"Rizhilu 日知錄 (Record of knowledge gained day by day).... Rizhi 日知 is the title taken from Lunyu, xix.5. In his Preface, Gu explained the basis for including some subjects and not others: “Since my childhood studies, I have always noted down what I perceived, and if it [turned out] to be incorrect, I revised it again and again, or if earlier men had said it before me, I omitted it entirely (Liang Ch'i-ch'ao, 1959 [50.6.4], 31). Rizhilu contains 1,020 entries divided into philosophy, government, the examination system, popular customs, astronomy, and geography...."-—Cf. Wilkinson, Chinese history, a manual, pp. 952-953.