A reciprocal and ongoing interaction about theory and clinical technique developed between Freud and Ferenczi in the years from 1908 to 1933. During the course of this ongoing dialogue, the concept of psychic trauma gradually transformed. Ferenczi continued to elaborate on this issue, and concluded with his work on the interaction of trauma and fantasy. Ferenczi initially refuted Freud's early trauma theses and finally conceptualized a metapsychological reformulation of trauma, an inverse development to Freud's formulations. Ferenczi highlighted two essential concepts in the theory and technique of trauma: the processes of identification and the splitting of the ego, while he stressed the enormous role of disavowal in the dynamics of trauma. The author hopes to demonstrate how Ferenczi's contributions added to developments of the concepts of disavowal and temporality, to the recovery of traumatic memory and the modification of the classical concept of interpretations.