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 elsewhere55 given 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]
What is life—not in the spiritual and transcendental sense, but in its physical and physiological aspects? What is this mysterious complex of processes and phenomena, common to everything animate, from the seaweed to the rose, and from the human body to the bacterium, this ability to “move” of itself, to change and yet to remain like itself, to take up dead substances into itself, to assimilate and to excrete, to initiate and sustain, in respiration, in nutrition, in external and internal movements, the most complex chemical and physical processes, to develop and build up through a long series of stages a complete whole from the primitive beginnings in the germ, to grow, to become mature, and gradually to break up again, and with all this to repeat in itself the type of its parent, and to bring forth others like itself, thus perpetuating its own species, to react effectively to stimuli, to produce protective devices against injury, and to regenerate lost parts? All this is done by living organisms, all this is the expression in them of “Life.” What is it? Whence comes it? And how can it be explained?
[pg 188]
The problem of the nature of life, of the principle of vitality, is almost as old as philosophy itself, and from the earliest times in which men began to ponder over the problem, the same antitheses have been apparent which we find to-day. Disguised under various catchwords and with the greatest diversities of expression, the antitheses remain essentially the same through the centuries, competing with one another, often mingling curiously, so that from time to time one or other almost disappears, but always crops up again, so that it seems as if the conflict would be a never-ending one—the antitheses between the mechanical and the “vitalistic” view of life. On the one side there is the conviction that the processes of life may be interpreted in terms of natural processes of a simple and obvious kind, indeed directly in terms of those which are most general and most intelligible—namely, the simplest movements of the smallest particles of matter, which are governed by the same laws as movement in general. And associated with this is the attempt to take away any special halo from around the processes of life, to admit even here no other processes but the mechanical ones, and to explain everything as the effect of material causes. On the opposite side is the conviction that vital phenomena occupy a special and peculiar sphere in the world of natural phenomena, a higher platform; that they cannot be explained by merely physical or chemical or mechanical factors, and that, if “explaining” means reducing to terms of such factors, [pg 189] they do in truth include something inexplicable. These opposing conceptions of the living and the organic have been contrasted with one another, in most precise form and exact expression, by Kant in certain chapters of the Kritik der Urteilskraft, which must be regarded as a classic for our subject.56 But as far as their general tendency is concerned, they were already represented in the nature-philosophies of Democritus on the one hand, and of Aristotle on the other.
All the essential constituents of the modern mechanical theories are really to be found in Democritus, the causal interpretation, the denial of any operative purposes or formative principles, the admission and assertion of quantitative explanations alone, the denial of qualities, the reduction of all cosmic developments to the “mechanics of the atom” (even to attractions and repulsions, thus setting aside the “energies”), the inevitable necessity of these mechanical sequences, indeed at bottom even the conviction of the “constancy of the sum of matter and energy.” (For, as he says, “nothing comes out of nothing.”) And although he makes the “soul” the principle of the phenomena of life, that is in no way contradictory to his general mechanical theory, but is quite congruent with it. For the “soul” is to him only an aggregation of thinner, smoother, and [pg 190] rounder atoms, which as such are more mobile, and can, as it were, quarter themselves in the body, but nevertheless stand in a purely mechanical relation to it.
Aristotle, who was well aware of the diametrical opposition, represents, as compared with Democritus, the Socratic-Platonic teleological interpretation of nature, and in regard to the question of living organisms his point of view may quite well be designated by the modern name of “vitalism.” Especially in his theory of the vegetable soul, the essence of vitalism is already contained. It is the ????? ?????? (logos enhylos), the idea immanent in the matter, the conceptual essence of the organism, or its ideal whole, which is inherent in it from its beginnings in the germ, and determines, like a directing law, all its vegetative processes, and so raises it from a state of “possibility” to one of “reality.” All that we meet with later as “nisus formativus,” as “life-force” (vis vitalis), as “endeavour after an end” (Zielstrebigkeit), is included in the scope of Aristotelian thought. And he has the advantage over many of his successors of being very much clearer.57
[pg 191]
The present state of the problem of life may be regarded as due to a reaction of biological investigation and opinion from the “vitalistic” theories which prevailed in the first half of last century, and which were in turn at once the root and the fruit of the German Nature-philosophy of that time.
