【Abstract】 This paper doubts the view that denies three sources and three components of Marxism. It claims that Anti-Duling constitutes philosophy, political economics and socialism, which proves the fact that Marxism is made up of three parts. Otherwise, Duling can’t attack Marxism according to these three aspects. Marx’s focus in his old age is totally for the need of writing Capital, not for setting up a new discipline. Thus, there is no issue of the fourth source and the fourth component of Marxism, not to say that they debase and deny Marxist research as tripartition because it is a whole. In fact, there is no whole without parts and there is no development of the Marxism without further and respective analysis of all parts.更多还原