This article articulates some of the problems that surround the use of the term trauma in psychoanalytic theory and suggests that the key element for a theory of pathogenesis and mental functioning is not the either/or of external versus internal causation or trauma versus drive. Rather, it is an understanding of whether, or to what extent, the raw data of existential experience is or is not transformed into psychological experience. From this perspective, trauma is whatever outstrips and disrupts the psyche’s capacity for representation or mentalization. Absent the potential for mental representation, these events and phenomena are historical only from an external, third-person perspective. Until they are mentalized, they remain locked within an ahistorical, repetitive process as potentials for action, somatization, and projection.