This book revisits the theory of social systems as a defense against anxiety first set out by Elliott Jaques and Isabel Menzies Lyth in papers which they published in 1955 and 1960, and which have been influential points of reference ever since. Menzies Lyth’s study of the nursing system of a general hospital, with its roots in both psychoanalysis and socio-technical systems thinking, has remained one of the most convincing demonstrations of the influence of unconscious anxieties on social behavior, and of their effects in inducing dysfunctional defensive systems in organizations. The theory of "social defenses against anxiety" remains one of the most significant contributions of the Tavistock school to the study of human relations.Contributors explore this theory as a generative paradigm, capable both of theoretical extension and of empirical application to different institutional settings. They review changes which have taken place in the theoretical and social context since these ideas were first advanced, and assess what conceptual revisions these developments require. The relevance of Menzies Lyth’s ideas to contemporary settings of health and nursing is examined, as is the value of these ideas in explaining anxieties and their concomitant social defenses in the private sector and in various fields of public education and welfare. Finally, the book discusses some educational and therapeutic practices which have evolved at the Tavistock and elsewhere to ‘contain’ unconscious anxieties and to mitigate damaging forms of defense against them.Contributors to the book include writers distinguished for their contributions to the fields of organizational consultancy, to applied socio-psychoanalytic thought, and to research and professional practice in several fields.