The document summarizes the evolution of systems theory and family therapy models. It describes early influences from cybernetics, systems theory, and the work of Bateson, Jackson, and Wiener. The Milan family therapy approach emphasized meaning, circular questioning, co-therapy, and end-of-session interventions to alter problematic family belief systems. Over time, the Milan school split with Cecchin and Boscolo focusing on social constructionism while Selvini Palazzoli and Prata developed strategic family therapy with an emphasis on problem-maintaining family interaction patterns.