伤寒专祖仲景。凡读仲景书。须将伤寒与中寒。分为两门。始易以通晓。为因年久残缺。补遗注释者。又
多失次错误。幸历代考正者渐明。逮陶节庵六书吴绶蕴要二书刊行。而伤寒之理始着。余于至理。未暇详辨。
先将伤寒中寒。逐一辨明。庶不使阴阳二证混乱。夫伤寒治之。得其纲领不难也。若求之多歧。则支离矣。先
以阳证言之。夫既云伤寒。则寒邪自外入内而伤之也。其入则有浅深次第。自表达里。先皮毛。次肌肉。又次
筋骨肠胃。此其渐入之势然也。若夫风寒之初入。必先太阳寒水之经。便有恶风恶寒头痛脊痛之证。寒郁
皮毛。是为表证。若在他经。则无此证矣。脉若浮紧无汗为伤寒。以麻黄汤发之。得汗为解。浮缓有汗为
伤风。用桂枝汤散邪。汗止为解。若无头疼恶寒。脉又不浮。此为表证罢而在中。中者何。表里之间也。乃
阳明少阳之分。脉不浮不沉。在乎肌肉之间。谓皮肤之下也。然有二焉。若微洪而长。即阳明脉也。外证鼻干
不眠。用葛根汤以解肌。脉弦而数。少阳脉也。其证胁痛耳聋。寒热往来而口苦。以小柴胡汤和之。盖阳明少
阳不从标本从乎中治也。若有一毫恶寒尚在表。虽入中还当兼散邪。过此为邪入里。为实热。脉不
浮不沉。沉则按之筋骨之间方是。若脉沉实有力。外证不恶风寒。而反恶热谵语大渴。六七日不大便。明其热
入里而肠胃燥实也。轻则大柴胡汤。重则三承气汤。大便通而热愈矣。以阴证言之。若初起。便怕寒。手足厥
冷。或战栗蜷卧不渴。兼之腹痛呕吐泄泻。或口出涎沫。面如刀刮。不发热而脉沉迟无力。此为阴证。不从阳
经传入热证治例。更当看外证如何。轻则理中汤。重则姜附汤四逆汤以温之。由此观之。可见伤寒者。由皮
毛而后入脏腑。初虽恶寒发热而终为热证。其人必素有火者。中寒
者。直入脏俯。始终恶寒。而并无发热等证。其人必无火者。一则发表攻里。一则温中散寒。两门判然明白。
何至混杂于中而使后人疑误耶。
寒伤荣。风伤卫。卫阳也。风亦阳也。阳从阳之类。故风能伤卫。血阴也。寒亦阴也。阴从阴之类。故寒
能伤荣。辛甘发散为阳。风宜辛散。寒宜甘发。桂枝辛而热者。故能发散卫中之风邪。麻黄甘而热者。故能发
散血中之寒邪。又桂枝麻黄。气味俱轻。阳中之阳。故能入太阳经。散皮肤间之风寒也。此二方者乃治冬月正
伤寒之的方。霜降后至春分前。此时太阳寒水用事。房劳辛苦之人其太阳寒水之气。乘虚而客入于太阳经。同
气相求。故易以伤也。仲景特以杀气最重。故详言之。其余时月则无伤寒。则二方不可用也。今人医牌上多书
治四时伤寒。名不正则言不顺矣。活人言头痛如破者。连须葱白汤。不可便与升麻葛根汤。恐太阳流入阳明。
是太阳邪气引入阳明。不能解也。未至少阳者。不可便与柴胡汤。如有恶寒证。本方加麻黄。恶风加桂枝。如
正阳明腑病。不恶寒有汗而渴。当用白虎汤。
太阳经表之表也。行身之背。阳明经表之里也。行身之前。少阳经半表半里也。行乎两胁之旁。
过此则少阴太阴厥阴俱入脏而为里。
大凡伤寒邪热传里结实。须看热气浅深用药。今之医不分当急下可少与宜微和胃气之论。一概用大黄芒
硝乱投汤剂下之。因兹枉死者多矣。余谓伤寒之邪。传来非一。治之则殊耳。病有三焦俱伤者。则痞满燥实
坚俱全。宜大承气汤。浓朴苦温以去痞。枳实苦寒以泄满。芒硝咸寒以润燥软坚。大黄苦寒以泄实去热。病
斯愈矣。邪在中焦。则有燥实坚三证。故用调胃承气汤。以甘草和中。芒硝润燥。大黄泄实。不用枳实浓朴。
恐伤上焦元气。调胃之名。由此立矣。上焦受伤。则痞而实。用小承
气汤。枳实浓朴之能除痞。大黄之泄实。去芒硝不伤下焦真阴。谓不伐其根本也。若夫大柴胡汤。则有表证尚
