Tianji (天机)
Tianji 天机, the 'heaven-mechanism' — the self-running order of things, moved by no known driver. The Zhuangzi's word for how the centipede walks its ten thousand feet — and what the modern idiom turned into a secret.
The term
天机 (tiānjī) — 天, heaven, the natural; 机, mechanism — the loom’s working part, the trigger, the catch that lets a thing run. The term appears in the Zhuangzi in two of the site’s verified passages, both times naming the same thing:
- The centipede (ch. 17): 今予动吾天机，而不知其所以然 — “I move my heaven-mechanism and do not know how it works.”
- The snake (ch. 17): 夫天机之所动，何可易邪？吾安用足哉？ — “How can what the heaven-mechanism moves be exchanged? What use would I have for feet?”
- And the tradition’s own gloss, in Cheng Xuanying’s subcommentary on the penumbra fable (ch. 2): 天机自张，莫知其宰 — “the heaven-mechanism spreads itself; no one knows its driver.”
Why the term matters
- It is the 自 family’s machinery-word. The ziran concept page holds the family (自然, 自化, 自取) — the book’s words for things running themselves. 天机 is the family’s most mechanical member: the mechanism that runs, whose driver is not known. The centipede’s answer is the family’s creed in one sentence: it moves, and does not know how — and the snake’s is the creed’s refusal of envy: what the mechanism moves cannot be exchanged, so questions like “why my feet and not yours” have no hold.
- Not a machine, and not a secret. The term’s two modern corruptions are both documented on this page: (1) machine-agnostic readings that make 天机 sound like a clockwork — the text’s own word is 张, spreads itself, a loom’s self-unfolding, not a mechanism with a maker; and (2) the idiom drift that matters most: modern Chinese 天机 survives chiefly in 天机不可泄露 — “heaven’s secrets must not be revealed” — where 天机 has become a secret to be kept. The Zhuangzi’s 天机 is the opposite of a secret: it is the open, self-running order, and the centipede tells it plainly. The site flags the drift on every use, per its idiom-drift discipline.
- 莫知其宰 — no driver known. Cheng Xuanying’s gloss ties the term to the chapter-2 question (若有真宰 — “as if there were a true driver”) and answers it negatively: the mechanism spreads itself, and the driver is not known — not denied, not affirmed, left unlocatable. The term is the site’s anchor for how the tradition handles the question of agency: movement without a locatable mover.
Usage notes
The term stays in pinyin with the gloss “heaven-mechanism”; the two ch. 17 attestations are always cited together (the site’s rule for terms with multiple uses); the modern “secret” drift is flagged wherever the term appears; 张 (spreads itself) is kept against “machine” translations.
Sources
- Zhuangzi ch. 17 (Qiushui): the centipede's 今予动吾天机，而不知其所以然 and the snake's 夫天机之所动，何可易邪 — verified on the kui-xian-chain page
- Cheng Xuanying's subcommentary on the penumbra fable (ch. 2), quoted in a Peking University Journal (2009) study: 夫待与不待，然与不然，天机自张，莫知其宰 — 'the heaven-mechanism spreads itself; no one knows its driver' — verified on the wang-liang-wen-jing page