瘟疫一证，历代明哲具有成方。如仲景有大青龙汤、阳旦汤，越婢汤、黄芩汤、白虎汤、大小柴胡汤、
三承气汤、麻黄升麻汤，诸条列瘟疫之见证，为汗法、下法、和法、双解法，轻重深浅，纤毫备具。特散见
于诸经条中而未尝直指其名为瘟疫，非不欲明言也。其书本伤寒立论，而互为区别之书，非专论瘟疫之书，
且上古文辞简易，详于辨证，而不详于立名，欲人从证上细辨，则不必于名上
区别，而自无混治之失。嗣是而后，河间有《宣明五气论》，则论瘟疫较详，立法更备。如桂苓甘露饮、黄
连解毒汤、三已效方、凉膈散、人参石膏汤、双解散诸方皆是，而亦未正其名。易老、东垣，大羌活汤、
九味羌活汤，立方更备，而亦无专书、无特名。至吴又可先生贯串古今，融以心得，着时行《瘟疫》一论，
真可谓独辟鸿蒙，揭日月于中天矣。顾其书具在，而时贤有未见而不用其法，或虽见其书。而不能信者，无
怪矣！有口诵其书，啧啧称道，而对证施方，仍多不用其法。口则曰此时证也，而手则仍用伤寒之方，拘伤
寒之法者，比比皆然。愚揣其情，必非知而不用也，知其名而未得其辨证之法耳！愚目击心伤，不揣固陋，
而取吴子之原本，或注释，或增订，或删改，意在辨瘟疫之体异于伤寒，而尤慎辨于见证之始，故首增辨气、
辨色、辨脉、辨舌、辨神诸论于开卷，使阅者一见了然，则吴子之书，人人可用，而瘟疫之横夭
者少，生全者多，诚斯世斯民之幸也！
上元戴天章麟郊甫识于存存书屋
乾隆四十八年岁在癸卯夏五月望日孙男嗣琦谨书
瘟疫这一病证，历代明智的医家都有现成的方剂。比如张仲景有大青龙汤、阳旦汤、越婢汤、黄芩汤、白虎汤、大柴胡汤与小柴胡汤、三承气汤（调胃承气汤、小承气汤、大承气汤）、麻黄升麻汤等，这些条文列举了瘟疫的表现症状，涵盖了汗法（发汗解表）、下法（泻下通便）、和法（和解少阳）、双解法（表里双解）等方法，轻重深浅，细致完备。只是这些内容散见于《伤寒论》各经的条文中，从未直接指明其名为“瘟疫”，这并不是不想说明白。因为该书是以伤寒立论，是与伤寒互为区别的书，并非专门论述瘟疫的书，况且上古时期的文辞简单浅易，侧重于辨证，而不侧重于确立病名，希望人们从症状上仔细辨别，就不必在名称上加以区分，自然就不会出现混淆治疗的失误。
此后，刘河间著有《宣明五气论》，对瘟疫的论述较为详细，立法更加完备。如桂苓甘露饮、黄连解毒汤、三已效方、凉膈散、人参石膏汤、双解散等方剂都是，但也未正其名。李东垣（李杲）及张元素（字易老），创制了大羌活汤、九味羌活汤，立方更加完备，但也无专书、无特名。到了吴又可先生贯通古今，融合个人心得，撰写了关于时行病的《瘟疫论》，真可以说是独辟蹊径，如日月高悬中天一般光辉。然而他的书虽然存在，但当时的贤者有的没见到而不用其法，或者虽见到了书却不能相信，这也不足为怪！有的人口中诵读他的书，啧啧称赞，但在面对具体病症施方时，仍然大多不使用他的方法。口里说是此时的证候，手里却仍用治疗伤寒的方剂，拘泥于伤寒治法的人，比比皆是。我揣测他们的情由，必定不是知道而不使用，而是知其名但未掌握其辨证的方法罢了！我目睹此情内心伤痛，不顾自己固陋浅薄，选取吴子（吴又可）的原著，有的加以注释，有的增订，有的删改，意在辨析瘟疫的本质异于伤寒，尤其谨慎地在见证之初进行辨别，所以在卷首增加了辨气、辨色、辨脉、辨舌、辨神等理论，使阅读者一目了然，那么吴子的书，人人都能使用，而因瘟疫横死夭折的人就会减少，生存保全的人就会增多，这确实是当今世道百姓的幸事啊！
The syndrome of plague (Wenyi, infectious epidemic disease) has had established prescriptions by wise physicians throughout history. For instance, Zhang Zhongjing [Zhang Ji] utilized Da Qing Long Tang (Major Green Dragon Decoction), Yang Dan Tang (Yang Shield Decoction), Yue Bi Tang (Yue Bi Decoction), Huang Qin Tang (Scutellaria Decoction), Bai Hu Tang (White Tiger Decoction), Xiao Chai Hu Tang (Minor Bupleurum Decoction) and Da Chai Hu Tang (Major Bupleurum Decoction), San Cheng Qi Tang (Three Inheriting Qi Formulas: Tiao Wei Cheng Qi Tang, Xiao Cheng Qi Tang, Da Cheng Qi Tang), and Ma Huang Sheng Ma Tang (Ephedra and Citron Verbena Root Decoction). These clauses list the clinical manifestations of plague, employing sweating methods (Han Fa), purgative methods (Xia Fa), harmonizing methods (He Fa), and dual-resolving methods (Shuang Jie Fa), covering degrees of severity and depth with meticulous detail. However, these contents are scattered among the clauses of various meridians in the *Shanghan Lun* (Treatise on Cold Damage) without explicitly naming them as "plague." This is not because they did not wish to clarify it. The book was established upon the theory of cold damage, serving as a text distinguishing itself from cold damage, rather than a specialized treatise on plague. Moreover, ancient literary expressions were simple and concise; they emphasized pattern differentiation (Bian Zheng) over nomenclature. They intended for practitioners to differentiate carefully based on symptoms, so there was no need to distinguish by name, thereby naturally avoiding errors in confused treatment.
