Alden Pyle is the "quiet American" of the title. A CIA agent working undercover, Pyle is thoughtful, soft-spoken, intellectual, serious, and idealistic. He comes from a privileged East Coast background. His father is a renowned professor of underwater erosion whose picture has appeared on the cover of "Time" magazine; his mother is well respected in their community. Pyle is a brilliant graduate of Harvard University. He has studied theories of government and society, and is particularly devoted to a scholar named York Harding. Harding's theory is that neither Communism nor colonialism is the answer in foreign lands like Vietnam, but rather a "Third Force", usually a combination of traditions, works best. Pyle has read Harding's numerous books many times and has adopted Harding's thinking as his own. Pyle also strives to be a member of this "Third Force". US military counter-insurgency expert Edward Lansdale, who was stationed in Vietnam 1953–1957, is sometimes cited as a model for Pyle's character. In fact Greene did not meet Lansdale until after completing much of the novel. According to Greene, the inspiration for the character of Pyle was Leo Hochstetter, an American serving as public affairs director for the Economic Aid Mission in Indochina who was assumed by the French to “belong to the CIA,” and lectured him on the “long drive back to Saigon on the necessity of finding a ‘third force in Vietnam.’”