喻昌曰。圣王御世。春无愆阳。夏无伏阴。秋无凄风。冬无苦雨。乃至民无夭札。物无
疵疠。太和之气。弥满乾坤。安有所谓瘟疫哉。然而周礼傩以逐疫。方相氏掌之。则
瘟疫之由来。古有之矣。乡人傩。孔子朝服而致其诚敬。盖以装演巨像为傩神。不
过仿佛其形。圣人以正气充塞其间。俾疫气潜消。乃位育之实功耳。古人元旦。汲
清泉以饮芳香之药。上已采兰草以袭芳香之气。重涤秽也。后汉张仲景着伤寒
论。欲明冬寒春温夏秋暑热之正。自不能并入疫病以混常法。然至理已毕具于
脉法中。叔和不为细绎。乃谓重感于寒。变为瘟疫。又谓春时应暖而复大寒。夏时
应大热而反大凉。秋时应凉而反大热。冬时应寒而反大温。此非其时而有其气。
是以一岁之中。长幼之病。多相似者。此则时行之气也。又谓冬温之毒。与伤寒大
异。冬温复有先后。更相重沓。亦有轻重。为治不同。又谓从春分节后。至秋分节前。
天有暴寒者。皆为时行寒疫也。盖以春夏秋为寒疫。冬月为瘟疫。所以又云三月
四月。或有暴寒。其时阳气尚弱。为寒所折。病热犹轻。五月六月。阳气已盛。为寒所
折。病热则重。七月八月。阳气已衰。为寒所折。病热亦微。后人奉此而广其义。谓春
感清邪在肝。夏感寒邪在心。秋感热邪在肺。冬感温邪在肾。埙篪递奏。举世若狂
矣。嗟嗟。疫邪之来。果寒折阳气。乘其所胜。而直入精神魂魄之脏。人无 类久矣。
更有谓疫邪无形象声臭。定时定方可言。是以一岁之中。长幼莫不病此。至病伤
寒者。百无一二。治法非疏里则表不透。非战汗则病不解。愈摹愈远。究竟所指之
疫。仍为伤寒伤温伤暑热之正病。疏里则下早可知。战汗则失表可知。只足自呈
败阙耳。夫四时不正之气。感之者因而致病。初不名疫也。因病致死。病气尸气。混
合不正之气。斯为疫矣。以故鸡瘟死鸡。猪瘟死猪。牛马瘟死牛马。推之于人。何独
不然。所以饥馑兵凶之际。疫病盛行。大率春夏之交为甚。盖温暑热湿之气。交结
互蒸。人在其中。无隙可避。病者当之。魄汗淋漓。一人病气。足充一室。况于连床并
榻。沿门阖境。共酿之气。益以出户尸虫。载道腐 。燔柴掩席。委壑投崖。种种恶秽。
上混苍天清净之气。下败水土物产之气。人受之者。亲上亲下。病从其类。有必然
之势。如世俗所称大头瘟者。头面腮颐。肿如瓜瓠者是也。所称虾蟆瘟者。喉痹失
音。颈筋胀大者是也。所称瓜瓤瘟者。胸高胁起。呕汁如血者是也。所称疙瘩瘟者。
遍身红肿。发块如瘤者是也。所称绞肠瘟者。腹鸣干呕。水泻不通者是也。所称软
脚瘟者。便清泄白。足重难移者是也。小儿痘疮尤多。以上疫证。不明治法。咸委劫
运。良可伤悼。大率瘟疫痘疹。古昔无传。不得圣言折衷。是以堕落叔和坑堑。曾不
若俗见摸索病状。反可顾名思义也。昌幸微窥仲景一斑。其平脉篇中云。寸口脉
阴阳俱紧者。法当清邪中于上焦。浊邪中于下焦。清邪中上。名曰洁也。浊邪中下。
名曰浑也。阴中于邪。必内栗也。表气虚微。里气不守。故使邪中于阴也。阳中于邪。
必发热头痛项强。颈挛腰痛胫酸。所谓阳中雾露之气。故曰清邪中上。浊邪中下。
阴气为栗。足膝逆冷。便溺妄出。表气微虚。里气微急。三焦相溷。内外不通。上焦怫
郁。脏气相熏。口烂蚀龈也。中焦不治。胃气上冲。脾气不转。胃中为浊。营卫不通。血
凝不流。若胃气前通者。小便赤黄。与热相抟。因热作使。游于经络。出入脏腑。热气
所过。则为痈脓。若阴气前通者。阳气微厥。阴无所使。客气内入。嚏而出之。声 咽
塞。寒厥相逐。为热所拥。血凝自下。状如豚肝。阴阳俱厥。脾气孤弱。五液注下。下焦
不阖。清便下重。令便数难。脐筑湫痛。命将难全。凡二百六十九字。阐发奥理。全非
伤寒所有事。乃论疫邪从入之门。变病之总。所谓赤文绿字。开天辟地之宝符。人
自不识耳。篇中大意。谓人之鼻气通于天。故阳中雾露之邪者。为清邪从鼻息而
上入于阳。入则发热头痛项强颈挛。正与俗称大头瘟虾蟆瘟之说符也。人之口
气通于地。故阴中水土之邪者。为饮食浊味。从口舌而下。入于阴。入则其人必先
内栗。足膝逆冷。便溺妄出。清便下重。脐筑湫痛。正与俗称绞肠瘟软脚瘟之说符
也。然从鼻从口所入之邪。必先注中焦。以次分布上下。故中焦受邪。因而不治。中
焦不治。则胃中为浊。营卫不通。血凝不流。其酿变即见中焦。俗称瓜瓤瘟疙瘩瘟
等证。则又阳毒痈脓。阴毒遍身青紫之类也。此三焦定位之邪也。若三焦邪混为
一。内外不通。脏气熏蒸。上焦怫郁。则口烂蚀龈。卫气前通者。因热作使。游行经络
脏腑。则为痈脓。营气前通者。因名客邪。嚏出声 咽塞。热拥不行。则下血如豚肝。
然以营卫渐通。故非危候。若上焦之阳。下焦之阴两不相接。则脾气于中。难以独
运。斯五液注下。下焦不阖。而命难全矣。伤寒之邪。先行身之背。次行身之前。次行
