Revision with unchanged content. This book in the history of psychoanalysis investigates C. G. Jung's psychotherapeutic technique of active imagination, a state of consciousness in which images from the unconscious are brought to the surface and expressed in a number of forms - painting, writing, sculpting - to help the individual work through and give form to psychological energy released during the process of individuation. As a case study, this research highlights the life work of Tina Keller, a physician who was intimately involved with the technique of active imagination while in analysis with Jung (1915-1924) and his primary associate, Toni Wolff (1924-1928). All research materials are investigated through an examination of primary documents, both published and unpublished, in English and German. The book includes chapters on a contemporary approach to historiography in psychology, a review of Jung's statements on active imagination, psychotherapeutics at the turn of the 20th century, and finally, on Tina Keller's analyses with Jung and Wolff. Anyone interested in a historical approach to Jung studies will find this book interesting and illuminating.