Oedipus complex is the crux of Freud's theory of personality, the unconscious sexual desire of a son for his mother and consequent jealousy and hatred of his father. Freud considered this complex to be universal and, if unresolved, to be at the seat of all other neuroses and the cause of a great deal of Guilt. Freud was fascinated by the myth of Oedipus, the tragic hero (of Sophocles, the Greek dramatist) who unwittingly killed his father and married his mother.