Pioneer psychoanalyst Sigmund Freud was fascinated by the story of King Oedipus, as Sophocles depicted him within Oedipus the King, as a work of literature. Clearly, however, Freud also recognized how Sophocles's story, at least in a literal sense if not a figurative or psychological one, paralleled his particular new theory of early childhood development, that at the four-year-old stage, a child "falls in love" with the opposite sex parent and wishes, then, to kill the same-sex parent in order to destroy a rival. Freud made the name "Oedipus" far better known than it would otherwise have been.
Without Sophocles's play, of course, there would be no term like "Oedipus Complex," to describe today's best-known (theoretical) stage of early childhood development. However, Freud's theory is also very far from the story of Oedipus and his unfortunate fate, as told by Sophocles. Therefore, to think of King Oedipus only in terms of the Oedipus Complex of Freudian fame, is to seriously distort what we know of Oedipus through Sophocles' play. Be that as it may, however, the name "Oedipus" today is recognized much more as part of the term "Oedipus Complex" than as a tragedy by Sophocles.
Toward that result, Freud took considerable (psychological) license with the original Oedipus story when he wrote, in 1940 (An outline of psychoanalysis. Standard ed., 23, qtd. In Hartocollis, June 2005):
The ignorance of Oedipus is a legitimate representation of the unconscious state into which, for adults, the whole [early childhood development experience] has fallen; and the coercive power of the oracle [i.e., fate, in today's terms]... A recognition of the inevitability of the fate which has condemned every son to live through the Oedipus complex. (pp. 191-192) An outline of psychoanalysis. Standard ed., 23, qtd. In Hartocollis, June 2005)
Further, as Freud (1900) states:
In my experience the chief part in the mental lives of all children who later become psychoneurotics [sic] is played by their parents. Being in love with the one parent and hating the other are among the essential constituents of the stock of psychical impulses which is formed at that time and which is of such importance in determining the symptoms of the later neurosis.... This discovery is confirmed by legend that has come down to us from classical antiquity: a legend whose profound and universal power to move can be understood if the hypothesis I have put forward in regard to the psychology of children has an equally universal validity. (The Interpretation of Dreams. (Standard ed., 4, pp. 260-261, qtd. In Hartocollis, June 2005)
Freud further states, within The Ego and the Id. Standard ed., 19 (qtd. In Hartocollis, June 2005), in terms of the 'Oedipus Complex':
The boy's identification with his father... takes on a hostile coloring and changes into a wish to get rid of his father in order to take his place with his mother. Henceforth... An ambivalent attitude to his father and an object- relation of a solely affectionate kind to his mother make up the content of the simple positive Oedipus complex in a boy. (p. 32)
It is perhaps because Freud's 'Oedipus Complex' is a concept so relatively easy to understand, while Sophocles's play is relatively difficult to understand, that the 'Oedipus Complex', rather than the ancient play by Sophocles, continues to so capture our imagination today. The play Oedipus Rex, on the other hand, while still occasionally performed, is most frequently read nowadays in college or university literature or drama classes. A clue to the key reason for that may well lie within Freud's own misleading term. The 'Oedipus Complex' of Freud is straightforwardly universal while Sophocles's great tragedy is universally complex.
Aristotle, Poetics. Aristotle, Poetics. Retrieved August 8, 2005, at http://www.perseus.tufts.edu/cgi-bin/ptext?doc=PerseusAabo%3Atlg%2C0086%2C03.html>.
Hartocollis, Peter. "Origins and Evolution of the Oedipus Complex as Conceptualized by Freud." Psychoanalytic Review, Vol. 92, No. 3 (June 2005). 315-334.
Oedipus the King by Sophocles." Oedipus the King. Retrieved August 6, 2005, from: http://classics.uc.edu/~johnson/tragedy/Oedipus_king.html.
Sophocles. Oedipus the King. The Bedford Introduction to World Literature.