Qianshu 潛書 "Book of profundity" is a philosophical treatise written by the early Qing-period 清 (1644-1911) scholar Tang Zhen 唐甄 (1630-1704), original name Tang Datao 唐大陶, courtesy name Tang Zhuwan 唐鑄萬, style Puting 圃亭. He hailed from Dazhou 達州 (modern Daxian 達縣, Sichuan) and was magistrate (zhixian 知縣) of Changzi 長子, Shanxi, but soon retired and settled down in Suzhou 蘇州, Jiangsu, where he began to write several scholarly studies, like the books Qianshu, Maoshi zhuanqian heyi 毛詩傳簽合義 (on the "Book of Songs") and Chunqiu shuzhuan 春秋述傳 (on the "Spring and Autumn Annals"). His collected writings are called Puting ji 圃亭集.
The 4 juan-long book Qianshu was originally called Hengshu 衡書 "Book of Balance", in imitation to Wang Chong's 王充 (27-97 CE) book Lunheng 論衡 from the Han period 漢 (206 BCE-220 CE). The compilation of this text took thirty years. It is divided into two parts with many sub-chapters. The first part deals with methods of teaching, and the second part with government and administration.
As a Confucian scholar, Tang Zhen followed the teachings of Mengzi 孟子 (385-304 or 372-289 BCE), Lu Jiuyuan 陸九淵 (1139-1193) and Wang Shouren 王守仁 (Wang Yangming 王陽明, 1472-1529). He followed Wang Yangming's concept of the innate goodness of man (zhi liang zhi 致良知), but criticized that the Neo-Confucians had too much concentrated on the theorization of the human nature (or man's xin xing 心性 "mind and character"), without being concerned with the practical application (shigong 事功) of the goodness in human character. The character had to be nourished by self-cultivation, which could only be made in a combination of insight and active practice.
In the second part of the book, Tang Zhen criticizes a political system in which individual persons, be it the emperor or some of his ministers, were endowed with too much power. Instead, the emperor would have to rely on worthy talents. A worthy ruler would clearly have to adapt rewards and punishments, to esteem education and military training, and to promote the agricultural output, in order to bring profit to the people (fu min 富民). Tang Zhen went so far that he demystified the position of emperor: "Although a venerable person, the Son of Heaven is still a human" (sui zun, yi ren ye 雖尊，亦人也), and most emperors since the Qin dynasty 秦 (221-206 BCE) had simply been "bandits" (zei 賊) because all of them had caused the death of so many innocent subjects. In Tang's eyes, an emperor had to be the subject of the whole people or the "lowest of all men under Heaven" (bi chu tianxia zhi xia 必處天下之下). As a consequence of the turbulent times in which Tang Zhen lived, he went so far as to be very suspicious towards traditional Confucian virtues as loyalty (zhong 忠), filial piety (xiao 孝), kindheartedness (ren 仁) and propriety (yi 義).
Although the Qianshu includes some "heretic" thoughts, it was highly praised by later scholars like Pan Lai 潘來 (1646-1708), Wang Yuan 王源 (1648-1710), Liang Qichao 梁啟超 (1873-1929) and Zhang Taiyan 章太炎 (Zhang Binglin 章炳麟, 1869-1936), who even said that it stood in one line with the thinkers Mengzi, Xunzi 荀子 (313 -238 BCE), Wang Yangming and Dai Zhen 戴震 (1723-1777).
The Qianshu was originally printed by Wang Wenyuan 王聞遠. Reprints were produced in 1883 and 1905. The first modern edition was published in 1955 by the Zhonghua shuju Press 中華書局. In 1984 the Sichuan renmin chubanshe 四川人民出版社 published a commented edition.