未除。而里证又急。不得不下者。只得以此汤通表里而缓治之。尤有老弱及血气两虚之人。亦宜用此。故
经云。转药孰紧。有芒硝者紧也。大承气最紧。小承气次之。柴胡又次之。其大柴胡加芒硝。方得转
药。盖为病轻者设也。仲景云。荡涤伤寒热积。皆用汤药。切不宜用丸药。不可不知。如欲用此三方。须以手
按病患。自胸至小腹。果有硬处。手不可近。方敢下手。然其至妙处。尤须辨舌之
燥滑若何。此金镜录三十六舌。不可不细玩也。
初病无热。便四肢厥冷。或胸腹中满。或呕吐腹满痛下利。脉细无力。此自阴证受寒。即真阴证。非从阳
经传来。便宜温之。不宜少缓。经云。发热恶寒者。发于阳也。无热恶寒者。发于阴也。治宜四逆汤。腹满腹
痛。皆是阴症。只有微甚不同。治难一概。腹痛不大便。桂枝芍药汤。腹痛甚。桂枝大黄汤。若自利腹
痛。小便清白。宜温中。理中四逆看微甚用。轻者五积散。重者四逆汤。无脉者通脉四逆汤。
使阴退而阳复也。
阴毒病。手足指甲皆青。脉沉细而急者。四逆汤。无脉者。通脉四逆汤。阴毒甘草汤。脐中葱熨。气海关
元着艾。可灸二三百壮。乃用温和补气之药。通其内外。以复阳气。若俱不效。死证也。
以上皆真阴证。人皆知之。至于反常。则不易晓。有发热面赤。烦躁揭去衣被。饮冷脉大。误为阳证投
寒药。死者多矣。必须凭脉下药。不问浮沉大小。但指下无力。按至筋骨。全无力者。必有伏阴。不可与
凉药。若已曾服过凉药。脉必鼓指而有力。脉又难凭矣。若一应茶汤。及寒热药俱吐者。此阴盛格阳。急用
白通汤。加人尿胆汁。以通拒格之寒。所以仲景伤寒论中。传经与直中并论者。正谓有阳证似阴。
阴证似阳。所宜详辨。但年久
散乱。后人误相补集。致使不明。如太阳证头痛发热。当脉浮而反沉。又似少阴矣。故用麻黄附子细辛汤。如
少阴证脉沉。应无热。而反发热者。又似太阳矣。须用干姜附子甘草汤。如阴证四肢厥逆。而阳证亦有厥逆
者。此四逆汤与四逆散不同。又如阴证下利。而阳证又有漏底者。此理中汤与黄龙汤不同。若此之类。疑似难明。
幸陶节庵六书。已明分矣。予又有说焉。若读伤寒书。而不读东垣书。则内伤不明。而杀人多矣。读东垣书。
而不读丹溪书。则阴虚不明。而杀人多矣。读丹溪书。而不读薛氏书。则真阴真阳不明。而杀人亦多矣。东垣曰
。邪之所凑。其气必虚。世间内伤者多。外感者间而有之。此一间字当作五百年间出之间。甚言其无外感也。
东垣脾胃论。与夫内伤外感辨。深明饥饱劳逸发热等证。俱是内伤。悉类伤寒。切戒汗下。以为内伤多。外感
少。只须温补。不必发散。外感多而内伤少。温补中少加发散。以补中益气汤一方为主。加减出入。如内
伤兼伤寒者。以本方加麻黄。兼伤风者。本方加桂枝。兼伤暑者。本方加黄连。兼伤湿者。本方加羌活。实万
世无穷之利。东垣特发明阳虚发热之一门也。然世间真阴虚而发热者十之六七。亦与伤寒无异。反不及论
何哉。今之人一见发热。则曰伤寒。须用发散。发散而毙。则曰伤寒之书法已穷。奈何。岂知丹溪发明之外。
尚有不尽之旨乎。予尝于阴虚发热者。见其大热面赤口渴烦躁。与六味地黄大剂。一服即愈。如见下部恶寒足
冷。上部渴甚燥极。或欲饮而反吐。即以六味汤中。加肉桂五味。甚则加附子冷冻饮料。下咽即愈。予尝以此活人
多矣。敢以私秘乎。因制补天要论一卷。以补前人之不迨。所望于高明者。再加裁夺。幸甚幸甚。且举伤寒
口渴一证言之。邪热入于胃腑。消耗津液故渴。恐胃汁干。急下之。以存津液。其次者。但云欲饮水