身之侧。由外廓而入。瘟疫之邪。则直行中道。流布三焦。上焦为清阳。故清邪从之
上入。下焦为浊阴。故浊邪从之下入。中焦为阴阳交界。凡清浊之邪。必从此区分。
甚者三焦相溷。上行极而下。下行极而上。故声 咽塞。口烂蚀龈者。亦复下血如
豚肝。非定中上不及下。中下不及上也。伤寒邪在外廓。故一表即散。疫邪行在中
道。故表之不散。伤寒邪入胃腑。则腹满便坚。故可攻下。疫邪在三焦。散漫不收下
之复合。此与治伤寒表里诸法。有何干涉。奈何千年愦愦。试折衷以圣言。从前谬
迷。不涣然冰释哉。治法。未病前。预饮芳香正气药。则邪不能入。此为上也。邪既入。
则以逐秽为第一义。上焦如雾。升而逐之。兼以解毒。中焦如沤。疏而逐之。兼以解
毒。下焦如渎。决而逐之。兼以解毒。营卫既通。乘势追拔。勿使潜滋。或问春夏秋蒸
气成疫。岂冬温独非疫耶。余曰。冬月过温。肾气不藏。感而成病。正与不藏精之春
温无异。计此时有春无冬。三气即得交蒸成疫。然遇朔风骤发。则蒸气化为乌有
矣。是以西北土高地燥。即春夏气难上升。何况冬月之凝冱。东南土地卑湿。为雾
露之区。蛇龙之窟。其温热之气。得风以播之。尚有可耐。设旦暮无风。水中之鱼。衣
中之虱。且为飞扬况于人乎。蒸气中原杂诸秽。益以病气死气。无分老少。触之即
同一病状矣。此时朔风了不可得。故其气转积转暴。虽有熏风。但能送热。不能解
凉。盛世所谓解愠阜财者。在兵荒反有注邪布秽之事矣。叔和以夏应大热而反
大寒为疫。讵知大寒。正疫气消弭之候乎。故疫邪炽甚。惟有北方。始能消受。诗恶
人。思欲投畀有北。以熄其焰。析义精矣。
喻昌说：圣明的君王治理天下，春天不会出现阳气过亢，夏天不会有阴气潜伏，秋天没有凄厉的寒风，冬天没有苦寒的暴雨。以至于百姓没有早夭和瘟疫之灾，万物没有病虫害，太和之气充满天地之间，哪里会有所谓的瘟疫呢？然而，《周礼》中有用傩舞来驱逐疫鬼的制度，由方相氏掌管，这说明瘟疫由来已久。孔子在乡人举行傩祭时，必定穿着朝服以示诚敬。这大概是因为装扮成巨像作为傩神，只是模仿其外形，圣人以正气充盈其中，使疫气潜消，这是实现万物生长繁育的实际功效。古人在元旦这一天，汲取清泉饮用芳香的药物；在上巳节采摘兰草熏香，都是为了洗涤污秽。后汉张仲景撰写《伤寒论》，想要阐明冬寒、春温、夏秋暑热的正病，自然不能将疫病混入常规治法中。然而至理已经完备地包含在脉法之中，王叔和没有细细推究，却说重感于寒，变为瘟疫；又说春季应当温暖却反而大寒，夏季应当大热却反而大凉，秋季应当凉爽却反而大热，冬季应当寒冷却反而大温。这种非其时而有其气的情况，导致一年之中，无论老少，生病的症状大多相似，这就是时行之气。又说冬温的毒邪，与伤寒大不相同。冬温又有先后之分，相互重叠，也有轻重之别，治疗方法不同。又说从春分节后到秋分节前，天空有暴寒出现，都称为时行寒疫。大概是将春夏秋三季称为寒疫，冬季称为瘟疫。所以又说三月四月，有时会有暴寒，此时阳气尚弱，被寒气遏制，发病热度较轻；五月六月，阳气已盛，被寒气遏制，发病热度则重；七月八月，阳气已衰，被寒气遏制，发病热度也微。后人奉承此说并扩大其义，认为春感清邪在肝，夏感寒邪在心，秋感热邪在肺，冬感温邪在肾，如同埙篪递奏一般，举世若狂。唉！疫邪的到来，难道是寒气折损阳气，乘其所胜，而直入精神魂魄之脏吗？人们这样误解已经很久了。更有的人说疫邪没有形象声臭，定时定方可言，因此一年之中，无论老少无不患病。至于患伤寒的，百无一二。治疗方法如果不是疏通里实，表邪就不能透发；如果不是战汗，病就不能解除。愈是描摹愈远，究竟所指的疫，仍然是伤寒、伤温、伤暑热的正病。疏通里实则可知下法过早，战汗则可知失于解表，只足以显露自身的败漏罢了。四时不正之气，感受它因而致病，起初并不叫疫。因病致死，病气尸气混合不正之气，这才成为疫。所以鸡瘟死鸡，猪瘟死猪，牛马瘟死牛马，推之于人，难道唯独不是这样吗？所以在饥荒战乱之际，疫病盛行，大体上在春夏之交最为严重。因为温暑热湿之气，交结互蒸，人在其中，没有缝隙可以躲避。病人遭受此气，魄汗淋漓，一个人的病气，足以充满一室。何况连床并榻，沿门阖境，共同酝酿的气，加上出门的尸虫，道路上的腐肉，烧柴掩席，抛尸沟壑悬崖，种种恶秽，上混苍天清净之气，下败水土物产之气。人感受了这些，亲上亲下，病从其类，有必然的趋势。如世俗所称的大头瘟，就是头面腮颐肿得像瓜瓠一样；所称的虾蟆瘟，就是喉痹失音，颈筋胀大；所称的瓜瓤瘟，就是胸高胁起，呕汁如血；所称的疙瘩瘟，就是遍身红肿，发块如瘤；所称的绞肠瘟，就是腹鸣干呕，水泻不通；所称的软脚瘟，就是便清泄白，足重难移。