Southern Sòng 宋 classicist, native of Lóngyóu 龍游 in Zhèjiāng (then administered as part of Qúzhōu 衢州). Zì Yuánsù 元肅, hào Kēshān 柯山. Birth and death years are unrecorded; the standard reference works (CBDB id 44692, LiǎngZhè míngxián lù 兩浙名賢錄, Sòng rén zhuànjì zīliào suǒyǐn) report only “lifedates unknown.” Active in the second half of the twelfth century, with a defensible floruit of ca. 1170–1200 bracketed by his jìnshì 進士 of 1178 (淳熙五年) and the Chúnxī-era 淳熙 (1174–1189) Mashā 麻沙 imprint of his Shàngshū xiángjiě 尚書詳解. With his friends Zhōu Shēng 周升 and Miù Jǐngrén 繆景仁 — both fellow Lóngyóu jìnshì — he was known locally as the “Three Eminents” (Sān jùn 三俊); after holding only the minor post of xiànwèi 縣尉 (county defender) he retired and the three jointly founded the Jīmíng Shūyuàn 雞鳴書院 to teach the local youth. He studied the Shàngshū under Cài Yuándìng 蔡元定 (1135–1198) of Jiànyáng 建陽. His magnum opus, the Kēshān shūzhuàn 柯山書傳 in 40 juǎn, survives in 26 juǎn as the Shàngshū xiángjiě preserved in the Sìkù quánshū (KR1b0011); under the early Míng Hóngwǔ 洪武 reform of the examination curriculum it was prescribed alongside Cài Shěn’s 蔡沉 Shū jízhuàn 書集傳 as a standard text for Shàngshū studies, before being eclipsed by the Cài commentary in the Yǒnglè 永樂 Shū dàquán 書大全.