A Review of the Systems of Ethics Founded on the Theory of Evolution

by Cora May Williams

CHAPTER I

THE CONCEPTS OF EVOLUTION

The preceding considerations have made it evident that the idea of Evolution has undergone a broadening process since Darwin first brought it before the world. It is necessary to glance briefly at some of the chief phases and the general significance of this process in order to define the extent and intent of the concept as far as science has made such definition possible.

To Darwin himself the struggle for existence was always between the unities represented by complete organisms whether as isolated individuals, or in family, tribal, or national groups. Everywhere in his calculations, appearing unchanged in his results, is found the unknown quantity of variation from ancestral type, the known factors being heredity, and natural and sexual selection in the struggle for existence. Wallace's ideas as to color in birds deprive the theory of sexual selection of one of its most important points of application in Darwin's work. It is, in fact, easy to see that sexual selection cannot neutralize natural selection, that any particular form of sexual selection can arise and finally survive only by a harmony with the direction of natural selection, and that the two must therefore appear, even from any standpoint of freedom of the will, as continually attaining coincidence. It has been said, above, that the struggle for existence was, for Darwin, between the organisms as unities. This consistent position of the specialist has been criticised, from a more general point of view, by Lewes in his essay on the Nature of Life,[96] in which he asserts that we must logically "extend our conception of the struggle for existence beyond that of the competition and antagonism of organisms—the external struggle; and include under it the competition and antagonism of tissues and organs—the internal struggle." "Mr. Darwin," he says, "has so patiently and profoundly meditated on the whole subject, that we must be very slow in presuming him to have overlooked any important point. I know that he has not altogether overlooked this which we are now considering; but he is so preoccupied with the tracing out of his splendid discovery in all its bearings, that he has thrown the emphasis mainly on the external struggle, neglecting the internal struggle; and has thus, in many passages, employed language which implies a radical distinction where—as I conceive—no such distinction can be recognized. 'Natural Selection,' he says, 'depends on the survival, under various and complex circumstances, of the best-fitted individuals, but has no relation whatever to the primary cause of any modification of structure.'[97] On this we may remark, first, that selection does not depend on the survival, but is that survival; secondly, that the best-fitted individual survives because of that modification of its structure which has given it the superiority; therefore, if the primary cause of this modification is not due to selection, the selection cannot be the cause of species. The facts which are relied on in support of the idea of 'fixity of species' show, at any rate, that a given superiority will remain stationary for thousands of years; and no one supposes that the progeny of an organism will vary unless some external or internal cause of variation accompanies the inheritance. Mr. Darwin agrees with Mr. Spencer in admitting the difficulty of distinguishing between the effects of some definite action of external conditions, and the accumulation through natural selection of inherited variations serviceable to the organism. But even in cases where the distinction could be clearly established, I think we should only see an historical distinction, that is to say, one between effects produced by particular causes now in operation and effects produced by very complex and obscure causes in operation during ancestral development.... Natural Selection is only the expression of the results of obscure physiological processes."

The last statement is one to which Darwin himself would certainly not have objected. It is an extension of the principle implicitly involved in all his work and explicitly stated in his later work, although the chief emphasis is laid on outer conditions. The extension of the idea of competition from the outer condition of organisms to the more ultimate physiological unities of organ and tissue is a philosophic gain. It is evident, however, that that for which Darwin is seeking is not a philosophical generalization which shall include outer and inner change under one highest law, but, first of all, the particular causes of particular variation interesting to the specialist in biology. It is made too clear for mistake in "The Variation of Animals and Plants under Domestication" that the uncertainty with regard to such particular forms of cause is the spring of his declaration of our ignorance as to variation. The possibility of an inclusion of lower in higher generalizations he would not deny; though the special laws first occupy his attention. Doubtless, his work is not, as is no man's, wholly free from inconsistencies and contradictions,—which are due, in part, to the fact that every scientific theory is, even in the thought of the individual, an evolution. But the declaration of mystery in the question of variation is not equivalent to a theory of accident, of transcendental mystery, or of some special organic or vital force, such as Claude Bernard especially opposed; it is merely and simply a statement of the mystery of present ignorance. This fact is expressly stated in Darwin's later work. We find, for instance, in the introduction to a letter to the editor of "Nature," written in 1873, the origin of many instincts referred to "modifications or variations in the brain, which we, in our ignorance, most improperly call spontaneous or accidental;" and we have, in "The Variation of Animals and Plants under Domestication,"[98] such passages as the following: "When we reflect on the individual differences between organic beings in a state of nature, as shown by every wild animal knowing its mate; and when we reflect on the infinite diversity of many varieties of our domesticated productions, we may well be inclined to exclaim, though falsely, as I believe, that variability must be looked at as an ultimate fact, necessarily contingent on reproduction. Those authors who adopt this latter view would probably deny that each separate variation has its own proper exciting cause. Although we can seldom trace the precise relation between cause and effect, yet the considerations presently to be given lead to the conclusion that each modification must have its own distinct cause." It is "probable that variability of every kind is directly or indirectly caused by changed conditions of life. Or, to put the case under another point of view, if it were possible to expose all the individuals of a species during many generations to absolutely uniform conditions of life, there would be no variability.... The causes which induce variability act on the mature organism, on the embryo, and, as we have good reason to believe, on both sexual elements before impregnation has been effected." Darwin further considers, in this same book, some of the probable particular causes of variation, as given in climate and food. And it may be remarked, in this connection, that Rolph's criticism of the impossibility of progress under conditions of want is irrelevant as applied to Darwin, since the latter himself says expressly: "Of all causes which induce variability, excess of food, whether or not changed in nature, is probably the most powerful";[99] again: "We have reason to suspect that an habitual excess of highly nutritive food, or an excess relatively to the wear and tear of the organization from exercise, is a powerful exciting cause of variability."[100] Rolph's criticism is probably due to forgetfulness of the fact that Darwin limited the struggle for existence to that of complete organisms with one another, and that, under such a limitation of the conception to external struggle, a condition of want cannot be conceived as necessarily precluding a monopoly of abundance by best-fitted individuals.