Lotze in his oft-quoted article, “Leben, Lebenskraft” (Life, Vital Force), in Wagner's “Hand-WÖrterbuch der Physiologie,” 1842, gave the signal for this reaction. The change, however, did not take place suddenly. The most important investigators in their special domain, the physiologist Johannes MÜller, the chemist Julius Liebig, remained faithful to a modified vitalistic standpoint. But in the following generation the revolution was complete and energetic. With Du Bois-Reymond, Virchow, Haeckel, the anti-vitalistic trend became more definite and more widespread. It had a powerful ally in the Darwinian theory, which had been promulgated meanwhile, and at the same time in the increasingly materialistic tendency of thought, which afforded support to the mechanical system and also sought foundations in it.
The naturalistic, “mechanical” interpretation of life was so much in the tenor of Darwin's doctrine that it would have arisen out of it if it had not existed before. It is so generally regarded as a self-evident and necessary [pg 192] corollary of the strictly Darwinian doctrine, that it is often included with it under the name of Darwinism, although Darwin personally did not devote any attention to the problem of the mechanical interpretation of life. Any estimate of the value of one must be associated with an estimate of the other also.
It goes without saying that the theory of life is dependent upon, and in a large measure consists of physico-chemical interpretations, investigations, and methods. For ever since the attention of investigators was directed to the problems of growth, of nutrition, of development and so on, and particularly as knowledge has passed from primitive and unmethodical forms to real science, it has been taken as a matter of course that chemical and physical processes play a large part in life, and indeed that everything demonstrable, visible, or analysable, does come about “naturally,” as it is said. And from the vitalistic standpoint it has to be asked whether detailed biological investigation and analysis can ever accomplish more than the observation and tracing out of these chemical and physical processes. Anything beyond this will probably be only the defining and formulating of the limits of its own proper sphere of inquiry, and a recognition, though no knowledge, of what lies beyond and of the co-operative factors. The difference between vitalism and the mechanical theory of life is not, that the one regards the processes in the organism as opposed to those in the inorganic world while the other identifies them, but that vitalism regards [pg 193] life as a combination of chemical and physical processes, with the co-operation and under the regulation of other principles, while the mechanical theory leaves these other principles out.
Notwithstanding the many noteworthy reactions, we are bound to regard the present state of the theory of life as on the whole mechanical. The majority of experts—not to speak of the popular materialists, and especially those who, sailing under the flag of materialistic interpretation, have their ships full of vitalistic contraband—regard as the ideal of their science an ultimate analysis of the phenomena of life into mechanical processes, into “mechanics of the atom.” They believe in this ideal, and without concealing that it is still very far off, do not doubt its ultimate attainability, and regard vitalistic assumptions as obstacles to the progress of investigation. Moreover, this aspect of the problem seems likely enough to be permanent with the majority, or, at any rate, with many naturalists, though it is obviously one-sided. For it has always been the task of this line of investigation to extend the sphere within which physical and chemical laws can be validly applied in interpreting vital processes, and the results reached along this line will always be so numerous and important that even on psychological grounds the mechanical point of view has the best chance for the future. Furthermore, the maxim that all the phenomena of nature must be explained by means of the simplest factors and according to the smallest possible [pg 194] number of laws, is usually regarded as one of the most legitimate maxims of science in general, so that the resolute pertinacity with which many investigators maintain the entire sufficiency of the mechanical interpretation, far from being condemned as materialistic fanaticism, must be respected as the expression of scientific conscience. Even when confidence in the one-sided mechanical interpretation of vital processes sometimes fails in face of the great and striking riddles of life, it is to be expected that it will revive again with each new success, great or small.58
The mechanical conception of life which now prevails is made up of the following characteristics and component elements. These also indicate the lines along which the arguments are worked out—lines which glimmered faintly through the mechanical theories of ancient times, but which have now been definitely formulated and supported by evidence.
