Any class which becomes heir to a society, inherits, at the same time, its characteristics. That is to say that if the working class crushes all other classes, for instance, it becomes heir of the society, that is, it becomes the material and social base of the society. The heir bears the traits of the one he inherits from, though they may not be evident at once. As time passes, attributes of other eliminated classes emerge in the very ranks of the working class. And the possessors of those characteristics take the attitudes and points of view appropriate to their characteristics. Thus the working class turns out to be a separate society, showing the same contradictions as the old society.

The Green Book (1975)