And among the representatives of these different standpoints there are most interesting personal differences: in some, like Weismann, we find a great loyalty to, and persistence in the position once arrived at, in others the most surprising transitions and changes of opinion. Thus Fleischmann, a pupil of Selenka’s, after illustrating during many years of personal research the orthodox Darwinian standpoint, finally developed into an outspoken opponent not only of the theory of selection but of the doctrine of descent. So also Friedmann.(6) Driesch started from the mechanical theory of life and advanced through the connected series of his own biological essays to vitalism. Romanes, a prominent disciple of Darwin, ended in Christian theism, and Wallace, the discoverer of “the struggle for existence,” landed in spiritualism. Nothing like an exhaustive view of the present state of Darwinism and its many champions can here be attempted. But it will be necessary to get to know what we may call its possibilities by a study of typical and leading examples. In the course of our study many of the problems to which the theory gives rise will reveal themselves, and their orientation will be possible. This task falls naturally into two subdivisions: (1) the present state of the theory of Evolution and Descent, and how far the religious conception of the world is or is not affected by it; (2) the truth as to the originative and directive factors of Evolution, especially as to “natural selection in the struggle for existence,” whether they are tenable and sufficient, and what attitude religion must take towards them. These two problems must be kept distinct throughout, and must be discussed in order. For the validity of what is characteristically _Darwinism_ is in no way decided by proving descent and evolution, although it appears so in most popular expositions.(7) The Theory of Descent. Again and again we hear and read, even in scientific circles and journals, that Darwinism breaks down at many points, that it is insufficient, and even that it has quite collapsed. Even the assurances of its most convinced champions are rather forced, and are somewhat suggestive of bills payable in the future.(8) But here again it is obvious that we must distinguish clearly between the Theory of Descent and Darwinism. Of the Theory of Descent it is by no means true that it has “broken down.” With a slight exaggeration, but on the whole with justice, Weismann has asserted that the Theory of Descent is to-day a “generally accepted truth.” Even Weismann’s most pronounced opponents, such as Eimer, Wolff, Reinke, and others, are at one with him in this, that there has been evolution in some form; that there has been a progressive transformation of species; that there is real (not merely ideal) relationship or affiliation connecting our modern forms of life, up to and including man, with the lower and lowest forms of bygone æons.