This volume spans a turbulent period, beginning with the unification of the psychoanalytic branch societies under the umbrella of the International Psychoanalytic Association. In 1923 the controversy over Otto Rank's The Trauma of Birth erupted. Ferenczi had worked closely with Rank, and the exchange of letters in which Freud and Ferenczi come to grips with their understanding of Rank is emotionally intense.

In 1926 Ferenczi gave a series of lectures on psychoanalysis in New York and became embroiled in a bitter controversy with American analysts over the practice of lay analysis, which eventually threatened to disrupt the unity of the International Association. Like Freud, Ferenczi supported lay analysis, but on his return from America his relationship with Freud deteriorated as Freud became increasingly critical of his theoretical and clinical innovations. Their troubled friendship was complicated still further by ill health -- Freud's cancer of the jaw and the pernicious anemia that finally killed Ferenczi in 1933.

The controversies between Freud and Ferenczi continue to this day, as psychoanalysts reassess Ferenczi's innovations and increasingly challenge the allegations of mental illness leveled against him after his death by Freud and Ernest Jones. The correspondence, now published in its entirety, will deepen understanding of these issues and of the history of psychoanalysis as a whole.