This chapter discusses sociolinguistic divisions associated with differences in social prestige, wealth, and power. Class divisions are based on status and power in a society. The linguistic data illuminates the structure of society, and identifies social divisions and points of conflict and convergence. The four central problems on language and class are the definition of class, the description of language use, the explanation of language change, and the construction of linguistic theory. One of the most influential thinkers on the subject of social class is Karl Marx. In Marx's view, the basic dynamic of human history is conflict between classes. The basic difference Bernstein sees between social classes is the range of codes they command: working-class people tend to be confined to the restricted code, whereas middleclass speakers are also versatile in using an elaborated code. The problem for linguistic theory is the variation in the meaning systems of language.