When Abraham Flexner died in 1959 at age 92, a New York Times obituary declared, "no other American of his time contributed more to the welfare of his country and of humanity in general." Flexner's famous Report in 1910 and his subsequent work at the Rockefeller Foundation helped transform American medical education from crude to world leader. Later, as founding director of the Institute for Advanced Study he attracted Albert Einstein and other luminaries to Princeton. Notwithstanding these achievements, Flexner was hypercritical of others, often abrasive, and his self-assurance irritated many of his colleagues to his detriment. Moreover, hewas an intellectual elitist who, like many of his generation, either denied or ignored certain moral hazards prevalent in America during his lifetime, including eugenics theory and institutional anti-Semitism. In this critical analysis, Dr. Nevins distinguishes between Flexner the progressive reformer and the humanly-flawed man himself.