It cannot be said that the world has shown great gratitude to psycho-analytic research for the discovery of the Oedipus complex; on the contrary, the idea has excited the most violent opposition in grown-up people; and those who omitted to join in denying the existence of sentiments so universally reprehended and tabooed have later made up for this by proffering interpretations so wide of the mark as to rob the complex of its value. My own unchanged conviction is that there is nothing in it to deny or to gloss over. We ought to reconcile ourselves to facts in which the Greek myth itself saw the hand of inexorable destiny. Again, it is interesting to find that the Oedipus complex, repudiated in actual life and relegated to fiction, has there come to its own. O. Rank in a careful study of this theme has shown how this very complex has supplied dramatic poetry with an abundance of motives in countless variations, modifications and disguises, in short, subject to just the distortion familiar to us in the work of the dream-censorship. So we may look for the Oedipus complex even in those dreamers who have been fortunate enough to escape conflicts with their parents in later life; and closely connected with this we shall find what is termed the _castration complex_, the reaction to that intimidation in the field of sex or to that restraint of early infantile sexual activity which is ascribed to the father. What we have already ascertained has guided us to the study of the child’s mental life, and we may now hope to find in a similar way an explanation of the source of the other kind of prohibited wishes in dreams, i.e. the excessive sexual desires. We are impelled therefore to study the development of the sexual life of the child, and here from various sources we learn the following facts. In the first place, it is an untenable fallacy to suppose that the child has no sexual life and to assume that sexuality first makes its appearance at puberty, when the genital organs come to maturity. On the contrary he has from the very beginning a sexual life rich in content, though it differs in many points from that which later is regarded as normal. What in adult life are termed “perversions” depart from the normal in the following respects: (1) in a disregard for the barriers of species (the gulf between man and beast), (2) in the insensibility to barriers imposed by disgust, (3) in the transgression of the incest-barrier (the prohibition against seeking sexual gratification with close blood-relations), (4) in homosexuality and, (5) in the transferring of the part played by the genital organs to other organs and different areas of the body. All these barriers are not in existence from the outset, but are only gradually built up in the course of development and education. The little child is free from them: he does not perceive any immense gulf between man and beast, the arrogance with which man separates himself