天地之數 The Reckoning of Heaven and Earth
蓋聞天地之數,有十二萬九千六百歲為一元。將一元分為十二會,乃子、丑、寅、卯、辰、巳、午、未、申、酉、戌、亥之十二支也。每會該一萬八百歲。且就一日而論:子時得陽氣,而丑則雞鳴;寅不通光,而卯則日出;辰時食後,而巳則挨排;日午天中,而未則西蹉;申時晡,而日落酉,戌黃昏,而人定亥。譬於大數,若到戌會之終,則天地昏曚而萬物否矣。再去五千四百歲,交亥會之初,則當黑暗,而兩間人物俱無矣,故曰混沌。又五千四百歲,亥會將終,貞下起元,近子之會,而復逐漸開明。邵康節曰:「冬至子之半,天心無改移。一陽初動處,萬物未生時。」到此,天始有根。再五千四百歲,正當子會,輕清上騰,有日,有月,有星,有辰。日、月、星、辰,謂之四象。故曰,天開於子。又經五千四百歲,子會將終,近丑之會,而逐漸堅實。《易》曰:「大哉乾元!至哉坤元!萬物資生,乃順承天。」至此,地始凝結。再五千四百歲,正當丑會,重濁下凝,有水,有火,有山,有石,有土。水、火、山、石、土,謂之五形。故曰,地闢於丑。又經五千四百歲,丑會終而寅會之初,發生萬物。曆曰:「天氣下降,地氣上升;天地交合,群物皆生。」至此,天清地爽,陰陽交合。再五千四百歲,正當寅會,生人,生獸,生禽,正謂天地人,三才定位。故曰,人生於寅。盖闻天地之数,有十二万九千六百岁为一元。将一元分为十二会,乃子、丑、寅、卯、辰、巳、午、未、申、酉、戌、亥之十二支也。每会该一万八百岁。且就一日而论:子时得阳气,而丑则鸡鸣;寅不通光,而卯则日出;辰时食后,而巳则挨排;日午天中,而未则西蹉;申时晡,而日落酉,戌黄昏,而人定亥。譬于大数,若到戌会之终,则天地昏曚而万物否矣。再去五千四百岁,交亥会之初,则当黑暗,而两间人物俱无矣,故曰混沌。又五千四百岁,亥会将终,贞下起元,近子之会,而复逐渐开明。邵康节曰:「冬至子之半,天心无改移。一阳初动处,万物未生时。」到此,天始有根。再五千四百岁,正当子会,轻清上腾,有日,有月,有星,有辰。日、月、星、辰,谓之四象。故曰,天开于子。又经五千四百岁,子会将终,近丑之会,而逐渐坚实。《易》曰:「大哉干元!至哉坤元!万物资生,乃顺承天。」至此,地始凝结。再五千四百岁,正当丑会,重浊下凝,有水,有火,有山,有石,有土。水、火、山、石、土,谓之五形。故曰,地辟于丑。又经五千四百岁,丑会终而寅会之初,发生万物。历曰:「天气下降,地气上升;天地交合,群物皆生。」至此,天清地爽,阴阳交合。再五千四百岁,正当寅会,生人,生兽,生禽,正谓天地人,三才定位。故曰,人生于寅。
逐句解 Line by line
It is said that in the reckoning of Heaven and Earth, 129,600 years make one yuán (a cosmic epoch).
數 (shù) here means the "number," the numerical order of the cosmos. 元 (yuán) is the largest time-unit in the scheme Wú is about to deploy. The whole framework is borrowed, almost figure for figure, from the Northern Song philosopher Shào Yōng (邵雍, 1011–77), better known by his honorific 邵康節, and his cosmological treatise 《皇極經世》. 蓋聞 ("it is said," "I have heard") is a classical essayist’s opening.
One yuán divides into twelve huì, corresponding to the twelve Earthly Branches: zǐ, chǒu, yín, mǎo, chén, sì, wǔ, wèi, shēn, yǒu, xū, hài.
The 元 splits into twelve 會 (huì), each named for one of the 十二地支, the twelve Earthly Branches. These same Branches name the twelve double-hours of the day — the very analogy the next lines exploit. (In Shao Yong’s full system the units nest further: 元 › 會 › 運 › 世; Wú keeps the top two.)
