Part 5 (1/2)
The theory of evolution is however still very young and it is beyond question that upon further investigation the rigid Darwinian ideas upon the origin of species will be considerably modified.
But what has the realist philosophy of a positive nature to contribute with respect to the evolution of organic life? ”The variation of species is an acceptable supposition, but there exists, in addition, the independent order of the products of nature belonging to the same species without any intervention of descent.” According to this we are to conclude that products of unlike species, that is species which vary, are descended from one another, but those of similar species not. But even this is not altogether correct, for he ventures to say of the varying species, ”The part played by descent is on the contrary a very secondary activity of nature.” There is heredity, then, but it is only to be reckoned as a factor of the second cla.s.s. Let us be glad that heredity of which Herr Duehring has said so much that is evil and mysterious is at least let in by the back door. It is just the same with natural selection, since after all his moral indignation with respect to the struggle for existence by means of which natural selection fulfils itself he suddenly exclaims, ”The most important const.i.tuent is to be found in the conditions of life and cosmic conditions, while natural selection as set forth by Darwin may be considered as secondary.” Natural selection still exists, even if a factor of the second cla.s.s, like the struggle for existence, and the clerical malthusian surplus-population theory. That is all, for the rest Herr Duehring refers us to Lamark.
Finally, he warns against misuse of the terms metamorphosis and evolution. Metamorphosis, he says, is a very obscure notion, and the concept of evolution is only admissible in so far as a law of evolution can be really proved. Instead of either of these expressions we should employ the term ”composition” and then everything would be all right. It is the same old story over again, Herr Duehring is satisfied if we change the names. If we speak of the evolution of the chicken in the egg we give rise to confusion because we have only an incomplete knowledge of the law of evolution. But if we speak of its ”composition” everything becomes clear. We must therefore say no longer ”this child is growing nicely” but, ”he composes himself splendidly,” and we congratulate Herr Duehring upon the fact that he is not only a peer of the author of the Niebelungen Ring in his opinion of himself but in his own particular capacity is also a composer of the future.
_Organic World (Conclusion)._
”One reflects upon our natural philosophical portion of positive knowledge in order to fix it relatively to all one's scientific hypotheses. Next in importance come all the actual acquisitions of mathematics as well as the leading principles of exact science in mechanics, physics and chemistry and particularly the scientific results in physiology, zoology, and antiquarian investigation.”
Herr Duehring speaks in this confident and decided fas.h.i.+on with respect to the mathematical and scientific scholars.h.i.+p of Herr Duehring. One cannot detect in its meager shape and in its scanty and audacious results the extent of positive knowledge which lies behind.
Every time the oracle is consulted for a definite statement as regards physics or chemistry we get nothing as regards physics but the equation which expresses the mechanical equivalent of heat, and concerning chemistry only this that all bodies are divisible into elements and combinations of elements. He who can speak as Duehring does about ”gravitating atoms” shows at once that he is quite at a loss to understand the difference between an atom and a molecule.
Atoms, of course, exist, not with respect to gravitation or any other physical or mechanical form of motion, but only as concerns chemical action. And if the last chapter on organic nature is read, the empty, self-contradictory, a.s.sertive, oracular, stupid, circuitous absolute nothingness of the final result lead one to the conclusion that Herr Duehring talks about things of which he knows very little and this conclusion becomes a certainty when we come to his proposal in the course of his writing on organic life (biology) to use the term ”composition” instead of evolution. He who can make such a suggestion as that gives evidence that he is not acquainted with the building up of organic bodies.
