Elements of Geometry (Jihe yuanben): the prefaces of Xu Guangqi and Matteo Ricci

Xu Guangqi’s preface comes first and is signed “Xu Guangqi of Wusong”. He writes that the study of measure and number flourished in Chinese antiquity and was lost, that “Master Li” (Ricci) had learned it from a famous teacher, and that he asked Ricci to put his mathematical books into Chinese; since nothing else could be discussed until this book was translated, the two of them translated its essential six books together. He then divides Ricci’s learning into three: the greater part is the cultivation of the self and the service of Heaven, the lesser is the investigation of things, and number is one branch of the lesser. He says that he hastens to pass on the lesser first because it is easier to believe, so that readers may see that the master’s learning can be trusted.

Ricci’s preface is dated to the dingwei year of Wanli, 1607. He writes that he came to lodge in the capital in the gengzi year, when he presented his gifts, and that Xu came in the winter of the guimao year (1603). At first, he says, Xu asked mostly about the way of the Lord of Heaven. When they took up Euclid, Ricci explained the text aloud and Xu wrote it down; they went through three drafts and finished the first six books early in the spring. Xu wanted to go on to the end, and Ricci asked him to stop and publish these first.

Both texts are first-hand statements by the two translators, and Xu’s is a Chinese scholar’s own account of what he was doing with the Jesuits. They are cited in Matteo Ricci at the Court of Beijing.