Medard Boss and the Promise of Psychotherapy reacquaints counselors, psychotherapists and psychiatrists practicing today with the ideas of this remarkable figure in the history of twentieth-century clinical psychology who quietly but radically deviated from the mainstream of standard thinking and practice of his time. It presents an appreciation of Boss the man as essential for understanding what psychotherapy has become and envisioning its original purpose. This study revisits certain events in Boss’s life that have not been sufficiently appreciated but deeply affected the development of his psychoanalysis without the psyche: da-seinanalysis (Daseinsanalyse). The book attempts to establish a terminology for therapy that is clear and consistent with Heidegger’s thought. It provides a rich range of materials for study—texts in translations, a glossary of key terms, and a comprehensive international bibliography—that will be of use in developing an approach to therapy as Boss envisioned it. Medard Boss and the Promise of Psychotherapy concludes with some hints at just what such therapy might look like, one that is based on the author’s own practice. It reflects what can be learned from Boss, both what he said and published and, perhaps more important, what was left unsaid. The book is written for advanced students as much as for established therapists and scholars.