The misconception that self psychology does not interpret aggression is related to Kohut's initial conceptualization of narcissism and its treatment. Several related but separate issues are considered, utilizing the theory of the five motivational systems put forward by Lichtenberg et al. Is aggression best viewed as proactive, like a drive, or as reactive to threat, frustration, or injury? How is reactive aggression transformed into eruptive aggression? What is the relationship between aggression and assertion? What are the clinical implications of contextualizing aggression? Illustrations from studies of murderers and serial killers, as well as detailed discussions of analytic cases, exemplify the clinical implications of the views presented.