Abstract: What kinds of radicalism, if any, turn out to be appealing? Do radicals from former eras speak to us – perhaps as cautionary tales, perhaps as models? Jeremy McCarter has written a magnificent book about five young radicals, who did their most important early work about a century ago, when the United States experienced an outpouring of left-wing thought. McCarter’s radicals were idealists, revolutionaries; they thought that society should and could be remade in fundamental ways. They were exploding with energy, humor, and wit. They loved drama, satire, and sex. Some of the largest and most intriguing lessons involve the tensions among the drama-chasing, principle-free, where-the-action-is radicalism of John Reed, who loved the Russian Revolution; the democratic radicalism of Alice Paul, who fought for women’s suffrage and objected to the subordination of women; and the technocratic radicalism of Walter Lippmann, who emphasized the role of “fake news” and the inevitability of epistemic gaps on the part of the citizenry, and who prized knowledge and expertise. Paul and Lippmann emerge as very different heroes of the period.