With this conception of Freud’s we have to return to the question of the etiology of the neuroses. We have seen that the psychoanalytic theory began with a traumatic event in childhood, which was only later on found to be a phantasy, at least in many cases. In consequence, the theory became modified, and tried to find in the development of abnormal phantasy the main etiological significance. The investigation of the unconscious, made by the collaboration of many workers, carried on over a space of ten years, provided an extensive empirical material, which demonstrated that the incest-complex was the beginning of the morbid phantasies. But it was no longer thought that the incest-complex was a special complex of neurotic people. It was demonstrated to be a constituent of a normal infantile psyche too. We cannot tell, by its mere existence, if this complex will give rise to a neurosis or not. To become pathogenic, it must give rise to a conflict; that is, the complex, which in itself is harmless, has to become dynamic, and thus give rise to a conflict. Herewith, we come to a new and important question. The whole etiological problem is altered, if the infantile “root-complex” is only a general form, which is not pathogenic in itself, and requires, as we saw in our previous exposition, to be subsequently set in action. Under these circumstances, we dig in vain among the reminiscences of earliest childhood, as they give us only the general forms of the later conflicts, but not the conflict itself. I believe the best thing I can do is to describe the further development of the theory by demonstrating the case of that young lady whose story you have heard in part in one of the former lectures. You will probably remember that the shying of the horses, by means of the anamnestic explanation, brought back the reminiscence of a comparable scene in childhood. We here discussed the trauma theory. We found that we had to look for the real pathological element in the exaggerated phantasy, which took its origin in a certain retardation of the psychic sexual development. We have now to apply our theoretical standpoint to the origin of this particular type of illness, so that we may understand how, just at that moment, this event of her childhood, which seemed to be of such potency, could come to constellation.