Classica Sinica Medica

月郭

yuè guō

The moon's rim · yue guo

Also rendered: the moon's rim (Keeps the 郭 image of an encircling wall) · the moon's disc (Loses the emphasis on the outline that 郭 carries)

Cosmology

Reviewed · 2026-09

At a glance

Pinyin
yuè guō
Simplified
月郭
Literal
郭 is the wall that runs round a city — 說文 glosses it as the outer wall beyond the inner one — and by extension the rim or outline of anything round. 月郭 is therefore not the moon but the moon's circumference, and that distinction carries the whole argument: what fills and empties in chapter 26 is the visible rim, and the body's blood is said to follow it. The chapter uses it twice, 月郭滿 and 月郭空, and builds a prohibition on each.
Shuowen
《說文解字》：郭，齊之郭氏虛。从邑𩫏聲。段玉裁曰：郭本外城之名，引申為凡外郭之稱，又引申為輪郭之郭。月郭即月之輪郭，與「廓」義近而字別，底本作郭。本篇之目：月郭滿，則血氣實，肌肉堅；月郭空，則肌肉減，經絡虚。

In brief

The moon’s visible circumference, treated in chapter 26 as the clock that the blood keeps. When the rim is full, blood and qi are replete and the flesh firm; when it is empty, flesh wastes, the channels empty, the defence qi leaves and the form is left alone. The clinical rule follows directly: do not supplement at the full moon and do not treat at all when the rim is empty. The chapter’s physiology of the calendar rests entirely on this word being about the rim rather than the moon as an object.

Senses in the classical corpus

1
The full rim 月郭滿
月輪圓滿，血氣實而肌肉堅
月郭滿，則血氣實，肌肉堅 — Suwen 26
2
The empty rim 月郭空
月輪虧缺，肌肉減而經絡虚
月郭空，則肌肉減，經絡虚，衛氣去，形獨居 — Suwen 26
3
A prohibition built on each 月郭空無治
月空則不可施治，犯之為亂經
月生無冩，月滿無補，月郭空無治 — Suwen 26
4
The consequence of ignoring it 月郭空而治
治之則陰陽相錯、真邪不别
月郭空而治，是謂亂經 — Suwen 26
5
Against the waxing moon 月始生
與月郭對舉：一以始生言，一以輪郭言
月始生，則血氣始精，衛氣始行 — Suwen 26
6
The rim as a calendar 以月之虚盛
候月之虛盛即候其郭之盈虧
先知日之寒温，月之虚盛，以𠉀氣之浮沈 — Suwen 26

Occurrences in the classics

Passages where the term does real work, with the original, pinyin and English on the same line.

Display
1 passages
素問·八正神明論 Suwen 26 · 八正神明論 Read in context →
月郭滿，則血氣實，肌肉堅。月郭空，則肌肉減，經絡虚，衛氣去，形獨居。 月郭满，则血气实，肌肉坚。月郭空，则肌肉减，经络虚，卫气去，形独居。
Yuè guō mǎn, zé xuè qì shí, jī ròu jiān.Yuè guō kōng, zé jī ròu jiǎn, jīng luò xū, wèi qì qù, xíng dú jū.
When the moon’s rim is full, blood and qi are replete and the flesh is firm. When the moon’s rim is empty, the flesh wastes, the channels and network vessels empty, the defence qi departs, and the form is left alone.
月相三變，本篇分為三層，而「月郭」之名專屬其中之二：「月始生」言其初生，「月郭滿」言其輪郭圓滿，「月郭空」言其輪郭虧缺——滿與空皆就郭而言，故知郭是輪郭之郭而非月體之名。**「郭」讀 guō**，與「廓」義近而字別，底本作郭；**「減」讀 jiǎn，從水旁，底本不作「减」**。「形獨居」（「居」讀 jū）是三層中最沉重的一句：衛氣已去，形體雖在而失其所養，與第八篇「形與神俱」之旨反照——彼言其全，此言其孤。下文「月郭空無治」即由此而出：非不欲治，治之無益而反亂其經。

Compounds built on this term

月郭
yuè guō
the moon's rim
本篇二見，一滿一空，各立一禁
月始生
yuè shǐ shēng
the moon begins to wax
與月郭滿、月郭空為三月相
月之虚盛
yuè zhī xū shèng
the moon's emptiness and abundance
統言月相盈虧
衛氣
wèi qì
defensive qi
本站已立目（id 219），月郭空則衛氣去

How it has been translated

Every rendering below is a decision about which reader is being addressed. There is no neutral option.

Wiseman & Fengthe moon's outlineThey render 郭 as outline, which keeps the word's concern with the edge rather than the body of the moon.
Unschuldthe circumference of the moonUnschuld chooses circumference, which is geometrically exact and slightly more abstract than the Chinese.
This sitethe moon's rim'Rim' is short, keeps the edge rather than the disc, and reads naturally in the two phrases where the term actually occurs: a rim can be full or empty in a way a disc cannot. We keep 郭 out of the English entirely, since 'wall' would be a false friend here.

Entry status

Review pending — who reviews this?

2026-09

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Reading path

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