小儿痘疮尤其多。以上疫证，如果不明白治法，全都委命于劫运，实在令人伤感悼惜。大体上古昔没有瘟疫痘疹的传承，得不到圣人的言论来折衷，所以堕落在王叔和的坑堑中，还不如世俗见解摸索病状，反而可以顾名思义。我幸而略微窥见张仲景的一斑，他在《平脉篇》中说：“寸口脉阴阳俱紧者，法当清邪中于上焦，浊邪中于下焦。”清邪中上，名叫洁；浊邪中下，名叫浑。阴受邪，必内栗（内心战栗）。表气虚微，里气不守，所以使邪中于阴。阳受邪，必发热头痛项强，颈挛腰痛胫酸。所谓阳中雾露之气，所以说清邪中上，浊邪中下。阴气为栗，足膝逆冷，便溺妄出。表气微虚，里气微急，三焦相溷，内外不通。上焦怫郁，脏气相熏，口烂蚀龈。中焦不治，胃气上冲，脾气不转，胃中为浊，营卫不通，血凝不流。若胃气前通者，小便赤黄，与热相抟，因热作使，游于经络，出入脏腑，热气所过，则为痈脓。若阴气前通者，阳气微厥，阴无所使，客气内入，嚏而出之，声嗌咽塞，寒厥相逐，为热所拥，血凝自下，状如豚肝。阴阳俱厥，脾气孤弱，五液注下，下焦不阖，清便下重，令便数难，脐筑湫痛，命将难全。凡二百六十九字，阐发奥理，全然不是伤寒所有的事，乃是论述疫邪进入的门径、变病的总纲，所谓赤文绿字，开天辟地的宝符，人们自己不认识罢了。篇中的大意是说，人的鼻气通于天，所以阳中雾露之邪，是清邪从鼻息而上入于阳，入则发热头痛项强颈挛，正与俗称大头瘟、虾蟆瘟的说法相符。人的口气通于地，所以阴中水土之邪，是饮食浊味，从口舌而下，入于阴，入则其人必先内栗，足膝逆冷，便溺妄出，清便下重，脐筑湫痛，正与俗称绞肠瘟、软脚瘟的说法相符。然而从鼻从口所入之邪，必先注中焦，以次分布上下。所以中焦受邪，因而不治。中焦不治，则胃中为浊，营卫不通，血凝不流。其酿变即见中焦，俗称瓜瓤瘟、疙瘩瘟等证，则是又阳毒痈脓、阴毒遍身青紫之类。这是三焦定位之邪。若三焦邪混为一，内外不通，脏气熏蒸，上焦怫郁，则口烂蚀龈。卫气前通者，因热作使，游行经络脏腑，则为痈脓。营气前通者，因名客邪，嚏出声嗌咽塞，热拥不行，则下血如豚肝。然以营卫渐通，故非危候。若上焦之阳，下焦之阴两不相接，则脾气于中，难以独运。斯五液注下，下焦不阖，而命难全矣。伤寒之邪，先行身之背，次行身之前，次行身之侧，由外廓而入；瘟疫之邪，则直行中道，流布三焦。上焦为清阳，故清邪从之上入；下焦为浊阴，故浊邪从之下入；中焦为阴阳交界，凡清浊之邪，必从此区分。甚者三焦相溷，上行极而下，下行极而上，故声嗌咽塞，口烂蚀龈者，亦复下血如豚肝。并非定中上不及下，中下不及上也。伤寒邪在外廓，故一表即散；疫邪行在中道，故表之不散。伤寒邪入胃腑，则腹满便坚，故可攻下；疫邪在三焦，散漫不收，下之复合。这与治疗伤寒表里诸法，有何干涉？奈何千年糊涂，试以圣人之言来折衷，从前的谬误迷惑，能不涣然冰释吗？治法：未病前，预先饮用芳香正气药，则邪不能入，此为上也。邪既入，则以逐秽为第一义。上焦如雾，升而逐之，兼以解毒；中焦如沤，疏而逐之，兼以解毒；下焦如渎，决而逐之，兼以解毒。营卫既通，乘势追拔，勿使潜滋。有人问：春夏秋蒸气成疫，难道冬温独非疫吗？我说：冬月过温，肾气不藏，感而成病，正与不藏精之春温无异。估计此时有春无冬，三气即得交蒸成疫。然而遇到朔风骤发，则蒸气化为乌有了。所以西北土高地燥，即使春夏之气也难上升，何况冬月的凝冱。东南土地卑湿，为雾露之区，蛇龙之窟，其温热之气，得风以播之，尚有可耐。设旦暮无风，水中的鱼，衣中的虱，且为飞扬，况于人乎？蒸气中原杂诸秽，益以病气死气，无分老少，触之即同一病状矣。此时朔风了不可得，故其气转积转暴，虽有熏风，但能送热，不能解凉。盛世所谓解愠阜财者，在兵荒反有注邪布秽之事矣。王叔和以夏应大热而反大寒为疫，岂知大寒，正是疫气消弭的征候吗？所以疫邪炽甚，惟有北方，始能消受。《诗经》厌恶坏人，思欲投畀有北，以熄其焰，析义精矣。
Yu Chang said: When a sage king governs the world, there is no excessive Yang in spring, no latent Yin in summer, no chilling wind in autumn, and no bitter rain in winter. Consequently, the people suffer no premature death or plague, and all things are free from disease and pestilence. The Qi of Great Harmony