chapter  18
9 Pages

Xu Guangqi (1562–1633)

A Good KnowledGe of MAtheMAtics enAbles Us to Apply the principles to other doMAins And thUs Meet the needs of the tiMe

From “Tiaoyi lifaxiuzheng suicha shu” 條議曆法修正歲差疏 (A Memorial to His Imperial Majesty on the Matter of Calendar Reform),129 collected in Zengding Xu Wending gong ji 增訂徐文定公集 (Revised and Enlarged Edition of Xu Guangqi’s Collected Writings), Volume 4


As a humble and lowly member of the Imperial Court, I serve in the ranks of the Ministry of Rites conscious of my unworthiness of the beneficence bestowed upon me. Of late, consequent to the discrepancy between the calendar’s prediction of a solar eclipse and the actual event,130 His Majesty granted approval for the proposal submitted by this department to reform the calendar computation system. As I was a member of the party that prepared such a proposal some years ago,131 I now hold and follow, in awe and trepidation, His Majesty’s order: “Regarding the reform of the calendar computation system, there are items under four headings, all to be executed according to the proposal submitted. Xu Guangqi of the Ministry

of Rites is to be in charge of the task. Li Zhizao 李之藻 [1565/1571-1630; see entry 10] is to finish his mourning as soon as possible and to take up office in the Ministry of Rites.132 By order of His Imperial Majesty.” The weight of the imperial command sat heavy on me as would a mountain on the back of a gnat. Even though conscious of my own inadequacy I accept with obedience and gratitude the task entrusted me. I am also aware that the knowledge of the computation of calendars is now almost lost. I am but a mere untutored student from the coastal regions, commended to office over a decade ago by the gracious ministers of the Ministry of Rites only because I have the humility to listen to and appreciate others’ views, not because I was able to establish new rules or because my abilities surpassed those before me. And indeed it was with the help of others that I sought to accomplish my task. Eighteen years have since passed,133 and age has caused me to forget some of the things I had learned. When I take up this task, I can but do as I used to, and that is, consult widely and learn from others so as to be worthy of His Imperial Majesty’s trust.