Subsequently, Liu Hejian authored *Xuan Ming Wu Qi Lun* (Discourse on Declaring the Five Qi), discussing plague in greater detail and establishing more comprehensive laws. Prescriptions such as Gui Ling Gan Lu Yin (Cassia Twig, Poria, and Sweet Dew Drink), Huang Lian Jie Du Tang (Coptis Decoction to Relieve Toxicity), San Yi Xiao Fang (Three Effective Formulas), Liang Ge San (Cool the Diaphragm Powder), Ren Shen Shi Gao Tang (Ginseng and Gypsum Decoction), and Shuang Jie San (Dual-Resolving Powder) are examples, yet none formally named the disease. Li Dongyuan (Li Gao) and Zhang Yishou (Zhang Yuansu, courtesy name Yilao) created Da Qiang Huo Tang (Major Notopterygium Decoction) and Jiu Wei Qiang Huo Tang (Nine-Ingredient Notopterygium Decoction), making their formulas even more comprehensive, but still lacking a dedicated book or specific title. It was not until Mr. Wu Youke integrated past and present knowledge with his personal insights that he wrote the *Wenyi Lun* (Treatise on Plague) regarding seasonal epidemics. His work can truly be described as pioneering a new path, shining like the sun and moon in the mid-sky.
Nevertheless, although his book exists, some contemporary scholars have either not seen it and thus do not use its methods, or have seen it but fail to believe in it; this is not surprising. There are those who recite his book with praise, yet when prescribing for specific conditions, they still largely disregard his methods. While verbally acknowledging it as a current epidemic syndrome, their hands continue to use formulas for cold damage, adhering strictly to cold damage methodologies—a phenomenon common everywhere. I speculate that their situation is certainly not one of knowing but refusing to use; rather, they know the name but have not mastered the method of pattern differentiation! Witnessing this with a pained heart, and disregarding my own ignorance and shallowness, I have selected Wu’s original text, adding annotations, revisions, deletions, or modifications. My intent is to distinguish the nature of plague from cold damage, particularly emphasizing careful differentiation at the initial stage of manifestation. Therefore, I added chapters at the beginning of the volume on differentiating Qi, complexion, pulse, tongue, and spirit (Shen/Essence-Spirit), enabling readers to understand clearly at a glance. Thus, Wu’s book can be used by everyone, reducing premature deaths from plague and increasing survival rates, which is indeed a blessing for the people of this era!
Dai Tianzhang, courtesy name Linjiao, from Shangyuan, recorded at Cun Cun Study Hall.
On the 15th day of the fifth month of summer, in the year Guimao (1783), respectfully inscribed by grandson Siqi.