This proposition seems almost self-evident, and will receive the instant assent of all who are familiar with the simplest phenomena of hypnotism. It is well known, and no one at all acquainted with hypnotic phenomena now disputes the fact, that perfect anesthesia can be produced at the will of the operator simply by suggestion. Hundreds of cases are recorded where the most severe surgical operations have been performed without pain upon patients in the hypnotic condition. The fact can be verified at any time by experiment on almost any hypnotic subject, and in case of particularly sensitive subjects the phenomena can be produced in the waking condition. How the subjective mind controls the functions and sensations of the body, mortal man may never know. It is certain that the problem cannot be solved by reference to physiology or cerebral anatomy. It is simply a scientific fact which we must accept because it is susceptible of demonstration, and not because its ultimate cause can be explained. The three foregoing fundamental propositions cover the whole domain of psycho-therapeutics, and constitute the basis of explanation of all phenomena pertaining thereto. It seems almost superfluous to adduce facts to illustrate the wonderful power which the subjective mind possesses over the functions of the body, beyond reminding the reader of the well-known facts above mentioned regarding the production of the phenomena of anesthesia by suggestion. Nevertheless, it must not be forgotten that the production of anesthesia in a healthy subject is a demonstration of subjective power which implies far more than appears upon the surface. The normal condition of the body is that of perfect health, with all the senses performing their legitimate functions. The production of anesthesia in a normal organism is, therefore, the production of an abnormal condition. On the other hand, the production of anesthesia in a diseased organism implies the restoration of the normal condition, that is, a condition of freedom from pain. In this, all the forces of nature unite to assist. And as every force in nature follows the lines of least resistance, it follows that it is much easier to cure diseases by mental processes than it is to create them; provided always that we understand the _modus operandi_.