This is the first of two companion papers describing concepts and techniques of a mentalization-based approach to understanding and managing family violence. We review evidence that attachment difficulties, sudden high levels of arousal, and poor affect control contribute to a loss of mentalizing capacity, which, in turn, undermines social learning and can favor the transgenerational transmission of violent interaction patterns. It is suggested that physically violent acts are only possible if mentalizing is temporarily inhibited or decoupled. However, being mentalized in the context of attachment relationships in the family generates epistemic trust within the family unit and reduces the likelihood of family violence. The implications of this framework for therapeutic work with families are discussed.