Doctrine of evolution

“ I now pass on to the consideration of those cases which, for reasons which I will point out to you by and by, are not to be regarded as demonstrative of the truth of evolution, but which are such as must exist if evolution be true, and which therefore are, upon the whole, evidence in favour of the doctrine. If the doctrine of evolution be true, it follows, that, however diverse the different groups of animals and of plants may be, they must all, at one time or other, have been connected by gradational forms ”

“ And Darwin concludes his presentment of the doctrine of evolution in the Origin of Species in 1859 with the following sentence:—
'There is a grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one ”

“ The following are among the most confident statements about evolution to be found in this essay. Speaking of the “Origin,” he says (p. 229) :—
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“... the general doctrine of evolution, to one side of which it gives expression, obtains, in the phenomena of biology, a firm base of operations whence it may conduct its conquest of the whole realm of nature.” ”

“ We began with the basic principles of organic structure and workings, and then we examined serially the larger categories of the evidences relating to evolution as a fact, and to the mode of its accomplishment by natural factors. Proceeding to the special case of our own species, we learned that human beings are inevitably a part of nature and not outside it; in structure, development, and palæontological history, mankind is subject to the control of the uniform laws which operate throughout the entire range of living things. ”

“ Evolution is the old heathen doctrine of chance. It professes to eliminate design and a personal active Creator. The theory of natural selection allows no design, no intelligence, no interference, no control, by the Creator. ”

“ The evolution doctrine, taken in one of its aspects, supposes one grand chain of animal organisms, rising higher and higher in the scale of animal life, but connected together by ordinary generation, so that they are of one kindred throughout; but that, as each distinct species grows out of predecessors, by gradual improvements and increments, forming more and more elaborate organisms, man is the consummate product of the whole process. ”

“ These are definite questions that bring us face to face with the fundamental problems relating to the dynamics or workings of evolution. We need not ask for or expect to find complete answers, for we know that it is impossible to obtain them. But we may expect to accomplish our immediate object, which is to see that evolution is natural. Our attention must be concentrated upon the three biological subjects of adaptation, variation, and inheritance, and we must learn why science describes them as real organic phenomena and the results of natural causes. ”

“ Quite obviously this succession of life was antagonistic to the former views of a literal Creation; and only on this supposed fact as an outline has the modern theory of biological evolution been built up. For if geology cannot furnish the most unquestionable proof that life has occurred in a very definite and invariable order, what is the use of talking about the development of one form of life into another by a gradual process of evolution? ”

“ VII SOCIAL EVOLUTION AS A BIOLOGICAL PROCESS We now reach a critical juncture in our study of the foundations of evolutionary doctrine, for we must pass at this point to an inquiry into the nature and origin of human social relations. In undertaking this task we may seem to leave the field which is properly that of organic evolution, and many perhaps will be unwilling to view such aspects of human life as materials for purely biological analysis, arrangement, and explanation. ”

“ But it is possible to obtain a clear conception of certain of the fundamental principles that fall into line with the other parts of the doctrine of organic evolution with which we have now become acquainted. ”

“ It is needless to say how great has been the influence of the doctrine of Evolution, or rather perhaps of the method of investigation to which it has given birth, upon the study of history, especially the history of institutions. ”

“ And we may add that the extent of its spread is directly proportioned to the need felt for this doctrine as a support of the theory of evolution, while the vociferance of its advocates is inversely proportioned to the evidence in its support.
As a result of extensive modern experiments and discussion, biologists have grown very cautious, and are by no means so positive as they were twenty years ago in affirming just how species have come into existence. ”

“ Therefore living species seem unchanged and unchangeable until a conviction that evolution is true, and a knowledge of the method of science by which this conviction is borne upon one, guide the student onwards in the further search for the efficient causes of the process. ”

“ In this conception we have the basis of the recent theory of evolution, so thoroughly worked out and widely extended since Darwin’s time—a theory including the doctrine that man himself is a result of descent, and not of special creation. ”

“ Therefore the evolution of an organic system in material respects involves its functional or dynamic evolution as an inseparable correlate; the two proceed in unity, and they cannot be regarded as entirely distinct without violating common-sense. ”

“ But, nevertheless, beliefs that fall within the scope of the definitions adopted above are to be found among all men, and they must be examined so that their agreements and differences may be demonstrated, and their common elements may be explained as the natural products of a process of evolution. ”

“ The unity of nature and of its processes is established more and more surely as the naturalist classifies the facts of structure, development, fossil history, and evolutionary method. Our own species is not unique ”

“ Let it simply be agreed, as it now is by all science, that the evolution of form is a universal and well evidenced principle, working out through the various well established and comprehensible incidents, such as natural selection, adaptation to environment, and so on—yet this statement of the fact is not an explanation of its cause. ”

“ We must conclude, with all the scope and power that can be given to natural selection, that Nature has not developed a higher and differently organized animal out of a lower and inferior type—has not made new species by the process called evolution, because the infinite God has not commissioned Nature to do that thing, but has reserved it unto himself to make special creations. ”

