Zhèng Shòuquán 鄭壽全 (1804–1901), zì Qīn’ān 欽安 (by which the author is universally known: Zhèng Qīn’ān 鄭欽安), was the founder of the Sìchuān “Fire-spirit School” 火神派 of Chinese medicine and the most consequential Qīng-period Shu (Sìchuān) physician. Native of Línqióng 臨邛 (modern Qiónglái 邛崍, Chéngdū) in Sìchuān, Zhèng trained under the Sìchuān physician Liú Zhǐtáng 劉止唐 and developed a distinctive Shānghán-grounded clinical doctrine emphasizing the centrality of yángqì and mìngmén huǒ 命門火 (gate-of-life fire) — articulated in his three principal works: Yī lǐ zhēn chuán 醫理真傳 (1869), Yī fǎ yuán tōng 醫法圓通 (1874), and Shānghán héng lùn 傷寒恆論 (KR3ef060). The “Fire-spirit” tradition Zhèng founded — characterized by bold use of large-dose fùzǐ 附子 (aconite) and gānjiāng 乾薑 — has had a continuous Sìchuān lineage through Lú Zhùzhī 盧鑄之, Lú Yǒngdìng 盧永定, Wú Pèihéng 吳佩衡, and into the modern period. Died in 1901, aged 97 by Chinese reckoning.