Introducing the Notion Qi, the Philosopher Zhang Zai, and the Text Zhengmeng (Rectifying the Ignorant) -- Zhang Zai's Critique of the Buddhist -- Zhang Zai's Vertical Development of Qi and His Critique of the Buddhist -- Zhang Zai's Critique of the Ordinary Person -- Zhang Zai's Horizontal Development of Qi and His Critique of the Ordinary Person -- Zhang Zai and John Dewey on Realizing Vital Harmony -- Zhang Zai and Sŏ Kyŏngdŏk's Philosophy of Qi.