There is a cacophony of conflicting descriptions of J. Robert Oppenheimer – as friends have remembered him, as historians have analyzed him. He has been labeled both warm and cold, friendly and condescending, affable as well as hurtful. Learning Sanskrit and cultivating the air of an aesthete, as a young professor he stretched the bounds of the scientist's persona. Yet in the space of a decade, the otherworldly theorist was transformed into a political insider par excellence. His fellow scientists remembered him as a visionary and capable leader at Los Alamos, while his security hearing brought to light foolish mistakes in judgment and human relationships. As a physicist he was known as an influential teacher, and in his own research he gathered a reputation for daring ideas, even if they often contained errors.

It is sometimes said that one's greatest strengths can also be one's greatest weaknesses, and in Oppenheimer's life this manifested itself quite literally: the personableness and diverse interests which allowed him to expertly run Los Alamos were part of the same character which led to the revocation of his security clearance. It is telling that the first atomic test would be named in reference to a poem by John Donne ("Trinity") and the next series of tests would be labeled simply alphabetically according to military protocol ("Able," "Baker," "X-ray," "Yoke," and "Zebra"). It is indicative of the changing of hands of the bomb, moving from the responsibility of intellectual eclectics like Oppenheimer into the protocols of military rank and policy.

Oppenheimer thus represents as well the fundamental transformation of science during the Second World War. Before Hiroshima, theoretical physics seemed to have almost no practical application in the material world. But during the war, because of its sudden military relevance, it quickly rose to number-one wartime priority. In the postwar world, the scientists who had before been considered marginal in everyday matters took on new claims to knowledge about the highest of world affairs. But there were limits to their influence, especially when their personal associations and opinions came under the scrutiny of national security.

Oppenheimer represents many things, but it is the common humanity present in his science, his teaching, his successes, and his failures which makes him a complex and rich historical character. It is perhaps in this spirit that the story of his life ought to be read.