Lǐ Jiǎn 李簡 was a thirteenth-century Yìjīng scholar from Xìndū 信都 (in modern Héběi 河北), active in the late-Jīn / early-Mongol-Yuán transition in the eastern part of north China. His own preface to the Xué Yì jì 學易記 (KR1a0081), dated zhōngtǒng jiànyuán gēngshēn 中統建元庚申 (1260), records that he moved with his family to Dōngpíng 東平 in rényín 壬寅 (1242), spent several years there in a circle of Yì commentators (Zhāng Zhōngyōng 張中庸, Liú Yì’ān 劉佚菴, Wáng Zhònghuī 王仲徽), and later, in jǐwèi 已未 (1259), held the post of deputy magistrate (cuì 倅) of Tài’ān 泰安, where he revised the manuscript into the form transmitted today.
The Sìkù editors (1779) misidentified the jǐwèi year of his Tài’ān posting as Yánvyòu 延祐 6 = 1319 (in the reign of Yuán Rénzōng 元仁宗), placing him a full sexagenary cycle later than he actually was; the original preface’s zhōngtǒng date is, however, unambiguous and preferred here. CBDB’s entry 41383 (fl. 1222) and 103071 (fl. 1319) are both inconsistent with this revised dating; no secure CBDB match has been identified.
His one surviving work is the Xué Yì jì, a nine-juàn collected commentary on the Yìjīng drawing on sixty-four named commentators from Zǐxià 子夏 down to his own contemporaries — including, importantly, the now-lost compilations of Yáng Bīnfū 楊彬夫 (fifty-house gloss) and Shàn Fēng 單渢 (thirty-house gloss). The work transmits otherwise irrecoverable fragments of these and other earlier Yì expositions.