Theories with regard to the special outer causes and resulting physiological conditions of variation have been gradually added to, as facts on this score have accumulated. But, as investigation advances, the question is seen to involve all the problems of the intricate chemical and mechanical nature of physiological structure in its manifold forms and degrees of organization. The field stretches out in this direction, under our contemplation, to an indefinite distance; and science appears as yet to have passed only the outer limits of its territory.

It is certain that the comparatively recent science of Physiological Chemistry will have many of the decisive words to say on this score, in the future. "When we see the symmetrical and complex outgrowths caused by a single atom of the poison of a gall-insect, we may believe that slight changes in the chemical nature of the sap or blood would lead to extraordinary modifications of structure," says the great seer of evolution himself.[101]

Among special theories of Evolution, a distinction may be made between: (1) such special theories as aim at biological simplification by reduction of all organic variation to one primary form of cellular process; (2) such theories as are content with less ultimate laws, by which the various ascertained forms of change are included in one general statement not involving special physiological or physical theory but applicable to all forms of life; (3) such theories as aim to give distinctive philosophic expression to a generalization like the last named, including in this statement both psychical and physiological phenomena; and (4) such theories as aim at an ultimate expression of the direction of evolution that shall include the phenomena of life, both physiological and psychical, under one head with all other natural phenomena. To the first class belong only "provisional" hypotheses, among the best known of which are those of Pangenesis, Perigenesis, and the Continuity of the Germ-Plasm. To the second, which are not merely tentative but have a broad foundation in known fact, belongs Haeckel's theory of Inheritance and Adaptation, a theory restated in substance, from independent research, by Eimer, whose ultimate general factors of analysis are the same with Haeckel's, though he deals, beyond these, with special facts and special theories of his own. Phases of the second class often entitle them to inclusion in the third. An example of the third class is found in Spencer's definition, "Life is the continual adjustment of inner relations to outer relations." The fourth and last class includes Fechner's "Tendency to Stability" and Spencer's theory of the rhythm of motion (see his "First Principles"), similar to which are certain ideas of Zöllner, Du Prel, and others; and similar elements to which are to be found in Haeckel's "Plastidule-Theory." In connection with this class, reference may be made to an article by Dr. J. Petzoldt in the "Vierteljahrschrift für wissenschaftliche Philosophie" under the title "Maxima, Minima, und Oekonomie," in which, among others, Fechner's views especially are discussed with reference to an ultimate principle of evolution. The first pages on the "Tendency to Stability" in Fechner's "Ideas concerning the Evolution of the Organic" ("Einige Ideen zur Schöpfungs- und Entwicklungsgeschichte der Organismen") are as follows:—

"For the sake of brevity I call relations of position and motions recurring at regular periods, that is after like intervals, in the particles forming a material system or in the centres of whole masses conceived as forming a larger system, 'stable relations.' Among such relations is to be reckoned the condition of rest of the particles or masses in relation to each other, as the extreme case, which we may call the state of 'absolute stability'; while a dissipation of the particles or masses, to infinity, in different directions, constitutes the other extreme of absolute instability.

"We do not speak of 'absolute stability,' but of 'full stability,' in cases where motion still takes place, but this brings continually, in exactly the same periods of time, the same relations of particles or masses, not only as regards position, but also as regards velocity and direction of the motion and change of velocity and direction....