Marxism has been for a long time the reference of the European Worker's Movement. It took the form of a millenarist faith and was embodied in large organizations. Orthodox marxism had no more reason for existence when the working class was integrated in the modern society. Communism gave a new inspiration but at the expense of an intellectual degeneration. When it became a state religion, marxism stopped to be creative and became a Gnosis. The varied forms of leftisms which emerged in the sixties are the last avatar of marxism in the developped countries. But they have only a remote relationship with Marx's doctrine. The same process took place in the Third World where the marxist-leninist vulgate was absorbed by nationalism.