This clinically focused book explores W. R. Bion’s thinking on primitive and unrepresented mental states and shows how therapists can work effectively with traumatized patients who are difficult to reach. The author illuminates how trauma survivors suffer from direct access to primal undifferentiated positions of the psyche that lie outside the symbolic order of the mind and are resistant to treatment. This access, unmediated by symbolic representation but represented in the body, disrupts the normal trajectory of development and of relationship. Integrating theory and clinical application, the book addresses processes of symbolization, somatic receptivity, and the use of countertransference when working therapeutically with undeveloped areas of the mind. It also demonstrates how primitive body relations and object relations include the body of the analyst as part of the analytic frame and are essential in establishing a therapeutic alliance. Illustrated with detailed clinical vignettes, Bion and Primitive Mental States is important reading for psychoanalysts, psychologists, social workers, and educators who wish to understand primitive states of mind and body in patients who have previously been considered untreatable.