“ Of all the mischievous misconceptions of Darwin’s theory none have worked so much harm as that which regards natural selection as the active and efficient cause of evolution. Although evolution is an established fact, our knowledge of its processes are incomplete and must always remain so until we have solved that most vexed of all biological problems, the “causes of variation.” ”

“ Let us turn to define Evolution—a word about which much ambiguity exists. In its narrower sense 'Evolution,' a term not at first used by Darwin, means the morphological and physiological variations of organic beings by the action of natural selection. It then came to be loosely applied to almost any specific theory about the origin and development of things. ”

“ And, therefore, those who adopt the notion of the special creation of species do, it is said, in truth impair the professed character of the power to which they assume that the phenomena of the existence of species are to be referred, whereas the hypothesis of the evolution of species out of other species is much more consistent with the professed conception of the ultimate power. ”

“ A much longer chapter will be required to describe the change which the advent of the Origin of Species has wrought in every department of science, and not of science only, but of philosophy. The principle of evolution, so early broached and so long discredited, has now at last been proclaimed and accepted as the guiding idea in the investigation of Nature. ”

“ Thus it only remains to treat in general of the question as to the reconcilableness of the idea of the origin of species through evolution, through gradual development, in general with a theistic view of the world. ”

“ When we turn to a department in which human influence has largely or wholly shaped the phenomena, we find numerous special creations that are not attributable to the operation of any law of development or evolution such as is supposed to have led to the production of one species of animal out of another, or out of several previous species. ”

“ If the theory that the different species of animals now known to us have been evolved successively by descent from some primordial simplest form through modifications induced by change of habitation, of medium of life, and accumulation of new structures occurring through an immense period of time, be a sound hypothesis, the process which has evolved superior out of inferior organizations ought, in consistency with itself and with all its supposed conditions, to be capable of being reversed, so as to lead to the evolution of inferior out of superior organisms. ”

“ And it is, perhaps, equally needless to observe that the mere fact of evolution, as distinguished from special creation—or of the gradual development of living mechanisms, as distinguished from their sudden and ready-made apparition—would not in any way affect the argument from design, unless it could be shown that the process of evolution admits the possibility of some other cause which is not admitted by the hypothesis of special creation. But this is precisely what is shown by the theory of evolution as propounded by Darwin. ”

“ But still, though thus united in the modern history of convictions, though united and confused in the collision of biological and traditional opinion, yet evolution and natural selection must be separated in theological no less than in biological estimation. Evolution seemed inconsistent with Creation; natural selection with Providence and Divine design. ”

“ The evolution theory could only pass beyond the rank of a hypothesis, if we should succeed in showing the impelling forces of such an origin of species through development. Such an attempt can be made in two ways—the metaphysical and the scientific-empirical. ”

“ Or if freedom is asserted of the whole range of animal will, not, however, of plant movement or the motions of the inorganic, we may again inquire as to the point of exact division between the animal and the plant. Evolution is, by definition, a gradual process, a growth in which there are no gaps, and of which our finest and most minute calculations by infinitesimals can give us only a faint conception. ”

“ If it was potent enough to differentiate the enormous multitude of these animals in all other traits, why did it not vary the number of segments with which the primitive race was endowed? Is the law of evolution limited or unlimited? If it is limited in its effects, then there are patterns of animal structure which it has not modified, and the presence of which in hundreds of thousands of different species must be explained as a form of structure designed for some end that was to be common to a great multitude of different beings. ”

“ That there are other factors of evolution not yet discovered is almost inevitable; they, however, will be but added ‘laws;’ supplementary and co-ordinated methods—giving greater completeness to our knowledge of the origin of species.
But having reached this conclusion, we are at once compelled to ask, What is the origin of this unceasing continuity of variation in all living things? this power to become constantly adapted to change of environment, and for ever, in the fittest form, to survive? ”

“ It is a general principle of evolution that the law of the whole is repeated with modifications, in the part. This is a necessary consequence of the Unity of Nature. We ought to expect therefore and do find, that the order of the use of the factors of evolution is the same in the evolution of the organic kingdom, in the evolution of each species, and in the evolution of each individual. ”

“ In general, the theory of evolution is an assertion of the unity of life, or, in its widest form, of the unity of existence. Progressive modifications and hereditary transmission of such modifications are, it is contended, sufficient to explain the different forms and species which life now manifests. ”

“ In the evolutionary theories of modern biology, it is precisely the problems of the origination of new species, and of the special character of the relations between the species and its environment by which this process is conditioned, that have attracted almost exclusive attention. And, with the steadily increasing success of evolutionary hypotheses in dealing with biological problems, there has naturally arisen a tendency to extend the application of the general concept of evolution far beyond the sphere in which it first originated. ”

“ But if there has ever been such an instance of the evolution of any known species of animal out of other species shown by satisfactory proof, or if we assume such an occurrence in the past as the theory calls for, what reason have we to suppose that the process of evolution is still going on, and to expect it to go on to the end of time? We must judge of the future by the past, for we have no other means of judging it. ”