剋雷格·卡爾霍恩（1952-），美國人，牛津大學社會學博士，現任倫敦政治經濟學院校長。曾擔任紐約大學社會學係主任，公共知識研究所創所所長，紐約社會科學研究委員會主席，以及世界各地多所大學的客座教授，包括南京大學和北京外國語大學。

The story of the rise of radicalism in the early nineteenth century has often been simplified into a fable about progressive social change. The diverse social movements of the era - religious, political, regional, national, antislavery, and protemperance - are presented as mere strands in a unified tapestry of labor and democratic mobilization. Taking aim at this flawed view of radicalism as simply the extreme end of a single dimension of progress, Craig Calhoun emphasizes the coexistence of different kinds of radicalism, their tensions, and their implications. "The Roots of Radicalism" reveals the importance of radicalism's links to pre-industrial culture and attachments to place and local communities, as well as the ways in which journalists who had been pushed out of "respectable" politics connected to artisans and other workers. Calhoun shows how much public recognition mattered to radical movements and how religious, cultural, and directly political - as well as economic - concerns motivated people to join up. Reflecting two decades of research into social movement theory and the history of protest, "The Roots of Radicalism" offers compelling insights into the past that can tell us much about the present, from American right-wing populism to democratic upheavals in North Africa.