One of the most distinctive features of the expiring century is the increasing vehemence of the opposition between science and Christianity. That is both natural and inevitable. In the same proportion in which the victorious progress of modern science has surpassed all the scientific achievements of earlier ages has the untenability been proved of those mystic views which would subdue reason under the yoke of an alleged revelation; and the Christian religion belongs to that group. The more solidly modern astronomy, physics, and chemistry have established the sole dominion of inflexible natural laws in the universe at large, and modern botany, zoology, and anthropology have proved the validity of those laws in the entire kingdom of organic nature, so much the more strenuously has the Christian religion, in association with dualistic metaphysics, striven to deny the application of these natural laws in the province of the so-called “spiritual life”—that is, in one section of the physiology of the brain.