probably construct one very similar to the one we are now considering.It is noteworthy that it has generally been the botanists who have especially supported these views of saltatory evolution in a definite direction and according to internal law, who have therefore tended to react most strongly from Darwinism. We find examples in Nägeli's[pg 172]large and comprehensive work,“Mechanisch-physikalische Theorie der Abstammungslehre”; and, before him, in Wigand's“Darwinismus und die Naturforschung Newton's und Cuvier's”; in von Kölliker's“Heterogenesis”; in von Baer's“Endeavour after an End”; in the chapter added by the translator, Bronn, to the first German edition of the“Origin of Species,”where he urges weighty objections against the theory of selection, and refers to the“innate impulse to development, persistently varying in a definite direction”; in Askenasy's oft-quoted“Beiträge zur Kritik der Darwinschen Lehre,”also referring to“variation in a definite direction,”for instance, in flowers; in Delpino's views, and in the works of many other older writers. But we must leave all these out of account here, since we are concerned only with the present state of the question.

But the question now arises, whether both Darwinism and Lamarckism must not be replaced, or at least reduced to the level of accessory theories and factors, by another theory of evolution which was in the field before Darwin, and which since his time has been advanced anew, especially by Nägeli, and has now many adherents who support it in whole or in part. This view affects the very foundations of the Darwinian doctrine. The theory of“indefinite”variation, bringing about easy transitions and affecting every part of[pg 171]the organism separately, which is the necessary correlate of the“struggle for existence,”is rejected altogether. Evolution takes place only along a few definite lines, predetermined through the internal organisation and the laws of growth. It is wholly indifferent to“utility,”and brings forth only what it must according to its own inner laws, not seldom even the monstrous. According to this view, new species arise, not in easy transition, but with a visible leap, by a considerable and far-reaching displacement of the organic equilibrium. What Darwin calls the correlation of parts, and in no way denies, is here maintained in strong opposition to his doctrine of the isolated variation of individual parts; every member or character of the organism depends upon others, and variation of one affects many, and in some way all of the rest.

This theory is for the most part intended by its champions to be purely naturalistic. But every one of its points yields support to teleological considerations, most obviously so the concrete instances of correlation. If any one were to attempt to make a theory of evolution from a decidedly teleological standpoint, he would probably construct one very similar to the one we are now considering.

It is noteworthy that it has generally been the botanists who have especially supported these views of saltatory evolution in a definite direction and according to internal law, who have therefore tended to react most strongly from Darwinism. We find examples in Nägeli's[pg 172]large and comprehensive work,“Mechanisch-physikalische Theorie der Abstammungslehre”; and, before him, in Wigand's“Darwinismus und die Naturforschung Newton's und Cuvier's”; in von Kölliker's“Heterogenesis”; in von Baer's“Endeavour after an End”; in the chapter added by the translator, Bronn, to the first German edition of the“Origin of Species,”where he urges weighty objections against the theory of selection, and refers to the“innate impulse to development, persistently varying in a definite direction”; in Askenasy's oft-quoted“Beiträge zur Kritik der Darwinschen Lehre,”also referring to“variation in a definite direction,”for instance, in flowers; in Delpino's views, and in the works of many other older writers. But we must leave all these out of account here, since we are concerned only with the present state of the question.

