This state is called the state of _introversion_, the libido is used for the psychical inner world instead of being applied to the external world. A regular attendant symptom of this retardation in the emotional development is the so-called parent-complex. If the libido is not used entirely for the adaptation to reality, it is always more or less introverted. The material content of the psychic world is composed of reminiscences, giving it a vividness of activity which in reality long since ceased to pertain thereto. The consequence is, that these patients still live more or less in a world which in truth belongs to the past. They fight with difficulties which once played a part in their life, but which ought to have been obliterated long ago. They still grieve over matters, or rather they are still concerned with matters, which should have long ago lost their importance for them. They divert themselves, or distress themselves, with images which were once normally of importance for them but are of no significance at their later age. The Complex of the Parents Amongst those influences most important during childhood, the personalities of the parents play the most potent part. Even if the parents have long been dead, and might and should have lost all real importance, since the life-conditions of the patients are perhaps totally changed, yet these parents are still somehow present and as important as if they were still alive. Love and admiration, resistance, repugnance, hate and revolt, still cling to their figures, transfigured by affection and very often bearing little resemblance to the past reality. It was this fact which forced me to talk no longer of father and mother directly, but to employ instead the term “image” (imago) of mother or of father for these phantasies no longer deal with the real father and the real mother, but with the subjective, and very often completely altered creations of the imagination which prolong an existence only in the patient’s mind. The complex of the parents’ images, that is to say, the sum of ideas connected with the parents, provides an important field of employment for the introverted libido. I must mention in passing that the complex has in itself but a shadowy existence in so far as it is not invested with libido. Following the usage that we arrived at in the “Diagnostische Associationsstudien,” the word “complex” is used for a system of ideas already invested with, and actuated by, libido. This system exists as a mere possibility, ready for application, if not invested with libido either temporarily or permanently. _The “Nucleus”-Complex._—At the time when the psychoanalytic theory was still under the dominance of the trauma conception and, in conformity with that view, inclined to look for the causa efficiens of the neurosis in the past, the parent-complex seemed to us to be the so-called root-complex—to employ Freud’s term—or nucleus-complex (“Kerncomplex”).