Āntiān lùn 安天論
Treatise on the Tranquil Heaven by 虞喜 (Yú Xǐ, Eastern Jìn classicist and astronomer, 281–356, 東晉, zhuàn 撰)
About the work
The most influential of the post-Hàn alternative cosmologies, composed by the Eastern Jìn polymath Yú Xǐ 虞喜 (281–356). The Āntiān lùn survives in substantial fragments preserved across Tàipíng yùlǎn 太平御覽 juàn 2 and 54, the Jìn shū tiānwén zhì 晉書·天文志, the Suí shū tiānwén zhì 隋書·天文志, Kǒng Yǐngdá’s 孔穎達 Shàngshū zhèngyì 尚書正義 (under the Yáodiǎn 堯典), Xú Jiān’s 徐堅 Chūxué jì 初學記 juàn 1, Wú Shū’s 吳淑 Shìlèi fù 事類賦 juàn 1 注, and Yú Shìnán’s 虞世南 Běitáng shūchāo 北堂書鈔 juàn 150. The Kanripo reconstruction collates these citations into a 1-juan working text.
Abstract
Composition window: c. 320–356, during Yú Xǐ’s mature scholarship in retirement in Yúyáo 餘姚 after declining repeated court appointments under Jìn Yuándì 晉元帝, Míngdì 明帝, and Chéngdì 成帝. The treatise was composed self-consciously as a response to Yáo Xìn’s 姚信 Xīntiān lùn 昕天論 (KR3f0059) and his clan-grandfather Yú Sǒng’s 虞聳 虞聳 Qióngtiān lùn 穹天論 (KR3f0062) — Yú Xǐ states this explicitly: “jìn jiàn Yáo Yuándào Xīntiān lùn, yòu dǔ zúzǔ Héjiānlì Sǒng lì Qióngtiān mó, bǐyì duō xián” 近見姚元道《昕天論》，又覩族祖河聞[間]立穹天模，鄙意多嫌 (“I have recently seen Yáo Yuándào’s Xīntiān lùn, and have also observed my clan-grandfather, [Hé]-jiān Chancellor Sǒng’s Qióngtiān model — my own opinion finds much to reproach in them”).
The central thesis is presented in a two-clause formulation: “tiān gāo qióng yú wúqióng, dì shēn cè yú bùcè, tiān què hū zài shàng, yǒu cháng ān zhī xíng; dì pò yān zài xià, yǒu jū jìng zhī tǐ, dāng xiāng fù mào, fāng zé jù fāng, yuán zé jù yuán, wú fāng yuán bù tóng zhī yì yě” 天高窮於無窮，地深測於不測，天確乎在上，有常安之形；地魄焉在下，有居靜之體，當相覆冒，方則俱方，圓則俱圓，無方圓不同之義也 (“the heaven extends in height to the limit of limitlessness, the earth extends in depth to the unfathomable; the heaven stands firm above with a constant and tranquil form, the earth’s pò-soul rests below in a still and unmoving body; the two are mutually superposed — if square, then both square; if round, then both round — there is no doctrine of differing square-and-round between them”). The cosmological commitment is to a static, infinite-extent heaven (whence āntiān 安天 — “tranquil heaven”) with the heavenly bodies independently mobile across its surface, “their light arrayed across it, each running its own course, like the tides of the rivers-and-seas, like the rising and disappearing of the myriad creatures.” The model is thus not merely an alternative to the rotating-sphere húntiān but a positive doctrine of an infinite-extent unchanging vault populated by independently mobile luminaries — close in structure to the surviving sketch of the xuānyè 宣夜 model that Yú Xǐ avowedly wishes to reconstruct: “yán tiāntǐ zhě sānjiā, húngài zhī shù jù cún, ér xuānyè zhī fǎ juémiè, yǒu yì xù zhī ér wèi huáng yě” 言天體者三家，渾蓋之術具存，而宣夜之法絕滅，有意續之而未遑也 (“of the three schools speaking of the heavenly body, the methods of hún and gài are both extant, but the xuānyè method has been extinguished — I had intended to continue it but have not had the leisure”).
The Āntiān lùn contains two methodologically important critical arguments against the rival cosmologies:
(1) Against the gàitiān “umbrella-and-yolk” image (“ruò tiān bì lǐ, dì sì luǎn hán huáng, zé dì shì tiān zhōng yī wù, shèngrén hé bié wéi míng ér pèi hū?” 若天必裏，地似卵含黃，則地是天中一物，聖人何別為名而配乎? — “if the heaven necessarily envelops, with the earth like the yolk inside the egg, then the earth is just one thing inside the heaven; why would the sages have given them separate names and paired them?”). The argument is theological-textual: the Yìjīng’s parallel naming of Qián 乾 (heaven) and Kūn 坤 (earth) entails their parity, which the yolk-inside-egg picture violates.
