Arnold Toynbee made his reputation as a scholar with A Study of History, (in 12 volumes, 1934-61), illustrating the theory that civilizations rose and fell according to challenge and response. He contributed regularly to the Manchester Guardian and the Observer, and wrote editorials for The Economist. During World War I, he worked in the Political Intelligence Department of the Foreign Office, and was a member of the British Delegation to the Paris Peace Conference in 1919. This study weaves together Toynbee's intellectual achievements and the personal difficulties of his private life, to provide both a portrait of a leading thinker and an evaluation of his work.