Xuányí 玄嶷, Tang Buddhist monk; lifedates not transmitted; floruit late 7th c. through the Wǔ Zétiān 武則天 reign. Native place not preserved; secular surname Dù 杜.
He is one of the very few documented cases in Chinese religious history of a senior Daoist priest who converted to Buddhism and became a major Buddhist apologist. As Dù Yì liànshī 杜叉鍊師 (or Dù Yī / Dù Chā), he had been head of the Hóngdàoguān 弘道觀 in Cháng’ān and “a master of the sānxuán 三玄 and the qīluè 七略, the senior leader of the Daoist priesthood of his day.” Under Wǔ Zétiān’s patronage in the Tiānshòu 天授 era (690–692) he converted to Buddhism and was assigned to the Fóshòujìsì 佛授記寺 / Dà Báimǎsì 大白馬寺 in Luòyáng. The empress imperially conferred on him 30 monastic Vassa years (賜三十夏) — a fictive seniority, granted because as a recent convert he would otherwise be in the lowest monastic seniority and unable to take leadership roles. The Sòng gāosēng zhuàn j. 17 records that “the conferral of fictive Vassa years began with this.”
His sole substantial Kanripo work is the 《甄正論》 Zhēnzhèng lùn (KR6r0145, T2112, 3 juan, ca. 696–705) — an anti-Daoist polemic written from the privileged position of a former Daoist priest, attacking the Daoist canonical texts (especially the Shàngqīng and Língbǎo corpora) as late Six-Dynasties forgeries. Per DILA Buddhist Person Authority A000301.
Works in the Kanripo corpus: KR6r0145 Zhēnzhèng lùn.