The war neurosis, like the peace neurosis, is the expression of a splitting of the personality. The conditions for such a splitting are brought about by the consistent narrowing of the personality complex as a result of the compulsory discipline and above all by the psychic and physical exhaustion of one or more years of war. The soldier severely burdened with undischarged mental material is compelled to meet abnormally heavy demands. An accident or a disastrous event then causes the obstructed personality to break down. Complexes with accentuated feelings held down in the unconscious become unduly powerful, and the neurosis becomes manifest. The passage from the psychical to the physical, however, signifies here more than a self-preserving process of the psyche. The act of falling ill is, in my opinion, at the same time the commencement of the healing process. The consistent use of analytic hypnosis has repeatedly shown that the physical symptoms in their mute expression strive to bring to the notice of the man the elements that are disturbing his personality and which are imprisoned and obstructed in his unconscious. Since the union between conscious and unconscious is interrupted within by the strong barrier of the resistance, a detour by way of external physical paths is necessary in order to re-establish the harmonious fitting together of the personality. If the predominant physical symptoms of the war neuroses are modes of expression of unconsciously determined ideas, the more psychic forms of these neuroses, the states of inhibition or excitement, are due to an effort on the part of the repressed affects to re-establish the disturbed psychic balance. A strict demarcation between aetiologically effective ideas and sensations is naturally not conceivable. The relationship can only be a quantitative one. All ideas obviously stand in a quite special relationship to the ego of the patient through their accentuation of feelings; on the other hand, the affects are bound to their causative ideas. The first part of our mental analytic therapy is to recognise the meaning of the neurotic healing tendency, the second, to convey our knowledge to the patient. The crowning point of our treatment consists in securing the spontaneous cooperation of the neurotic who, freed of his emotional inhibition, and now in harmony with himself, has, through his wider mental field of vision, a greater scope for the activity of his will power. Man can only desire what he knows. By reason of this the analyst comes to realise that the diagnosis, “mala voluntas”, which so often brings the doctor who is untrained in analysis into conflict with his patient, mostly betokens a “mala potentia” of the doctor who knows nothing about the functions of the unconscious.