Philosophy of the Unconscious

by Eduard Von Hartmann

  When one considers that almost every year brings to light new and surprising intermediate forms, and that already the old zoological classification has become absolutely untenable, the appeal of the opponents of Darwin to the want of intermediate forms may, in fact, be looked upon as a lost battle. One may at length regard it as an established fact that, if one traces backwards the pedigree of the now living kinds, not the species, but the genera have their corresponding representatives in former geological periods, and that these representatives of different genera and orders are distinguished in still remoter epochs only as now different species of a genus or order. Thus Owen in his “Palæontology” assures us “that he never let slip a good opportunity of communicating the results of observations, which prove the more generalised structures of extinct animals, compared with the specialised forms of more recent animals.” (Comp., as supplement to this and the last chapter, Ernest Häckel’s excellent popular work, “The Natural History of Creation.”)

  As the transition from water to land animals, so also that from water to land plants takes place through amphibious organisms. The anatomical structure of a stalk and leaf living in water must, to be capable of life, be at least as different from one living in the air as gills from lungs. Thus Utricularia vulgaris consists of two different organisms as it were, one of which is represented by the part of a plant living under water, the other by the branches bearing the blossoms rising into the air. In each of the three great divisions of the vegetable kingdom (Cryptogams, Monocotyledons, Dicotyledons) there are atmospheric plants (e.g., Marsilia, Sagittaria, Polygonum) which prove their origin from aquatic plants by the circumstance that when one puts them under water their young shoots send forth stalks and leaves with the anatomical structure of aquatic plants, which more aërial plants, that have, as it were, forgotten their more remote ancestors, do not do.

  Although we have thus recognised natural selection in the struggle for existence as an important contributory to the origin of new species, yet I can by no means grant that with this principle the history of the origin of the organic world is at all exhausted. Not because this hypothesis would not be quite compatible with our presumptions concerning the essence of the Unconscious,—for if this at all facilitated matters, it would be quite natural for it to concern itself only with the individual, and leave the progress of species to go on quite mechanically by itself,—but only, because the facts to be explained are far more numerous than the range of the principle of explanation, can I not deem the same sufficient.

  In the present general interest in the Darwinian theory and the frequent over-estimate of its reach, it may reward us to spend a few moments in considering to what extent it appears to be insufficient (comp. also vol. i. pp. 287–289).

  If we assume that by the struggle for existence alone organisation has developed from the primitive original cell to its present pitch, that thus every more highly developed species has only proceeded from the proximate lower one owing to its having possessed a higher degree of vitality, the consequence necessarily follows that every higher species on its own ground surpasses every lower species in vitality, and surpasses it indeed in a so much higher degree, the greater the interval of their stages of organisation, since indeed with every new advance in development a new accession of vitality results, and these increments mount up. This direct consequence is now, however, in complete contradiction with the facts of the case, which yield the result that every stage of organisation, taken as a whole, possesses the same vitality, and that only within the same stage of organisation the different species or varieties are distinguished by a greater or less vitality; which harmonises also with the circumstance that the struggle for existence in the competition for the conditions of life occurs the more frequently, is the more embittered, and the more certainly terminates in the complete annihilation of the one side, the more related are the competing species or varieties, whilst the species dwell beside one another the more peacefully, and render more assistance in the preservation of life, the farther they stand from one another in the pedigree of organisation. In every locality, if we disregard the difference of land and sea, all the stages of organisation are found represented, and all thrive excellently well beside one another; whereas, according to the Darwinian theory, taken strictly, at every locality at least only one species, and that the highest, must remain, because this surpasses all others in capacity of living under those circumstances. That is, however, just what is remarkable and grand in Nature, that every final type of a class is so perfect in itself, that one may indeed go beyond it, yet only by adding new anatomical-morphological structural details, but not by enhancement of the physiological functions or of its accommodation to the conditions of life, for both are finished. Had not really all stages of organisation on the average the same vitality, in the struggle for existence waged for millions of years all lower species must have long ago been completely superseded by the higher ones, whereas the fossil relics show that, under the most diverse circumstances, there have been relatively few classes of animals and plants which at the present time have not their perfectly life-capable representatives.

