Frances Tustin describes the life and clarifies the work of an outstanding clinician whose understanding of autistic and psychotic children has brilliantly illuminated the relationship between autism and psychosis for others in the field. Sheila Spensley defines Tustin's position in traditional and contemporary psychoanalytic theory and explains how it is related to work in infant psychiatry and developmental psychology. She makes Tustin's original concepts accessible to the non-specialist reader and shows how relevant they are to work in other areas such as learning disability and work with adult patients.