4. Where we encounter an acute hysteria during the most acute production of hysterical symptoms, and the consecutive overwhelming of the ego by the morbid products (hysterical psychosis), even the cathartic method will change little the expression and course of the disease. One finds himself in the same position to the neurosis as the doctor to an acute infectious disease. For some time past, now beyond the reach of influence, the etiological moments exerted a sufficient amount of effect, which becomes manifest after overcoming the interval of incubation. The affection can not be warded off, it has to run its course, but meanwhile one must bring about the most favorable conditions for the patient. If during such an acute period one can remove the morbid products, the newly formed hysterical symptoms, it may be expected that their places will be taken by new ones. The physician will not be spared the depressing impression of fruitless effort, the enormous expenditure of exertion, and the disappointment of the relatives, to whom the idea of the necessary duration of time of an acute neurosis is hardly as familiar as in the analogous case of an acute infectious disease; these, and many other things, will probably make most impossible the consequent application of the cathartic method in the assumed case. Nevertheless, it still remains to be considered whether, even in an acute hysteria, the frequent removal of the morbid products does not exercise a curative influence by supporting the normal ego which is occupied with the defense, and thus preventing it from merging into a psychosis or into ultimate confusion. That the cathartic method can accomplish something, even in an acute hysteria, and that it can even reduce the new productions of the morbid symptoms quite practically and noticeably, is undoubtedly evident from the case of Anna O., in which Breuer first learned to exercise this process.[30]