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I Ching Birth Hexagram · Hexagram 18 of 64

Hexagram 18, 蠱 Gǔ: worms in the bowl, and the work of repair

蠱 Gǔ is hexagram 18 of the Zhouyi, which sets wind below a mountain, where it blows against the slope and stirs up what has lain still. The character shows worms in a bowl and means decay; the tradition reads the hexagram as the repair of what has gone bad, and its Judgment, unexpectedly, promises great progress.

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Hexagram 18, 蠱 Gǔ, drawn as six lines numbered from the bottom: broken, whole, whole, broken, broken, whole. The lower, inner trigram is 巽 Xùn, Wind; the upper, outer trigram is 艮 Gèn, Mountain. 1 2 3 4 5 6 Upper, outer 艮 Gèn, Mountain Lower, inner 巽 Xùn, Wind 18 蠱 Gǔ Lines numbered from the bottom
The figure of 蠱 from the bottom line up: Wind inside, Mountain outside. Three broken lines, three whole.

Facts

Number
18 of 64, in the received order
Character and pinyin
蠱 Gǔ ䷑
Our title
Repairing Decay
Lines, bottom to top
yin, yang, yang, yin, yin, yang
Lower trigram (inner)
☴ 巽 Xùn, Wind
Upper trigram (outer)
☶ 艮 Gèn, Mountain
Within (nuclear)
54 歸妹 Guī Mèi, The Younger Sister Weds
King Wen pair
17 隨 Suí, Following
Legge's name (1882)
Kû
Part of the text
The first part (上經), 1 to 30

Meaning

The character 蠱 is a bowl with worms in it, and its sense runs from decay to the harm that comes of neglect. The figure puts the wind under the still mountain, a stagnant air trapped beneath a slope. The surprise is the Judgment. It does not lament the rot; it promises great progress, allows the great crossing, and gives the book's most quoted rule of timing: weigh the three days before the turning point and the three days after it.

The Image turns the picture outward and inward at once: the superior man stirs people up and nourishes his own character. In our reading, 蠱 is the hexagram of repair. Something was left too long, and the work is to set it right, deliberately, thinking about what led to the break and what follows it. The line texts place that work in a family, which makes it a matter of inheritance as much as of effort.

The lines

Five of the six lines speak of a child dealing with what a parent left undone. The first and third take on the father's troubles, the first carefully and the third with some small regret but no great fault; the second deals with the mother's and is told not to push its correctness to the limit. The fourth looks on the father's troubles indulgently and comes to regret it; the fifth deals with them and wins praise. The top line stands outside the work: it "does not serve either king or feudal lord", in Legge's words, and attends to its own affairs.

Its pair and opposite is 隨, hexagram 17; within 蠱 lies 歸妹, hexagram 54.

In the birth cast

The time cast arrives at 蠱 when the year, month and day leave 7 on eight, which puts 艮 mountain above, and the same total with the hour added leaves 5, which puts 巽 wind below. Which line moves depends on what the whole total leaves on six, and each line turns the figure into a different hexagram:

  • Line 1 (初六) moving: becomes 26 大畜 Dà Xù, Great Restraint
  • Line 2 (九二) moving: becomes 52 艮 Gèn, Stopping
  • Line 3 (九三) moving: becomes 4 蒙 Méng, The Untaught Mind
  • Line 4 (六四) moving: becomes 50 鼎 Dǐng, The Cauldron
  • Line 5 (六五) moving: becomes 57 巽 Xùn, Entering Wind
  • Line 6 (上九) moving: becomes 46 升 Shēng, Ascent

Lines 2 to 5 give the hexagram within, 54 歸妹 Guī Mèi, The Younger Sister Weds. Everyone born in the same lunar day and double hour has the same cast, so the figure describes a moment, not a person.

Correspondences

Each item with how it stands: “sourced” is in the work cited, “our construction” is EsoTerrier’s own, and “disputed” means the sources disagree.

