Development of the internal family systems model: Honoring contributions from family systems therapies.

We describe Richard Schwartz's development of the Internal Family Systems model (IFS) from his position as a Structural/Strategic family therapist. Four decades ago, Schwartz struggled to help clients who exhibited serious risk of harm to self and others. Through a process of inquiry, he began to work with the positive intentions behind his most challenging clients' harmful thoughts and behaviors. He applied foundational ideas from family systems thinking to patterns of internal experiences. As he experimented with ways of applying these ideas, he created an approach to healing. We summarize the IFS model delineating ways a range of family systems theory and practice inform its development and contribute to its best practice. Our purposes are to inform IFS practitioners who are not trained in foundational family systems models as well as to acknowledge the significant contributions family therapy theories made in the development and best practice of the IFS model.