者。不可不与。不可多与。并无治法。纵有治者。徒知以芩连知
柏麦冬五味天花粉。甚则石膏知母以止渴。此皆有形之水。以沃无形之火。安能滋肾中之真阴乎。若以六味地
黄大剂服之。其渴立愈。何至传至少阴。而成燥实坚之证乎。既成燥实坚之证。仲景不得已而以承气汤下之。
此权宜之伯术。然谆谆有虚人老弱人之禁。故以大柴胡代之。陶氏以六乙顺气汤代之。岂以二汤为平易乎。
代之而愈。所丧亦多矣。况不愈者十之八九哉。当时若多用六味地黄饮子大剂服之。取效虽缓。其益无穷。
况阴虚发热者。小便必少。大便必实。其上证口渴烦躁。与伤寒无异。彼之承气者。不过因亢则害。下之以承
真阴之气也。予今直探其真阴之源而补之。如亢旱而甘霖一施。土木皆濡。顷刻为清凉世界矣。何不可哉。况
肾水既虚矣。复经一下之后。万无可生之理。慎之慎之。吾为此惧。故于补天要论中详言之。
陶节庵亦悟此理。有云自气而至血。血而复之气者。大承气汤下之。自血而之气气而复之血者。生地黄
黄连汤主之。二者俱不大便。此是承气汤对子。又与三黄石膏汤相表里。是皆三焦胞络虚火之用也。病既
危急。只得以此汤降血中之火耳。陶以血为阴。故有此论。惜乎其不识真阴真阳之至理也。
合而言之。真知其为阳虚也。则用补中益气汤。真知其为阳虚直中也。则用附子理中汤。真知其为阴虚
也。则用六味肾气汤。真知其为阴虚无火也。则用八味肾气汤。其间有似阴似阳之假证也。则用寒因热用之
法从之。不可少误。惟以补正为主。不可攻邪。正气得力。自然推出寒邪。汗出而愈。攻之一
字。仁人之所恶也。百战百胜。战之善者也。不战而屈人之兵。善之善者也。故曰善战者服上刑。
伤寒学说专门尊崇张仲景。凡是阅读张仲景的著作，必须将“伤寒”与“中寒”分为两个门类，这样才容易通晓。因为年代久远，原书多有残缺，后来进行补遗和注释的人，又大多次序错乱、错误百出。幸好历代考订校正的人逐渐使道理明晰，等到陶节庵的《六书》和吴绶的《蕴要》两书刊行之后，伤寒的道理才开始显著。我对于其中的至理，无暇详细辨析，先将伤寒和中寒逐一辨明，以免阴阳两种证候混淆。治疗伤寒，只要抓住纲领就不难；如果追求过多的歧路，就会支离破碎。
先谈阳证。既然称为伤寒，就是寒邪从外部侵入内部而伤害人体。寒邪入侵有浅深次第，由表入里，先伤皮毛，次伤肌肉，又次伤筋骨肠胃，这是逐渐深入的趋势。至于风寒初起，必定先侵犯太阳寒水之经，出现恶风、恶寒、头痛、脊痛等症状。寒邪郁闭在皮毛，这就是表证。如果在其他经络，就没有这些症状了。脉象浮紧且无汗的，属于伤寒，用麻黄汤发汗解表，出汗后病愈；脉象浮缓且有汗的，属于伤风，用桂枝汤疏散邪气，汗止后病愈。如果没有头痛恶寒，脉象也不浮，这说明表证已罢而在半表半里之间。“中”指什么？就是表里之间，即阳明和少阳的分界处。脉象不浮不沉，位于肌肉之间，也就是皮肤之下。这里又有两种情况：如果脉象微洪而长，就是阳明脉，外证表现为鼻干、失眠，用葛根汤解肌发表；如果脉象弦而数，就是少阳脉，症状为胁痛、耳聋、寒热往来且口苦，用小柴胡汤和解。这是因为阳明和少阳不从标本，而从乎中治。如果还有一点点恶寒说明邪气仍在表，即使进入半表半里，也应当兼用散邪的方法。超过这个程度就是邪气入里，成为实热证。脉象不浮不沉，沉则按之在筋骨之间才是。如果脉象沉实有力，外证不恶风寒，反而恶热、谵语、大渴，六七天不大便，明确是热邪入里导致肠胃燥实。轻症用大柴胡汤，重症用三承气汤（调胃承气汤、小承气汤、大承气汤），大便通畅后热邪就消除了。
