司外揣内

sī wài chuǎi nèi

Reading the outside from the inside · si wai chuai nei

Also rendered: Reading the outside from the inside (keeps both directions) · Presiding over the outer to measure the inner (literal, and it is long) · Inferring the interior from the exterior (clinical, and it is an interpretation)

Reviewed · 2026-10-25

At a glance

Pinyin
sī wài chuǎi nèi
Simplified
司外揣内
Literal
司 sī — to have charge of, to preside over; 外 wài — outside; 揣 chuǎi — to measure, to reckon by estimate; 内 nèi — inside.
Shuowen
《說文》:司,臣司事於外者。揣,量也,从手耑聲。「司外揣内」本篇1見,與「司内揣外」對舉,為全篇之結。

In brief

The chapter’s closing formula, and the earliest statement in the book of what examination is. The physician does not open the body; he reads the shadow the sun casts, the form the mirror holds, the echo the drum returns. 揣 is a cautious word — to measure by estimate rather than to know directly — and the caution is the point: the inference is exact because the correspondence is exact, not because the eye is sharp. Read with its other half, 司内揣外, it covers both directions, the far read from without and the near from within, and the pair is what later medicine divides into the four examinations. The chapter asks that the formula be stored in the chamber of the numinous orchid, and the request is not decorative: a method this general was felt to be dangerous knowledge.

Senses in the classical corpus

1
The far 故遠者司外揣内
所以远的司外揣内
Therefore the far is examined from outside by reckoning what is within.
故遠者司外揣内 — 靈樞·外揣
2
The near 近者司内揣外
近的司内揣外
The near is examined from within by reckoning what is without.
近者司内揣外 — 靈樞·外揣
3
What it rests on 動摇則應和,盡得其情
动摇就应和,完全得到实情
When moved they respond, and the true condition is fully obtained.
動摇則應和,盡得其情 — 靈樞·外揣
4
The image 若清水明鏡之不失其形也
像清水明镜不失去形貌
As clear water and a bright mirror do not lose the form.
若清水明鏡之不失其形也 — 靈樞·外揣

Occurrences in the classics

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

Display
1 passages
靈樞·外揣 Read in context →
故遠者司外揣内,近者司内揣外,是謂陰陽之極,天地之蓋。請藏之靈蘭之室,弗敢使泄也。 故远者司外揣内,近者司内揣外,是谓阴阳之极,天地之盖。请藏之灵兰之室,弗敢使泄也。
gù yuǎn zhě sī wài chuǎi nèi, jìn zhě sī nèi chuǎi wài, shì wèi yīn yáng zhī jí, tiān dì zhī gài. qǐng zàng zhī líng lán zhī shì, fú gǎn shǐ xiè yě.
Therefore the far is examined from outside by measuring what is within, and the near is examined from within by measuring what is without. This is the utmost of yin and yang, the cover of heaven and earth. I ask that it be stored in the chamber of the Numinous Orchid, and not be allowed to leak out.
「司外揣内」本篇1見,與「司内揣外」互文,為陰陽之極、天地之蓋,全篇之結在此。

Compounds built on this term

司内揣外
sī nèi chuǎi wài
reading the inside from the outside
相對之半
天地之蓋
tiān dì zhī gài
the cover of heaven and earth
此語之極

How it has been translated

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

This sitereading the outside from the insideplain and exact
Literalpresiding over the outside, measuring the insideexact, and it is unwieldy
Methodologicalexternal examination by inferenceclear, and it loses the symmetry

Entry status

Review pending — who reviews this?

2026-10-25

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Reading path

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