The new period and the new tasks called for the emergence of a new leader. Since Deng had made valuable contributions during the long revolutionary years, had waged a resolute struggle against the Gang of Four and had already achieved notable success in his efforts to restore order, he had earned enormous prestige in the Party and among the people. With the strong backing of Ye Jianying and other veterans and in accordance with the People's wishes, in July 1977, at the Third Plenary Session of the Tenth Central Committee, Deng was reinstated as Vice-Chairman of the Central Committee, Vice-Premier of the State Council, Vice-Chairman of the Military Commission and Chief of the General Staff of the People's Liberation Army. In march 1978 he was elected Chairman of the Fifth national Committee of the Chinese People's Political Consultative Conference.
The ten years of turmoil had made more and more people realize that it was high time to repudiate "Left" thinking and to set things to rights. Deng lived up to the people's expectations and displayed his far-sightedness as a strategist. Faced with a multitude of problems in every area, he soon came to understand that the key to them all was correct ideology. He explicitly understood as an integral whole. he emphasized that its essence was seeking truth from facts, and accordingly he strongly opposed the "two whatevers" (the view that whatever policy decisions Chairman Mao had made and whatever instructions he had given must be followed unswervingly). He encouraged discussion on the criterion of truth, with the result that the rigid bonds that had constricted people's thinking for so long were broken. People both inside and outside the Party began to seriously examine the current situation and to tackle the problems they discovered. This great movement to emancipate people's minds led to the convocation of the Third Plenary Session of the Party's Eleventh Central Committee.
This Session, convened in December 1978, marked a fundamental turning point in the history of the Chinese Communist Party. At a working conference of the Central Committee held before the Session, Deng delivered a speech which turned out to be the keynote of the Third Plenary. In this speech he explained in detail that people should emancipate their minds and seek truth from facts. Just as the Chinese people had followed this principle in the past in making revolution, so now, he said, they must rely on it in construction. In accordance with this principle, the Plenary Session discarded the notion that in a socialist society class struggle remained the "key link" and made the strategic decision to shift the focus of the Party's work to socialist modernization, so as to concentrate on development of the productive forces. Deng stressed that the Chinese people should be dedicated and steadfast in pursuit of socialist modernization and not let themselves be hindered by interference from any quarter. This was a fundamental rectification of the political line, and it ushered in a new era of reform and opening to the outside world. In March 1979 Deng made it clear that to maintain the correct orientation in the modernization drive it was essential to adhere to the Four Cardinal Principles: keeping to the socialist road and upholding the dictatorship of the proletariat (the people's democratic dictatorship), leadership by the Communist Party and Marxism-Leninism and Mao Zedong Thought.