In the year 1859 great commotion was caused in the world of thought by the appearance of _Darwin’s_ book on the “Origin of Species.” It stated that the various species had gradually evolved from most simple, primordial forms, and this by natural selection; not, therefore, in the sense that the Creator had put the laws of evolution into nature, but that in the struggle for existence the survival of the fittest was the result of natural selection. Soon it was claimed that man, too, in his rational life, was the result of an evolution from animal stages; indeed, the whole universe had arisen by the survival of the accidentally fittest. Evolution was to be substituted for creation. In Germany, _E. Haeckel_ was the man who considered it the task of his life to spread those ideas as the established result of science. In our own time a belated high tide is sweeping over the intellectual lowlands. _Darwin_ himself was an agnostic; to begin with, he lacked all religious training; his mother had died early, his father was a free-thinker, and his education at school was rationalistic. The doubt of all higher truths, and finally, according to his own confession, the doubt respecting the power of reason, were his companions through life. Yet he confesses: “... I never was an atheist in the sense that I would deny the existence of God. I think, in general (and more so the older I grow), but not at all times, agnostic would be a more accurate description of my state of mind” (_F. Darwin_, The Life and Letters of Charles Darwin, I, 304). Remarkable, however, is the following passage at the end of _Darwin’s_ chief work: “It is a great belief, indeed, of the Creator having breathed the embryo of all life surrounding us into a few forms, or in but one single form, and an endless row of most beautiful, most wonderful forms having evolved and are still evolving from such a simple beginning, while our planet, following the laws of gravitation, has steadily revolved in its circle.” What _Darwin_ was lacking in a high degree was a philosophical training of the mind.