De Vries's Mutation-theory.The work that has probably excited most interest in this connection is De Vries'“Die Mutationstheorie: Versuche und Beobachtungen über die Entstehung von Arten im Pflanzenleben.”46In a short preliminary paper he had previously given some account of his leading experiments on a species of evening primrose (Œnothera lamarckiana), and the outlines of his theory. In the work itself he extends this, adding much concrete material, and comparing his views in detail with other[pg 173]theories. Darwin, he says, had already distinguished between variability and mutability; the former manifesting itself in gradual and isolated changes, the latter in saltatory changes on a larger scale. The mistake made by Wallace and by the later Darwinians has been that they regarded this latter form (“single variation”) as unimportant and not affecting evolution, and the former as the real method of evolutionary process. That fluctuating individual variations do occur De Vries admits, but only within narrow limits, never overstepping the type of the species. Here De Vries utilises the recent statistical investigations into the phenomena of individual variation and their laws, as formulated chiefly by Quetelet and Bateson, which were unknown to Darwin and the earlier Darwinians. The actual transition from“species to species”is made suddenly, by mutation, not through variation. And the state of equilibrium thus reached is such a relatively stable one that individual variations can only take place within its limits, but can in no way disturb it.De Vries marshals a series of facts which present insurmountable difficulties to the Darwinian theory, but afford corroboration of the Mutation theory. In particular, he brings forward, from his years of experiment and horticultural observation, comprehensive evidence of the mutational origin of new species from old ones by leaps, and this not in long-past geological times, but in the course of a human life and before our very eyes. The main importance of the book lies in the record of these[pg 174]experiments and observations, rather than in the theory as such, for the way had been paved for it by other workers.In contrast to Darwinism, De Vries states the case for“Halmatogenesis”(saltatory evolution) and“Heterogenesis”(the production of forms unlike the parents), taking his examples from the plant world, but his attitude to Darwinism is conciliatory throughout. Eimer, on the other hand, is sharply antagonistic, especially to Weismann; he takes his proofs from the animal kingdom, and in the second volume of his large work already mentioned, which deals with the“orthogenesis of butterflies,”he attempts to set against the Darwinism“chance theory,”a proof of“definitely directed evolution,”and therefore of the“insufficiency of natural selection in the formation of species.”

The work that has probably excited most interest in this connection is De Vries'“Die Mutationstheorie: Versuche und Beobachtungen über die Entstehung von Arten im Pflanzenleben.”46In a short preliminary paper he had previously given some account of his leading experiments on a species of evening primrose (Œnothera lamarckiana), and the outlines of his theory. In the work itself he extends this, adding much concrete material, and comparing his views in detail with other[pg 173]theories. Darwin, he says, had already distinguished between variability and mutability; the former manifesting itself in gradual and isolated changes, the latter in saltatory changes on a larger scale. The mistake made by Wallace and by the later Darwinians has been that they regarded this latter form (“single variation”) as unimportant and not affecting evolution, and the former as the real method of evolutionary process. That fluctuating individual variations do occur De Vries admits, but only within narrow limits, never overstepping the type of the species. Here De Vries utilises the recent statistical investigations into the phenomena of individual variation and their laws, as formulated chiefly by Quetelet and Bateson, which were unknown to Darwin and the earlier Darwinians. The actual transition from“species to species”is made suddenly, by mutation, not through variation. And the state of equilibrium thus reached is such a relatively stable one that individual variations can only take place within its limits, but can in no way disturb it.

De Vries marshals a series of facts which present insurmountable difficulties to the Darwinian theory, but afford corroboration of the Mutation theory. In particular, he brings forward, from his years of experiment and horticultural observation, comprehensive evidence of the mutational origin of new species from old ones by leaps, and this not in long-past geological times, but in the course of a human life and before our very eyes. The main importance of the book lies in the record of these[pg 174]experiments and observations, rather than in the theory as such, for the way had been paved for it by other workers.

In contrast to Darwinism, De Vries states the case for“Halmatogenesis”(saltatory evolution) and“Heterogenesis”(the production of forms unlike the parents), taking his examples from the plant world, but his attitude to Darwinism is conciliatory throughout. Eimer, on the other hand, is sharply antagonistic, especially to Weismann; he takes his proofs from the animal kingdom, and in the second volume of his large work already mentioned, which deals with the“orthogenesis of butterflies,”he attempts to set against the Darwinism“chance theory,”a proof of“definitely directed evolution,”and therefore of the“insufficiency of natural selection in the formation of species.”

