Parallel Paths: A Study in Biology, Ethics, and Art. T. W. Rolleston

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СКАЧАТЬ the great importance of natural selection in the development of the organic world has been fully recognised by most naturalists, the objection has been raised that it alone is not a sufficient explanation of all the different processes in the phylogeny of an organism. Attention has been called to such organs as would be incapable of exercising their function until in an advanced stage of development, and so could not originally have been of any advantage in a struggle for existence. How could natural selection tend to develop an organ which would be useless so long as it was still in a rudimentary condition? This objection has led to the supposition of an internal force residing in the substance of the organisms themselves and controlling their development in certain definite directions. Many naturalists indeed have gone so far as to affirm that only the less advantageous qualities have been affected by the struggle for existence, while the more advantageous have been uninfluenced by it”9

      One can easily imagine what a modern Paley bent on reconciling orthodoxy and evolution would say to this. He would cry, Design, forethought, intelligence—here is the clearest evidence of it! And indeed there are many modern biologists who do not shrink from the admission that the processes of nature must ultimately be interpreted in terms of will or intention, not in terms of chance or blind mechanism. Thus, to the Darwinian argument that organs can be and are, demonstrably, formed by gradual adaptation to surrounding conditions without assuming the necessity of purposeful design, it is often replied that the very fact of adaptability is itself one of the strongest evidences if not of design at least of purpose. And J. v. Uexküll, who describes life as consisting essentially in the fact that it proceeds according to design (planmässig), has the following remarkable passage in his Experimental Biology10:—

      “When we look backwards, every phase in the process of development seems to us to have proceeded in a strictly causal manner from physico-chemical processes. But when we turn to look forward, it is certain that the physico-chemical processes if left to their own causality must immediately bring about the destruction of the organism. In fact, the clearest definition we can give of dying is to say of an organism that its processes now go on no longer teleologically (zweckmässig) but only causally.”11

      

      Yet the modern Paley would be rash in arguing from facts like these (supposing them fully established) to the conscious, intelligent contrivance of a single foreseeing Mind. For very few things in this universe appear to be done as a presiding, conscious intelligence would do them. Conscious intelligence would not have evolved the giant armadillo only that the whole species might be destroyed by the sabre-toothed tiger, and would not have armed the sabre-toothed tiger for the attack on the armadillo in such a way that when he had exterminated the victim-species the formation of his teeth rendered it impossible for him to prey on any other animal.12 Conscious intelligence would not have allowed the relic of a disused organ, in the shape of the vermiform appendix, to be a constant source of danger and suffering to countless generations of men—danger against which no exercise of prudence or energy can secure them.

      Let us examine a couple of other crucial cases. The embryo of every mammalian animal is prepared in the womb for the life it is to live under wholly different conditions. Lungs are formed when there is no air for them to breathe, eyes when there is no light, a digestive system when nourishment is derived as yet direct from the mother’s blood. This capacity for anticipatory development during a period of gestation or incubation becomes absolutely necessary for the maintenance of life as soon as animals, ceasing to multiply by merely dividing in two, become more highly organized and have to devote special germ-cells to reproductive purposes. Here is certainly purpose, or, as I should prefer to call it, directivity—here we recognize what Reinke calls the X-factor in nature. But conscious, intelligent contrivance? We must recollect how many of these embryos are destined to perish at birth or before attaining any appreciable degree of independent life. Would not intelligence foresee that, and bring to birth only what was destined to endure?

      Again, there are certain species of butterflies which have put on a coloration and a form the effect of which is to aid them in evading the attacks of birds. They were not created so; they have become so; and the precise manner of the becoming will be fully discussed in a later chapter. Let us assume for the moment that this adaptation did not occur by a series of lucky accidents or by any merely mechanical process. Are we, then, bound to attribute it to intelligent contrivance? The question will be best answered by simply putting a case which admits of no doubt. Suppose there were an island in which there were no birds, except such as prey on fishes or on each other, but never on insects. The butterflies on this island, if there were any, would certainly show no trace of protective form or coloration. But at some time or other insect-eating birds might be introduced to the island, as the English sparrow has been introduced in Australia. Then, if the extermination of the butterflies did not proceed too rapidly, we might expect, in the course of generations, to see protective adaptations assumed. But could we expect to see them assumed in anticipation of the advent of the destroyers? We could not. Naturalists, however much they may differ, as they do differ, upon the question as to how protective adaptations actually take place, would all agree that they could not possibly take place in anticipation of needs not yet present. If they did, we should have a miracle, and where miracle comes in knowledge goes out. The cases where conscious, intelligent contrivance would be unmistakably recognizable are just the cases which never occur. The signal service rendered by the champions of the evolution theory,

      Quos nec fama Deûm, nec fulmina, nec minitanti

      Murmure compressit Cœlum,

      is that they conquered the realm of organic nature for true knowledge, and gave the drama of its development a new and profound interest, by showing with an uncompromising courage only equalled by the extraordinarily minute and patient research which justified it, that the apparent instances of divine contrivance with which nature teems must be explained by the responsiveness, the adaptability, of living protoplasm. Needless to say, this demonstration does not in the least disprove the existence of God as a supreme, conscious, personal Intelligence.13 But it does forbid us to deduce the existence of such a Being from the observation of natural phenomena. A living, developing universe has been set in the place of a Divine Mechanician operating on dead matter.

      The question, what conception we are to form of the forces of evolution, will be more fully discussed in the succeeding chapters on Biology, as a foundation for views which will afterwards be put forward in relation to Ethics and to Art.

      But first we must clear the ground a little by considering what it really is that we are to study, and if it be possible to study it at all. Nature-study if it is to be possible must begin, and if it is to be fruitful must end, in something which is not strictly the study of nature, but which we call Philosophy.

      One of the most brilliant examples of that union of philosophic speculation with nature-study which is so marked a feature of the German thought of our day is H. von Keyserling’s work, The Structure of the World.14 Keyserling begins by laying it down as a postulate of thinking that “The Universe is a rounded, inwardly coherent Whole.”

      A postulate of thinking this is indeed, and more than that—it is a postulate of living. If under all the variety and apparent discontinuity of the universe there does not lie One all-pervading and unifying Power, then meditation and action are alike vain, for none can tell the hour when some incursion of the unknown may not shatter our cosmos into chaos, or leave us in a new universe with the edifice of our past experience, the familiar home of the spirit, lying in ruins around us. Every one assumes, consciously or unconsciously, that there is such a Power, that the universe is One, that however mysterious, however little known or understood it may be, it is not essentially deceptive or incalculable. The savage and the philosopher alike assume this, and act upon the assumption. It is perhaps possible not merely to assume but to prove it. For let us try to imagine what would be the case if it were not true. If the Principle, the ultimate Reality of the universe, be not one СКАЧАТЬ