Naturalism and Religion

by Rudolf Otto

Differences of Opinion As To the Factors In Evolution.

The theory of natural selection in the struggle for existence rapidly gained wide acceptance, but from the first it was called in question from many sides. Bronn, who translated Darwin's works into German, was and remained loyal to the idea of a “developmental law”—that there is within the organism an innate tendency towards self-differentiation and progress, thus a purely [pg 143] teleological principle.[34] Similarly, von Baer emphasised the idea of an endeavour to realise an aim; von Kölliker, that of “heterogenesis”; Nägeli, that of an impulse towards perfection—all three thus recognising the theory of evolution, but dissenting from the view that the struggle for existence is the impelling factor and actual guide in the process. Very soon, in another direction, antagonism became pronounced between the strictly Darwinian elements of the theory (the struggle for existence and its corollaries) and the accessory Lamarckian elements. Through these and other controversies the present state of the question has emerged.

The main antithesis at present is the following. On the one side, the “all-sufficiency of natural selection” is maintained, that is, progressive evolution is regarded as coming about without direct self-exertion on the part of the organisms themselves, simply through the fact that fortuitous variations are continually presenting themselves, and are being selected and established according to their utility in the struggle for existence. On the other side—with Lamarck—the progress is regarded as due to effort and function on the part of the organism itself. (Increased use of an organ strengthens it; a changed use transforms it; disuse causes it to degenerate. Thus new characters appear, old ones pass away, and in the course of thousands of [pg 144] years the manifold diversity of the forms of life has been brought about.)

Further, by those of the one side variation is regarded as occurring by the smallest steps that could have selective value in the struggle for existence. To the others variation seems to have taken place by leaps and bounds, with relatively sudden transformations of the functional and structural equilibrium on a large scale. In regard to these the rôle of the struggle for existence must be merely subsidiary. This saltatory kind of evolution-process is called “halmatogenesis,” or, more neatly, “kaleidoscopic variation,” because, as the pictures in a kaleidoscope change not gradually but by a sudden leap to an essentially new pattern, so also do the forms of life. Associated with this is the following contrast. One side believes in free and independent variation of any organ, any part, any function, physical or mental, any instinct, and so on, apart from change or persistence in the rest of the organism; the other side believes in the close connectedness of every part with the whole, in the strict “correlation” of all parts, in variation in one part being always simultaneously associated with variation in many other parts, all being comprised in the “whole,” which is above and before all the parts and determines them. And further, to one school variation seems without plan in all directions, simply plus or minus on either side of a mean; to the other, variation seems predetermined and in a definite direction—an “orthogenesis,” in fact, which is inherent in the organism, and which is indifferent [pg 145] to utility or disadvantage, or natural selection, or anything else, but simply follows its prescribed path in obedience to innate law. The representatives of this last position differ again among themselves. Some regard it as true in detail, in regard, for instance, to the markings of a butterfly's wing, the striping of a caterpillar, the development of spots on a lizard; while others regard it as governing the general process of evolution as a whole. Finally, there is the most important contrast of all. On the one side, subordination, passivity, complete dependence on the selective or directive factors in evolution, which alone have any power; on the other, activity, spontaneous power of adaptation and transformation, the relative freedom of all things living, and—the deepest answer to the question of the controlling force in evolution—the secret of life. This last contrast goes deeper even than the one we have already noted, that between the Darwinian and the Lamarckian principle of explanation; and it leads ultimately from the special Darwinian problem to quite a new one, to be solved by itself—the problem of the nature and secret of living matter.

Weismannism.

In regard to almost all the points to which we have referred, the most consistent and decided champion of Darwinism in its essential principles is the zoologist of Freiburg, August Weismann.[35] In long chapters on [pg 146] the protective coloration of animals, on the phenomena of mimicry—that resemblance to foreign objects (leaves, pieces of wood, bark, and well-protected animals) by which the mimics secure their own safety from enemies—on the protective devices in plants, the selective value of “the useful” is demonstrated. In regard to the marvellous phenomena of “carnivorous” plants, the still more marvellous instincts of animals, which cannot be interpreted on Lamarckian lines as “inherited habit,” but only as due to the cumulative influence of selection on inborn tendencies, as well as in regard to “symbiosis,” “the origin of flowers,” and so on, he attempts to show that the heterodox attempts at explanation are insufficient, and that selection alone really explains. At the same time the Darwinian principle is carried still further. It is not only among the individuals, the “persons,” that the selective struggle for existence goes on. Personal selection depends upon a “germinal selection” within the germ-plasm, influencing it, and being influenced by it—for instance, restrained.

In order to explain the mystery of heredity, Weismann [pg 147] long ago elaborated, in his germ-plasm theory, the doctrine that the developing individual is materially preformed, or rather predetermined in the “idants” and “ids” of the germ-cell. Thus every one of its physical characters (and, through these, its psychical characters), down to hairs, skin spots, and birth-marks, is represented in the “id” by “determinants” which control the “determinates” in development. In the course of their growth and development these determinants are subject to diverse influences due to the position they happen to occupy, to their quality, to changes in the nutritive conditions, and so on. Through these influences variations in the determinants may be brought about. And thus there comes about a “struggle” and a process of selection among the determinants, the result of which is expressed in changes in the determinates, in the direction of greater or less development. On this basis Weismann attempts to reach explanations of the phenomena of variation, of many apparently Lamarckian phenomena, and of recognised cases of “orthogenesis,” and seeks to complete and deepen Roux's theory of the “struggle of parts,” which was just another attempt to carry Darwinism within the organism.

What distinguishes Weismann, and makes him especially useful for our present purpose of coming to an understanding in regard to the theory of selection is, that his views are unified, definite and consistent. In his case we have not to clear up the ground and to [pg 148] follow things out to their conclusions, nor to purge his theories from irrelevant, vitalistic, or pantheistic accessory theories, as we have, for instance, in the case of Haeckel. His book, too, is kept strictly within its own limits, and does not attempt to formulate a theory of the universe in general, or even a new religion on the basis of biological theories. Let us therefore inquire what has to be said in regard to this clearest and best statement of the theory of selection when we consider it from the point of view of the religious conception of the world.

Whatever else may be said as to the all-sufficiency of natural selection there can be no doubt that it presupposes two absolute mysteries which defy naturalistic explanation and every other, and which are so important that in comparison with them the problem of the struggle for efficacy and its meaning fades into insignificance. These are the functions and capacities of living organisms in general, and in particular those of variation and inheritance, of development and self-differentiation. What is, and whence comes this mysterious power of the organism to build itself up from the smallest beginnings, from the germ? And the equally mysterious power of faithfully repeating the type of its ancestors? And, again, of varying and becoming different from its ancestors? Even the “mechanical” theory of selection is forced to presuppose the secret of life. Weismann indeed attempts to solve this riddle through his germ-plasm theory, the [pg 149] predisposition of the future organism in the “ids,” determinants, and biophors, and through the variation of the determinants in germinal selection, amphimixis and so on. But this is after all only shifting the problem to another place, and translating the mystery into algebraical terms, so to speak, into symbols with which one can calculate and work for a little, which formulate a definite series of observations, an orderly sequence of phenomena, which are, however, after all, “unknown quantities” that explain nothing.