From Strange Rebels: 1979 and the Birth of the 21st Century, by Christian Caryl (Basic Books, 2014), Kindle Loc. 2656-2682:
In May 1978, the prominent national newspaper Guangming Daily published an article with the innocuous title “Practice Is the Sole Criterion for Judging Truth.” The piece was quickly picked up by a series of other publications, including the leading army newspaper. The title sounds dull enough, but it went off like a bomb. The article, collectively authored by a team of academics working under the direction of rising party reformer Hu Yaobang, argued that Communist ideology was not the only yardstick for determining what was true. If Marxism was indeed a scientific theory, as it claimed to be, its findings ought to be tested through experiment: apply them to reality and see if they worked. Marx had said that the social and political prescriptions derived from his theory had to be subjected to constant empirical testing to make sure that they coincided with the dictates of historical materialism. And just to be sure that everyone got the point, the authors of the article undergirded their argument with a slogan from Mao himself—the one they used as the article’s title.
They were, in short, using Mao’s own words to undermine the central Maoist postulate of the Cultural Revolution, namely, the idea that the imperative of “revolution” overrode all else, including professional expertise, scientific knowledge, or economic efficiency. To many Chinese, the article’s paean to pragmatism sounded like a healthy dose of common sense after years of hysteria. Yet this was exactly what the Whateverists did not want to allow. After all, during the Cultural Revolution, Mao and his adepts had followed a rather different principle: for them it was revolutionary zeal, directed against the entrenched establishment, that had become the decisive litmus test for the correctness of policy. It was this same mind-set that had led to the persecution of countless engineers, managers, scholars, and scientists on the grounds of insufficient “class consciousness”—with devastating consequences for the Chinese economy.
Prioritizing “practice,” as the authors of the new article demanded, thus represented an implicit challenge to those who considered themselves to be the keepers of the chairman’s flame. If this new argument won the day, unwavering loyalty to Maoist slogans would no longer be the deciding factor in career advancement or political struggle. Professional skill, managerial competence, or scholarly acumen would come to the forefront. Deng, who does not appear to have been directly involved in the publication of that article, was quick to see its uses in his reckoning with Hua. Since his return to the center of party life, Deng had already been putting a different Mao quote at the center of his speeches: “Seek truth from facts.” This, of course, was a dig at Hua and his adherents, who continued to stress that truth was whatever Mao had said it was. Among the things that Deng had learned from his long years of involvement in party intrigues was the importance of defining the terms of debate. He now set out to deploy his “good,” pragmatic Mao against the “bad,” doctrinaire one of the Cultural Revolutionaries. Would the party cling to the Mao celebrated by the Gang of Four, inflexible, rigid, and dogmatic? Or would Chinese Communists reach back to the earlier version of Mao that was now held up high by Deng and his friends—a Mao who had (allegedly) celebrated the virtues of practicality and sober realism?