Xu Guangqi

Xu Guangqi a Ming dynasty scholar, official and convert to Christianity (1562-1633) who worked with the Jesuit missionary Matteo Ricci to translate Western learning into Chinese. A statesman of high office and a practical reformer, he is remembered for his contributions to astronomy, mathematics, agriculture and military technology, and as the leading Chinese promoter of the new knowledge from Europe.

Early Life and Education

Xu Guangqi was born in 1562 in Shanghai, then a modest town in the Yangtze delta, into a family of some learning but little wealth. He received a classical education and passed the provincial examinations, but his career advanced slowly, and for years he earned a living as a teacher in various parts of the country while preparing for the higher examinations.

His life was changed by two encounters. The first was with the Jesuit missionaries who had reached China in the late sixteenth century and who impressed him by their learning in mathematics, astronomy and geography. The second was with Matteo Ricci himself, the Italian priest whose depth of scholarship and personal integrity won his deep admiration. Xu was baptised as a Christian in 1603, taking the name Paul.

His conversion was not a rejection of Chinese culture but an attempt to integrate it with what he believed to be the truths of Western science and religion. He argued that the morality of the Confucian tradition was compatible with Christianity and that European learning offered a method and a body of knowledge from which China could greatly benefit. This constructive synthesis remained the guiding idea of his life.

The Translation of Euclid and Western Learning

The most famous of Xu Guangqi's collaborations with Ricci was the translation of the first six books of Euclid's Elements of Geometry into Chinese, published in 1607 under the title of the Principles of Geometry. The work introduced the deductive method of Greek mathematics to Chinese readers, together with a vocabulary of technical terms that would shape the language of mathematics in East Asia.

The translation was a joint enterprise. Ricci, who knew the Latin text, explained the propositions and their proofs aloud, and Xu, who grasped the mathematics with remarkable speed, rendered them into polished classical Chinese. The division of labour, with its dependence on mutual trust and shared intellectual purpose, became a model for the later transmission of Western works into China.

Terms coined in the course of this and related translations, such as the words for point, line, plane and angle, entered the Chinese language and are still in use. The translation also made a deep impression on Chinese scholars by demonstrating the power of a system of reasoning that moved from a small number of axioms to a great edifice of conclusions.

Astronomy, the Calendar and Reform

Much of Xu Guangqi's official career was occupied with the reform of the calendar and with astronomy. The traditional Chinese calendar had fallen into serious error, and the prediction of eclipses, on which the legitimacy of the throne partly depended, had become unreliable. Xu argued that the methods of European astronomy could restore accuracy and he worked with the Jesuits to translate and adapt them.

He was appointed to lead the reform of the calendar, and under his direction the Jesuit and Chinese scholars produced the Chongzhen calendar, a comprehensive system based on the astronomy of Tycho Brahe and later of Kepler. He did not live to see it adopted, but it became the basis of the calendar used in China for the rest of the imperial period.

He also made astronomical instruments and compiled tables, and he trained Chinese scholars in the mathematical methods on which the new astronomy depended. His insistence on observation and calculation as the test of astronomical theory marked a departure from the traditional approach to this science.

Agriculture, Military Affairs and Public Service

Xu Guangqi was above all a practical reformer, and his largest scholarly work was a comprehensive treatise on agriculture, the Complete Book of Agricultural Administration, which he compiled over many years. It gathered together the farming knowledge of China, discussed in detail the cultivation of crops, the management of land and water, and the relief of famine, and added observations drawn from his own reading and experience.

The book was motivated by his concern for the welfare of the population and by the recurring famines that afflicted the country. It recommended new crops that could be grown on marginal land, including the sweet potato and other plants introduced from the Americas, and it argued for the importance of agricultural improvement as the foundation of a stable society.

He was also drawn into military affairs, and he urged the reform of the army and the adoption of European firearms and artillery, which he regarded as essential for the defence of the empire against its northern enemies. He supervised the casting of cannon, wrote on military strategy and logistics, and combined this work with the general reform of the state finances and administration.

High Office, Influence and Legacy

In his last years Xu Guangqi rose to the highest offices of state, becoming a grand secretary and a close adviser to the Chongzhen emperor, and he used this position to press for the adoption of Western astronomy, the reform of the calendar and the modernisation of the military. His personal integrity and his technical competence gave him an authority unusual even among senior officials.

He died in 1633, at the height of his influence, and the projects on which he had laboured were carried to completion by his colleagues. He is honoured in both the Chinese and the Catholic traditions, as a great statesman and scholar and as the most important Chinese Christian of his era, and his tomb in Shanghai became a place of commemoration.

His legacy is the belief that knowledge is universal and that a civilised people should be willing to learn from wherever genuine learning is to be found. In an age of cultural self-sufficiency he argued for the open reception of foreign science, and he devoted his life to the translation, adaptation and application of what he had learned. He remains the outstanding example of the meeting of Chinese and European thought in the late Ming.

See also

• Matteo Ricci
• Chinese Rites controversy
• Euclid's Elements
• Jesuit China missions