The struggle of man against fate is essentially a struggle within man himself, between his conscious mind and his unconscious drives. The voices of several of the actors in Sophocles's drama are the voices of Oedipus's unconscious. The riddle of the Sphinx is thus interpreted: 'four' refers to the primal scene (four parental legs), the result of which is 'two', the legs of the child, who later develops a 'third' leg, the penis. The Sphinx personifies the mother in her aspect of Medusa; the child splits her into mother and whore. Various other aspects of the tragedy are interpreted in dynamic terms.