This is, so far as I can see, the essence of Freud's theory. But this conception neglects the following important question: What is the cause of this fixation of the libido to the old infantile phantasies and habits? We have to remember that almost all persons have at some time had infantile phantasies and habits exactly corresponding to those of a neurotic, but they do not become fixed to them; consequently, they do not become neurotic later on. The ætiological secret of the neurosis, therefore, does not consist in the mere _existence_ of infantile phantasies, but lies in the so-called _fixation_. The manifold statements of the existence of infantile sexual phantasies in neurotic cases are worthless, in so far as they attribute an ætiological value to them, for the same phantasies can be found in normal individuals as well, a fact which I have often proved. It is only the fixation which seems to be characteristic. It is important to demand the nature of the proofs of the real existence of this infantile fixation. Freud, an absolutely sincere and thorough empiricist, would never have evolved this hypothesis had he not had sufficient grounds for it. The grounds are found in the results of the psychoanalytic investigations of the unconscious. Psychoanalysis discloses the unconscious existence of manifold phantasies, which have their end root in the infantile past and turn around the so-called "_Kern-complex_," or nucleus-complex, which may be designated in male individuals as the Œdipus-complex and in females as the Electra-complex. These terms convey their own meaning exactly. The whole tragic fate of Œdipus and Electra took place within the narrow confines of the family, just as the child's fate lies wholly within the family boundaries. Hence the Œdipus conflict is very characteristic of an infantile conflict, so also is the Electra conflict. The existence of these conflicts in infancy is largely proven by means of psychoanalytic experience. It is in the realm of this complex that the fixation is supposed to have taken place. Through the highly potent and effective existence of the nucleus-complex in the unconscious of neurotics, Freud was led to the hypothesis, that the neurotic has a peculiar fixation or attachment to it. Not the mere existence of this complex--for everybody has it in the unconscious--but the very strong attachment to it is what is typical of the neurotic. He is far more influenced by this complex than the normal person; many examples in confirmation of this statement will be found in every one of the recent psychoanalytic histories of neurotic cases.