Liuzi 劉子 is a philosophical treatise compiled by an unknown author during the Liang period 梁 (502-557). It is also called Liuzi xinlun 劉子新論 "A new discussion of Master Liu", Liuzi 流子 "Master Liu1" or Deyan 德言 "Words about virtue".
There is a large discussion about who was "Master Liu". Some think it was Liu Xie 劉勰 (c. 470—c. 522/538年), author of the literary critique Wenxin diaolong 文心雕龍, others think it was Liu Zhou 劉晝 from the Northern Qi period 北齊 (550-577) or even Liu Xin 劉歆 (d. 23 CE) from the Han period 漢 (206 BCE-220 CE). The transmitted shape of the book was created by Liu Xiaobiao 劉孝標 (462-521) of the Liang period, and Yuan Xiaozheng 袁孝政 of the Tang period 唐 (618-907). The estimated dates of the compilation thus range from the Han to the Tang period. The modern scholar Yu Jiaxi 余嘉鍚 follows statements in the book catalogues Zhizhai shulu jieti 直齋書錄解題, and Junzhai dushu zhi 郡齋讀書志 which hold that the book was a compilation of Liu Zhou 劉晝 (516-567), so that the date of compilation must have been in the mid 6th century.
Liu Zhou, courtesy name Kongzhao 孔昭, hailed from Bohai 渤海 (modern Fucheng 阜城, Hebei). He was a Confucian scholar in northern China, but was never appointed to a state office. He has compiled the books Liuzi, Didao 帝道 "The way of the ruler" and Jinxiang biyan 金箱璧言 "The golden box of jade words". The Liuzi seems to have been compiled for the rulers of the Northern Qi dynasty in order to provide them with examples from history and philosophical writings to demonstrate how good government would work. Liu Zhou was very disappointed that the ruling family Gao 高 was never considered reading the memorials he submitted to the throne or to consult his political-philosophical writings.
The content of the 10-juan-long book Liuzi is very rich. It deals with philosophy, politics, economy, military and cultural matters. It covers all aspects of governing a state and cultivating the self; it explains the influence of Yin and Yang, the Daoist Way and its Virtue, Confucianism, Mohism, legalism, the propositions dialecticians, and the machinations of the coalition advisors; it touches aspects of agriculture and nature, things of everyday life and virtually everything that can be heard an seen.
In the philosophical sphere, the author gives proof of the adaption of Daoist concepts in Confucian thinking during the Southern Dynasties period 南朝 (420~589). This integration led to a new interpretation of the Confucian Classics.
Various scholars have classified the Liuzi as a Daoist writing or a Confucian text, but the mixed nature of its philosophical content resulted in the decision to classify it as a product of "miscellaneous thinkers" (zajia 雜家). In fact, the first four chapters can be attributed to the school of Huang-Lao thought 黃老 that prevailed during the Han period. This school of thought stressed the need for self-cultivation that could only be achieved by purifying one's heart and making oneself free of worldly categories of right or wrong. On the other hand, a wise man had to dedicate himself to the welfare and the security of the state. Liu Zhou stresses the importance of learning for the creation of a perfect individual character. Spirit and heart had to be purified. Only then ruler and minister or upper and lower classes would mutually trust each other and thorough understand the position of state and society in the universe. Reliability and self-confidence as expressions of the Confucian virtues of loyalty, filial piety, kindheartedness and righteousness were based on the adoption of knowledge. A ruler endowed with these virtues would be like the wind moving the grass (the people) and a vessel giving shape to the water (society). Any ruler had to rely on competent advisors and should promote men of great abilities. Yet in the eyes of Liu Zhou, this was not sufficient for a perfect government. The legalist concept of an objective law that rules the bureaucracy gave Liu Zhou the impetus to stress the need to adapt laws and regulations to contemporary circumstances. A blind perpetuation of antiquity would not profit a modern state.
