Dreams.—In the dream, mankind, in epochs of crude primitive civilization, thought they were introduced to a second, substantial world: here we have the source of all metaphysic. Without the dream, men would never have been incited to an analysis of the world. Even the distinction between soul and body is wholly due to the primitive conception of the dream, as also the hypothesis of the embodied soul, whence the development of all superstition, and also, probably, the belief in god. "The dead still live: for they appear to the living in dreams." So reasoned mankind at one time, and through many thousands of years.