These great ideas of Lamarck, which threw light on the whole field of organic life, and were closely approached by Goethe in his own speculations, gave rise to the theory that we now know as transformism, or the theory of evolution or descent. But the far-seeing Lamarck was--as Caspar Friedrich Wolff had been fifty years before--half a century before his time. His theory obtained no recognition, and was soon wholly forgotten. It was brought into the light once more in 1859 by the genius of Charles Darwin, who had been born in the very year that the _Philosophie Zoologique_ was published. The substance and the success of his system, which has gone by the name of Darwinism (in the wider sense) for forty-six years, are so generally known that I need not dwell on them. I will only point out that the great success of Darwin's epoch-making works is due to two causes: firstly, to the fact that the English scientist most ingeniously worked up the empirical material that had accumulated during fifty years into a systematic proof of the theory of descent; and secondly, to the fact that he gave it the support of a second theory of his own, the theory of natural selection. This theory, which gives a causal explanation of the transformation of species, is what we ought to call "Darwinism" in the strict sense. We cannot go here into the question how far this theory is justified, or how far it is corrected by more recent theories, such as Weismann's theory of germ-plasm (1844), or De Vries's theory of mutations (1900). Our concern is rather with the unparalleled influence that Darwinism, and its application to man, have had during the last forty years on the whole province of science; and at the same time, with its irreconcilable opposition to the dogmas of the Churches.