Hartmann's monograph was one of four works which produced a major revision of psychoanalytic theory. Following a brief summary of the monograph, this essay assesses its impact on contemporary psychoanalytic thinking. It considers some confusions about and revisions of Hartmann's ideas and explores terrain first broached in this work which has become very influential but which has not yet been fully exploited. Lastly, this essay will consider Hartmann's hope that psychoanalysis would become a general psychology.