This ambitious and provocative book by a Barnard political scientist argues that social democracy "must be recognized as the most successful ideology and movement of the twentieth century" -- one that has reconciled "a well-functioning capitalist system, democracy, and social stability." The bulk of the book is a history of social democracy, and readers who need or want a clear, well-written narrative of that important movement will find it here. But overall, there is an imbalance between the pre-1945 material and the very short section on the postwar era, when the differences between the social democratic parties of the major European countries stood out more than did their similarities. A common critique of capitalism and an awareness of Marxism's flaws could never produce a unified movement; after 1945, the "triumph" of social democracy was more a matter of political coalitions and ideological dilution. Turning to the present, Berman's attempt to "save" social democracy's critique of the market from the temptations of Tony Blair's "Third Way" and the seemingly inexorable march of globalization remains vague. Nonetheless, this is a strong, useful defense of a political ideology and a political movement that have done much good and fought evil with courage and lucidity.