Personality and social psychologists already use ideas that are closely related to defense mechanisms, but few of our paradigms include extensive theoretical or empirical treatment of such mechanisms. Yet defense mechanisms focus on negative affect and protection of the self, and many of the controversies, issues, and impasses contemporary researchers confront also concern negative affect and self-protection. This article discusses whether we might find systematic consideration of defense mechanisms and defensive processing to be broadly useful across several related areas of personality and social psychology in which the relationships between self and affect are implicated. Areas considered include positive illusions and adaptation, the interpretation of reports of negative affect, and related concepts from the coping, self-regulation, affect regulation, and goals literature. Thinking about defense mechanisms would seem to have both specific value for sharpening our understanding of different possible interpretations of our data, and broad heuristic value for thinking about personality integration and social behavior.