The writer of the present treatise is quite well aware that the great majority of intelligent and educated people at the present day will deny that any real knowledge of the human soul as a spiritual entity, separable from the physical body during life and demonstrably surviving its death, exists now, has heretofore existed, or, if possible for man, is likely to exist for some time to come. Some will unhesitatingly declare such a thing _unknowable_ for man. I hold the firm _conviction_ that this knowledge has been for ages the possession of certain individuals, few in number in any age or country, and that this knowledge has resulted through conformity to certain definite and specific requirements, formulated under well-known laws of man's spiritual being, involving a definite individual experience and resulting in a scientific and exact demonstration. I ask the reader to note two points in the foregoing statement: First, that for myself I use the word "conviction," and not "knowledge"; and, second, that the demonstration of real knowledge referred to, is made by, and confined to an individual, in each instance. With these individuals the knowledge is a _scientific demonstration through personal experience_. With me, the "firm conviction" is a matter of "circumstantial evidence," supported by analogy, and fortified by empirical testimony, such as acquaint the world with the facts and findings of science, and which I think admit of no other consistent and rational interpretation. In the foregoing pages I have endeavored to give outlines, analogies, and suggestions which seem to fortify the conviction referred to. While these are fragmentary and desultory, owing to the fact that the circumstances are so varied, the subject so vast, and the materials so abundant, yet, taken as a whole, they seem overwhelming, and, except to the careful, persistent, and intelligent student, confusing. It must be clearly apprehended that no one familiar with the subject can reasonably suppose, nor has it ever been claimed by a real Master of the "Art," that this knowledge ever has been, or can be, communicated to, or acquired by groups of individuals at any time, or under any circumstances. Through all the past, and at the present time, it is designated as an _individual experience_. True, the ethics, and the philosophy, and even the principles of exact psychic science that in the past constituted the "Lesser Mysteries," can be, and often have been, taught to groups, or classes. In the present "School of Natural Science," this preparatory training constitutes the "Ethical Section."