Craig Calhoun is Director of the London School of Economics and Global Distinguished Professor of Sociology at New York University. His most recent book is The Roots of Radicalism: Tradition, the Public Sphere, and Early Nineteenth-Century Social Movements.

Georgi Derluguian is Associate Professor of International Studies and Sociology at Northwestern University and is the author of Bourdieu's Secret Admirer in the Caucasus: A World-System Biography.