J. Robert Oppenheimer was a puzzle to everyone. The nuclear physicist most responsible for the creation of the atomic bomb, he was a genius both scientifically and otherwise. His standards were impossibly high. He read widely in many languages, wrote poetry, and did superb science. Yet in Jeremy Bernstein's intensely interesting biographical memoir, Oppenheimer emerges as a man unsure of his identity and captive to an element of self-destructiveness in his makeup.