The authors present a summary of sadomasochism, its centrality in all pathology and the difficulties encountered by all analysts in working with sadomasochism. An integrative model is presented with determinants and manifestations from all phases of development, including the transmission of pathology between generations. Addiction to pain and the formation of hostile omnipotent beliefs are described as components of sadomasochism that explain how resistant sadomasochism is to change and growth. The emergent idea of two systems of self-regulation is presented and its utility for technique is described. Specific focus on developmental aspects offers therapists developmental markers they can use in clinical work.