The rapid pace of social change during the second half of the twentieth century, which characterizes postmodernity has also affected the development of psychotherapy. Stierlin participated actively in this development over the past forty years. This book describes this crucial stage in the history of psychotherapy within the conceptual framework of cybernetics and systemic theory that revolutionized the entire contemporary scientific conception. Stresses the urgent need to reconsider the individual as something more than the mere element of a whole and to raise again the question of the subject as agent. The evolution of Western societies in which family systems obey becoming less traditional and predictable models, requires special attention to the process of individualization.