Lìxiàng běnyào 曆象本要
Essentials of the Calendar and Celestial Phenomena by 楊文言 (撰)
About the work
The Lìxiàng běnyào 曆象本要, in two juàn, is a Qīng primer by Yáng Wényán 楊文言 setting out the conceptual basis (“essentials,” běnyào 本要) of post-Chóngzhēn / Shíxiàn-era Western-style astronomy. It is structured as a glossary of “new calendrical terms” (xīn lìfǎ míng 新曆法名), each definition contrasted explicitly with the inherited Chinese usage that the Jesuit reform had displaced or modified.
Abstract
The work has no separate signed preface; the rationale is implicit in the opening definitions. The body proceeds as a sequence of paired old/new definitions: (i) degrees of the celestial sphere — anciently 365¼, now 360 (古 365¼ → 今 360); (ii) the celestial body, now recentred on the zōngdòng 宗動 / primum mobile of the Aristotelian-Tychonic cosmology; (iii) the roundness of heaven and earth (今言天地皆圓 — both heaven and earth are spherical, hence why the polar-altitude and gnomon methods all assume a round earth); (iv) fixed stars vs. seven luminaries, now placed on different spherical layers, accounting for eclipses, occultations, and planetary retrograde motion; (v) the use of the eccentric or epicycle (bùtóngxīn tiān 不同心天 / jiā běnlún 加本輪) for solar and planetary anomaly; (vi) the suìlún 歲輪 epicycles for planetary stations and retrogrades; (vii) the justification of dividing the circle into 360° (rational arithmetic, easier proportions); (viii) precession evidenced by the pole star’s drift of more than 3° from the true pole.
The work is unmistakably post-Chóngzhēn lìshū in vocabulary and conceptual content, presupposing the Jesuit-mediated translation programme of Xú Guāngqǐ, Lǐ Tiānjīng, Schall and Rho. NotBefore is set at 1645 (the Shíxiàn reform); notAfter at c. 1700 (early-to-mid Kāngxī era), within which the paucity of biographical detail prevents tighter dating. CBDB returns Yáng Wényán at c_personid 623877 (Qing dynasty, no other detail).
Translations and research
No substantial secondary literature located. The work belongs to the second-tier Qīng popularising-pedagogical literature on the post-Shíxiàn astronomy, treated in surveys such as:
- Jami, Catherine. 2012. The Emperor’s New Mathematics: Western Learning and Imperial Authority during the Kangxi Reign (1662–1722). Oxford: Oxford University Press.
- Hashimoto Keizō 橋本敬造. 1988. Hsü Kuang-ch’i and Astronomical Reform. Suita: Kansai University Press.
- 陳美東 Chén Měidōng. 2003. Zhōngguó kēxué jìshù shǐ: Tiān-wén-xué juǎn 中國科學技術史·天文學卷. Beijing: Kē-xué chū-bǎn-shè.
- Engelfriet, Peter M. 1998. Euclid in China. Leiden: Brill. — Treats the Sino-Western technical-vocabulary ground that this work occupies.
Other points of interest
The work is one of the more compact and pedagogically transparent Qīng restatements of the Tychonic-cosmological framework that the Jesuits brought to China — closer to a teaching manual than to a research treatise. The explicit affirmation of a spherical earth (“天地皆圓”) in Lìxiàng běnyào is one of many Qīng-era Chinese-language reaffirmations of a doctrine that Chinese cosmology had (with regional and traditional exceptions) generally not held in pre-Jesuit form.