t’i yung, Chinese terms often rendered into English as ‘substance’ and ‘function’, respectively. Ch’eng Yi (1033–1107), in the preface to his Commentary to the Book of Changes, says: ‘Substance (t’i) and function (yung) come from the same source, and there is no gap between the manifest and the hidden.’ Such thought is characteristic of the Chinese way of thinking. Chu Hsi (1130–1200) applied the pair of concepts to his theory of human nature; he maintained that jen (humanity) is nature, substance, while love is feeling, function. In the late Ch’ing dynasty (1644–1912) Chang Chih-tung (1837–1909) advocated Chinese learning for t’i and Western learning for yung. See also CHINESE PHILOS- OPHY , CHU HS. S.-h.L.