t’ai-chi Chinese term meaning ‘Great Ultimate’, an idea first developed in the ‘Appended Remarks’ of the I-Ching, where it is said that in the system of Change there is the Great Ultimate. It generates the Two Modes (yin and yang); the Two Modes generate the Four Forms (major and minor yin and yang); and the Four Forms generate the Eight Trigrams. In his ‘Explanation of the Diagram of the Great Ultimate,’ Chou Tunyi (1017–73) spoke of ‘Non-ultimate (wu-chi) and also the Great Ultimate!’ He generated controversies. Chu Hsi (1130–1200) approved Chou’s formulation and interpreted t’ai-chi as li (principle), which is formless on the one hand and has principle on the other hand. See also CH ‘IEN , K’UN ; CHOU TUN -YI ; CHU HS. S.-h.L.