The conflict between knowing and not knowing, speech and silence, remembering and forgetting, is the central dialectic of psychological trauma. This conflict is manifest in the individual disturbances of memory, the amnesias and hypermnesias, of traumatized people. It is manifest also on a social level, in persisting debates over the historical reality of atrocities that have been documented beyond any reasonable doubt. Social controversy becomes particularly acute at moments in history when perpetrators face the prospect of being publicly exposed or held legally accountable for crimes long hidden or condoned. This situation obtains in many countries emerging from dictatorship, with respect to political crimes such as murder and torture. It obtains in this country with regard to the private crimes of sexual and domestic violence. This article examines a current public controversy, regarding the credibility of adult recall of childhood abuse, as a classic example of the dialectic of trauma.