In a parallel line comes the effective aid by the stimulation of hope and the suppression of fear, by suggestion of a feeling of encouragement and the inhibition of the emotions of worry. This is a field where even the average physician is most easily inclined to play the amateur psychotherapist. He knows how convalescence is disturbed by psychical depression and how much more quickly health returns, if it is confidently expected; he knows how many dangerous operations are disturbed by despondency and helped by bravery; he knows what a blessed change has come into the treatment of tuberculosis since a psychical factor of social interest has set in; he knows how many ills disappear when regular occupation and interesting work are established or the strain of distasteful work removed. Even the mere suppression of the pain works backwards on the bodily disease which produces it. The pain was a starting point for disturbing reactions; with its disappearance through psychotherapeutic influence, the reactions of the irritated brain come to rest, the diseased body can carry on its struggle without interference and may win the day. Often the psychical influence may not even change the symptoms at all but may remove other troublesome effects. The sufferer from locomotor ataxia may learn to walk again through mental education without any restitution of his spinal cord. In short, there are endless ways in which psychical influence may work towards the general health and towards the victory over bodily disease; and all that may be acknowledged without the slightest concession to the metaphysical creeds of mental healers and Christian Scientists. But to make use of those means and to harness such influences, it cannot be enough to rely on the common-sense of the physician any more than we should trust the common-sense of the surgeon to use his knife without condescending to the study of anatomy. The psychological study of the anatomy of the soul shows a not less complicated system of mental tissues and mental elements.