The paper traces the relationship between attachment processes and the development of thecapacity to envision mental states in self and others. We suggest that the ability to mentalize, torepresent behavior in terms of mental states, or to have “a theory of mind” is a keydeterminant of self-organization which is acquired in the context of the child's early socialrelationships. Evidence for an association between the quality of attachment relationship andreflective function in the parent and the child is reviewed and interpreted in the context of currentmodels of theory of mind development. A model of the development of self-organization isproposed which has at its core the caregiver's ability to communicate understanding of thechild's intentional stance. The implications of the model for pathological self-developmentare explored, with specific reference to the consequences of maltreatment.