Wuli xiaoshi 物理小識

Wuli xiaoshi 物理小識 is a book on various issues of natural sciences, mainly physics, written during the late Ming period 明 (1368-1644) by Fang Yizhi 方以智 (1611–1671), courtesy name Mizhi 密之, style Luqi 鹿起 or Maogong 曼公, from Tongcheng 桐城, Anhui. He obtained the jinshi degree in 1640 and served as examining editor (jiantao 檢討) in the Hanlin Academy (Hanlinyuan 翰林院). After the conquest of Beijing by the Manchus, he travelled to the southeast and served the Prince of Gui 桂王 (r. 1646-1661). After the latter's ruin, he took the monk's robe, lived from the sales of medical herbs and adopted the clerical name Dazhi 大智, with the courtesy name Wuke 無可 and the styles Hongzhi 弘智, Yaodi Heshang 藥地和尚 or Jiwan Laoren 極丸老人.

Fang had great knowledge in many fields and was particularly interested in nature. Apart from the Wuli xiaoshi, he wrote the books Yaodi paozhuang 藥地炮莊, Yiru 易袽, Gujin xingshuo heguan 古今性說合觀, Yiguan wenda 一貫問答, Dongxijun 東西均, Lingwai gao 嶺外稿, Qingyuan zhilüe 青原志略 and Tongya 通雅. His collected writings are called Fushan ji 浮山集.

The Wuli xiaoshi with a length of 12 juan starts with a general introduction (Zonglun 總論). The main text is divided into fifteen categories covering various practical issues of the science of physics and the material world. The arrangement resembles the chapters of traditional encyclopaedias. While integrating ancient Chinese scientific knowledge, Fang Yizhi also paid attention to incorporating some information on Western science and technology. The book contains many unique insights, like the earliest record of coking and using coke. In Great Britain, the technique of producing coke was invented by Abraham Darby (1676–1717) in 1713, which is more than half a century later than the book of Fang Yizhi. Fang also proposed the theory of "light appearing fuller and shadows thinner" (guang fei ying sou 光肥影瘦), meaning that the sun disk, as seen by the human eye, appears larger than the actual luminous body. This corrected Matteo Ricci's (1552–1610) erroneous claim that the sun's radius was more than 160 times that of Earth's and that the sun was only a little over 16 million "miles" (li 里, c. 500 m) away from Earth.

Fang's book is highly appreciated by modern scholars because of its emphasis on the need of exact measuring and the proof of evidence (gui zhi ce, zheng qi que you zhe 貴質測，征其確疣者). It is therefore dubbed an example of "primitive materialism" (pusu weiwuzhuyi 樸素唯物主義; Feng 1987).

Fang's proposition in the sense of natural philosophy is that "everything is made of matter, and empty spaces are filled with matter" (yi qie wu jie qi suo wei ye; kong jie qi suo shi ye 一切物皆氣所為也，空皆氣所實也). All movements were "caused by fire", which was the source of the constant change of matter (qi 氣) and caused the "transformation and creation" (hua sheng 化生) of all things. Fang urged to verify things by themselves when the search for the "ultimate principle” was inconclusive or unfeasible" (zhi li bu ce, yin wu ze yi zheng zhi 至理不測，因物則以征之). In doing so, he contradicted the Neo-Confucian belief that searching for the inherent principle (li 理) in all parts and objects of the universe was the ultimate method to discover the truth. Compared to the Neo-Confucians' philosophical speculations, Fang’s methods are quite modern. He advocates exact measuring (zhi ce 質測; i.e., science) to decode the subtleties of things (tong ji 通幾; i.e. philosophy). Philosophy was built on the fundament of natural sciences, served as a guide for it and could address its shortcomings. The two disciplines supported each other without contradiction, just as the natural sciences brought to China by the Jesuits were not in opposition to the religious faith they spread by mission.

The book was first printed in 1664 by Master Yu 于氏 in a (perhaps enlarged) version edited by Fang Yizhi's son Fang Zhongtong 方中通 and Yang Yuan 楊暄. A reprint was published in 1884. It is found in the collection Fang Yizhi quanshu 方以智全書 from 1985 (Shanghai guji chubanshe 上海古籍出版社) and the series Siku quanshu 四庫全書 and Wanyou wenku 萬有文庫 (Shangwu yinshuguan 商務印書館 1937). Parts of the Wuli xiaoshi are based on older texts on natural science, like Zhang Hua's 張華 (232-300) old Bowuzhi 博物志, Zanning's 贊寧 (919–1001) Wulei xianggan zhi 物類相感志 or Wang Xuan's 王宣 Wulisuo 物理所. The latter, written by Fang Yizhi's teacher, presented the blue print for his Wuli xiaoshi.