All organic bodies, the very lowest excepted, develop from small cells by the increment of visible pieces of alb.u.men with a central cell. The cell generally develops an outer skin and the contents are more or less fluid. The lowest cell-bodies develop from one cell; the enormous majority of organic beings are many-celled and among the lower forms these take on similar, and among the higher forms greater variations of, groupings and activities. In the human body for example are bones, muscles, nerves, sinews, ligaments, cartilage, skin, all either made up of cells or originating in them. But for all organic bodies, from the amoeba which is a simple and for the most part unprotected piece of alb.u.men with a cell centre in the midst to man, and from the smallest one-celled desmidian to the highest developed plant, the mode is one and the same by which the cells propagate themselves, that is by division. The cell centre is first laced across its midst, the lacing which separates the centre into two k.n.o.bs becomes stronger and stronger and at last they become separated and two cell centres are formed. The same occurrence takes place in the cell itself. Each of the cell centres becomes the middle point of a collection of cell stuff which by knitting ever closer becomes combined with the other, and finally both of them part and live on as separate cells. Through such repeated cell divisions the full sized animal gradually develops from the germ of the animal egg after fructification and the subst.i.tution of used up cells in the full grown animal is brought about similarly. To call such a process ”composition” and to speak of the term ”evolution” as a purely imaginary term belongs to one who does not know anything of the matter, hard as it is to imagine such ignorance at this date.
We have still somewhat to say with respect to Herr Duehring's views of life in general. Elsewhere he sets forth the following statement with respect to life. ”Even the inorganic world is a self-regulated system but one may undertake to speak of life in the proper sense first when the organs and the circulation of matter through special separate channels from a central point to another germ collection of a minor formation begin.”
If life begins where the separate organs begin then we must hold all Haeckel's protozoa (Protistenreich) and probably many others as dead; all organisms at least up to those composed of one cell and those included are not capable of life. If the means of circulation of matter through different channels is the distinguis.h.i.+ng mark of life we must place outside of this definition all the upper cla.s.ses of the colenterata entirely, with the exception of the medusae, and therefore all the polypi and other plant animals are also to be considered as being outside the cla.s.s of living creatures. And if the circulation of matter through different ca.n.a.ls from an inner point is the distinguis.h.i.+ng characteristic of life we must reckon all animals as dead which either have no heart or several hearts. Besides these there belong also to this category all worms, starfish and ringed creatures (annuloids and annulous according to Huxley's definition) a portion of the sh.e.l.l fish, crabs, and finally a vertebrate animal, the lancelet (amphioxus) and all plants.
When Herr Duehring therefore undertakes to distinguish life narrowly and strictly, he gives four mutually contradictory modes of distinguis.h.i.+ng life, one of which condemns not only the whole of plant life but about half the animal kingdom to eternal death. No one can accuse him of having deceived us when he promised us peculiar results based on individual ideas.
In another place he says ”There is a simple fundamental type in nature belonging to all organisms from the lowest to the highest” and this type is to be met ”in the subordinate movements of the most undeveloped plants.” This is again an absolutely false statement. The simplest type in the whole of organic nature is the cell, and it lies universally at the foundation of the highest organisms. On the other hand there is a substance among the lowest organisms lower even than the cell, the protomoeba, a single piece of undifferentiated protoplasm, without any differentiation, a complete series of monads and the entire cla.s.s of siphoneae. All of these are connected with the higher organisms only by virtue of the fact that protoplasm is its substantial foundation, and that they fulfill the functions of protoplasm, that is they live and die.
Further Herr Duehring tells us ”physiologically the concept of existence consists in this, that it embraces a single nerve apparatus.
Sensation is therefore the characteristic of all animal organisms that is the capacity of conscious subjective recognition of circ.u.mstances.
The sharp line of differentiation between plants and animals consists in the leap to sensation. This distinguis.h.i.+ng line cannot any more be abolished by known forms of transition than it can be brought into existence by the logical necessity of externally distinguishable characteristics.” And further ”Plants are totally and eternally without sensation and are devoid of the faculty for it.”
In the first place Hegel says that ”sensation is the specific differentiation, the distinguis.h.i.+ng mark of the animal.” Thus one of Hegel's erudite statements becomes an indubitable truth of the last instance merely by being copied into Herr Duehring's book.
In the second place we now arrive for the first time at the forms of transition between animals and plants. That these intermediate forms exist, that there are organisms concerning which we are unable to say flatly whether they are plants or animals, that we are therefore unable to fix accurately the frontiers between plant and animal life, all these things make Herr Duehring logically anxious to fix a decisively distinguis.h.i.+ng line, which in the next breath he declares cannot be thoroughly relied on. But there is no need for us to go to the doubtful region; intermediate between plants and animals are sensitive plants which at the least contact fold their leaves or close their petals. Are insect eating plants utterly without sensation? Even Herr Duehring cannot make such an a.s.sertion without indulging in ”unscientific half-poetry.”
