Deng Xiaoping’s criticism of the “two whatevers” and the Party-led discussion of the criteria of truth made ideological preparations for the successes of the Third Plenary Session of the Eleventh Party Central Committee. Manuscript of Deng Xiaoping’s letter to the Party Central Committee on the question of “guiding the whole Party, the military and all people in the country with accurate and complete Mao Zedong Thought” written on April 10, 1977 (above). An article by a guest commentator was published on May 11, 1978, in the Guangming Daily entitled “Practice Is the Sole Criterion of Testing Truth” (below).