In speaking of an evolution theory, in distinction from the descent theory, we mean, as is evident from the first part of our work, that way and mode of
constructing the doctrine of the descent of species which permit this descent to take place, not by the leaps of a metamorphosis of germs, but by transitions so imperceptably small that the difference of two generations which lie in the same line of descent, is never greater than those differences which always take place between parents and children of the same species—transitions so gradual that only the continuation of these individual changes in a single direction produces an increase and, finally and gradually, the new species. The treatment of the question as to what position this evolution theory takes regarding theism, is even more simple than answering the question as to the position of the descent idea in reference to theism.
For now we have no longer to discuss the different possibilities of a development, as heretofore we have discussed those of a descent, but only the idea of a gradual development or of an evolution in general. Of such possibilities, it is true, we find several. In the first place, we can look for the inciting principle of the development of species either in the interior of organisms, or we can see it approaching the latter from without. The only scientific system which has made any attempt at mentioning and elaborating the inciting principle of development is that of Darwin; a system that chooses the second of the alternatives just stated and sees the essential principle that makes the transmission of individuals a progress beyond one species, approaching the individuals from without. But while we shall have to treat of this specific Darwinian theory—the selection theory—still more in detail in the following section, we shall also there have to point, out
everything that theism has to say in reference to a principle of development which approaches the organisms from without. Another possible explanation of the origin of species through development is to be found in the fact that we look for the inciting principle of development in the interior of organisms. This is done, so far as we know, by all those scientists who, although inclined to an evolution theory, are adversaries of the selection theory; but none of them claim to have found the inciting agencies of development. Thus, as in the preceding section, we are again referred only to the wholly abstract possibility of conceiving these inciting agencies either as coming into existence anew in the organism with each smallest individual modification which leads to a development of the species, or as being before present in the organisms, but still latent, and only coming into activity when they are set free. But the question whether theism could accept the one or the other possibility had to be treated of in the preceding section, and was there answered in the affirmative.
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.
In the first place, we wish to render evident the fact which is so often overlooked by the friends of monism and still more by theistic adversaries of the idea of evolution, that the idea of a development of species, and also of man, does not offer to theistic reasoning any new or any other difficulties than those which have been long present, and which had found their solution in the religious consciousness long before any idea of evolution disturbed the
mind. It is true, the question as to the origin of mankind is, to speak in the language of natural history, a still unsolved problem; and the supposition of its gradual development out of the animal kingdom is still an hypothesis—one of all those attempts at solving this problem which still wait for confirmation or refutation. But there is another quite analogous question whose position has long ceased to be a mere problem, and whose solution is no longer a mere hypothesis; namely, the question as to the origin of the perfect human or any other organic individual. To speak again in the language of natural history, this origin is no longer a problem—that is, without regard to the obscurity in which the existence and origin of every creature, as to its last causes, is always and will always be veiled for us. We know that the human, and, in general, every organic individual, becomes that which it is through development. It begins the course of its being with the existence of a single cell, the egg, and goes through all stages of this development by wholly gradual and imperceptible transitions, so that the precise moment cannot exactly be fixed when any organ, any physical or psychical function, comes into existence, until perfect man is developed. Man has this mode of coming into existence in common with all organized beings, down to the lowest organisms which stand above the value and rank of a single cell. At this place, and with the design of our present discussion in view, we ought not to render the importance of this fact obscure by a teleological comparison of the different eggs and germs with one another. If we look upon that which is to come out of the germs, and which certainly if prepared and present in the first vital functions of the
germ, although we are not able to observe, prove, and estimate it by means of the microscope and the retort, then of course the difference in the value of the germs must be immense; and from this point of view we certainly look upon the germ of man differently than upon the germ of an oyster. But here the question is not as to the differences of value of organisms: no scientist who remains within the limits of his realm, will ever deny them; but we treat of the question whether such valuable objects come into existence suddenly or gradually—whether it is possible, or even a fact which repeats itself before our eyes, that a form of being of higher value comes forth from a form of being of a lower value in gradual development. And here it is an undisputed fact that all qualities of man, the physical as well as the spiritual, come into existence in such a gradual development that not in a single one of them can be fixed any moment of which it may be said: on the other side of this moment it did not exist, but on this side it did exist. All differentiations of his body, from the first differentiation of the egg-cell into a complexity of cells up to the last formation of his organs, take place in the same gliding development. All his psychical and spiritual functions and forces come into existence in this form of gradual development. Where, in the development of the human individual, is the moment in which consciousness, language, self-consciousness, memory, will, the perception of God, moral responsibility, the perception of the idea and the ideal, or whatever else we may mention, came into existence? Nowhere; all this, and all the rest, is developed in a gradual process. The only marked time in this development is the time of birth:
it brings a great change into physical life, and is perhaps the beginning epoch of the spiritual development of man. But even the birth is not absolutely bound to a certain time; the child may be born too early, by weeks or even months, and its development nevertheless takes place; and even after birth, how slowly and gradually spiritual development begins and continues!
With this gradual process of individual development which we have long known, we have never found any difficulty in bringing two things into harmony. First, we always judged the value of the single qualities of man only in the proportion in which they were really present and came into existence, and in such a way that we entirely followed the flowing development of the individual. Therefore we looked upon the suckling, for instance, not at all as a morally responsible individual; upon the child of two years as more responsible, but to a far less degree than the child of school-age, and the latter again to a less degree than the man; and thus we have been long accustomed to reason, when looking upon all single qualities of man. Second, we did not find any difficulty in bringing into perfect harmony the idea of a gradual process of individual development and of the dependence of the latter on a complex totality of natural causes: with the idea of the absolute dependence on God, the Creator, of that which arose through development. Every religiously reasoning man has always looked upon himself as the child of his parents, gradually developed under the activity of complex natural causes, as well as the creature of God, that owes the existence of all its forces and parts of body and soul to God. Should it then, be so difficult, or is it only