The importance of agriculture for the state can be derived from both legalism and Confucianism. In legalism, the peasantry is important to deliver taxes, corvée labour and recruits for the army. In Confucianism, the peasantry is seen as the people towards which the ruler had to display benevolence. Liu Zhou lived in a time when the economy of northern China had been devastated after centuries of war, and there was a high need for the reconstruction of agriculture. Wars were, in Liu Zhou's eyes, important for the security of a state, but a ruler had to discern between wars that were necessary and such that only wasted money and lives.
The Liuzi is first mentioned in the imperial bibliography Jingji zhi 經籍志 in the official dynastic history Suishu 隋書, where it is identified as lost. It is, nonetheless, included in all important official and private bibliographies of the Song period 宋 (960-1279). The text of the Liuzi is included in many Ming- 明 (1368-1644) and Qing-period 清 (1644-1911) series, like the Daoist Canon Daozang 道藏, the Ershijia zishu 二十家子書 Wujiayan 五家言, Han-Wei congshu 漢魏叢書, Zhuzi qishang 諸子奇賞, Baizi quanshu 百子全書, and also in the Republican reprint series Congshu jicheng 叢書集成. Excerpts from the Liuzi can be found in many other books.
There are in consequence a several different editions of the Liuzi that differ in quite a few textual passages. The earliest known version has been found as four fragments among the manuscripts discovered in Dunhuang 敦煌 in 1899. Three of them are know kept in the National Library in Paris. The fragment preserved in China has been published by Luo Zhenyu 羅振玉 (1866-1940) as Liuzi canjuan 劉子殘卷. It was owned by He Mumin 何穆忞 (1880-1916) from Jiangyin 江阴 before Luo obtained it. Its present whereabouts are unknown. Fu Cengxiang 傅增湘 (1872-1949) has compared the four Dunhuang manuscript versions (edited by Wang Zhongmin 王重民) with the versions of Liu Youyun 劉幼雲.
The received version of the Liuzi is based on a Song-period version that found its actual shape in the Liuzi xinlun 劉子新論 by Sun Xingyan 孫星衍 (1753-1818) and Huang Pilie 黃丕烈 (1763-1825). Other important editions are the so-called Jifu edition 吉府本 of the Chongde Academy 崇德書院, the version of the Daoist Canon, the version in the series Zihui 子彙 and Cheng Rong's 程榮 (c. 1600) Han-Wei congshu 漢魏叢書, the Jifu congshu 畿輔叢書, the edition of the Shi'en Studio 世恩堂, that of Jiang Yihua 蔣以化, the version in the Siku quanshu 四庫全書 and that in the Baizi quanshu 百子全書.
There are also a lot of manuscript versions published by Ye Ziyin 葉子寅, Zhang Shaoren 張紹仁, Huang Pilie and Lu Zhuosheng 陸拙生 (a Ming-period version), the Jingshe Studio 精舍 of Longchuan 龍川, the Jinxuan Studio 謹軒 of Lan Ge 藍格, and the version of Peng Yuanrui 彭元瑞 (1731-1803). The chapter Zapian 雜篇 is not included in the Zhuzi qishang version and Liu Qiqin's 史起欽 Liuzi zuanyao 劉子纂要. The Siku quanshu version is, although based on Jiang Yihua's editions, not fully identical to the latter.
The oldest commentary on the Liuzi was written by the Tang-period scholar Yuan Xiaozheng. The most important commentaries were written during the Qing period by Ye Ziyin, Sun Xingyan, Lu Wenchao 盧文弨 (1717-1795), Huang Pilie and Lu Chuosheng, as well as the modern scholars Fu Cengxiang, Luo Zhenyu, Sun Kaidi 孫楷第 (1898-1986), Wang Zhongmin, Chen Naiqian 陳乃乾, Yang Mingzhao 楊明照 (1909-2003, Liuzi lihuo 劉子理惑) as well as Lin Qitan 林其錟 and Chen Fengjin 陳鳳金 (Lizu jijiao 劉子集校).