In December 1957, Professor William L. Langer (1896-1977), America's most distinguished historian of Europe, delivered his famous Presidential Address to the American Historical Association, advocating the use of psychoanalysis in history. The historian's "Next Assignment," said Langer, is "the urgently needed deepening of our historical understanding through exploitation of the concepts and findings of modern psychology," by which he explicitly meant psychoanalysis and "dynamic" or "depth" psychology. The question I wish to pose is: why, of all people, was this conservative scholar of diplomatic history, "the most established branch of the historian's craft," the one to champion a radical new method of historical research to his peers? The social climate and politics of the historical community in general in the late 1950's were not hospitable to behavioral science innovations. Robert Wohl recalls the reactions to Langer's "Next Assignment": "I can remember very well the snide remarks about the address that were being made in the Princeton History Department in the first few months of 1958; many of my professors regarded Langer as a strange man lacking in common sense." 1 Where did "the next assignment" come from in Langer's life?