Each huì comes to 10,800 years.
該 (gāi) here means "amounts to, comes to." Twelve 會 × 10,800 = 129,600 years, exactly one 元. The arithmetic is deliberately exact: the cosmos runs like clockwork.
Take a single day as the measure: at the zǐ hour the yang-breath is born; at chǒu the cock crows; at yín there is not yet light; at mǎo the sun rises; at chén, after the morning meal; at sì, things settle into their order;
The governing conceit: the cosmic epoch is shaped like a single day, each Branch both an hour and a phase of the world’s life. Note the homely period-names — 雞鳴 (cock-crow), 食後 (after the morning meal), and below, 晡 (the late-afternoon meal), 黃昏 (dusk), 人定 ("when people are settled," the hài hour). The passage is essentially a poem of the hours.
at noon (wǔ) the sun stands at the zenith; at wèi it slips toward the west; at the shēn hour comes the late-afternoon meal, and the sun sets at yǒu; at xū falls the dusk; and at hài people settle to rest.
天中 = the zenith; 西蹉 = the sun "slipping" westward. The day-cycle now descends toward darkness — setting up the cosmic "dusk" of the next line.
Reasoning by the same scale on the grand cosmic clock: when the xū huì reaches its end, Heaven and Earth grow dim and the ten thousand things fall into decay.
A key reading: 否 is pǐ here, not fǒu — it carries the sense of the hexagram 否 (Obstruction): stoppage and decay, the "bad" pole of the cycle (as in 否極泰來, "when 否 peaks, 泰 returns"). 昏曚 (hūn méng) = dim and lightless. The world, like a day, has its dusk.
After another 5,400 years, as the hài huì begins, all turns to darkness; between Heaven and Earth no beings remain at all — and this is called chaos (hùndùn).
兩間 ("between the two") = the world between Heaven and Earth; 俱無 = utterly without [living things]. The return of 混沌 closes the loop opened in the poem: chaos is not only the beginning but a recurring phase — the cosmos dies back into formlessness before it is reborn.
After a further 5,400 years, as the hài huì nears its close, the cycle turns again — "when zhēn ends, yuán begins anew" — and as the zǐ huì approaches, light gradually returns.
貞下起元 is a four-word formula from the 《易經》: the virtues of the hexagram 乾 run 元亨利貞 (origination, success, advantage, firmness); when 貞 (the end, winter) is reached, 元 (the new beginning) arises once more. It is the engine of cyclical renewal — ending turning back into beginning.
Shao Kangjie wrote: "At the winter solstice, the midpoint of zǐ, the heart of Heaven does not shift; where the single yang first stirs, the ten thousand things are not yet born."
The couplet is by Shào Yōng himself (from his 擊壤集). 冬至 (winter solstice) is the year’s "midnight," matching the zǐ hour; 一陽初動 is the first stirring of yang — in Yijing terms the hexagram 復 (Return), one yang line rising beneath five yin. The "heart of Heaven" (天心) that does not move is the still point at the turn of the cycle. Wú quotes the philosopher to lend his fantasy the authority of Song metaphysics.
At this point, Heaven first has its root.
始 = "begins to." With the first stirring of yang, Heaven acquires a 根 (root) — a seed of being from which the manifest cosmos will grow.
After another 5,400 years, right at the zǐ huì, the light and clear rises upward: there is sun, there is moon, there are stars, there are asterisms. Sun, moon, stars and asterisms are called the Four Images. Hence it is said: Heaven opens at zǐ.
輕清上騰 — the light-and-clear (yang) rising — is the first act of differentiation. 辰 here means the fixed stars / asterisms. Note that Wú glosses 四象 ("the Four Images") loosely as sun-moon-stars-asterisms, rather than the Yijing’s technical four bigrams. 天開於子 ("Heaven opens at zǐ") is itself a famous Shao-Yong formula.
After another 5,400 years, as the zǐ huì draws to its close and the chǒu huì approaches, things grow firm and solid. The Book of Changes says: "Great indeed is the Creative and its origin! Perfect indeed is the Receptive and its origin! The ten thousand things draw their life from it, in obedient accord with Heaven." At this point, Earth first congeals.
