In "The Healing of the Self," Heinz Kohut further develops the psychology of the self, which he no longer presents in the language of classical drive theory as he did in his book on narcissism. To outline a psychology of the self and arrive at a definition of what leads to the healing of the pathological self, Kohut subjects a wide range of theoretical concepts to re-examination: How does the concept of drive change with the emphasis on the self, and how does drive theory relate to the psychology of the self? How is the concept of aggression as a drive affected by the introduction of a psychology of the self, and what role does aggression play within the framework of the psychology of the self? To what extent is it appropriate to speak of components of the self rather than functions of a psychic apparatus?.