  The capacity of accommodation of a class, and even of a species, within its own limits, is, in general, far greater than one thinks. This follows partly from the continued existence of not a few species from their origin to the present time, where, in truth, the environment has sufficiently changed, partly from the great circles of distribution of the classes and species of the present day. Several classes people the whole earth or all seas; many species have a distribution over twenty to thirty degrees of latitude. Lastly, it is proved by the capacity of acclimatisation of species, which often borders on the miraculous, if the instances only range over sufficient periods of time. Thus the common peach-tree, which is probably an Indian plant, would not thrive in Greece in the time of Aristotle, whereas we get good peaches at the present day in North Germany. Accordingly, the capacity of accommodation of species within their specific limits, partly by internal physiological changes that are withdrawn from observation, partly by the formation of varieties, is so great, that they are quite well able to adapt themselves to a very considerable alteration of the climate, &c., without degenerating. Extremely numerous are the examples in which closely related species dwell beside one another in a locality without noticeable change of their relative number, and yet the struggle for existence is most violent precisely within the specific limits between varieties and still slighter differences. Should, however, this struggle occur or be absent in a particular case, yet in no one of the cases here considered will a transgression of the limits of the species show itself. Lastly, there will not easily happen so great a change of external circumstances, nor a species pass under such different circumstances, that the capacity for accommodation and acclimatisation within the limits of the species recognised by us as so considerable would not suffice for these claims. But if subsequently a second change of the conditions essential to life occurs at the same place, it will mostly be a return to the formerly existing circumstances; then the species will simply adapt itself to this change by repeating the former stages in a reverse direction (as is observable in the before-mentioned experiments with transplantation of plants to different descriptions of soil), and there is again no occasion for the passage into a new or a more remote species. If, on the other hand, the second change of the conditions essential to life is in the same direction, the species will more easily become extinct at this place (e.g., the fauna of the European glacial epoch), than pass into a new species, which is more remote from its stock than its previously attained standpoint.

  How could the commencement of a new path of development, after an exhaustive working through of the last attained stage of organisation, and perhaps a pause of thousands of years, be intelligible from the struggle for existence? We have seen that it is precisely the more imperfect forms of the preceding stage from which proceeds the development of the higher stage. Apart from the already mentioned c
ircumstance that these more imperfect forms of all the species of the lower stage remain longest unchanged, thus, according to Darwin’s view, must be the most stable and the least capable of an individual variation and further advance; apart also from this, that, if only the struggle for existence had created the later forms of the lower stage, these primitive forms must have all already changed for the same reason and by the same process into more developed forms of the same grade, or indeed must long ago have been annihilated by the more capable forms in the immeasurable intervals; apart from all this, one would think that, if from some unknown cause these primitive forms that have maintained themselves had actually received an impulse to further development, that then through the struggle for existence always only a repetition of the development lying far nearer to them into the already existing higher forms of the same stage must have been called forth, rather than a transition to the morphologically diverging higher stage, since notoriously the higher forms of the lower stage show themselves also under the new circumstances mostly just as capable of life as the species of the higher stage. This consideration obtains the more weight the more geology attains to the knowledge, that the climates and vital conditions of earlier geological periods (with the exception of the first times after the cooling of the earth’s surface) always far more closely resembled those of any localities whatsoever of the present surface than the older geology, dreaming of catastrophes and vast revolutions, assumed.—Most unintelligible on Darwinian presuppositions is the passage from the unicellular to the multicellular organisms, since it is just the incredible indifference of the unicellular plants to their environment, i.e., their capacity of accommodating themselves even to the most varied circumstances by relatively slight modifications, that makes the want of a motive for the conversion into compound types so very conspicuous.

  Lastly, if one asks positively of what kind are the useful adaptations that arise through the struggle for existence, the answer is: They are exclusively of a physiological nature. Here lies the proper limit of the Darwinian principle clearly before our eyes; it is sufficient so long as it has to do with the elaboration and transformation of an existing organ for a physiological function required by the circumstances; it leaves us in the lurch when a morphological change is to be explained. That morphological changes are also possible by the addition of individual variations is not to be doubted, and Darwin proves it by many examples, especially by the skeleton of pigeons; but in all the cited cases an artificial breeding takes place. A couple of teeth, of vertebræ, or a toe more or less, a vertebra formed thus or thus, are for the struggle for existence perfectly indifferent, and yet these are the marks by which zoology most surely distinguishes species; the struggle for existence, on the contrary, can obviously only produce a change in such elements of the organism as have some importance for the same, and will so much more energetically work for their transformation the greater their significance for the struggle for existence. The struggle for existence brings it about that one and the same organ (in morphological reference) undertakes the most diverse physiological functions, whereas in species, placed under similar vital conditions but of different origin, often the same performance is carried on by organs morphologically quite different. (Thus, e.g., the parasitic mites living on animal hairs have an organ for clinging to the hair, on which they roam; this is, however, represented in Listrophorus by the transformed lip, in Myobia by the more advanced pair of feet, in Mycoptes by the third, or also at the same time the fourth pair of feet.) With all these changes, however, the morphological fundamental type remains unaltered and untouched.

