Mr Runciman studies the relation of sociology to political philosophy, clarifies an number of disputed and often unclear topics in the social sciences, and extends traditional political philosophy in the direction of developments which, in 1969 at the time of this book's publication, were recent. After defining his terms and considering the scope and limits of the social sciences as a whole, he examines the sociological writings of Marx, Max Weber and other sociologists, and then goes on to discuss such contemporary sociological problems as the study of voting behaviour, alternative theories and models of society, and the changing of class structure in industrialized societies. In a final essay he considers whether there is a point at which conflict between rival political philosophies is necessarily unresolvable. For this second edition Mr Runciman has made extensive corrections in the text to take account of further work.