Yiyao 疑耀

Yiyao 疑耀 "Doubts and illuminations" is a "brush-notes"-style book (biji 筆記) written during the late Ming period 明 (1368-1644) and attributed to the "heterodox" philosopher Li Zhi 李贄 (1527-1602). A statement in Wang Shizhen's 王世貞 Gufuyuting zalu 古夫于亭雜錄 suggests that the book was written by Zhang Xuan 張萱, a disciple of Li Zhi. The same conclusion was made by the compilers of the descriptive bibliography Siku quanshu zongmu tiyao 四庫全書總目提要. Zhang Xuan was a secretariat drafter (zhongshu sheren 中書舍人) and participated in the compilation of the catalogue Wenyuange shumu 文淵閣書目.

His Yiyao of 7 juan length is a work of textual criticism on ancient writings, rich in material and well-supported by evidence. It follows the principle of examining historical facts with a methodical approach. Zhang Xuan advocates for the unity of Confucianism and Buddhismy (ru fo gui yi 儒佛歸一), expressing his views with logical argumentation. However, some of the content is based on memory and not directly cited from sources. For example, his reference to a "forged letter" of Wen Yanbo 文彥博 (1006-1097) ignored the account of Shi Cangshu 石蒼舒 (fl. 1068) in the book Yuzhao xinzhi 玉照新志. He also did not realise that the phrase "jadeite flecked with gold" (feicui xie jin 翡翠屑金) comes from Ouyang Xiu's 歐陽修 (1007-1072) Guitianlu 歸田錄. Additionally, statements from books on materia medica such as "cicada larvae can cure blindness" are erroneous or far-fetched.

The text is found in the series Lingnan yishu 嶺南遺書, Siku quanshu 四庫全書 and Congshu jicheng chubian 叢書集成初編.