fills heaven and earth; how could there be such a thing as epidemic plague (Wenyi)? However, the *Rites of Zhou* prescribes the Nuo dance to drive away epidemics, managed by the Fangxiang Shi, indicating that epidemics have existed since ancient times. When the villagers performed the Nuo ritual, Confucius wore his court robes to show sincerity and reverence. This was likely because the giant statues used as Nuo deities merely imitated their forms; the sages filled this space with righteous Qi, causing the epidemic Qi to dissipate secretly. This is the practical achievement of nurturing and sustaining life. In ancient times, on New Year's Day, people drew clear spring water to drink aromatic medicines; on the Shangsi Festival, they gathered orchids to scent themselves, both practices aiming to cleanse filth.
In the Later Han Dynasty, Zhang Zhongjing wrote the *Treatise on Cold Damage* (*Shanghan Lun*) to clarify the normal diseases of winter cold, spring warmth, and summer/autumn heat. Naturally, he could not merge epidemic diseases into these conventional methods. However, the profound principles were fully contained within the pulse methods. Wang Shuhe did not carefully analyze them but instead claimed that contracting cold twice transforms into an epidemic. He also stated that when spring should be warm but is extremely cold, summer should be hot but is extremely cool, autumn should be cool but is extremely hot, and winter should be cold but is extremely warm. This phenomenon of having the Qi of one season in another causes illness among people of all ages with similar symptoms throughout the year; this is called the Qi of the Time Course (Shixing Zhi Qi). He further stated that the toxicity of Winter Warmth (Dongwen) is vastly different from cold damage. Winter warmth has sequences and overlaps, varying in severity, requiring different treatments. He also claimed that