Eimer's Orthogenesis.Organisation is due to internal causes. Structural characters crystallise out, as it were.“Orthogenesis,”or the definitely determined tendency of evolution to advance in a few directions, is a law for the whole of the animate world. In active response to the stimuli and influences of the environment the organism expresses itself in“organic growth”without any relation to utility. Butterflies in particular, and especially their markings and coloration, are taken as illustrations. In the Darwinian theory of“mimicry”these played a brilliant part. The great resemblance[pg 175]to leaves, to dried twigs, or to well-protected species which are secure from enemies, was regarded as the most convincing proof of the operation of natural selection. But Eimer shows that markings, striping, spots, the development of pattern, and the alleged or real resemblances to leaves, are really subject to definite laws of growth, in obedience to which they gradually appear, developing according to their own internal laws, varying and progressing altogether by internal necessity, and without any reference to advantage or disadvantage, In association with this orthogenesis, Eimer recognises halmatogenesis, correlation and“genepistasis”(coming to a standstill at a fixed and definite stage), and these seem to him to make the Darwinian theory utterly impossible. The text and the illustrations of the book show how, in the sequence of evolution (according to Eimer's laws of transformation), the groupings of stripes, bands, and eye-spots must have appeared on the butterfly's wing, how convex or concave curvings of the contour must have come about at certain points, so that the form of a“leaf”and the lines of its venation resulted, how the eye-spots must have been moulded and shunted, so that they produced the effect of rust or other spots on withered leaves. Particular interest attaches to the detailed arguments against the idea that the butterfly must receive some advantage from its“mimicry.”Even the Darwinians have to admit that in a whole series of cases the advantage is not obvious. They talk with some embarrassment of“pseudomimicry.”[pg 176]Some butterflies that are supposed to be protected have the protective markings on the underside, so that these are actually hidden when the insects are flying from pursuing birds. Many of the leaf-like butterflies are not wood-butterflies at all, but meadow species,47and so Eimer's arguments continue.A specially energetic fellow-worker on Eimer's line is W. Haacke, a zoologist of Jena, author of“Gestaltung und Vererbung,”and“Die Schöpfung des Menschen und seiner Ideale.”48In the first of these works Haacke combats, energetically and with much detail, Weismann's“preformation theory,”and defends“epigenesis,”for which he endeavours to construct graphic diagrams, his aim being to make a foundation for the inheritance of acquired characters, definitely directed evolution, saltatory, symmetrical, and correlated variation.The principles of the new school are very widespread to-day, but we cannot here follow their development in the works of individual investigators, such as Reinke, R. Hertwig, O. Hertwig, Wiesner, Hamann, Dreyer, Wolff, Goette, Kassowitz, v. Wettstein, Korschinsky, and others.49

Organisation is due to internal causes. Structural characters crystallise out, as it were.“Orthogenesis,”or the definitely determined tendency of evolution to advance in a few directions, is a law for the whole of the animate world. In active response to the stimuli and influences of the environment the organism expresses itself in“organic growth”without any relation to utility. Butterflies in particular, and especially their markings and coloration, are taken as illustrations. In the Darwinian theory of“mimicry”these played a brilliant part. The great resemblance[pg 175]to leaves, to dried twigs, or to well-protected species which are secure from enemies, was regarded as the most convincing proof of the operation of natural selection. But Eimer shows that markings, striping, spots, the development of pattern, and the alleged or real resemblances to leaves, are really subject to definite laws of growth, in obedience to which they gradually appear, developing according to their own internal laws, varying and progressing altogether by internal necessity, and without any reference to advantage or disadvantage, In association with this orthogenesis, Eimer recognises halmatogenesis, correlation and“genepistasis”(coming to a standstill at a fixed and definite stage), and these seem to him to make the Darwinian theory utterly impossible. The text and the illustrations of the book show how, in the sequence of evolution (according to Eimer's laws of transformation), the groupings of stripes, bands, and eye-spots must have appeared on the butterfly's wing, how convex or concave curvings of the contour must have come about at certain points, so that the form of a“leaf”and the lines of its venation resulted, how the eye-spots must have been moulded and shunted, so that they produced the effect of rust or other spots on withered leaves. Particular interest attaches to the detailed arguments against the idea that the butterfly must receive some advantage from its“mimicry.”Even the Darwinians have to admit that in a whole series of cases the advantage is not obvious. They talk with some embarrassment of“pseudomimicry.”[pg 176]Some butterflies that are supposed to be protected have the protective markings on the underside, so that these are actually hidden when the insects are flying from pursuing birds. Many of the leaf-like butterflies are not wood-butterflies at all, but meadow species,47and so Eimer's arguments continue.