再谈阴证。如果初起就怕冷，手足厥冷，或者战栗蜷卧、不口渴，兼有腹痛、呕吐、泄泻，或者口吐涎沫，面色像刀刮一样苍白，不发热而脉象沉迟无力，这就是阴证。它不是从阳经传入的热证治法，更应当看外证如何。轻症用理中汤，重症用姜附汤或四逆汤来温补。由此看来，所谓伤寒，是由皮毛而后传入脏腑，起初虽然恶寒发热，但最终变为热证，这种人必定素体有火。所谓中寒，则是直入脏腑，始终恶寒，并没有发热等证，这种人必定没有火。一个是发表攻里，一个是温中散寒，两个门类判然分明，怎么会混杂在一起让后人疑惑误诊呢？
寒伤荣血，风伤卫气。卫属阳，风也属阳，阳从阳类，所以风能伤卫。血属阴，寒也属阴，阴从阴类，所以寒能伤荣。辛甘发散为阳，风宜用辛散，寒宜用甘发。桂枝气味辛热，所以能发散卫中的风邪；麻黄气味甘热，所以能发散血中的寒邪。另外，桂枝和麻黄气味都轻，属于阳中之阳，所以能进入太阳经，散发皮肤间的风寒。这两个方子是治疗冬季正伤寒的确切方剂。霜降后到春分前，此时太阳寒水当令，房劳过度或辛苦劳累的人，其太阳寒水之气乘虚而入客于太阳经，同气相求，所以容易受伤。张仲景特意因为此时杀气最重，所以详细论述。其余时节就没有伤寒，这两个方子不可使用。现在人的医牌上多写治疗四时伤寒，名不正则言不顺。《活人书》说头痛如破的，用连须葱白汤，不可直接用升麻葛根汤，恐怕太阳邪气流入阳明，是将太阳邪气引入阳明，不能解除。未到少阳阶段的，不可直接用柴胡汤。如果有恶寒症状，本方加麻黄；恶风加桂枝。如果是正阳明腑病，不恶寒、有汗且口渴，应当用白虎汤。
太阳经主一身之表，行于背部；阳明经主一身之里，行于身前；少阳经主半表半里，行于两胁旁侧。过了这些，少阴、太阴、厥阴都入脏而为里。
大凡伤寒邪热传里结实，必须看热气深浅用药。现在的医生不分应当急下还是可少量给予以微微调和胃气的理论，一概用大黄、芒硝乱投汤剂攻下，因此枉死的人很多。我认为伤寒之邪，传变途径不一，治疗方法也不同。病在三焦俱伤的，痞、满、燥、实、坚俱全，宜用大承气汤。厚朴苦温以去痞，枳实苦寒以泄满，芒硝咸寒以润燥软坚，大黄苦寒以泄实去热，病就好了。邪在中焦，则有燥、实、坚三证，所以用调胃承气汤。用甘草和中，芒硝润燥，大黄泄实，不用枳实、厚朴，是怕损伤上焦元气，“调胃”之名由此确立。上焦受伤，则痞而实，用小承气汤。枳实、厚朴能除痞，大黄泄实，去掉芒硝是不伤下焦真阴，叫作不伐其根本。至于大柴胡汤，是有表证尚未去除，而里证又急迫，不得不下的，只能用此汤通表里而缓和地治疗。特别是老弱及气血两虚之人，也适宜用此方。所以经云：转药哪个紧迫？有芒硝的紧迫。大承气最紧迫，小承气次之，柴胡汤又次之。大柴胡汤加芒硝，才算得上转药，这是为病情较轻者设立的。张仲景说：荡涤伤寒热积，都用汤药，切不宜用丸药，不可不知道。如果想用这三个承气方，必须用手按压病人，从胸到小腹，果然有硬处，手不敢靠近，才敢下手。然而其中奥妙之处，尤其需要辨别舌苔的干燥滑腻如何，《金镜录》三十六舌，不可不细细玩味。
初病无热，就四肢厥冷，或者胸腹中胀满，或者呕吐、腹满痛、下利，脉细无力，这是自阴证受寒，就是真阴证，不是从阳经传来，应当立即温补，不宜稍缓。经云：发热恶寒的，发于阳；无热恶寒的，发于阴。治宜四逆汤。腹满腹痛，都是阴症，只有轻重不同，治疗难以一概而论。腹痛不大便，用桂枝芍药汤；腹痛剧烈，用桂枝大黄汤。如果是自利腹痛，小便清白，宜温中，根据轻重选用理中汤或四逆汤。轻者用五积散，重者用四逆汤。无脉的用通脉四逆汤，使阴退而阳复。
