Immanuel Wallerstein, Ph.D., is Senior Research Scholar of Sociology at Yale University, former president of the International Sociological Association, and former chairman of the Gulbenkian Commission on the Restructuring of the Social Sciences. He writes in three domains of world-systems analysis: the historical development of the modern world-system, the contemporary crisis of the capitalist world-economy, and the structures of knowledge. His books include The Modern World-System (Academic Press, 1980), Utopistics, or Historical Choices for the Twenty-first Century (New Press, 1998), and Unthinking Social Science: The Limits of Nineteenth-Century Paradigms (Temple University Press, 2001). He holds his Ph.D. from Columbia University.