fǎn zuǒ
Also rendered: Contrary assistance (this site; 反 is the direction it comes from, 佐 the help it gives) · Paradoxical adjuvant (current in pharmacology; it is accurate about the ingredient and drops the chapter's word 反)
Reviewed · 2026-10-14
At a glance
Assistance given from the contrary side, and the last resort of the chapter’s order of prescriptions: 偶之不去，則反佐以取之，所謂寒熱温涼，反從其病也. Where the ordinary rule is 治寒以熱，治熱以寒, 反佐 takes a drug of the same disposition as the disease and puts it in the formula, so that the medicine follows the illness instead of opposing it — 反從其病 — and by following it, gets in. The chapter gives no formula and no proportion; it gives the principle, and the principle is the same one it states later in the passage on 反治: 熱因寒用，寒因熱用，塞因塞用，通因通用，必伏其所主，而先其所因. Though the name says 反, what the physician is doing is finding the way in, which is why the next sentence of that passage adds 其始則同，其終則異.
Passages where the term does real work, with the original, pinyin and English on the same line.
Every rendering below is a decision about which reader is being addressed. There is no neutral option.
| This site | contrary assistance | help given from the side the disease is on, brought in when odd, even and doubled formulae have all failed |
| Literal | contrary aid | exact, and 佐 is always help for someone else rather than aid in general |
| Descriptive | adding a little of the disease's own disposition | clear, and too long to stand beside the chapter's two graphs |
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