夫 症为外感证中之最剧。其毒厉之气。往往夭札人性命。而仲景伤寒论中。于六经之证治。
则 言之。谆谆详尽。绝无一字论及 症者。何也。其意盖以中风伤寒。及温病痉湿 等症。皆人
所自致。犹天地之气。冬月温暖。不能闭藏其来复之阳。少阳之生气不布而疾疫饥荒。人身之肾。属坎而为冬脏。
真阳藏于两肾寒水之中。若失精泄汗。寒水包藏之气受伤。则藏阳败泄。少阳之气不能升发。而卫外之阳气不密。
风寒温暑之邪。皆可乘虚而入。生气通天论所谓顺之则阳气固。虽有贼邪。弗能害也。失
之则卫气解散。此谓自伤。气之削也。又云。阳气者。若天与日。失其所则折寿而不彰。是故。阳因而上。卫
外者也。又云。阳者卫外而为固也。寒水伤则阳不固。阳不固则外气入。故曰冬伤于寒。春必温病。此皆
外感之内因也。故有内因则病。无内因则邪气不能入。故云虽有贼邪弗能害。仲景所以名之曰伤寒论。而
不曰中风温暑论也。叔和不达其旨。谬以冬伤于寒为伤寒。故有寒毒藏于肌肤之说。为千载之误。至于疫病
则不然。与伤寒大异。其有内因者固病。而无内因者亦病。何也。疫病之传染。或一乡之内。或一里之中。
甚至连州跨郡。沿门阖境。溅染缠绵。老幼皆然。床连枕藉。烟火寂然。病气盈室。亲故不敢入其门。
役不敢近其处。至于死丧相继。腐 载途。若此者。岂皆尽有内因。乘虚而入邪。皆因疫气沾染所致耳。
所谓疫者。乃天地郁蒸之气。如秋行夏令。冬行春令。春行初夏之令。全无闭藏清肃之气。纯是温暖不正之邪。
人在气中。感触而成瘟疫。一人始之。其毒厉之气。从鼻息而入。其水土之邪。从食饮而入。病则脉颇相同。
症颇相类。遂相传染。蔓衍牵连。如水之HT 至。如火之延烧。一时难止难灭。如天下之大工大役。无能免者。
故谓之疫。其病状虽有不齐。大概皆发 疹。所以 为时行疫气之所致。非伤寒条例中病。故论中但有中
风伤寒。温暑痉湿 之病。而无发 一证也。然发 时疫。以仲景之用心。岂竟弃置而弗论哉。夫仲景所撰。
原云伤寒卒病论合十六卷。以理度之。必非漫然弃置。大约在卒病论六卷之中。其六卷既失。遂至遗亡
而不得见耳。顾名思义。盖以忽然得之。故曰卒病。时疫乃厉气所染。非积渐所致。岂非卒病乎。后人以
卒病疑为杂病者。大谬不然之论也。观其附于伤寒论之后。必非
杂病之缓而可待者。故知其为卒病无疑也。然而 疹之发。皆因时行之一气所使。非关人事。所以一
人始之。则凡病者皆然。若无此气。则虽有时行之他病。而绝无 疹矣。朱奉议活人书第十三问云。夏
月天气大热。玄府开。脉洪大。正宜发汗。但不可用麻黄桂枝热性之药。须于麻黄桂枝汤中。加石膏黄
芩知母升麻。不加则转助热气。便发 黄。此论颇合大青龙之义。未为不可。其他谬说。及节庵陶华
所云误投热药。或当汗不汗。当下不下。汗下未解所致。皆不经之论也。夫 黄皆时疫之气。其发越之候。
迟速不齐。有六七日而出者。有十日半月而出者。更有寒热头痛表证既解之后。重复发热而出者。有
始终不得出而死者。此等或可委之于用药之误。至有才见发热。并未服药。不二三日而斑点即见者。
岂亦误用麻黄桂枝辛热之药而然邪。亦有春秋并无天时之大热。及隆冬尽遇严冽之寒天。而亦发者。岂
亦夏月天气大热而然邪。若云玄府开。则已汗自出。脉洪大则已属阳明。又非玄府紧闭。脉浮紧可汗
之寒邪表症矣。而云正宜发汗。则仲景之法已乱。六经之序已淆。且不论伤寒中风温暑。又不分寒热
虚实而概加诸药。使后人颠倒错乱。其可谓之活人书乎。全生集乎。总由卒病论六卷遗亡。无 证之
明文可征耳。二书盛行于世。令人视桂枝麻黄两汤为鸩毒。坐视人之夭枉而莫之敢用者。非此说入人之深。
渐渍日久之害乎。
症（一种烈性传染病）是外感病证中最严重的一种。其毒厉之气，往往导致人们夭折死亡。而在张仲景的《伤寒论》中，对于六经的病证治疗，论述得详尽透彻，却绝无一字提及症这种病。为什么呢？其用意大概在于，中风、伤寒以及温病、痉病、湿病等病症，都是人体自身原因导致的，就像天地之气一样，冬季本该温暖却反常寒冷，不能闭藏来复之阳气，少阳的生气无法布散，从而引发疾疫饥荒。人体的肾，属坎卦，为冬脏。真阳藏于两肾寒水之中。如果因失精或过汗，导致寒水包藏之气受损，则藏阳败泄，少阳之气不能升发，卫外的阳气不固密。风寒温暑之邪，皆可乘虚而入。《素问·生气通天论》所谓“顺之则阳气固，虽有贼邪，弗能害也”，若违背此道，则卫气解散，这叫做自伤，是元气的削弱。又说：“阳气者，若天与日，失其所则折寿而不彰。”因此，阳气向上运行，负责卫护体表。又说：“阳者，卫外而为固也。”寒水受伤则阳气不固，阳气不固则外邪入侵，所以说“冬伤于寒，春必温病”。这些都是外感病的内因。所以有内因就会生病，没有内因则邪气不能侵入，故说“虽有贼邪，弗能害也”。张仲景因此将其命名为《伤寒论》，而不是称为《中风温暑论》。王叔和未能领会其中的深意，错误地将“冬伤于寒”理解为就是伤寒，因而提出了“寒毒藏于肌肤”的说法，造成了千年的误解。至于疫病则不然，与伤寒大不相同。有内因的人固然会生病，但没有内因的人也会生病。为什么呢？疫病的传染性，有时在一乡之内，有时在一里之中，甚至连州跨郡，沿门阖境，沾染缠绵，无论老幼皆然。病人床榻相连，枕藉交错，烟火寂寥，病气充满房间，亲友不敢进门，役卒不敢靠近。以至于死丧相继，尸体载途。像这种情况，难道都是有内因、乘虚而入吗？都是因为沾染了疫气所致。所谓的疫，乃是天地郁蒸之气，如同秋天行夏令，冬天行春令，春天行初夏之令，完全没有闭藏清肃之气，全是温暖不正之邪。人在气中，感触而成瘟疫。一人先染，其毒厉之气从鼻息而入，水土之邪从饮食而入。发病时脉象颇相同，症状颇相类，于是相互传染，蔓延牵连，如水之漫延，如火之燃烧，一时难以停止熄灭。如天下之大工大役，无人能免，所以称之为疫。其病状虽然不齐，但大多都发疹（斑疹），所以疹是由时行疫气所致，不是伤寒条例中的病，故《伤寒论》中只有中风、伤寒、温暑、痉湿等病，而没有发疹这一证候。然而发疹时疫，以张仲景的用心，难道竟然弃置而不论述吗？张仲景所撰写的，原名为《伤寒卒病论》，合十六卷。推究其理，必定不是随意弃置。大约那六卷在《卒病论》中。那六卷既然失传，遂至遗亡而不得见罢了。顾名思义，因为忽然得之，所以叫卒病。时疫乃厉气所染，非积渐所致，难道不是卒病吗？后人将卒病疑为杂病，是大谬不然的论断。看它附于《伤寒论》之后，必定不是杂病那种缓慢可待的疾病，所以知道它是卒病无疑。