Most fortunately, two fundamental instincts--self-preservation and the propagation of the species--act powerfully to prevent this last fatal result, and instead the harassed individual seeks from others the aid which is lacking within himself. He may turn to the priest who seeks and often secures the final common path for faith in an over-ruling Providence, a faith which in many incontrovertible instances has proved sufficient in very truth to move mountains of lesser stimuli; or he turns to a physician, who too often treats the final outcome of the hyperactivity only. The physician who accepts the theory of the kinetic diseases, however, will not only repair as far as he may the lesions caused by the disordered and forced activities, but will, by compelling and forceful suggestion, secure the final common path for right conduct, that is, for a self- and species-preservative course of action as opposed to wrong conduct-a self- and species-destructive course of action. By forcefully imparting to his patient the knowledge of the far-reaching effects of protracted emotional strain, of overwork, and of worry, the physician will automatically raise his threshold to the damaging activating stimuli which have produced the evil results. Even though some parts of his organism may have been permanently disabled, a patient thus protected may yet rise to a plane of poise and efficiency far above that of his uncontrolled fellows. In extreme cases it does not seem unreasonable to believe that the uncontrolled patient might be rescued by the same principle which has proved effective in saving patients from the emotional and traumatic strain of surgical operations--the principle of anoci-association. That is, by disconnecting one or more of the activating organs from the brain, the motor mechanism might be saved from its self-destruction. Under this hypothesis, that man in disease, as in health, is the product of his phylogeny as well as of ontogeny, the sphere of the physician's activities takes on new aspects of far-reaching and inspiring significance. Prognosis will become definite in proportion to the physician's knowledge not only of the ontogenetic history of the individual patient, but also of the phylogenetic history of the race. As that knowledge increases, as he appreciates more and more keenly the significance of environment in its effect upon individual development, in so far will the physician be in a position to contribute mightily to the welfare of the race. THE KINETIC SYSTEM[*] [*] Address delivered before the New York State Medical Society, April 28, 1914, to which has been added a further note regarding studies of hydrogen ion concentration in the blood. In this paper I formulate a theory which I hope will harmonize a large number of clinical and experimental data, supply an interpretation of certain diseases, and show by what means many diverse causes produce the same end effects.