The significance of the ego in "The Ego and the Id" and its unfulfilled promise.

It is not well known that The Ego and the Id, where Freud presented his second model of the mind, and introduced a new role for the Ego, was ignored by many of the major theorists that followed. I will attempt to demonstrate the importance of this new view of the ego for clinical psychoanalysis, and what has been lost by its being ignored.