然而疹的发出来，都是因为时行的一气所使，与人事无关。所以一人先染，则凡患病者皆如此。如果没有此气，则虽有时行的其他病，也绝无疹。朱奉议在《活人书》第十三问中说：“夏月天气大热，玄府开，脉洪大，正宜发汗。但不可用麻黄、桂枝等热性之药。须在麻黄桂枝汤中，加石膏、黄芩、知母、升麻。不加则转助热气，便发疹发黄。”此论颇合大青龙汤之义，未为不可。其他的谬说，以及节庵陶华所说的误投热药，或当汗不汗，当下不下，汗下未解所致，都是不经之论。夫疹发黄都是时疫之气，其发越的时机，迟速不齐。有六七日而出的，有十日半月而出的，更有在寒热头痛表证既解之后，重新发热而出的，有始终不得出而死的。这些情况或许可以归咎于用药之误。至于才见发热，并未服药，不二三日而斑点即见的，难道也是误用麻黄、桂枝辛热之药造成的吗？也有春秋并无天时之大热，及隆冬尽遇严冽之寒天，而亦发的，难道也是夏月天气大热造成的吗？如果说玄府开，则已汗自出；脉洪大则已属阳明，又非玄府紧闭、脉浮紧可汗之寒邪表症了。而说正宜发汗，则张仲景之法已乱，六经之序已淆。且不论伤寒、中风、温暑，又不分寒热虚实而概加诸药，使后人颠倒错乱，这能称为《活人书》吗？《全生集》吗？总由《卒病论》六卷遗亡，无疹证的明文可征罢了。这两本书盛行于世，令人视桂枝、麻黄两汤为鸩毒，坐视人之夭枉而莫敢用者，不是这种学说深入人心、渐渍日久之害吗？
Zheng (a severe infectious disease) is the most critical among exogenous syndromes. Its toxic and fierce Qi often causes premature death. However, in Zhang Zhongjing's *Treatise on Cold Damage* (Shanghan Lun), although the treatment of syndromes of the Six Channels is discussed in meticulous detail, there is not a single word mentioning Zheng. Why? The intention is likely that Wind-stroke (Zhongfeng), Cold Damage (Shanghan), as well as Warm diseases (Wenbing), Jing-syndrome (Jingbing), and Dampness syndrome (Shibing) are all conditions self-induced by the individual. This is akin to the Qi of Heaven and Earth: if winter should be warm but instead fails to store the returning Yang, the Shengqi (vital generating Qi) of Shaoyang cannot disperse, leading to epidemics and famine. In the human body, the Kidney belongs to Kan and is the Zang organ of Winter. True Yang is stored within the cold water of the two Kidneys. If essence loss or excessive sweating injures the Qi of storage enveloped by cold water, then the stored Yang collapses and leaks, the Qi of Shaoyang cannot rise and develop, and the defensive Yang outside the body becomes insecure. Pathogens such as Wind, Cold, Warmth, and Summer-heat can all enter through deficiency. As stated in the *Suwen: Treatise on the Interaction between Human Vitality and Heaven*, "If one follows this, Yang Qi remains secure; even if there are harmful pathogens, they cannot cause harm." Conversely, if one deviates from it, Defensive Qi dissipates, which is called self-injury and the depletion of Qi. It also states, "The Yang Qi of humans is like the sky and the sun; if it loses its proper function, lifespan is shortened and brilliance is obscured." Therefore, Yang Qi moves upward and guards the exterior. It is further stated, "Yang guards the exterior and provides security." When cold water is injured, Yang is not secure; when Yang is not secure, external Qi enters. Hence, it is said, "If one is injured by Cold in Winter, one will suffer from Warm