The late Abraham Pais, author of the award winning biography of Albert Einstein, Subtle is the Lord, here offers an illuminating portrait of another of his eminent colleagues, J. Robert Oppenheimer, one of the most charismatic and enigmatic figures of modern physics. Pais introduces us to a precocious youth who sped through Harvard in three years, made signal contributions to quantum mechanics while in his twenties, and was instrumental in the growth of American physics in the decade before the Second World War, almost single-handedly bringing it to a state of prominence. He paints a revealing portrait of Oppenheimer's life in Los Alamos, where in twenty remarkable, feverish months, and under his inspired guidance, the first atomic bomb was designed and built, a success that made Oppenheimer America's most famous scientist. Pais describes Oppenheimer's long tenure as Director of the Institute of Advanced Study at Princeton, where the two men worked together closely.He shows not only Oppenheimer's brilliance and leadership, but also how his displays of intensity and arrogance won him powerful enemies, ones who would ultimately make him one of the principal victims of the Red Scare of the 1950s. J. Robert Oppenheimer is Abraham Pais's final work, completed after his death by Robert P. Crease, an acclaimed historian of science in his own right. Told with compassion and deep insight, it is the most comprehensive biography of the great physicist available. Anyone seeking an insider's portrait of this enigmatic man will find it indispensable.