The Ego and the Id, the work that introduced the structural model of id, ego and super-ego, gives Freud's most complete description of the complex. In the simplified case of a boy, an early object cathexis of the mother, which begins at the breast, exists side by side with an identification with the father. As the boy's sexual wishes toward the mother grow stronger and the father comes to be felt as an obstacle, the identification with him takes on a hostile tone. This ambivalence toward the father, together with a purely tender object striving toward the mother, makes up what Freud called the simple, positive Oedipus complex.
Freud treated this as a simplification. Because of the child's original bisexuality, he wrote, the more complete complex is twofold, "ein positiver und negativer". The boy also has a tender, feminine attitude toward his father and a corresponding jealous hostility toward his mother. Real cases form a series running from the normal positive form to the reversed negative one. When the complex dissolves, its four strivings combine into an identification with the father and one with the mother.
In The Dissolution of the Oedipus Complex5 (1924) Freud tied the complex to the phallic genital organisation of childhood (see phallic phase) and asked why it ends. He gave two answers and treated them as compatible. Seen ontogenetically, the complex founders on its own failure, the result of its inner impossibility. Seen phylogenetically, it passes because its time has come, as milk teeth fall out.
In the boy, Freud held, the decisive agent is the threat of castration. At first the boy does not believe it. Later the sight of the female genitals makes it credible, and the threat then takes effect retroactively ("nachträglich"). Both kinds of Oedipal satisfaction would cost him his penis: the masculine one as punishment, the feminine one as its precondition. His narcissistic interest in the organ wins out, and his ego turns away from the complex.
What follows is the formation of a new agency. The object cathexes are given up and replaced by identifications. The paternal or parental authority introjected into the ego forms the core of the super-ego, which borrows the father's severity and perpetuates his prohibition of incest. The libidinal strivings are partly desexualised and sublimated (see sublimation), partly inhibited in their aim and turned into tenderness, and the latency period begins.
Freud insisted that in the ideal case this is more than a repression: it amounts to "einer Zerstörung und Aufhebung des Komplexes", a destruction and abolition of the complex. Where the complex is merely repressed, it persists unconscious in the id and later exerts a pathogenic effect.
The Ego and the Id states the same outcome in structural terms. The father and mother identifications leave a precipitate in the ego, which stands over against the rest of the ego as ego ideal or super-ego. This agency has what Freud called a double face. It says both "So (wie der Vater) sollst du sein" ("you ought to be like your father") and "So (wie der Vater) darfst du nicht sein" ("you may not be like your father"), since some things remain the father's prerogative. Freud described it as a reaction formation that owes its existence to the repression of the Oedipus complex, and he called it the heir of the complex.
The girl's development gave Freud more difficulty. In the 1924 paper he asked whether she too passes through a phallic organisation and a castration complex. His answer was yes, "aber es kann nicht dasselbe sein wie beim Knaben" (but it cannot be the same as in the boy). Her hope of one day having a penis can branch off into a masculinity complex. Her Oedipus complex is far more unequivocal than the boy's and culminates in the long-held wish to receive a child from her father as a gift. Because that wish is never fulfilled, she gives it up only slowly, and what closes her complex owes more to upbringing and outside intimidation than to the castration threat. The castration complex, which ends the boy's Oedipus complex, thus prepares the girl's. Freud called his insight into these processes "unbefriedigend, lücken- und schattenhaft" (unsatisfactory, incomplete and vague).