When The Ego and the Mechanisms of Defense was first published in German in 1936 it was at once recognized as a major contribution to psychoanalytic psychology, and its translation into English quickly followed. More than half a century later it enjoys the status of a classic and a founding text in ego psychology . Written by a pioneer of child analysis, and illustrated by fascinating clinical pictures drawn from childhood and adolescence, it discusses those adaptive measures by which painful and unwanted feeling-states are kept at bay or made more bearable. The author’s arguments have a clarity and cogency reminiscent of her father’s and the work is remarkable undated. Nothing stands still, but The Ego and the Mechanisms of Defense has unmistakably passed the test of time.