In social and political theories of class inequality and stratification, property and power perform a key role. However, theorists have yet to clearly define these concepts, their mutual boundaries and scopes of application. Moreover, a 'primacy puzzle' remains unsolved: is power ultimately dependent on property, or property upon power? Which is primary, which derivative? Dick Pels seeks answers to the property/power puzzle by undertaking a broad historical inquiry into its intellectual origins and present-day effects. He re-examines the increasingly misleading terms of the debate between property and power by placing the traditional controversy within the framework of intellectual rivalry. He traces the intricate pattern of rivalry between the two master concepts through a series of case studies, including: * Marxism vs. anarchism * the fascist assertion of the primacy of the political * social science as power theory * the managerial revolution * the knowledge society and the new intellectual classes Having examined knowledge as property-and-power, Pels elaborates a radical and reflexive theory of intellectual rivalry This book unravels the dialectics of social-scient dichotomies and provides a novel and informative way of organizing twentieth century social theory. The work makes a valuable contribution to sociological theory and to the history of thought.