Book excerpt: William Appleman Williams, who died in 1990, was arguably the most influential and controversial historian of his generation. His revisionist writings, especially in American diplomatic history, forced historians and others to abandon old clichés and confront disturbing questions about America's behavior in the world. Williams defined America's social, moral, constitutional, and economic development in uncompromising, iconoclastic, and original terms. He saw history as "a way of learning;" and applied the principle brilliantly in books and essays which have altered our vision of the American past and present. In this rich collection, Henry Berger has drawn from Williams's most important writings—including "The Tragedy of American Diplomacy," "The Contours of American History," and "The Roots of the Modern American Empire" to present his key arguments. There are twenty-one selections in all, from books, essays, and articles, including two never before published. Mr. Berger has added notes to the selections and an enlightening introduction which explores Williams's career and ideas. This is an exceptionally valuable book.