Xueli xiaobian 學曆小辯.
By Tang Ruowang 湯若望 (Johann Adam Schall von Bell).
One juan. Bamboo paper in one ce with a paper case. No date or place of publication.

The cover bears a label with the title and a Latin inscription: “Refutatio duorum librorum | 曆測 Li ts’e | 曆元 Li-yüan | qui antiquam astronomiam | propugnabant.”

Formerly in the second year of the Chongzhen reign when the Ministry [of Rites] proposed to apply the Western method in the Calendar formation, we were doubtful of its practicability. But then several million characters were written on this method and published in book form. These writings were clear and orderly. We still had some doubts. Later we participated in a survey of a solar eclipse and twice in a survey of a lunar eclipse. We could not but be convinced by the facts. Of late, we have been told to carry on our studies. Every day we study under the direction of the Western masters. We do not only deal with books, but we also make experiments with instruments. We do not only listen with our ears, but we also experiment with our own hands. What they told us are true facts and shown with proofs. [We feel that] if the ancients writers were to come back, even they would find it hard to make objections . . .

The Xueli xiaobian was written under the following circumstances. By imperial order the Astronomical Bureau was started on 6 November 1629 (22.IX Chongzhen 2) under the direction of Xu Guangqi. This was known as the Xiju 西局, since the calendar was drawn up according to the Western method. The new establishment aroused the jealousy of the traditional astronomers and they were very unhappy about it. In 1630 the censor of Sichuan recommended a student named Leng Shouzhong 冷守中, who had written a book on the calendar, based on the Huangji jingshi 皇極敬世 (Cosmological Chronology) of Shao Yong 邵雍 (1011–1077). His book was sent to the Bureau for inspection. Xu Guangqi read through it and pointed out the mistakes. He wanted, however, to indicate the error by facts. It happened that in the 4th month of Chongzhen 4 (1–30 May 1631) there was an eclipse of the moon in Sichuan. Xu took this occasion and asked Leng Shouzhong to make the observation. Leng’s calculation proved to be wrong by two hours, while the Western method of calculation was perfectly exact. Leng therefore was told to continue his study with “greater humility.” The traditional school felt greatly humiliated and kept on arguing. In the sixth month (29 June–28 July 1631) an old and more serious scholar of Mancheng Xian 滿城縣, Wei Wenkui 魏文魁, presented to the court two books he had written under the name of his son Wei Xiangqian 魏象乾 : the Liyuan 曆元 ¸ and the Lice 曆測. These books were sent to the Bureau for examination. Xu Guangqi read them with great interest and praised their author as an assiduous scholar. Nevertheless, he did not hesitate to point out the mistakes in these two books and exhorted Wei to improve his works by correcting them. Also a number of the students at the Bureau reacted against Wei Wenkui. The discussions became acrimonious and Wei blamed the Bureau for the errors. It was under these circumstances that the Xueli xiaobian was written. Some authors attribute it to Xu Guangqi. It is possible that the book was written by Xu under the name of Schall. Notice that the other copy of this text (Jap-Sin I, 158) does not mention an author.

Xu Guangqi died in 1633. His successor, Li Tianjing 李天經 (jinshi of 1613), who in his early days had studied in the traditional school, found himself in an embarrassing situation. To please Wei Wenkui he declared impartiality and established a Dongju 東局 with the aim of reforming the old traditional school. By then there were four Astronomical Bureaus in the capital: that of the Datong calendar 大統曆 (used since 1384), of the Mohammedan calendar 回回曆, of the Western calendar (the Xiju 西局) and of Wei Wenkui’s calendar (the Dongju 東局). They fought among themselves, in particular Li Tianjing and Wei Wenkui. Eventually, Wei lost ground and with his death the Xiju was recognized by the emperor.

Cf. Wang Ping 王萍, Xifang lisuanxue zhi shuru 西方曆算學之輸入 (Taipei, 1966), pp. 55–61; Yang 1949, vol. 1, pp. 151–156; Li Zhengfu 黎正甫, “Mingji xiugai lifa shimo” 明季修改曆法始末 in: Dalu zazhi shixue congshu 大陸雜誌史學叢書, second series, ce 4, pp. 262–264; CJC, juan 31, ce 4, pp. 382–384; Fang Hao 方豪 1954, vol. 4, pp. 23–24; Bo Shuren 薄樹人, “Xu Guangqi de tianwen gongzuo” 徐光啟的天文工作, HKC, pp.110–142.

Cf. Pfister, p. 179, no. 8; Feng 1938, p. 207; Hsü 1949, p. 378; Courant 4951; Jap-Sin I, 158.

Albert Chan, Chinese books and documents in the Jesuit Archives in Rome, pp. 369-371.