A specially energetic fellow-worker on Eimer's line is W. Haacke, a zoologist of Jena, author of“Gestaltung und Vererbung,”and“Die Schöpfung des Menschen und seiner Ideale.”48In the first of these works Haacke combats, energetically and with much detail, Weismann's“preformation theory,”and defends“epigenesis,”for which he endeavours to construct graphic diagrams, his aim being to make a foundation for the inheritance of acquired characters, definitely directed evolution, saltatory, symmetrical, and correlated variation.

The principles of the new school are very widespread to-day, but we cannot here follow their development in the works of individual investigators, such as Reinke, R. Hertwig, O. Hertwig, Wiesner, Hamann, Dreyer, Wolff, Goette, Kassowitz, v. Wettstein, Korschinsky, and others.49

The Spontaneous Activity of the Organism.What is particularly luminous in all the theories that express the most recent anti-Darwinian tendency is that they tend to bring into prominence the mysterious powers of living organisms, by means of which, instead of passively waiting for natural selection and the continual accumulation of unceasing variations, they are able spontaneously and of themselves to bring forth what is necessary for self-maintenance, often what is new and different, of course not unlimitedly, but with considerable freedom and often with a surprising range of possibilities. It is, perhaps, partly the fault of the one-sidedness of strict Darwinism that this consideration has been so slowly brought into prominence and subjected to investigation and experiment. It is bound up with the capacity that all forms of life have of reacting spontaneously to“stimuli”and, to a certain extent, of helping themselves if the conditions of existence be unfavourable. They are able, for instance, to produce protective adaptations[pg 178]against cold or heat, to“regenerate”lost parts, often to replace entire organs that have been lost, and, under certain circumstances, to produce new organs altogether. If all this be true, it seems almost like caprice to follow only the roundabout theory of the struggle for existence, and not to take account of these spontaneous capacities of the living organism directly and before all other factors in the attempt to explain evolution. There is no end to the illustrations that are being adduced, that must force investigation to pass from merely superficial considerations of the struggle for existence type to the deeper and more real problems themselves.An effectively modified and adapted type of Alpine flora has not been evolved by a laborious process of selection lasting for many thousand years; the organism may quickly and immediately produce the new characters by its own reaction. Crustaceans gradually transferred from a salt-water to a fresh-water habitat, or conversely, produce in a few generations the type of a new“species”with correlated variations (Schmankewitsch). Birds weaned by careful experiment from a diet of seeds to one of flesh, or conversely, produce changes of effective correlation and adaptation in the characters of their alimentary system. Plants that have been deprived of their normal organs for absorbing water and prevented from growing new ones produce entirely new and effective“hydatodes.”50[pg 179]It is instructive to notice that Darwinism seems likely to be robbed of its stock illustration, namely,“protective coloration.”By its own internal power of reaction, and sometimes within one generation, and even in the lifetime of an individual, an organism may assume the colour of the substratum beneath it (soles, grasshoppers), of its surroundings (Eimer's tree frogs), the colour and spottiness of the granite rock on which it hangs, the colour of the leaves and twigs among which it lives (Poulton's butterfly pupæ), and even that of the brightly coloured sheets of paper amidst which it is kept imprisoned. Certain spiders assume a white, pink, or greenish“protective coloration”corresponding to the tinted blossom of the plants which they frequent, and so on.51Eimer alleged that direct psychical factors co-operated in bringing about these changes. In any case, all this carries us far beyond the domain of mere naturalistic factors into the mystery of life itself. Even what is called the“influence of the external world,”and the“active acquirement of new characters,”have their basis and the reason of their possibility in this domain. And the whole domain is saturated through and through with“teleology.”A recognition of the impressive secret of the organism led Gustav Wolff to become a very pronounced critic of Darwinism, especially in the form of Weismannism.[pg 180]As far back as 1896, in a lecture“On the present position of Darwinism,”in which he dealt only with Weismann, he criticised and analysed that author's last attempt to uphold Darwinism by the construction of his theory of“germinal selection.”He concluded with the wish:“That a spirit of earnestness would once more enter into biological investigation, which would no longer attempt to find in nature just what it wanted to find, but would be ready to follow truth at all costs, and to approach the riddle of life with an open mind.”His“Beiträge zur Kritik der Darwinischen Lehre,”which appeared first as papers in the“Biologisches Centralblatt,”did not see the light in book form until 1898. The doctrine of selection was regarded as so unassailable that no publisher would take the risk of the book. Its appearance is a sure indication of the general modification of opinions that had taken place in the interval. The first and second essays are merely critical objections to the theory of selection, very similar to those frequently urged before, but more precisely stated.52The third is intended to show that there is in the forms of life themselves, as a faculty of adaptation peculiar to them, a primary purposiveness, which is unquestionably active throughout the lifetime and development of every individual, but which is also the deepest cause of“phylogenesis,”or the formation[pg 181]of a race. This doctrine makes both the Darwinian and Lamarckian theories merely secondary. For the phenomena which suggest the Lamarckian interpretation presuppose this most essential factor—the primary adaptiveness. Wolff concludes with a very striking instance—discovered by himself—of this primary adaptiveness of the organism—the regeneration of the lens in the newt's eye.More comprehensively, but from a precisely similar standpoint, Driesch has followed up the discussion of this problem.53He is, of all modern investigators, perhaps the one who has most persistently and thoroughly[pg 182]worked out the problem of causal and teleological interpretation, and he has also thrown much light on the scientific and epistemological aspects of the problem. That he could, in a recent volume of the“Biologisches Zentralblatt,”write a respectful and sympathetic exposition of the Hegelian nature-philosophy—as regards its aims, though not its methods—is as remarkable a symptom as we can instance of the modern trend of views and opinions.54

