At the beginning of the war a soldier at the front was wounded on August, 12th, 1914. Before his wound was completely healed he secretly left the hospital and went again to the front, soon getting a second and after a few months a third wound. After repeated returns to the front he was one day blown up by a shell explosion and was unconscious for two days. After these four traumata he certainly presented the phenomena following upon shock, but no neurotic picture, being neither particularly anxious, depressed nor excited. Another man at the front during a night attack fell into a hole without injuring himself, but immediately developed neurotic trembling of a most severe kind, and presented the picture of a mental breakdown. How are such differences to be explained? The previous history of such people, and naturally, still more, a penetrating analysis, teaches us why the one in spite of the severest physical and mental influences of the war remains to all intents and purposes healthy, and why the other reacts to relatively trifling stimuli with a severe neurosis. It transpires with great regularity that the war neurotics already before the trauma were labile people—to designate it, to begin with, by a general expression—and especially so as regards their sexuality. Many of these men were unable to carry out their tasks in practical life, others that were capable of doing this, however, showed little initiative and manifested little impelling energy. In all of them sexual activity was diminished, their sexual hunger (libido) being checked through fixations; in many of them already before the campaign potency was weak or they were only potent under certain conditions. Their attitude towards the female sex was more or less disturbed through partial fixation of the sexual hunger (libido) in the developmental stage of narcissism. Their sexual and social capacity of functioning was dependent on their making certain concessions to their narcissism. In the war these men were placed under completely changed conditions and in the face of extraordinary demands. They had always to be prepared for unconditional self-sacrifice in favour of the mass. This signifies the renunciation of all narcissistic privileges. The healthy person is able to accomplish such a complete suppression of his narcissism: he loves according to the transference type, and so is capable of sacrificing his ego for the whole. In this respect those disposed to neuroses are inferior to healthy persons. It is not only demanded of these men in the field that they must tolerate dangerous situations—a purely passive performance—but there is a second demand which has been much too little considered, I allude to the aggressive acts for which the soldier must be hourly prepared, for besides the readiness to die, the readiness to kill is demanded of him.