We have written this book to reach not only those who refuse to see the wonderful influence of the Mental States over the Physical Conditions, but also for our "metaphysical" friends who have become so enamored with the power of the Mind that they practically ignore the existence of the Body, indeed, in some cases, actually denying the existence of the latter. We believe that there is a sane middle-ground in "metaphysical healing," as there is in the material treatment of disease. In this case, not only does Truth lie between the two extremes, but it is composed of the blending and assimilation of the two opposing ideas and theories. But, even if the reader does not fully agree with us in our general theories and conclusions, he will find within the covers of this book a mass of _facts_ which he may use in building up a new theory of his own. And, after all, what are theories but the threads upon which are strung the beads of _facts_--if our string does not meet with your approval, break it and string the beads of fact upon a thread of your own. Theories come, and theories go--but _facts_ remain. CHAPTER I THE SUBCONSCIOUS MIND In order to understand the nature of the influence of the mind upon the body--the effect of mental states upon physical functions--we must know something of that wonderful field of mental activity which in the New Psychology is known as "The Subconscious Mind," and which by some writers has been styled the "Subjective Mind;" the "Involuntary Mind;" the "Subliminal Mind;" the "Unconscious Mind," etc., the difference in names arising because of the comparative newness of the investigation and classification. Among the various functions of the Subconscious Mind, one of the most important is that of the charge and control of the involuntary activities and functions of the human body through the agency of the sympathetic nervous system, the cells, and cell-groups. As all students of physiology know, the greater part of the activities of the body are involuntary--that is, are independent (or partly so) of the control of the conscious will. As Dr. Schofield says: "The unconscious mind, in addition to the three qualities which it shares in common with the conscious--_viz._, will, intellect and emotion--has undoubtedly another very important one--nutrition, or the general maintenance of the body." And as Hudson states: "The subjective mind has absolute control of the functions, conditions and sensations of the body." Notwithstanding the dispute which is still raging concerning _what_ the Subconscious mind _is_, the authorities all agree upon the fact that, whatever else it may be, it may be considered as that phase, aspect, part, or field of the mind which has charge and control of the greater part of the physical functioning of the body.