 The philosophers often treated as founding figures of Neo-Confucianism are a group that lived in a period that came to be called the Northern Song (960–1127). This includes Zhou Dunyi (1017–1073), who produced a diagram and supplementary exposition that characterizes all phenomena as being governed by Taiji 太極 (variously translated as the Great Ultimate, Supreme Polarity, or the Supreme Pivot), a kind of ordering principle that explains the natural fluctuations of yin and yang or stillness and activity (Adler 2014). Another founding figure was Zhang Zai (1020–1077). Zhang developed influential ways of thinking about human nature and the cultivation of virtue, ones that account for variations of character in terms of varying qualities of qi 氣 (psychophysical energy, vital stuff). He also developed a metaphysics that conceived of individuals as part of a cosmic whole, related by nature to all other things as though members of a family or parts of the same body, and thus having family-like obligations to care for all others. One of his brief but stirring encapsulations of this view became perhaps the most famous inspirational essay in the Neo-Confucian tradition, called “The Western Inscription” as it had been written on the western wall of his study (Tiwald &amp; Van Norden 2014: 134–136).