At the Sixth International Congress of Psychotherapy in 1964, Foulkes made this statement: Psychoanalysis is a biological theory which has only very reluctantly been pushed into being a social theory by the pressure of psychotherapy. Psychoanalytic theory arose out of the attempt Freud was making, as a practising physician, to find a therapy for the psychoneuroses. His first attempt was frankly neurological and he abandoned it because it had nothing to say to the psychological problems he was faced with. His second attempt was psychobiological and gave more scope for psychological thinking. The term 'ego' in particular is a concept which is steadily enriching its content and changing in a profound way, to open up deeper levels of psychic experience where new insights and concepts are called for. To try to work on new material with nothing but the old conceptual tools retards deeper understanding.