(2) Against the standard cosmological fēigǔ fire-vs-water account (the gàitiān school held that the sun travels through the “flying valley,” fēigǔ 飛谷, which contains water; Yú Xǐ asks: “qiě gǔ yǒu shuǐ tǐ, rì wéi huǒ jīng, bīng tàn bù gòng qì, dé wú shāng rì zhī míng hū?” 旦谷有水體，日為火精，冰炭不共器，得無傷日之明乎? — “since the valley has water-substance, but the sun is fire-essence, and ice and charcoal cannot share a vessel, would this not damage the sun’s brightness?”). The reductio is from physical incompatibility: the sun as fire-essence cannot traverse a water-bearing valley.
A second methodological remark — preserved across several citations — is Yú Xǐ’s gloss on the Zhōubì 周髀 + xuānyè 宣夜 tradition: “Zhōubì xuānyè, huò rén xìngmíng, yóu xīngjiā yǒu Gān Shí yě” 周髀宣夜，或人姓名，猶星家有甘石也 (“‘Zhōubì’ and ‘Xuānyè’ are perhaps personal names — just as the astronomers have Gān [Dé 甘德] and Shí [Shēn 石申]”); and the elaboration “xuān, míng yě; yè, yōu yě” 宣，明也；夜，幽也 (“xuān means ‘bright,’ yè means ‘dark’”), preserved at the Shàngshū zhèngyì of Kǒng Yǐngdá. The latter remark is the source for the gloss now standard in Chinese astronomical historiography.
The Āntiān lùn preserves three further substantive fragments:
(a) Luò Xiàhóng 落下閎 (the calendrical official of Hàn Wǔdì who instituted the Tàichū lì 太初曆 in 104 BCE) is described as having “turned the húntiān in the middle of the earth, fixed the seasonal nodes, and produced the Tàichū lì” — preserved in the Suí shū tiānwén zhì under Yú Xǐ’s name.
(b) The lunar man-and-tree myth (“sú chuán yuè zhōng xiānrén guìshù” 俗傳月中仙人桂樹) — the popular legend of the immortal-and-cassia-tree on the moon — is rationalised by Yú Xǐ as a chronological observation: at the start of each lunation, the immortal’s feet appear; as the moon waxes, the form is gradually completed; the cassia tree appears later. The text is preserved at Xú Jiān’s Chūxué jì juàn 1 and Tàipíng yùlǎn juàn 4.
The Āntiān lùn is the principal documentary witness to Yú Xǐ’s astronomical-and-cosmological thought. He is also the discoverer of suìchā 歲差 (the precession of the equinoxes) at the rate of 1° per 50 years — the earliest extant Chinese statement of this phenomenon, anticipating Zǔ Chōngzhī 祖沖之 (429–500) by a generation. The precession discovery is conventionally placed in another of his works (variously the Āntiān lùn itself, or a separate Tiānwén lùn 天文論), but on the present fragments the suìchā doctrine is not directly preserved and must be inferred from later citation.
For Yú Xǐ’s biography, see 虞喜. The cosmological trilogy in the Kanripo division is completed by KR3f0059 (Yáo Xìn) and KR3f0062 (Yú Sǒng).
Translations and research
- Cullen, Christopher. Astronomy and Mathematics in Ancient China: the Zhou Bi Suan Jing. Cambridge, 1996, pp. 5–7, 36 — surveys Yú Xǐ’s place in the cosmological inventory; pp. 223–227 on his suì-chā discovery.
- Needham, Joseph. Science and Civilisation in China, vol. 3 (1959), pp. 224–227 — English summary of the Ān-tiān lùn fragments with discussion of its philosophical significance; pp. 261–262 on precession.
- Sivin, Nathan. Granting the Seasons: The Chinese Astronomical Reform of 1280, with a Study of Its Many Dimensions and an Annotated Translation of Its Records. Springer, 2009 — discusses Yú Xǐ’s place in the long history of Chinese astronomical theory.
- Yamada Keiji 山田慶兒, Mikan no rekikaku 未完の歴革, 1980 — Japanese-language survey of Chinese cosmological history; substantial coverage of the post-Hàn cosmological-treatise corpus.
- Chén Měi-dōng 陳美東, Zhōngguó kē-xué jì-shù shǐ: tiān-wén-xué juàn 中國科學技術史·天文學卷, Kē-xué chū-bǎn-shè, 2003, ch. 4 — standard modern Chinese astronomical-history survey.
- Sūn Xiǎo-chún 孫小淳 and Kistemaker, Jacob. The Chinese Sky during the Han: Constellating Stars and Society. Brill, 1997.
Other points of interest
Yú Xǐ’s Āntiān model has been read by some Chinese historians of science (notably Jiāng Xiǎoyuán 江曉原 and Chén Měidōng) as anticipating the modern infinite-universe cosmology in two respects: the explicit affirmation that the heaven extends “to the limit of limitlessness” (qióng yú wúqióng 窮於無窮), and the doctrine that the luminaries move independently across the vault rather than being affixed to a single rotating sphere. The historiographical claim should be made with care — Yú Xǐ’s framework is not modern observational-cosmological in motivation, and the suìchā discovery (the empirical result for which he is most justly celebrated) is methodologically separate from the Āntiān cosmology — but the Āntiān lùn’s emphasis on the “unfathomable” extent of heaven and earth, against the bounded-sphere image of the orthodox húntiān, is a substantive and influential alternative within the pre-Sòng cosmological tradition.