What is particularly luminous in all the theories that express the most recent anti-Darwinian tendency is that they tend to bring into prominence the mysterious powers of living organisms, by means of which, instead of passively waiting for natural selection and the continual accumulation of unceasing variations, they are able spontaneously and of themselves to bring forth what is necessary for self-maintenance, often what is new and different, of course not unlimitedly, but with considerable freedom and often with a surprising range of possibilities. It is, perhaps, partly the fault of the one-sidedness of strict Darwinism that this consideration has been so slowly brought into prominence and subjected to investigation and experiment. It is bound up with the capacity that all forms of life have of reacting spontaneously to“stimuli”and, to a certain extent, of helping themselves if the conditions of existence be unfavourable. They are able, for instance, to produce protective adaptations[pg 178]against cold or heat, to“regenerate”lost parts, often to replace entire organs that have been lost, and, under certain circumstances, to produce new organs altogether. If all this be true, it seems almost like caprice to follow only the roundabout theory of the struggle for existence, and not to take account of these spontaneous capacities of the living organism directly and before all other factors in the attempt to explain evolution. There is no end to the illustrations that are being adduced, that must force investigation to pass from merely superficial considerations of the struggle for existence type to the deeper and more real problems themselves.

An effectively modified and adapted type of Alpine flora has not been evolved by a laborious process of selection lasting for many thousand years; the organism may quickly and immediately produce the new characters by its own reaction. Crustaceans gradually transferred from a salt-water to a fresh-water habitat, or conversely, produce in a few generations the type of a new“species”with correlated variations (Schmankewitsch). Birds weaned by careful experiment from a diet of seeds to one of flesh, or conversely, produce changes of effective correlation and adaptation in the characters of their alimentary system. Plants that have been deprived of their normal organs for absorbing water and prevented from growing new ones produce entirely new and effective“hydatodes.”50

It is instructive to notice that Darwinism seems likely to be robbed of its stock illustration, namely,“protective coloration.”By its own internal power of reaction, and sometimes within one generation, and even in the lifetime of an individual, an organism may assume the colour of the substratum beneath it (soles, grasshoppers), of its surroundings (Eimer's tree frogs), the colour and spottiness of the granite rock on which it hangs, the colour of the leaves and twigs among which it lives (Poulton's butterfly pupæ), and even that of the brightly coloured sheets of paper amidst which it is kept imprisoned. Certain spiders assume a white, pink, or greenish“protective coloration”corresponding to the tinted blossom of the plants which they frequent, and so on.51Eimer alleged that direct psychical factors co-operated in bringing about these changes. In any case, all this carries us far beyond the domain of mere naturalistic factors into the mystery of life itself. Even what is called the“influence of the external world,”and the“active acquirement of new characters,”have their basis and the reason of their possibility in this domain. And the whole domain is saturated through and through with“teleology.”

