This book presents a critical comparison and evaluation of the assumptions underlying explanations of social order and conflict which are to be found in the work of Durkheim and Marx, and of their most important followers. Its major theme is that, although the two bodies of theory rest on fundamentally opposed ideas of social structure and social action, both have to draw on auxiliary hypotheses which are to a high degree complementary - the residual categories of the one theory proving to be those that are analytically central to the other. This is most evident when Durkheimian theory seeks to account for social disorder, and Marxist theory for its absence. This challenging argument is developed in detail, by reference to a wide range of empirical research, and points the way to new ways of thinking about how societies alternate between the poles of solidarity and schism.