Perry Anderson examined the working-class movements and its theory differently according to the development and prosperity of the Western Marxism in Europe, which created another new field for this academic study. At the same time, in light with the development of the international workers' movements and its background, he updated his understanding of the working-class movements frequently and analyzed the decline of the left-wing movement realistically, which brought about the shift to renewals of his idea about modern society. That is not just a criticism against the Western Marxism, but also a positive step forward over the classic Marxism.