The Rizhilu 日知錄 "Records of daily [gains] in knowledge" is a collection of short essays written by the early Qing period 清 (1644-1911) writer and philosopher Gu Yanwu 顧炎武 (1613-1682), actual name Gu Jiang 顧絳, courtesy name Gu Ningren 顧寧人, pen name Jiang Shanyong 蔣山佣, Studio name Tinglin 亭林. Gu Yanwu came from Kunshan 昆山 (modern Kunshan, Jiangsu) and was a member of the Restoration Society 復社 that fought against the overwhelming influence of the eunuch cliques at the imperial court. He also participated in the resistance fights against the Manchus after 1644 and gave up all state offices after the Manchus had conquered China. Instead, he traveled through all provinces and collected information he esteemed as important or interesting. He was very interested in all matters of statecraft and all types of literature. Gu Yanwu was one of the founders of the philological school (xunguxue 訓詁學) of Confucians that started a new, heavily text-oriented movement in the interpretation of the Confucian Classics. In his later years he dwelled in Huayin 華陰 and died in Quwo 曲沃 (both located in modern Shanxi). Gu Yanwu has written a lot of commentaries to the Classics and ancient bronze and stone inscriptions, like Yinxue wushu 音學五書, Yun buzheng 韵補正, Jinshi wenzi ji 金石文字記, Shijing kao 石經考, Jiujing wuzi 九經誤字, Zuozhuan dujie buzheng 左傳杜解補正 or Wujing yitong 五經異同.
The 32 juan "scrolls" long Rizhilu is the result of 30 years of incessant yet accidental work. Gu Yanwu used to makes notes during his lecture of ancient and contemporary literature and put them together into one book. The Rizhilu is not divided into thematic chapters but only very roughly into topics. The first seven juan, for instance, deal with comments on the Confucian Classics, juan 8 to 12 with politics, juan 13 with customs and habits, juan 14 and 15 with rituals, the next two scrolls with the system of the selection of officials, scrolls 18 to 21 with literature, scrolls 22 to 24 with miscellaneous topics, juan 25 with errors in ancient writings, 26 with history, 27 with commenting books, 28 with varia, 29 with the military and foreign affairs, 30 with astronomy and astrology, 31 with geography, and 32 with textual critique. Gu Yanwu understood his book as a help to perceive all important matters of life in order to become a perfect man (junzi 君子). Instead of relying on older books, he said, it was more important to study the really important points in case. The Rizhilu was therefore arranged as a kind of abstract of all the things he had studied throughout his life. Especially in the field of textual interpretation, Gu Yanwu's comments are of great value, in contrast to the late Ming period scholars that continued to speculate about the universe in the manner of the Song period Neo-Confucians.
During Gu's lifetime, only an extract of 8 juan was printed, and the rest was in circulation only in the shape of manuscript copies. The first print of the whole book was arranged by Pan Leishu 潘耒述 in 1695. Later prints were made by the Jingyi Studio 經義齋, one print as part of the collection Qingjingjie 清經解, one print during the Tongzhi reign 同治 (1862-1874), one in 1887, and one in 1912. Huang Rucheng 黄汝成 has written commentaries to the book, the Rizhilu jishi 日知錄集釋, that were printed in 1834 and again as part of the collectaneum Sibu beiyao 四部備要. A further commented and corrected version seems to have been compiled by Yang Ning 楊寧 during the Yongzheng reign 雍正 (1723-1735) that was kept in the library of Lu Baojing 盧抱經 as a manuscript.
Source: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, vol. 1, p. 675. Changchun: Jilin daxue chubanshe.