in an address to students, that “of all scientific pursuits which practically concern the community, there is none perhaps which rests upon so uncertain and insecure a basis as medicine,” gives us a certain right to offset the hypotheses of ancient scientists against those of the modern ones. No man, however gross and material he may be, can avoid leading a double existence; one in the visible universe, the other in the invisible. The life-principle which animates his physical frame is chiefly in the astral body; and while the more animal portions of him rest, the more spiritual ones know neither limits nor obstacles. We are perfectly aware that many learned, as well as the unlearned, will object to such a novel theory of the distribution of the life-principle. They would prefer remaining in blissful ignorance and go on confessing that no one knows or can pretend to tell whence and whither this mysterious agent appears and disappears, than to give one moment’s attention to what they consider old and exploded theories. Some might object on the ground taken by theology, that dumb brutes have no immortal souls, and hence, can have no astral spirits; for _theologians as well as laymen labor under the erroneous impression that soul and spirit are one and the same thing_. But if we study {181} Plato and other philosophers of old, we may readily perceive that while the “_irrational_ soul,” by which Plato meant our astral body, or the more ethereal representation of ourselves, can have at best only a more or less prolonged continuity of existence beyond the grave; the divine spirit—wrongly termed _soul_, by the Church—is immortal by its very essence. (Any Hebrew scholar will readily appreciate the distinction who comprehends the difference between the two words רוח _ruah_ and נפש _nephesh_.) If the life-principle is something apart from the astral spirit and in no way connected with it, why is it that the intensity of the clairvoyant powers depends so much on the bodily prostration of the subject? The deeper the trance, the less signs of life the body shows, the clearer become the spiritual perceptions, and the more powerful are the soul’s visions. The soul, disburdened of the bodily senses, shows activity of power in a far greater degree of intensity than it can in a strong, healthy body. Brierre de Boismont gives repeated instances of this fact. The organs of sight, smell, taste, touch, and hearing are proved to become far acuter in a mesmerized subject deprived of the possibility of exercising them bodily, than while he uses them in his normal state.