A recognition of the impressive secret of the organism led Gustav Wolff to become a very pronounced critic of Darwinism, especially in the form of Weismannism.[pg 180]As far back as 1896, in a lecture“On the present position of Darwinism,”in which he dealt only with Weismann, he criticised and analysed that author's last attempt to uphold Darwinism by the construction of his theory of“germinal selection.”He concluded with the wish:

“That a spirit of earnestness would once more enter into biological investigation, which would no longer attempt to find in nature just what it wanted to find, but would be ready to follow truth at all costs, and to approach the riddle of life with an open mind.”

His“Beiträge zur Kritik der Darwinischen Lehre,”which appeared first as papers in the“Biologisches Centralblatt,”did not see the light in book form until 1898. The doctrine of selection was regarded as so unassailable that no publisher would take the risk of the book. Its appearance is a sure indication of the general modification of opinions that had taken place in the interval. The first and second essays are merely critical objections to the theory of selection, very similar to those frequently urged before, but more precisely stated.52The third is intended to show that there is in the forms of life themselves, as a faculty of adaptation peculiar to them, a primary purposiveness, which is unquestionably active throughout the lifetime and development of every individual, but which is also the deepest cause of“phylogenesis,”or the formation[pg 181]of a race. This doctrine makes both the Darwinian and Lamarckian theories merely secondary. For the phenomena which suggest the Lamarckian interpretation presuppose this most essential factor—the primary adaptiveness. Wolff concludes with a very striking instance—discovered by himself—of this primary adaptiveness of the organism—the regeneration of the lens in the newt's eye.

More comprehensively, but from a precisely similar standpoint, Driesch has followed up the discussion of this problem.53He is, of all modern investigators, perhaps the one who has most persistently and thoroughly[pg 182]worked out the problem of causal and teleological interpretation, and he has also thrown much light on the scientific and epistemological aspects of the problem. That he could, in a recent volume of the“Biologisches Zentralblatt,”write a respectful and sympathetic exposition of the Hegelian nature-philosophy—as regards its aims, though not its methods—is as remarkable a symptom as we can instance of the modern trend of views and opinions.54

