AS IN MY PREVIOUS BOOKS, I KEEP MY ACKNOWLEDGMENTS brief. Several colleagues in the UCLA history department have perused a number of chapters or have responded to my queries. I would like to thank David N. Myers, Gabriel Piterberg, and J. Arch Getty in particular and the participants of the European Colloquium in general for their comments and pointed disagreements. Both Teo Ruiz, chair of the history department, and Scott Waugh, dean of social sciences, have made it possible for me to teach, write, and keep a roof over my head: I am indebted to them. Paul Breines, as usual, gave parts of this book a superb reading. Peter Dimock and Plaegian Alexander, my editors at Columbia backed me and this book from its beginnings. Michael Haskell cooly and expertly piloted the manuscript past various shoals. I also want to pay homage to Paul Piccone, longtime editor of Telos, who died as I was completing this work. In his writings and arguments, indeed, in the very texture of his life, Paul incarnated the nonconformist intellectual willing to challenge all academic pieties. I should note that it was Paul (and Telos) who brought out in 1978 the first book in English of Gustav Landauer, who figures in my study here. Paul will be missed. Finally, I owe too much to Cristina Nehring, my love as well as a brilliant wordsmith, who brought to this book not only her flawless editorial ear but her passionate spirit and fierce intelligence.