This book is an English translation of material presented in 1937 before the Vienna Psychoanalytic Society and then published in German in 1939 in a psychoanalytic periodical. In the year 1958 Dr. Hartmann was presented the Charles Frederick Menninger Award for the impact of this book on psychoanalytic theory and method through the intervening years. Apparently, the publication of the book today in an English translation is motivated by the desire to make available the first formal consideration of ego psychology in the psychoanalytic field and the beginnings of a new direction in psychoanalysis. However, Hartmann's publications in the subsequent twenty years, along with those of his colleagues, have amplified and advanced the field of ego psychology far beyond what is in this initial work. There is a serious defect in this book for which the editorial board of theJournal of the American Psychoanalytic Associationshould be held responsible.