In recent literature, Freud's relation with pioneers of psychoanalysis has been reevaluated. This paper describes the evolution of the relation between Freud and Ferenczi during their most controversial period—1925-33. The consequences of this evolution on psychoanalytic theory and practice are shown. The links between events of the protagonists' lives, their reflections about them, and the resulting theoretical elaboration (e.g. on homosexuality, female sexuality, problems of separation) are also taken into account. This work is essentially based on their recently published correspondence.