For Xi Jinping, the cadres and leading officials of the Communist Party of China are prone to one devastating weakness: lack of conviction. Xi attributes both hesitation in crisis and graft in prosperity to faltering faith. He often describes emotional attachment to the party’s revolutionary heritage and sincere belief in the eventual realization of communist utopia as “spiritual calcium” that fortifies the spines of party cadres in face of hardship and sacrifice. In contrast, cadres afraid to defend the Party or its historic mission suffer from "a calcium deficiency" [缺钙] and are thus stricken with “soft bone disease.” Their pusillanimous character threatens the GREAT REJUVENATION OF THE CHINESE NATION.
Xi Jinping introduced this metaphor in one of his earliest speeches as General Secretary. In his very first address to a meeting of the POLITBURO, Xi told the senior leadership of the Party that
Belief in Marxism and a faith in socialism and communism is the political soul and spiritual pillar of a Communist, enabling them to withstand all test. To put it more vividly, ideals and convictions are the spiritual calcium of Communists, and if these ideals and convictions are missing or irresolute, then there is a lack of spiritual calcium that leads to soft bone disease. This has proved true by the cases of some Party members and officials who acted improperly due to lack of ideals and confused faith.” (Xi 2014, 16).
Xi’s comments about officials who “act improperly” came soon after the fall of Bo Xilai and just before Xi began his historic anti-corruption campaign. Soft bone disease is thus Xi’s go-to explanation for the general institutional rot he inherited. To tame corruption the Party must do more than jail the corrupt: it must rekindle belief in the old revolutionary faith.
This is not the only context where the calcium metaphor shows up: it found just as commonly in official discussions of political security. Xi Jinping’s famous judgment that the Soviet Union collapsed because there “was no one man enough to stand up and resist” [但竟无一人是男儿，没什么人出来抗争] should be read in light of Xi’s many statements on soft bone disease. From this perspective the spinelessness of the CPSU was less a problem of manly toughness and more a problem of waning faith. The Soviets faltered because they no longer received the spiritual nourishment that stiffens conviction in the face of opposition and doubt. Many of Xi’s signature concepts and policies were designed to prevent the Communist Party of China from sharing their fate.
Xi Jinping. 2014. Governance of China, vol I. Beijing: Foreign Language Press.