In the third place Herr Duehring is again giving free rein to his imagination when he says that sensation is psychologically existent, even when the nerve apparatus is exceedingly simple. This is found regularly among reptiles yet Herr Duehring is the first to say that they have no sensation because they have no nerves. Sensation is not necessarily bound up with nerves but it is bound up with some alb.u.minous substance the true nature of which has not yet been discovered.
In addition, the biological knowledge of Herr Duehring becomes exceedingly evident in that he is not ashamed to fling at Darwin the question do animals develop from plants? so that it is a question whether he is more ignorant with regard to plants or animals.
Of life in general Herr Duehring can only tell us ”The change in the form of matter which fulfills itself by plastic constructive arrangement remains a distinguis.h.i.+ng characteristic of the individual life-process.”
That is all that we learn of life and with respect to the plastic creative arrangement we sink knee deep in the nonsense of Duehring's jargon. If we want to learn what life is we shall have to look at the problem a little more closely on our own account.
That organic change in matter is the most universal and distinctive evidence of life has been declared by physiological chemists and chemical physiologists times without number during the last thirty years and their utterances are translated by Herr Duehring into his own clear and elegant language. But to define life as an organic change of matter is simply to define life as life, for organic change of matter, or change of matter with plastic creative arrangement is a statement which must itself be explained by life, and the explanation in its turn by the difference between organic and inorganic, that is between that which is alive and that which is not alive. So that with this explanation we do not get at the problem.
Organic change, as such, is frequently found where life does not exist. There are whole series of processes in chemistry, which by the proper combination of the elements, produce again their own conditions, so that thereby a certain body is the creator of a process. Thus in the manufacture of sulphuric acid by the burning of sulphur, there is created in this process sulphuric dioxide SO_{2}, and if one add steam and nitric acid thereto, the sulphuric dioxide takes up the water and the oxygen and becomes H_{2} SO_{4}. Nitric acid gives off oxygen and becomes nitric oxide, this nitric oxide simultaneously takes up new oxygen from the atmosphere and is transformed into a higher oxide of nitrogen and from this acid sulphuric dioxide is again given off and made by the same process, so that, theoretically, an infinitely small amount of nitric acid should be effective to transform an unlimited quant.i.ty of sulphuric dioxide, oxygen and water into sulphuric acid. Change in matter regularly occurs through the pa.s.sing of fluids through dead organic and inorganic membranes as in the artificial cells of Traube. It therefore appears that there is no progress by the way of organic change for the quality of organic change which was to explain life must itself be explained by life. We must therefore seek it elsewhere.
Life is a mode of existence of protoplasm and consists essentially in the constant renewal of the chemical const.i.tuents of this substance.
Protoplasm is here understood in the modern chemical sense and comprises under this name all substances a.n.a.logous to the white of an egg, otherwise called protein substances. The name is not satisfactory, for the ordinary white of egg plays the least active role of all transformed substances, since it only serves as mere nourishment for the yolk, for the self-developing germ. As long however as so little is known of the chemical const.i.tuents of protoplasm the name is better than any other because more inclusive.
Whenever we discover life we also find it bound up with protoplasm, and when we find a piece of protoplasm not in solution there we find also life, without exception. Doubtless the presence of other chemical const.i.tuents is necessary to a living body, to produce the various differentiations of these elements of life. They are not necessary to life in itself, hence they enter as food and become transformed into protoplasm. The lowest forms of life with which we are acquainted are nothing but simple pieces of protoplasm and yet they have all the appearance of living objects.
But in what consist these signs of life which are common to all living objects? In this, that the protoplasm takes from its surroundings other matter suitable to itself and a.s.similates it while other former portions of the body become decomposed and are thrown off. Other things, not living bodies, decompose or make combinations, but cease thereby to be what they were. The rock worn by atmospheric action is no longer rock, the metal which becomes oxidised goes off in rust. But what causes the destruction of dead bodies is the essential of the existence of living protoplasm. From the very moment when the unbroken interchange in the const.i.tuents of protoplasm ceases, the continual interchange of receiving and throwing off, from that moment the protoplasmic substance itself ceases, becomes decomposed, that is, dies.