This article presents a macro theory of self-regulation: defensive and expansive self-regulation theory (DERT). It rests on two fundamental assumptions. First, it assumes the coexistence of two competing psychological systems: a defensive system motivated by the need for physical and psychological security, whose function is to protect the organism from harm to life and self, and an expansive system motivated by the needs for competence, relatedness and autonomy, whose function is the development of knowledge, skills, and social support. Second, DERT assumes a threefold distinction regarding consciousness, with psychological processes qualifying as either nonconscious, conscious or metaconscious. Based on the previous assumptions, the theory posits the coexistence of two self-regulatory modes: a defensive regulation, consisting of self-protective responses aimed at avoiding, escaping or fighting survival threats and self-threats, and an expansive regulation, consisting of non-defensive metaconsciousness of one’s psychological states and processes. Defensive regulation is assumed to be generally adaptive in the context of survival threats but not in that of self-threats. What is called for in the context of self-threats is expansive regulation, namely non-defensive metaconsciousness of the identifications, evaluations and interpretations of self, others and the world that cause the self-threats in the first place. The theory predicts that defensive and expansive regulation of self-threats cause psychological distress and well-being, and negative and positive interpersonal relationships, respectively.