between the Spring Equinox and the Autumn Equinox, sudden cold spells are all called "Time Course Cold Epidemic" (Shixing Hanyi). Essentially, this labels the epidemics of spring, summer, and autumn as cold epidemics, and those of winter as true epidemics. Thus, it was said that in March and April, sudden cold occurs when Yang Qi is still weak and suppressed by cold, resulting in mild heat symptoms; in May and June, Yang Qi is strong but suppressed, resulting in severe heat symptoms; in July and August, Yang Qi is declining and suppressed, resulting in slight heat symptoms.
Later generations adopted this view and expanded its meaning, claiming that spring feels clear pathogenic factors affecting the Liver, summer feels cold pathogenic factors affecting the Heart, autumn feels hot pathogenic factors affecting the Lung, and winter feels warm pathogenic factors affecting the Kidney. Like the alternating notes of Xun and Chi instruments, this madness spread through the world. Alas! Did epidemic pathogens arrive by cold suppressing Yang Qi, exploiting its weakness, and entering directly into the Zang organs of spirit, vitality, and soul? People have misunderstood this for a long time. Others argue that epidemic pathogens have no form, sound, or smell, allowing for fixed timing and prescriptions, which is why everyone falls ill regardless of age, while only one or two out of a hundred contract cold damage. If treatment does not unblock the interior, the exterior cannot be released; if it does not induce battle sweating (Zhanhan), the disease will not resolve. The more one describes it, the further from the truth. Ultimately, the referred "epidemic" remains the standard diseases of cold damage, warmth damage, and heat damage. Unblocking the interior reveals premature purgation; inducing battle sweating reveals missed exterior release. These errors only expose one's own deficiencies.
