The present article continues previous work done by these authors in a series on "frames of reference" in psychoanalysis. The authors deal with the problems and limitations of the topographic model. A number of problems are touched on which led Freud to formulate a new theoretical construct in 1923. These include problems of the unconscious in the mental system, the location of repressive forces, the idea of an unconscious sense of guilt, internalization of objects, the problem of narcissism and "the self," anxiety, and aggression.