The empirical research in this book covers a wide range of substantive topics: from friendship patterns and class mobility to housework and class consciousness. What unites the topics is not a preoccupation with a common object of explanation, but rather a common explanatory factor: class. This is what class analysis attempts to do – explore the relationship between class and all sorts of social phenomena. This does not mean, of course, that class will be of explanatory importance for everything. Indeed, as we will discover, in some of the analyses of this book class turns out not to be a particularly powerful factor. Class analysis is based on the conviction that class is a pervasive social cause and thus it is worth exploring its ramifications for many social phenomena, but not that it is universally the most important. This implies deepening our understanding of the limits of what class can explain as well as of the processes through which class helps to determine what it does explain.

The most elaborated and systematic theoretical framework for class analysis is found in the Marxist tradition. Whatever one might think of its scientific adequacy, classical Marxism is an ambitious and elegant theoretical project in which class analysis provides a central part of the explanation of what can be termed the epochal trajectory of human history. The aphorism “class struggle is the motor of history” captures this idea.