William Yandell Elliott, Williams Professor of History and Political Science Emeritus, died yesterday morning at his home in Haywood, Va. after a long illness. He was 82 years old.

Elliott, a political philosophy scholar and Ph.D. dissertation adviser to diplomats and foreign policy experts including Henry A. Kissinger '50, Pierre Trudeau and Ralph Bunche, taught and conducted research at Harvard from 1925 to 1963. He continued his research and writing at his home in Virginia after his retirement.

Author and editor of more than a dozen works, including "The New British Empire" (1932) and "The Need for Constitutional Reform" (1935), Elliott vigorously examined and criticized contemporary political philosophy and governmental process.

His first book, "The Pragmatic Revolt in Politics," published in 1928, contended that government must be concerned with social purpose.

He wrote and edited large parts of ten other books, ranging in subject from international control of non-ferrous metals to the impact of television on American culture.

"He was a man of powerful intellect and terrific courage," Harvey C. Mansfield Jr. '53, professor of Government, said yesterday. Elliott supervised Mansfield's undergraduate thesis.

Elliott also played an important role in American government during the 1940s. At the beginning of World War II, he served as consultant to the U.S. defense program and after the war, Elliott directed the governmental staff which studied and reported on the economic reconstruction of Europe.

Elliott, who actively published while he taught more than the required course load at Harvard, also found time to deal with students. "I remember him as generous and warm-hearted," Mansfield said, "and inspiring to the point of being frightening."