  In the animal kingdom the thorough-going acknowledgment of the assertion that only the physiological but not the morphological changes are decisive for the degree of vitality, is encumbered with difficulties, because the occurrence of sympathetic changes frequently causes morphological changes to go also hand in hand with the physiological change of an organ, often at quite other parts of the body, which phenomenon, springing from special laws of organic plastic activity of the Unconscious, is altogether calculated to confuse the judgment. Our assertion, however, appears quite clearly justified in the vegetable kingdom. The competent judgment of Nägeli (“Origin and Conception of the Species of Natural History,” Munich, 1865, p. 26) on this point runs: “The highest organisation manifests itself in two moments, in the most varied morphological articulation, and in the most thorough division of labour. Both moments usually concide in the animal kingdom, since the male organ also possesses the same function. In plants, however, they are independent of one another; the same function can be undertaken by quite different organs; even in closely allied plants the same organ can carry on all possible physiological functions. Now it is remarkable that the useful adaptations which Darwin instances as regards animals, and which one can discover in quantities for the vegetable kingdom, are exclusively of a physiological nature; that they always show the improvement and transformation of an organ for a particular function. A morphological modification in the vegetable kingdom which could be explained by the Darwinian theory is unknown to me, and I do not even see how it could take place, since the general processes of formation are so indifferent as regards physiological performances. The Darwinian theory requires the assumption, confessed by itself, that indifferent characters should be variable; the useful, on the contrary, constant. The purely morphological peculiarities of plants must accordingly most easily, the relations of organisation conditioned by a definite function with the greatest difficulty be capable of alteration. Experience shows the contrary. The relative positions and the co-ordination of the cells and organs are both in nature and under cultivation the most constant and persistent marks. In a plant that has opposite leaves and quaternary corollas it will be far easier to produce all possible functional variations in the leaves than a spiral arrangement of the same, although these, as altogether indifferent for the struggle of existence, could have attained no constancy through natural selection.” Had Darwin borrowed his examples more from plants than from animals, he would perhaps himself have perceived the limitation of the action of the struggle for existence. It is clear that the latter can only alter the behaviour of organisms to the external conditions of life, i.e., their functions, and the organs only so far as the functions are dependent upon them, but that it can have no influence on those qualities of organisms, whose alteration as regards the relations between the organisms and the external world brings to the former neither advantage nor disadvantage. To the latter attributes belong, however, in plants, and even in animals, most of the fundamental principles of the morphological type, e.g., the numerical proportions selected for the same.

  We have here found a confirmation of our preceding assertion, that natural selection in the struggle for existence is an extremely valuable aid for the exhaustive elaboration of an existing type within the same organisation, but cannot serve for the explanation of the passage from a lower to a higher stage of organisation, since a raising of the morphological type is always connected with such. In his most recent researches (Botan. Mittheilungen, 1868) on the behaviour of individuals of one and the same species of plants, on the one hand under the same, on the other hand under different external circumstances, Nägeli comes to the conclusion that the formation of unlike varieties occurs just as much under like, as the formation of like varieties under unlike circumstances; whence we may conclude as follows:—(1.) The external circumstances do not suffice as sole cause of the formation of varieties, but presuppose as second favourable condition a quality inherent in the plant, a “tendency to vary” (and that, too, in definite directions). (2.) But without a doubt this inner quality of the plant can by itself suffice to introduce, even under similar external circumstances, a formation of different varieties. This confirms our preceding assumptions. Among zoologists, quite recently Kölliker has declared for the hypothesis of Nägeli, that the transformation of existing organisms by the accidental change of external circumstances yields in importance and
range to the tendency inherent in the organic world of development from internal causes according to preordained laws, no matter by what name this creative principle, this productive activity is called; in this sense he desires his former announcement of “heterogeneous generation” (comp, above, p. 301) to be interpreted.1

  Before quitting the subject, a special expedient may be mentioned, the actual use of which indeed has not hitherto been proved, whose possible application is, however, so interesting, that I will not withhold from the reader a short indication of the same.—Until fifteen years ago, it passed as a scientific axiom that, of all animals that undergo a metamorphosis, only the most perfect state is transmissible. Now, however, we already know three exceptions. The young of Leptodera appendiculata, a parastic tape-worm living in the foot of the common slug, represent the larva form of their parents; with abundant food and moisture they do not, however, undergo the chrysalis change, but propagate among one another any number of times without diminution of fertility. A second example is that of Cecidomyia, already mentioned in the last chapter (p. 281). A third, the Mexican Axolotl, whose identity with the likewise long-known Amblystoma was established through the circumstance, that in aquaria the metamorphosis of the Axolotl into Amblystoma was directly observed in certain cases. The larva form of this animal has external gills like the Proteus, which undergoes no metamorphosis, whereas the perfect form is without gills. Now here manifestly the larva form is the older and original, and one must assume that, under favourable circumstances, one of these salamander-like animals underwent a metamorphosis for the first time, a change which was facilitated in its descendants by inheritance. The Axolotl now has not attained the next stage of development, where the metamorphosis, as in most Amphibia, is a regular phase of the life-history. As, however, the progress from the fish-salamanders to the higher Amphibia takes place by the capacity for metamorphosis becoming by transmission normal, one may imagine the further progress from the Amphibia to the reptiles brought about by this, that under favourable circumstances an Amphibian acquires the power of bringing forth young in the final form, or, in other words, of transferring the metamorphosis to the embryonic life. The preceding reflections on metamorphosis may be extended to the alternation of generations (comp. Häckel), but hitherto data are too much wanting for the attainment of certain results on this subject.—