The Sadducees denied the separate existence of spirits; but, in our Savior's famous argument with them. He showed that the Old Testament clearly taught this doctrine when it represented God as saying, "I am the God of Abraham, and the God of Isaac, and the God of Jacob," adding, "He is not the God of the dead, but the God of the living." (_Mark xii_, 26.) Thereby teaching that these persons, although their bodies had been long dead, were still living. So, likewise, St. Paul speaks of being absent from the body, yet present with the Lord. St. John declares that he saw the souls of those who had been slain for their testimony of Jesus. (_Rev. vi_, 9.) In examining the scientific evidence of these scriptural views concerning a spiritual existence, it will be necessary to inquire into the origin of {203} life as exhibited in physiology. This is confessedly a difficult question, yet one of great importance, since, driven from the sciences of astronomy and geology, infidelity has sought to entrench itself in natural history as in a citadel. Yet, even here, the ground crumbles beneath its feet; and the time is not far distant when a man, having a scientific education, will be ashamed to avow himself an infidel. We have seen that astronomy and geology bear testimony to the truths revealed in the scriptures; so, likewise, does the science which treats of the functions of living beings. Napoleon is said to have remarked to Dr. Antomarchi, at St. Helena, "You physicians are unbelievers because you cannot find the soul with your dissecting knife." However applicable this might have been to physicians of that day, it would fail of application now, since, by means of the microscope, man has been able to penetrate still more deeply into the recesses of nature's mysteries. With this instrument, science has been able to detect the beginnings of living structure, and to trace the fundamental laws of the process of development.