At a time when the Manhattan Project was synonymous with large-scale science, physicist J. Robert Oppenheimer (1904–67) represented the new sociocultural power of the American intellectual. Catapulted to fame as director of the Los Alamos atomic weapons laboratory, Oppenheimer occupied a key position in the compact between science and the state that developed out of World War II. By tracing the making (and unmaking) of Oppenheimer´s wartime and postwar scientific identity, Charles Thorpe illustrates the struggles over the role of the scientist in relation to nuclear weapons, the state, and culture. A stylish intellectual biography, Oppenheimer maps out changes in the roles of scientists and intellectuals in twentieth-century America, ultimately revealing transformations in Oppenheimer´s persona that coincided with changing attitudes toward science in society.