Contrast Between Darwinian and Post-Darwinian Views.The new views that have thus arisen have been definitely summarised and clearly contrasted with Darwinism by the botanist Korschinsky. He died before completing his general work,“Heterogenesis und Evolution,”but he has elsewhere55given an excellent summary of his results, which we append in abstract.Darwin.(1) Everything organic is capable of variation. Variations[pg 183]arise in part from internal, in part from external causes. They are slight, inconspicuous, individual differences.Korschinsky and the Moderns.(1) Everything organic is capable of variation. This capability is a fundamental, inherent character of living forms in general, and is independent of external conditions. It is usually kept latent by“heredity,”but occasionally breaks forth in sudden variations.Darwin.(2) The struggle for existence. This combines, increases, fixes useful variations, and eliminates the useless. All the characters and peculiarities of a finished species are the results of long-continued selection; they must therefore be adapted to the external conditions.Korschinsky and the Moderns.(2) Saltatory variations.—These are, under favourable circumstances, the starting-point of new and constant races. The characters may sometimes be useful, sometimes quite indifferent, neither advantageous nor disadvantageous. Sometimes they are not in harmony with external circumstances.Darwin.(3) The species is subject to constant variation. It is continually subject to selection and augmentation of its characters. Hence again the origin of new species.Korschinsky and the Moderns.(3) All fully developed species persist, but through heterogenesis a splitting up into new forms may take place, and this is accompanied by a disturbance of the vital equilibrium. The new state is at first insecure and fluctuating, and only gradually becomes stable. Thus new forms and races arise with gradual consolidation of their constitution.Darwin.(4) The sharper and more acute the effect of the environment, the keener is the struggle for existence, and the more rapidly and certainly do new forms arise.Korschinsky and the Moderns.(4) Only in specially favourable conditions, only when the struggle for existence is weak, or when there is none, can new forms arise and become fixed. When the conditions are severe no new forms arise, or if they do they are speedily eliminated.Darwin.(5) The chief condition of evolution is therefore the struggle for existence and the selection which this involves.Korschinsky and the Moderns.(5) The struggle for existence simply decimates the overwhelming[pg 184]abundance of possible forms. Where it occurs it prevents the establishment of new variations, and in reality stands in the way of new developments. It is rather an unfavourable than an advantageous factor.Darwin.(6) If there were no struggle for existence there would be no adaptation, no perfecting.Korschinsky and the Moderns.(6) Were there no struggle for existence, there would be no destruction of new forms, or of forms in process of arising. The world of organisms would then be a colossal genealogical tree of enormous luxuriance, and with an incalculable wealth of forms.Darwin.(7) Progress in nature, the“perfecting”of organisms, is only an increasingly complex and ever more perfect adaptation to the external circumstances. It is attained by purely mechanical methods, by an accumulation of the variations most useful at the time.Korschinsky and the Moderns.(7) The adaptation which the struggle for existence brings about has nothing to do with perfecting, for the organisms which are physiologically and morphologically higher are by no means always better adapted to external circumstances than those lower in the scale. Evolution cannot be explained mechanically. The origin of higher forms from lower is only possible if there is a tendency to progress innate in the organism itself. This tendency is nearly related to or identical with the tendency to variation. It compels the organism to perfect itself as far as external circumstances will permit.All this implies an admission of evolution and of descent, but a setting aside of Darwinism proper as an unsuccessful hypothesis, and a positive recognition of[pg 185]an endeavour after an aim, internal causes, and teleology in nature, as against fortuitous and superficial factors. This opens up a vista into the background of things, and thereby yields to the religious conception all that a study of nature can yield—namely, an acknowledgment of the possibility and legitimacy of interpreting the world in a religious sense, and assistance in so doing.The most important point has already been emphasised. Even if the theory of the struggle for existence were correct, it would be possible to subject the world as a whole to a teleological interpretation. But these anti-Darwinian theories now emerging, though they do not directly induce teleological interpretation, suggest it much more strongly than orthodox Darwinism does. A world which in its evolution is not exposed, for good or ill, to the action of chance factors—playing with it and forcing it hither and thither—but which, exposed indeed to the most diverse conditions of existence and their influences, and harmonising with them, nevertheless carries implicitly and infallibly within itself the laws of its own expression, and especially the necessity to develop upwards into higher and higher forms, is expressly suited for teleological consideration, and we can understand how it is that the old physico-teleological evidences of the existence of God are beginning to hold up their heads again. They are wrong when they try to demonstrate God, but quite right when they simply seek to show that nature does not contradict—in[pg 186]fact that it allows room and validity to—belief in the Highest Wisdom as the cause and guide of all things natural.As far as the question of the right to interpret nature teleologically is concerned, it would be entirely indifferent whether what Korschinsky calls“the tendency to progress,”and the system of laws in obedience to which evolution brings forth its forms, can be interpreted“mechanically”or not; that is to say, whether or not evolution depends on conditions and potentialities of living matter, which can be demonstrated and made mechanically commensurable or not. It may be that they can neither be demonstrated nor made mechanically commensurable, but lie in the impenetrable mystery inherent in all life. Whether this mystery really exists, and whether religion has any particular interest in it if it does, must be considered in the following chapter.

The new views that have thus arisen have been definitely summarised and clearly contrasted with Darwinism by the botanist Korschinsky. He died before completing his general work,“Heterogenesis und Evolution,”but he has elsewhere55given an excellent summary of his results, which we append in abstract.

Darwin.(1) Everything organic is capable of variation. Variations[pg 183]arise in part from internal, in part from external causes. They are slight, inconspicuous, individual differences.

Korschinsky and the Moderns.(1) Everything organic is capable of variation. This capability is a fundamental, inherent character of living forms in general, and is independent of external conditions. It is usually kept latent by“heredity,”but occasionally breaks forth in sudden variations.

Darwin.(2) The struggle for existence. This combines, increases, fixes useful variations, and eliminates the useless. All the characters and peculiarities of a finished species are the results of long-continued selection; they must therefore be adapted to the external conditions.

Korschinsky and the Moderns.(2) Saltatory variations.—These are, under favourable circumstances, the starting-point of new and constant races. The characters may sometimes be useful, sometimes quite indifferent, neither advantageous nor disadvantageous. Sometimes they are not in harmony with external circumstances.

