“[W]e have never prided ourselves on the completeness and finality of our knowledge and capacity. We are just as ready now as we were earlier…to learn new things and to alter our methods in any way that can improve them.” With these words, delivered to a psychoanalytic congress in the last months of the Great War, Sigmund Freud inaugurated a period of far-reaching revision and open-ended experimentation for his science. Over the following two decades, Freudians in central Europe would push their thought in new directions, developing revised models of the mind, innovative theories of the relationship between individual and society, and experimental therapeutic techniques while simultaneously pioneering novel applications of analytic thought and practice to social problems. ,As they fashioned these new methods and perspectives, psychoanalysts were reflecting on and responding to a series of crises that wracked interwar Europe in the aftermath of total war and the dissolution of venerable empires. Focusing on Vienna, the site, after 1920, of an ambitious experiment in municipal socialism, this project explores how psychoanalysts sought to reconstruct and renovate society by recasting their own theory and practice between the world wars. A product of a liberal bourgeois milieu, psychoanalysis found itself untethered from its prewar moorings in the mass democratic era that dawned in the aftermath of war and revolution. As they sought to adapt psychoanalysis to this new era, Freudians were not only reflecting on the crises that marked the interwar conjuncture but were rethinking selfhood and the social bond for a new era. In the midst of this widespread revision and experimentation, this project traces the emergence and consolidation of a novel form of Freudian thought and practice – ego psychology – that sought to reinforce a threatened democratic order by strengthening the individual’s psychical defenses.