Trigram virtues (Shuogua, chapter 7)
巽 entering, pervading below; 艮 stopping, at rest above, in our English sourced
Trigram family places (Shuogua)
eldest daughter below, youngest son above sourced
Trigram body and animal images (Shuogua)
thighs and fowl below; hands and dog above sourced
Trigram phases (a classical correspondence: the Plum Blossom text's table)
Wood below, Earth above. The Han assignment of 梅花易數, book 1, also used by Jing Fang; not stated as such in the Zhouyi sourced
Inverse and opposite
Upside down: 17 隨 Suí, Following; every line flipped: 17 隨 Suí, Following sourced
Human Design gate
Gate 18, from 183.875° to 189.5° of the tropical zodiac on Ra Uru Hu's wheel (1987): a modern placing, not the I Ching's sourced
Our English title
Repairing Decay: EsoTerrier's own, from the sense of 蠱 our construction

How the schools read it

The Zhouyi, in Legge's translation (1882)
“(He should weigh well, however, the events of) three days before the turning point, and those (to be done) three days after it.”
The Image (大象), one of the Wings, in our paraphrase
Wind at the foot of a mountain; the superior man helps the people and nourishes his own virtue.
The Plum Blossom method (Ming)
A figure reached by numbers: 艮 above when the year, month and day leave 7 on eight, 巽 below when the same total with the hour leaves 5.
Human Design (Ra Uru Hu, 1987)
Takes the number for its gate 18 and puts it on the zodiac; its own reading, which we do not quote.
EsoTerrier
Wind under the mountain, and things left to spoil: the work of setting right what came before, done decisively, with thought given to the days before and after.

Claims about it

  • Gate 18 of Human Design, at 183.875° to 189.5° of the zodiac, is where the I Ching itself places hexagram 18.

    false

    What the record shows: The wheel is Shao Yong's circle rotated by Ra Uru Hu in 1987 to 1989 so that hexagram 41 starts at 2° Aquarius. No Chinese source we found puts the hexagrams on degrees of the zodiac.

  • Being born under 蠱 Gǔ fixes a person's character.

    unverified

    What the record shows: A modern reading with no source in the tradition. The Zhouyi has no birth hexagram; the cast reads a figure, not a person, and everyone born in the same lunar day and double hour shares it.

Elsewhere on EsoTerrier

Sources

Primary texts (6)
  1. James Legge (trans.), The Yî King, Sacred Books of the East XVI. Oxford: Clarendon Press, 1882. Public domain; quoted briefly and credited. en.wikisource.org/wiki/Sacred_Books_of_the_East/Volume_16
  2. 梅花易數 (Meihua yishu, the Plum Blossom method), attributed to Shao Yong, book 1: the time rule, the trigram numbers and phases, and the casts of the plum blossom and the peonies. zh.wikisource.org/wiki/梅花易數/卷一
  3. 周易 (Zhouyi), the received Chinese text of the hexagram and line statements with the Ten Wings. ctext.org/book-of-changes
  4. The same, the 1882 Oxford edition scanned (archive.org), for hexagrams 33 to 64 and the appendices. archive.org/details/sacredbooksofchi16conf
  5. The Unicode Standard, Yijing Hexagram Symbols, U+4DC0 to U+4DFF. unicode.org/charts/PDF/U4DC0.pdf
  6. 京氏易傳 (Jingshi yizhuan), attributed to Jing Fang, three books. zh.wikisource.org/wiki/京氏易傳
Studies and other sources (3)
  1. "King Wen sequence", Wikipedia. en.wikipedia.org/wiki/King_Wen_sequence
  2. Jovian Archive, "Gates and hexagrams in Human Design" (cited for the wheel's origin only). jovianarchive.com/pages/gates-and-hexagrams-in-human-design
  3. "Hexagram (I Ching)", Wikipedia. en.wikipedia.org/wiki/Hexagram_(I_Ching)
Our own research (5)
  1. EsoTerrier, I Ching research, 10 to 14 October 2026: the method, the validation (61 births), the variants and the lists.
  2. EsoTerrier calculation engine, the I Ching service and its reference tables (titles, glosses and readings our own).
  3. EsoTerrier, Gene Keys research, 9 October 2026: the legal and trade-mark report, on which hexagram names are free to use.
  4. EsoTerrier, Human Design research, 9 October 2026: the wheel, gate 41 at 2° Aquarius, 5.625° per gate.
  5. EsoTerrier, engine audit of 14 October 2026: the reworded titles, readings and trigram qualities, with the passages each rests on.

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By EsoTerrier. Written with AI assistance from our research and checked against its sources; last revised 19 October 2026. How we write these pages.

First published ; last revised . Corrections: support@esoterrier.com.