Treatise on Geometry


Yuan rong jiao yi (Treatise on geometry) is an 1847 edition of a work dictated in 1608 by the Italian Jesuit Matteo Ricci (1552–1610) to official and scholar Li Zhizao (1565–1630). Ricci, whose Chinese name was Li Madou, was one of the founding figures of the Jesuit mission in China. Li Zhizao was baptized by Ricci in 1610 and took the name Leo. He studied with Ricci and wrote prefaces to a number of his books. Ricci dictated several works to Li, who put them into acceptable Chinese. The treatise was first printed in Beijing in 1614, after Ricci’s death and while Li was posted to Shanzhou (present-day Puyang Xian, Hebei Province). It was reprinted by his friend Wang Mengpu, with a preface by Li himself. Ricci’s treatise was included in the collection of 19 works by missionaries, edited by Li, entitled Tian xue chu han (Preliminary works on astronomy), issued together with three other works by Ricci and Xu Guangqi. This 1847 edition is included in Hai shan xian guan cong shu (The Haishan Xianguan Collection), which was published in Fanyu circa 1845–49, based on the books in the private library of the merchant Pan Zhencheng (1714–88). Ricci’s source was a commentary by German Jesuit Clavius on the 13th-century work on spheres by the scholar, monk, and astronomer Johannes de Sacrobosco (circa 1195–circa 1256). The Ricci book discusses the sphere and its volume, beginning with the statement that everything on earth has a shape. It then explains these shapes, such as the circle, rectangle, polygon, and equilateral triangle and it notes that of all geometrical figures with the same surface area, the sphere has the greatest volume. The book contains 18 propositions, and the text retains the idea of the divine perfection of the celestial sphere.

Last updated: March 7, 2014