To the CPC, Marxism–Leninism provides a vision of the contradictions in capitalist society and of the inevitability of a future socialist and communist societies. Marx and Engels first created the theory behind Marxist party building; Lenin developed it in practice before, during and after the Russian Revolution of 1917. Lenin's biggest achievement came in party-building, through concepts such as the vanguard party of the working class and democratic centralism. According to the "People's Daily", Mao Zedong Thought "is Marxism–Leninism applied and developed in China". Mao Zedong Thought was conceived not only by Chairman Mao Zedong, but by leading party officials. According to Xinhua, Mao Zedong Thought is "an integration of the universal truth of Marxism–Leninism with the practice of the Chinese revolution." Currently, the CPC interprets the essence of Mao Zedong Thought as "Seeking truth from facts": "we must proceed from reality and put theory into practice in everything. In other words, we must integrate the universal theory of Marxism–Leninism with China's specific conditions." While analysts generally agree that the CPC has rejected orthodox Marxism–Leninism and Mao Zedong Thought (or at least basic thoughts within orthodox thinking), the CPC itself disagrees. Some Western commentators also talk about a "crisis of ideology" within the party; they believe that the CPC has rejected communism. Wang Xuedong, the Director of the Institute of World Socialism, said in response, "We know there are those abroad who think we have a 'crisis of ideology,' but we do not agree." According to former General Secretary Jiang Zemin, the CPC "must never discard Marxism–Leninism and Mao Zedong Thought." He said that "if we did, we would lose our foundation." He further noted that Marxism in general "like any science, needs to change as time and circumstances advance." Certain groups argue that Jiang Zemin ended the CPC's formal commitment to Marxism with the introduction of the ideological theory, the Three Represents. However, party theorist Leng Rong disagrees, claiming that "President Jiang rid the Party of the ideological obstacles to different kinds of ownership [...] He did not give up Marxism or socialism. He strengthened the Party by providing a modern understanding of Marxism and socialism—which is why we talk about a 'socialist market economy' with Chinese characteristics." Marxism in its core is, according to Jiang Zemin, methodology and the goal of a future, classless society, not analyses of class and of the contradictions between different classes.