diseases in Spring." These are all internal factors of exogenous diseases. Thus, with an internal factor, disease occurs; without an internal factor, pathogenic Qi cannot enter. Therefore, it is said, "Even if there are harmful pathogens, they cannot cause harm." Zhang Zhongjing therefore named his work *Treatise on Cold Damage* rather than *Treatise on Wind-stroke, Warmth, and Summer-heat*. Wang Shuhe failed to comprehend this purport and erroneously interpreted "injured by Cold in Winter" as simply Cold Damage, thus proposing the theory that "Cold toxin hides in the skin and muscles," causing a millennium-long error.
Epidemic diseases (Yi), however, are different and greatly distinct from Cold Damage. Those with internal factors certainly get sick, but those without internal factors also get sick. Why? The transmission of epidemic diseases may occur within a village, within a neighborhood, or even across prefectures and commanderies, spreading door-to-door and region-wide, lingering and persistent, affecting both old and young alike. Beds are connected, pillows are piled up, hearths are silent, and the room is filled with disease Qi. Relatives and friends dare not enter the door, and servants dare not approach the place. Death and mourning follow one another, and corpses fill the roads. In such cases, could it be that everyone has internal factors and invites pathogens through deficiency? No, it is solely due to contamination by epidemic Qi. What is referred to as "Yi" is the stagnant and steaming Qi of Heaven and Earth, similar to Summer commands occurring in Autumn, Spring commands in Winter, or early Summer commands in Spring. There is no Qi of storage and purification, only warm and improper pathogens. Humans living in this Qi contract plague and epidemic diseases upon contact. One person starts it; the toxic and fierce Qi enters through the nose and breath, while the pathogens of soil and water enter through food and drink. The pulse is quite similar, and symptoms are quite alike, leading to mutual contagion, spreading and connecting like overflowing water or spreading fire, difficult to stop or extinguish at once. Like great works or large corvée labor under heaven, no one can escape, hence it is called Yi. Although the clinical manifestations vary, generally they all present with macules and papules (Zhen). Therefore, Zhen is caused by seasonal epidemic Qi, not by the rules of Cold Damage. Thus, the treatise only mentions Wind-stroke, Cold Damage, Warmth, Summer-heat, Jing, and Dampness, but does not mention the syndrome of developing macules and papules.
