within his ranks today it does not operate. Great mental capacity is not today the most important survival factor among humanity. As the archeologist Keith has pointed out a great philosopher or artist may lead a life of misery, want, and despair, and leave no descendants, while a thoughtless, happy Burman will live out his days believing that the earth is flat and Buddha an all-powerful god, but will leave behind him a large and rapidly multiplying family. During the years just prior to the appearance of the “Origin,” Darwin had an almost complete confidence in the power of natural selection to account for all the phenomena of evolution. Even in the year when that work appeared, he wrote Lyell: “Grant a simple archetypal creature, like the Mud-fish or Lepidosiren, with five senses and some vestige of mind, and _I believe Natural Selection will account for the production of every vertebrate animal_.” In publication, however, he was more cautious, saying, “I am convinced that Natural Selection has been the main, but not the exclusive means of modification.” From his extreme position on the effective ability of natural selection to seize upon a variation and so foster it that a new species would appear, Darwin slowly but not unwillingly receded. Ten years after the first publication of the Darwinian theory[16], he admitted that variations might not have been so supremely important as he supposed; in 1878 he believed in the direct action of environment in producing variations, as did Buffon; in 1880 he adopted Lamarck’s theory of the use and disuse of parts. In 1881, in the “Descent of Man,” Darwin lays much stress upon sexual selection, the idea that members of one sex rendered themselves particularly attractive in order to capture the attentions of their would-be mates. This, however, is really a subdivision of the natural selection idea--in the general reliability of which the famous evolutionist still believed. * * * * * As we have said, in the estimate of Darwin’s general environment, the world of the middle nineteenth century did not welcome the new prophet of natural law in the natural world. Many scientists accepted Darwinism, or at least, the principle of evolution, without reserve; others made reservations; most of the “intelligentsia” declared it to be without the slightest element of truth. The public in general, and especially the church, clung to the old, valueless doctrine of a multitude of special creations by an omnipotent deity, apparently forgetting that the greatest of the church fathers, Aquinas and Augustine, had been prominent evolutionists in their day. There arose about Darwin’s theories a storm of argument that lasted for many years, and involved scientists, theologians, philosophers, and laymen throughout the world.