Hexagram 18 — Work on What Has Been Spoiled (Decay) 蠱

The upper trigram is Mountain (艮), ☶ — keeping still, limit, stopping. The lower trigram is Wind (巽), ☴ — gentle, penetrating. The interplay of these two forces, with the upper sitting above the lower, is what gives this hexagram its character.

The classical Chinese name 蠱 (Gǔ) carries the connotations that the King Wen sequence assigned to position #18 in the order of change: Inherited rot — old systems and family patterns that were left to decay. The work is reform, not blame: cleanly fix what was left for you.

This hexagram is also rendered in English as Decay, Corruption, Repairing, Branch — different translators emphasise different facets of its meaning.

What follows on this page is the full classical reading: the Judgment attributed to King Wen, the Image attributed to the Duke of Zhou, all six line texts, and the three derived hexagrams (互卦, 錯卦, 綜卦) that classical practitioners always read alongside the primary one. The page closes with a contemporary application section — how the configuration tends to land in modern decisions.

The Judgment (彖辭) is the line attributed to King Wen, written while he was imprisoned by the last Shang ruler. It states the configuration’s essential character and indicates the favorable or unfavorable trajectory of the situation. For 蠱, it sets the time-quality of the moment: Inherited rot — old systems and family patterns that were left to decay. The work is reform, not blame: cleanly fix what was left for you.

The decision quality the judgment recommends here is direct: Three days before, three days after — prepare carefully, follow through carefully. The repair work is the path to supreme success.

The Image (大象傳, “Greater Image”) is the second classical layer, attributed to the Duke of Zhou. It takes the natural picture suggested by the two trigrams — mountain (艮, ☶) above wind (巽, ☴) — and uses it to describe how the noble person (君子) responds. Image readings are a guide to right conduct: not what will happen, but what one ought to do.

For hexagram #18, the image points to a specific style of inner posture appropriate to this configuration. The classical formulation should be read as a behavioral instruction, not as a metaphor.

Each hexagram has six lines (爻), counted from the bottom up. When you cast the I Ching using the traditional yarrow-stalk or three-coin method, certain lines emerge as “changing lines” — these are the ones whose line text (爻辭) speaks directly to your question. Below are all six line texts for hexagram 18 in classical Chinese with English rendering. If your reading produced a changing line, the relevant text is the one whose position matches.

Line position carries its own structural meaning: lines 2 and 5 are the “central” positions of their respective trigrams (and line 5 is the ruler’s position). Yang lines in odd positions and yin lines in even positions are “correct”; mismatches indicate friction.

Whichever hexagram you cast, classical practice does not stop at the surface. The next thing you read is the 互卦 (hù guà) — the nuclear or mutual hexagram. Below is what it is for 蠱 Gǔ, and how to read its meaning.

The 互卦 (Nuclear hexagram, sometimes also called the “mutual” or “inner” hexagram) is constructed from the inner four lines (lines 2, 3, 4, and 5) of the primary hexagram. Lines 2-3-4 form the new lower trigram; lines 3-4-5 form the new upper trigram. What it shows is the inner pattern of the situation — the structural undercurrent beneath the surface configuration.

The nuclear hexagram of 蠱 Gǔ is hexagram #54, 歸妹 Guī Mèi — The Marrying Maiden. An irregular union — the maiden marries below her station. Wrong place, wrong role; nothing major can be undertaken. Yet the principle of subordination, accepted gracefully, brings late good fortune.

What this means in practice: the surface configuration of Work on What Has Been Spoiled (Decay) is being driven, underneath, by the energetics of The Marrying Maiden. When you act on this hexagram, the inner texture of your situation is shaped by the nuclear — so it is the nuclear, not just the primary, that you must respect.

The second derived reading is the 錯卦 (cuò guà) — the inverse or polar opposite. Every yang line becomes yin and every yin line becomes yang. The result is the configuration that lies on the other side of every choice in the primary.

The 錯卦 (Inverse, sometimes called “Opposite” or “Crossed”) is constructed by flipping every line of the primary hexagram — every yang becomes yin, every yin becomes yang. It is the hexagram’s polar opposite: the situation that would result if every active force became receptive and every receptive force became active.

The inverse of 蠱 Gǔ is hexagram #17, 隨 Suí — Following. Following — leading by adapting to what is true. Thunder rests inside the lake; the strong yields to the time and the situation, gaining far more than by force.

Reading the inverse is how classical practitioners check their interpretation against its mirror. The wisdom of Work on What Has Been Spoiled (Decay) is sharpened by knowing what its absolute negation looks like — Following is the warning, the contrast, or sometimes the secret complement of the primary configuration.

The third derived reading is the 綜卦 (zōng guà) — the reverse or inverted hexagram. The whole figure is turned upside down. This is how the situation reads from the perspective of the other party, or how the same event would be described looking back from its conclusion.

The 綜卦 (Reverse, sometimes called “Inverted” or “Turned”) is constructed by turning the entire hexagram upside down — line 1 becomes line 6, line 2 becomes line 5, and so on. It is the situation seen from the other side — what the same event looks like to your counterpart, or what the same hexagram becomes when read from the top down rather than the bottom up.

The reverse of 蠱 Gǔ is hexagram #17, 隨 Suí — Following. Following — leading by adapting to what is true. Thunder rests inside the lake; the strong yields to the time and the situation, gaining far more than by force.

