It may reasonably be doubted whether methods of persuasion alone would have cured this man. In any case, it is clear that it would have taken a very long time. It is also probable that hypnotic suggestion alone, if continued, would very quickly have removed the symptoms. It may be doubted, however, whether it would have effected a permanent cure in a person so open to auto-suggestion. It seems, therefore, that a judicious combination of methods was advisable. We are of the opinion that hypnotic treatment, when used with skill, discretion, and discrimination, has its place in the treatment of shell-shock and similar conditions, both in the acute and chronic stages. In the majority of cases of some considerable duration, however, and in practically all those in which the trouble is due to some ante-war worry or emotion, it may be regarded as provable that hypnosis _alone_ will be of relatively slight use and in many cases may be positively harmful, for under such circumstances, even with the most favourable conditions, it would result merely in the removal of symptoms; and the removal of one may be followed by the appearance of another, which may even be induced by the process of hypnosis. Moreover, in cases where there is a tendency to the development of a double personality hypnosis may have the effect of increasing the risk. Further, if the patient has sufficient of his own will-power to enable the process of re-education to be carried out, it is clearly undesirable, both on psychological and ethical grounds, for the doctor to impress his influence from without. In considering the possibility of the usefulness of hypnotic suggestion it is important to bear in mind that various factors may come into play in impressing an event upon the patient’s memory, or in determining the effect of the shock from which he is suffering when he arrives in hospital. In the first place there is the vividness or intensity of the stimulus; in the second, the degree of recency; in the third, the frequency of the stimulus; and in the fourth its relevancy. By the latter is meant the extent to which a given event appeals to the individual’s past experience, and becomes integrated into his personality.