This works deals to a large extent with Marxist criticism. Marxism's impact on the organization of the international labor movement its impact on world history the Russian, the Chinese and Cuban revolutions Marxism's influence on the social sciences mainly sociology, historiography and economics Marxism's indirect influence on philosophy, linguistics and anthropology this all makes it evident that Marxism deserves careful consideration in the study of literary theory. In the first chapter of Part 3, an overview of Marx's and Engels' ideas about literature are given, while contrasting their ideas with Lenin's and Trotsky's ideas. In the second chapter of Part 3, the writer draws up three Marxist theses for literary theory. He also develops three Marxist criteria to distinguish classes because 'class' and 'class struggle' are central concepts of Marxist Theory though the writer acknowledges these concepts lesser usefulness for literary theory. The faulty theories of present-day Marxist critics are covered as well. Finally, the Marxist theses for literary theory are applied in analyzing Dazai's novel The Setting Sun.