In the King Wen sequence, 蠱 and 隨 sit as a paired set — one is the situation, the other is the situation viewed from the opposite end. When you read your own hexagram, your counterpart in the situation is reading the reverse. Knowing the 綜卦 is how you read both halves of the same event.

In contemporary practice, hexagram 18 蠱 Gǔ tends to surface in readings around questions of:

• taking over a turnaround
• fixing legacy code
• healing family patterns
• reorganizing inherited systems

The decision-quality recommendation, distilled from the Judgment, the Image, and the line texts together, is: Three days before, three days after — prepare carefully, follow through carefully. The repair work is the path to supreme success.

If you cast this hexagram and want to integrate its reading with your personal chart, the next step is to layer it onto your BaZi (Four Pillars) or Zi Wei Dou Shu profile — the same hexagram lands differently on a Yang Wood day master in a hot summer than it does on a Yin Water day master in winter. The I Ching tells you the shape of the moment; your BaZi tells you the terrain the shape will land on.

For questions about career — promotions, role changes, business decisions, leaving or staying — hexagram 18 蠱 Gǔ (Work on What Has Been Spoiled (Decay)) describes the time-quality your professional situation is sitting in. Inherited rot — old systems and family patterns that were left to decay. The work is reform, not blame: cleanly fix what was left for you.

The trigram configuration of Mountain above Wind (keeping still, limit, stopping over gentle, penetrating) is the lens. Read the upper trigram (Mountain) as how your work appears to others — the visible shape of the role, the project, the public face. Read the lower trigram (Wind) as the inner ground you are bringing to it — your competence, motivation, and disposition.

The decision-quality recommendation, distilled from the Judgment, applies directly to career deliberations: Three days before, three days after — prepare carefully, follow through carefully. The repair work is the path to supreme success.

If your reading produced a changing line, the most career-relevant positions are line 5 (the ruler’s seat — how authority is moving above you) and line 2 (the worker’s central position — how your own role is moving). For hexagram 18, line 5 reads: 六五：幹父之蠱，用譽。 — Six in the Fifth: Setting right what has been spoiled by the father. One meets with praise.

For questions about relationships — love, family, friendship, partnerships, conflict — hexagram 18 蠱 Gǔ (Work on What Has Been Spoiled (Decay)) describes the energetic shape between the parties involved, regardless of which side asked the question. Inherited rot — old systems and family patterns that were left to decay. The work is reform, not blame: cleanly fix what was left for you.

Read the configuration as a meeting of two forces: Mountain above Wind (keeping still, limit, stopping over gentle, penetrating). The upper trigram (Mountain) describes how the situation looks from the outside between you, while the lower trigram (Wind) describes the inner ground each person is bringing to the meeting. Misalignment between the two is often what the cast is pointing at.

The decision-quality recommendation, applied to the relational frame: Three days before, three days after — prepare carefully, follow through carefully. The repair work is the path to supreme success.

If your reading produced changing lines, lines 2 and 5 are the most relationally significant — they are the central positions of the lower and upper trigrams respectively, and classical practice reads them as the “hearts” of each side of the relationship. The reverse hexagram (綜卦) is also worth reading for relationship questions: it shows the same situation from the other person’s perspective.

For questions about making a decision — whether to act, when to act, which option to choose, whether to wait — hexagram 18 蠱 Gǔ (Work on What Has Been Spoiled (Decay)) is among the most direct of the I Ching’s answers. The Judgment of every hexagram is, structurally, a recommendation about decision quality.

The decision recommendation for this configuration: Three days before, three days after — prepare carefully, follow through carefully. The repair work is the path to supreme success.

If your reading produced a changing line, treat the line text as a more specific instruction within that overall recommendation. The line texts (爻辭) of hexagram 18 are the I Ching’s answer to the more granular form of your question; read the relevant line above (in the “The six lines” section) for the specific configuration of action your situation calls for. Line 5 (the ruler’s position) is the most authoritative line for decision questions when a clear path forward is needed.

For complex decisions, also read the inverse (錯卦) of this hexagram — it shows you the polar-opposite course of action, which is the test the I Ching uses for whether a recommendation is robust to its own negation.

For questions about health and vitality, hexagram 18 蠱 Gǔ (Work on What Has Been Spoiled (Decay)) describes the energetic quality your body and mental state are operating in. Inherited rot — old systems and family patterns that were left to decay. The work is reform, not blame: cleanly fix what was left for you.

In classical Chinese-medicine correspondences, the upper trigram (Mountain) governs the hand (TCM organ: spleen), and the lower trigram (Wind) governs the thigh (TCM organ: gallbladder). For health questions, this hexagram’s configuration draws attention to those two channels in particular.

In Five-Element terms, the upper trigram is Earth and the lower is Wood; the relation between these two elements (generative, controlling, or weakening) is part of how the hexagram lands on your specific BaZi chart.

The decision-quality recommendation, applied to health: Three days before, three days after — prepare carefully, follow through carefully. The repair work is the path to supreme success. The I Ching does not diagnose, but it does indicate the time-quality of recovery, depletion, or balance — which is exactly what classical practitioners read it for in medical contexts. Layer this reading onto your BaZi (Four Pillars) chart to see how the hexagram’s elemental configuration interacts with your day master’s elemental balance — the same hexagram lands very differently on a hot-summer Yang Wood than it does on a winter-frozen Yin Water.