Pathogenic factors of the four seasons cause disease upon contraction, initially not called "epidemic." Only when death occurs from the disease, and the Qi of the sick and corpses mixes with the irregular Qi, does it become an epidemic. Just as chicken plague kills chickens, swine plague kills pigs, and cattle/horse plague kills cattle and horses, humans are no different. Therefore, during famines and wars, epidemics prevail, especially at the transition of spring and summer. The Qi of warmth, summer-heat, heat, and dampness interweave and steam each other. People within this environment have no gap to avoid it. Those affected sweat profusely; one person's disease Qi can fill a room. Especially when beds are adjacent and houses are connected, the jointly brewed Qi, combined with corpse insects outside and rotting flesh on roads, burning wood to cover bodies, and casting corpses into ditches and cliffs—all sorts of foulness—mixes with the pure Qi of heaven above and corrupts the Qi of soil and water below. Humans who receive this, following the principle of "like attracts like," inevitably fall ill.
For example, the so-called "Big Head Plague" (Datou Wen) involves swelling of the head, face, cheeks, and jaw like a gourd. The "Toad Plague" (Xama Wen) involves throat obstruction, loss of voice, and swollen neck tendons. The "Melon Rind Plague" (Guanang Wen) involves high chest and rising ribs, vomiting blood-like fluid. The "Lump Plague" (Geda Wen) involves widespread redness and swelling, with lumps like tumors. The "Intestine Twisting Plague" (Jiaochang Wen) involves abdominal rumbling, dry retching, and watery diarrhea without relief. The "Soft Leg Plague" (Ruanjiao Wen) involves clear urine and white stool, with heavy legs difficult to move. Pediatric smallpox is also common. For these epidemic conditions, if the treatment method is unknown, victims resign themselves to fate, which is truly lamentable. Generally, ancient texts lacked transmission on epidemic plagues and pox, lacking sage guidance to correct errors, thus falling into Wang Shuhe's pitfalls. It would be better than worldly guesses based on symptoms, which might allow understanding by name. Fortunately, I have glimpsed a fragment of Zhang Zhongjing's wisdom. In the *Ping Mai Pian* (Chapter on Pulse Assessment), he states: "When both Yin and Yang pulses at the Cun position are tight, clear pathogenic factors attack the Upper Jiao, and turbid pathogenic factors attack the Lower Jiao." Clear factors attacking above are named "Jie" (Pure); turbid factors attacking below are named "Hun" (Turbid). Attack on Yin causes internal trembling. With deficient superficial Qi and insecure interior Qi, pathogens enter the Yin. Attack on Yang causes fever, headache, stiff neck, neck spasm, lower back pain, and leg soreness. This is known as Yang being struck by fog and dew. Hence, clear factors attack above, turbid factors attack below. Yin strike causes trembling, cold feet and knees, and involuntary urination/defecation. With slightly deficient superficial Qi and slightly urgent interior Qi, the Three Jiaos become confused, and interior/exterior communication stops. Upper Jiao stagnation leads to organ Qi steaming each other, causing mouth ulcers and gum erosion. Middle Jiao dysfunction leads to Stomach Qi rushing upward, Spleen Qi failing to transform, turbidity in the Stomach, blocked Ying and Wei Qi, and stagnant blood flow. If Stomach Qi flows forward, urine becomes dark yellow, combats heat, acts as a vehicle for heat, travels through meridians and organs, and where heat passes, abscesses and pus form. If Yin Qi flows forward, Yang Qi is slightly inverted, Yin has no command, external pathogens enter internally, sneezing expels them, voice and throat become blocked, cold inversion chases heat, heat suppresses it, blood coagulates and exits downward, resembling pig liver. If both Yin and Yang invert, Spleen Qi is isolated and weak, five fluids pour downward, Lower Jiao fails to close, clear stool feels heavy, frequent difficult defecation occurs, umbilical cramping and shallow pain arise, and life is endangered. These 269 characters elucidate profound principles, entirely unrelated to cold damage, but rather discussing the entry portal and general transformation of epidemic pathogens—the "red script and green characters," the treasure talisman of creation, unrecognized by people.
