Abstract According to the domestic and international situation as related above, Mao Zedong sensed an impending danger of capitalist restoration. It seemed to him that various struggles waged before in villages, factories, schools, and cultural circles, and the socialist education movement (the four cleanups movement) in the wake of the struggle against Right opportunism, still could not solve the problem. Only through a more open and comprehensive mass movement launched from the bottom up to expose the negative side in every aspect within and outside the Party could the question be settled thoroughly, the ideology be radically reformed, and the power usurped by the capitalist-roaders seized back. He gradually focused his attention on the inside of the Party Central Committee, holding that the policies and line pursued by Liu Shaoqi and Deng Xiaoping ran counter to the "three red flags" and stood for revisionism, which represented the struggle between the two classes and the two roads. The socialist society for which he had been unremittingly fighting was to take class struggle as the key link, criticize and restrict "bourgeois rights, " which, featuring "large-scale, public ownership, and purity, " would combine industry, agriculture, culture and education, and military affairs, restrict the development of the commodity economy, and be quite egalitarian in distribution. The "socialist revolution" launched to reach this goal was to him the continuation of the struggle against the Guomindang reactionaries and a great political revolution in which one class would overthrow another. Only by constantly initiating the struggle between the two classes, two lines, and two roads was it possible to build and consolidate the kind of socialism he envisaged. Therefore he said that in the later stage of the Cultural Revolution, such a revolution would have to be waged time and again in the future. So-called theoreticians like Kang Sheng and Chen Boda extolled the erroneous "Left" thesis and practice as a creative development of Marxism and as the "third milestone" of Marxism after Lenin; Lin Biao, on the other hand, praised it as "the pinnacle of Marxism."