The quotation fuses two lines of the 《易經》 Tuàn (彖) commentary — 大哉乾元 on the hexagram 乾 (the Creative) and 至哉坤元…乃順承天 on 坤 (the Receptive). 乾 is read qián. The pairing is pointed: Heaven (乾, active) initiates; Earth (坤, receptive) completes — and only now, at the turn from zǐ to chǒu, does Earth begin to congeal (凝結).
After another 5,400 years, right at the chǒu huì, the heavy and turbid settles downward: there is water, fire, mountain, stone, and earth. Water, fire, mountain, stone and earth are called the Five Forms. Hence it is said: Earth is opened at chǒu.
重濁下凝 — the heavy-and-turbid (yin) settling — mirrors 輕清上騰 above; 重 is read zhòng (heavy), not chóng. Note the text’s curious 五形 ("Five Forms": water, fire, mountain, stone, earth) where one expects 五行, the Five Phases (metal, wood, water, fire, earth). It is a deliberate, concrete variant — the literal forms the solidifying Earth takes — and the editions preserve it. 地闢於丑: Earth is split open and established at chǒu.
After another 5,400 years, as the chǒu huì ends and the yín huì begins, the ten thousand things burst into life. The Almanac says: "The breath of Heaven descends, the breath of Earth ascends; Heaven and Earth mingle, and all things are born." At this point, Heaven is clear and Earth is fresh, and yin and yang are joined.
發生萬物 = the bursting-forth of all things. The 曆 (Almanac) names the mechanism: Heaven’s qi descending and Earth’s qi rising, their union (交合) generating life — the same yin-yang reciprocity, now creative rather than destructive. 天清地爽 = a clear sky and a fresh earth, the world made ready for living things.
After another 5,400 years, right at the yín huì, humans are born, beasts are born, birds are born; this is what is meant by Heaven, Earth and Humanity — the Three Powers take their places. Hence it is said: Humanity is born at yín.
At the yín huì the three orders of living creatures appear, completing the 三才 (the Three Powers: Heaven, Earth, Humanity), the fundamental triad of Chinese cosmology, with humanity set between the other two. 人生於寅 completes the triple formula 天開於子、地闢於丑、人生於寅. Only now, the cosmic stage fully set, can the novel narrow at last to a single mountain and a single stone.
Before a single line of story, Wú gives us a cosmogony on a vast arithmetical scale — and the framework is not his invention. It is taken, almost number for number, from the Northern Song thinker Shào Yōng (邵雍, 1011–77), whose 《皇極經世》 organised all of time into nested cycles: 元 (129,600 years), 會, 運, 世. Wú keeps the two largest units and Shao Yong’s signature formula — 天開於子、地闢於丑、人生於寅 ("Heaven opens at zǐ, Earth at chǒu, humanity at yín"). That a comic fantasy about a monkey should open by quoting Song Neo-Confucian cosmology tells you something essential: the book’s playfulness rides on a genuinely learned, syncretic frame.
The passage’s beauty is its central analogy — the life of the cosmos unfolds like the hours of one day, each of the twelve Earthly Branches serving at once as an hour and as a cosmic phase. Onto this Wú threads quotations from across the tradition: a solstice verse by Shao Yong himself, the great Tuàn-commentary praises of 乾 and 坤 from the 《易經》, an almanac on the mingling of Heaven’s and Earth’s qi. The effect is a miniature anthology of Chinese cosmological thought — Confucian, Daoist and Yijing strands braided together — set as a portal to the narrative. This learned texture beneath the surface fun is exactly what scholars such as Andrew Plaks emphasise in the Ming masterworks.
Two small readings repay attention. 否 in 萬物否矣 is pǐ, the hexagram of Obstruction — the world’s "dusk" — not the everyday fǒu; and the text calls the materials of the solidifying Earth the 五形 ("Five Forms": water, fire, mountain, stone, earth) rather than the expected 五行 (Five Phases) — a concrete, almost tactile variant the editions faithfully keep. Above all, notice the rhetorical patience. This whole grand machinery exists to deliver one quiet payoff: that only after the cosmos itself is fully made can the story narrow to a single sea, a single mountain, a single stone. The monkey, when he comes, will be born into a universe the author has built from nothing.