The abuse of children is presumed by most mental health professionals to occur at the hands of parents who were themselves harshly traumatized by abuse or neglect. A 14-month-old child is presented who was well treated by his family and developed well until 6.5 months of age, after which, due to traumatization of his mother, the child became neglected and physically abused. In a therapeutic-observational environment, as the child recovered from his massive depression, much explosive destructive behavior not seen in him before was observed. From his past studies and those of other psychoanalysts, the author presents the collectively advanced hypothesis that excessive unpleasure mobilizes hostility in humans and suggests that this hypothesis may be fruitfully applied to explain why the abused become abusers. The hypothesis may also serve to guide the treatment of abused children so as to prevent their becoming tomorrow's abusers. Furthermore, the hypothesis suggests that strategies can be proposed toward preventing child abuse.