This paper includes clinical material that illustrates the essential role of aggression in healthy development and illustrates how constructive aggression was stimulated and utilized in a self psychological analysis to further a patient's self-cohesiveness. A framework for understanding the restorative function of aggression, particularly in the form of self-assertiveness and for mastery and self-demarcation, is presented. The roles of depression, marijuana abuse, chronic overeating, and narcissistic rage as indicators of pathology involving aggression, and the resistance to the expression of that pathology, are developed and discussed.