The process of regression is beautifully demonstrated in an illustration already used by Freud. The libido can be compared with a stream which is dammed up as soon as its course meets any impediment, whence arises an inundation. If this stream has previously, in its upper reaches, excavated other channels, then these channels will be filled up again by reason of the damming below. To a certain extent they would appear to be real river beds, filled with water as before, but at the same time, they only have a temporary existence. It is not that the stream has permanently chosen the old channels, but only for as long as the impediment endures in the main stream. The affluents do not always carry water, because they were from the first, as it were, not independent streams, but only former stages of development of the main river, or passing possibilities, to which an inundation has given the opportunity for fresh existence. This illustration can directly be transferred to the development of the application of the libido. The definite direction, the main river, is not yet found during the childish development of sexuality. The libido goes instead into all possible by-paths, and only gradually does the definite form develop. But the more the stream follows out its main channel, the more the affluents will dry up and lose their importance, leaving only traces of former activity. Similarly, the importance of the childish precursors of sexuality disappears completely as a rule, only leaving behind certain traces. If in later life an impediment arises, so that the damming of the libido reanimates the old by-paths, the condition thus excited is properly a new one, and something abnormal. The former condition of the child is normal usage of the libido, whilst the return of the libido towards the childish past is something abnormal. Therefore, in my opinion, it is an erroneous terminology to call the infantile sexual manifestations “perversions,” for it is not permissible to give normal manifestations pathological terms. This erroneous usage seems to be responsible for the confusion of the scientific public. The terms employed in neurotic psychology have been misapplied here, under the assumption that the abnormal by-paths of the libido discovered in neurotic people are the same phenomena as are to be found in children. The Infantile Amnesia Criticized