The main idea of the chapter is: Human nose Qi connects with Heaven; thus, Yang struck by fog/dew is clear pathogenic factors entering Yang via respiration, causing fever, headache, stiff neck, and spasm, matching the popular descriptions of Big Head and Toad Plagues. Human mouth Qi connects with Earth; thus, Yin struck by soil/water is turbid dietary flavors entering Yin via mouth/tongue, causing internal trembling, cold limbs, involuntary excretion, heavy clear stool, and umbilical pain, matching the descriptions of Intestine Twisting and Soft Leg Plagues. However, pathogens entering via nose/mouth must first settle in the Middle Jiao, then distribute up and down. Thus, Middle Jiao infection leads to dysfunction. Middle Jiao dysfunction causes stomach turbidity, blocked Ying/Wei Qi, and stagnant blood. Its manifestations appear in the Middle Jiao, corresponding to popular Melon Rind and Lump Plagues, which are akin to Yang Toxicity abscesses and Yin Toxicity whole-body cyanosis. These are pathogens located in specific Jiaos. If Three Jiao pathogens mix into one, blocking interior/exterior, steaming organ Qi, and stagnating Upper Jiao, mouth ulcers occur. If Wei Qi flows forward, heat travels meridians/organs, causing abscesses. If Ying Qi flows forward, named guest pathogens, sneezing blocks throat, heat suppression causes bloody stool like pig liver. Since Ying/Wei gradually connect, it is not critical. If Upper Jiao Yang and Lower Jiao Yin do not connect, Spleen Qi in the middle cannot operate alone. Five fluids pour down, Lower Jiao fails to close, and life is endangered.
Cold damage pathogens travel the back, then front, then sides of the body, entering from the exterior. Epidemic pathogens travel the central pathway, distributing through the Three Jiaos. Upper Jiao is Clear Yang, so clear pathogens enter from above. Lower Jiao is Turbid Yin, so turbid pathogens enter from below. Middle Jiao is the boundary of Yin/Yang, where clear/turbid separate. Severe cases confuse the Three Jiaos; extreme ascent leads to descent, extreme descent leads to ascent. Thus, throat blockage and mouth ulcers accompany bloody stool like pig liver. It is not that upper/middle misses lower, or lower/misses upper. Cold damage pathogens are on the exterior, so releasing the exterior disperses them. Epidemic pathogens are in the central pathway, so releasing the exterior fails. Cold damage pathogens enter the Stomach/Fu organs, causing fullness and hard stool, allowing purgation. Epidemic pathogens are in the Three Jiaos, scattered and unrestrained; purgation causes re-aggregation. How does this relate to cold damage exterior-interior methods? Why remain confused for millennia? Let us use sage words to correct past errors.
Treatment: Before illness, pre-drink aromatic righteous Qi medicine to prevent pathogen entry (superior method). Once entered, removing filth is the primary principle. Upper Jiao is like mist; lift and remove it, plus detoxify. Middle Jiao is like fermentation vat; dredge and remove it, plus detoxify. Lower Jiao is like a drain; drain and remove it, plus detoxify. Once Ying/Wei connect, pursue and extract pathogens forcefully, preventing hidden proliferation.
Q: Summer/Autumn steam creates epidemics; is Winter Warmth not an epidemic? A: Excessive warmth in winter causes Kidney Qi to fail to store, leading to illness, identical to Spring Warmth from failing to store Essence. At this time, there is spring but no winter; three Qi interact to create epidemics. However, sudden north winds evaporate this steam. Northwest lands are high and dry; even spring/summer Qi struggles to rise, let alone winter freezing. Southeast lands are low and wet, areas of fog/dew and dragons/snakes. Their warm Qi spreads with wind, tolerable. Without wind day or night, fish in water and lice in clothes fly about; how much more so for humans? Steam contains filth, plus disease/corpse Qi. Young and old alike contracting it show identical symptoms. North winds are unavailable here, so Qi accumulates and becomes violent. Even warm breezes only send heat, not coolness. What brings peace and wealth in prosperous times brings evil and filth in war and famine. Wang Shuhe considered summer coldness as epidemic; little did he know that extreme cold is actually the sign of epidemic dissipation. Thus, intense epidemics are best endured in the North. The *Classic of Poetry* expresses hatred for bad men by wishing to cast them into the North to extinguish their flame. This analysis is precise.