However, given Zhang Zhongjing's careful consideration, did he completely abandon discussing epidemic diseases with macules and papules? Zhang Zhongjing's original work was titled *Treatise on Cold Damage and Sudden Diseases* (Shanghan Zubing Lun), comprising sixteen volumes. Reasoning from this, it is certain that it was not casually discarded. It is likely that these were contained in the six volumes of the *Treatise on Sudden Diseases*. Since those six volumes were lost, they became extinct and unseen. By examining the name, since it is acquired suddenly, it is called "Sudden Disease" (Zubing). Epidemic diseases are contracted from fierce Qi, not accumulated gradually; are they not sudden diseases? Later scholars who suspected Zubing to be miscellaneous diseases made a grossly incorrect argument. Observing that it was appended after the *Treatise on Cold Damage*, it must not be a miscellaneous disease that is slow and can wait. Thus, it is undoubtedly a sudden disease. However, the emergence of macules and papules is driven by the seasonal Qi and has nothing to do with human affairs. Therefore, once one person contracts it, all patients exhibit the same condition. Without this Qi, even if there are other seasonal diseases, there would absolutely be no macules and papules.
Zhu Fengyi, in Question 13 of *Huoren Shu* (Book for Saving People), stated: "In summer, when the weather is extremely hot, the Xuanfu (pores) open, and the pulse is surging and large, sweating is indeed appropriate. However, one must not use hot-natured herbs like Ephedrae Herba (Mahuang) or Cinnamon Twig (Guizhi). One must add Gypsum Fibrosum (Shigao), Scutellariae Radix (Huangqin), Anemarrhenae Rhizoma (Zhimu), and Cimicifugae Rhizoma (Shengma) to the Guizhi Tang or Mahuang Decoction. If not added, it will further assist the heat Qi, leading to the development of macules/papules and yellowing." This argument aligns well with the principle of Da Qing Long Tang and is acceptable. Other erroneous theories, such as those by Tao Hua (Jie'an) claiming that misadministration of hot herbs, failure to sweat when sweating was indicated, failure to purge when purging was indicated, or unresolved conditions after sweating and purging, are baseless arguments.
The yellowing associated with macules/papules is due to epidemic Qi. The timing of their emergence varies in speed. Some appear after six or seven days, some after ten days or half a month, and some reappear with fever after the resolution of chills, fever, headache, and exterior syndromes. Some never emerge and result in death. Such cases might be attributed to medication errors. However, what about those who show fever, take no medicine, and have spots appear within two or three days? Could this also be due to the mistaken use of acrid-warm herbs like Ephedrae Herba and Cinnamon Twig? Furthermore, some occur in spring and autumn without extreme heat, or in deep winter amidst severe cold. Could this also be due to the extreme heat of summer? If one claims the Xuanfu are open, then spontaneous sweating has already occurred; if the pulse is surging and large, it belongs to Yangming, which is not the exterior syndrome of cold pathogens with closed Xuanfu and floating-tight pulse suitable for sweating. To claim that sweating is precisely indicated here disrupts Zhang Zhongjing's methods and confuses the order of the Six Channels. Moreover, regardless of Cold Damage, Wind-stroke, Warmth, or Summer-heat, and without distinguishing between cold-heat and deficiency-excess, applying various drugs indiscriminately causes confusion for later generations. Can this be called *Huoren Shu*? Or *Quansheng Ji*? This is entirely because the six volumes of *Zubing Lun* were lost, leaving no explicit text to verify the syndrome of macules and papules. These two books became popular, making people view Guizhi Tang and Mahuang Decoction as poison, sitting idly by while people died prematurely, daring not to use them. Is this not the deep-rooted and gradual harm caused by these theories?