Darwin.(3) The species is subject to constant variation. It is continually subject to selection and augmentation of its characters. Hence again the origin of new species.

Korschinsky and the Moderns.(3) All fully developed species persist, but through heterogenesis a splitting up into new forms may take place, and this is accompanied by a disturbance of the vital equilibrium. The new state is at first insecure and fluctuating, and only gradually becomes stable. Thus new forms and races arise with gradual consolidation of their constitution.

Darwin.(4) The sharper and more acute the effect of the environment, the keener is the struggle for existence, and the more rapidly and certainly do new forms arise.

Korschinsky and the Moderns.(4) Only in specially favourable conditions, only when the struggle for existence is weak, or when there is none, can new forms arise and become fixed. When the conditions are severe no new forms arise, or if they do they are speedily eliminated.

Darwin.(5) The chief condition of evolution is therefore the struggle for existence and the selection which this involves.

Korschinsky and the Moderns.(5) The struggle for existence simply decimates the overwhelming[pg 184]abundance of possible forms. Where it occurs it prevents the establishment of new variations, and in reality stands in the way of new developments. It is rather an unfavourable than an advantageous factor.

Darwin.(6) If there were no struggle for existence there would be no adaptation, no perfecting.

Korschinsky and the Moderns.(6) Were there no struggle for existence, there would be no destruction of new forms, or of forms in process of arising. The world of organisms would then be a colossal genealogical tree of enormous luxuriance, and with an incalculable wealth of forms.

Darwin.(7) Progress in nature, the“perfecting”of organisms, is only an increasingly complex and ever more perfect adaptation to the external circumstances. It is attained by purely mechanical methods, by an accumulation of the variations most useful at the time.

Korschinsky and the Moderns.(7) The adaptation which the struggle for existence brings about has nothing to do with perfecting, for the organisms which are physiologically and morphologically higher are by no means always better adapted to external circumstances than those lower in the scale. Evolution cannot be explained mechanically. The origin of higher forms from lower is only possible if there is a tendency to progress innate in the organism itself. This tendency is nearly related to or identical with the tendency to variation. It compels the organism to perfect itself as far as external circumstances will permit.

All this implies an admission of evolution and of descent, but a setting aside of Darwinism proper as an unsuccessful hypothesis, and a positive recognition of[pg 185]an endeavour after an aim, internal causes, and teleology in nature, as against fortuitous and superficial factors. This opens up a vista into the background of things, and thereby yields to the religious conception all that a study of nature can yield—namely, an acknowledgment of the possibility and legitimacy of interpreting the world in a religious sense, and assistance in so doing.

The most important point has already been emphasised. Even if the theory of the struggle for existence were correct, it would be possible to subject the world as a whole to a teleological interpretation. But these anti-Darwinian theories now emerging, though they do not directly induce teleological interpretation, suggest it much more strongly than orthodox Darwinism does. A world which in its evolution is not exposed, for good or ill, to the action of chance factors—playing with it and forcing it hither and thither—but which, exposed indeed to the most diverse conditions of existence and their influences, and harmonising with them, nevertheless carries implicitly and infallibly within itself the laws of its own expression, and especially the necessity to develop upwards into higher and higher forms, is expressly suited for teleological consideration, and we can understand how it is that the old physico-teleological evidences of the existence of God are beginning to hold up their heads again. They are wrong when they try to demonstrate God, but quite right when they simply seek to show that nature does not contradict—in[pg 186]fact that it allows room and validity to—belief in the Highest Wisdom as the cause and guide of all things natural.

As far as the question of the right to interpret nature teleologically is concerned, it would be entirely indifferent whether what Korschinsky calls“the tendency to progress,”and the system of laws in obedience to which evolution brings forth its forms, can be interpreted“mechanically”or not; that is to say, whether or not evolution depends on conditions and potentialities of living matter, which can be demonstrated and made mechanically commensurable or not. It may be that they can neither be demonstrated nor made mechanically commensurable, but lie in the impenetrable mystery inherent in all life. Whether this mystery really exists, and whether religion has any particular interest in it if it does, must be considered in the following chapter.

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