Tai Chen (1724–77), Chinese philologist, philosopher, mathematician, and astronomer. A prominent member of the K’ao-cheng (evidential research) School, Tai attacked the Neo-Confucian dualism of li (pattern) and ch’i (ether), insisting that li is simply the orderly structure of ch’i. In terms of ethics, li consists of ‘feelings that do not err.’ In his Meng-tzu tzu-yi shu-cheng (‘Meanings of Terms in the Mencius Explained and Attested’), Tai argues for the need to move from mere yi-chien (opinions) to pu-te chih-yi (undeviating standards) by applying the Confucian golden rule – not as a formal principle determining right action but as a winnowing procedure that culls out improper desires and allows only proper ones to inform one’s actions. Beginning with tzu jan (natural) desires, one tests their universalizability with the golden rule, thereby identifying those that accord with what is pi-jan (necessary). One spontaneously k’o (approves of) the ‘necessary,’ and Tai claims this is what Mencius describes as the ‘joy’ of moral action. See also MENCIUS. P.J.I.