In this final volume of Robert Denoon Cumming’s four-volume history of the phenomenological movement, Cumming examines the bearing of Heidegger’s philosophy on his original commitment to Nazism and on his later inability to face up to the implication of that allegiance. Cumming continues his focus, as in previous volumes, on Heidegger’s connection with other philosophers. Here, Cumming looks first at Heidegger’s relation to Karl Jaspers, an old friend on whom Heidegger turned his back when Hitler consolidated power, and who discredited Heidegger in the denazification that followed World War II. The issues at stake are not merely personal, Cumming argues, but regard the philosophical relevance of the personal. After the war Heidegger disavowed Sartre, a move related to Heidegger’s renunciation of his association with the phenomenological movement at large, and one that illustrates the dynamics of the history Cumming himself has completed. Serving as convincing punctuation for this remarkable series, this book demonstrates the importance of the history of philosophy in coming to grips with the proclaimed end of philosophy.