阴毒病，手足指甲皆青，脉沉细而急的，用四逆汤；无脉的用通脉四逆汤；阴毒甘草汤；脐中用葱熨法，气海、关元穴艾灸，可灸二三百壮，然后用温和补气之药，通其内外，以恢复阳气。如果都不见效，就是死证。
以上都是真阴证，人们都知道。至于反常的情况，就不容易明白。有的发热面赤，烦躁揭去衣被，饮冷脉大，误认为是阳证投以寒药，死者很多。必须凭脉下药，不问脉象浮沉大小，只要指下无力，按至筋骨全无力，必定有伏阴，不可给凉药。如果已经服用过凉药，脉必鼓指而有力，脉象就难以凭信了。如果一切茶汤及寒热药都吐出来，这是阴盛格阳，急用白通汤，加入人尿、胆汁，以通达拒格之寒。所以张仲景《伤寒论》中，传经与直中并论，正是因为有阳证似阴、阴证似阳，应当详细辨别。但因为年代久远散乱，后人误相补集，致使不明。比如太阳证头痛发热，应当脉浮反而脉沉，又像是少阴病了，所以用麻黄附子细辛汤。比如少阴证脉沉，应无热，反而发热的，又像是太阳病了，须用干姜附子甘草汤。比如阴证四肢厥逆，而阳证也有厥逆的，这是四逆汤与四逆散不同。又如阴证下利，而阳证又有漏底（完谷不化）的，这是理中汤与黄龙汤不同。像这类疑似难明的，幸好陶节庵《六书》已经明确区分了。我又有一番说法：如果读伤寒书，而不读李东垣的书，则内伤不明，杀人很多。读李东垣的书，而不读朱丹溪的书，则阴虚不明，杀人很多。读朱丹溪的书，而不读薛己的书，则真阴真阳不明，杀人也很多。李东垣说：邪之所凑，其气必虚。世间内伤者多，外感者间或有之。这个“间”字当作“五百年间出一”之间，极言没有外感。李东垣的《脾胃论》以及《内伤外感辨》，深刻阐明饥饱劳逸发热等证，都是内伤，完全类似伤寒，切忌汗下。认为内伤多，外感少，只需温补，不必发散。外感多而内伤少，温补中少加发散，以补中益气汤一方为主，加减出入。如内伤兼伤寒者，在本方加麻黄；兼伤风者，本方加桂枝；兼伤暑者，本方加黄连；兼伤湿者，本方加羌活。这是万世无穷的利益。李东垣特别阐明了阳虚发热这一门。然而世间真阴虚而发热的占十之六七，也与伤寒无异，反而不及讨论为什么呢？现在的人一见发热，就说伤寒，必须用发散，发散而死，就说伤寒的治法已穷尽。奈何，难道不知道朱丹溪阐发的之外，还有未尽的旨意吗？我曾经对阴虚发热者，见其大热、面赤、口渴、烦躁，用六味地黄丸大剂量服用，一服即愈。如果见下部恶寒足冷，上部渴甚燥极，或者想喝却反吐，就在六味地黄汤中加入肉桂、五味子，严重时加附子，冷冻饮料，下咽即愈。我曾经以此救活很多人，敢以此作为私秘吗？因此撰写《补天要论》一卷，以弥补前人的不足，希望高明之士再加裁夺，幸甚幸甚。且举伤寒口渴一证来说。邪热入于胃腑，消耗津液故口渴，恐胃汁干枯，急下之以存津液。其次的，只说想喝水的，不可不给，不可多给，并无具体治法。纵有治法的，只知道用黄芩、黄连、知母、黄柏、麦冬、五味子、天花粉，严重时用石膏、知母来止渴。这些都是有形之水，去浇灌无形之火，怎么能滋补肾中的真阴呢？如果用六味地黄丸大剂量服用，口渴立刻痊愈，何至于传到少阴，而成燥实坚的证候呢？既已成燥实坚之证，张仲景不得已而以承气汤下之，这是权宜之术，然而谆谆告诫有虚人老弱之禁，所以用大柴胡汤替代。陶氏用六乙顺气汤替代，难道认为这两汤平易吗？替代而愈，损失也很多，何况不愈的十之八九呢？当时如果多用六味地黄饮子大剂量服用，取效虽缓，其益无穷。况且阴虚发热者，小便必少，大便必实，其上证口渴烦躁，与伤寒无异。彼之承气汤，不过是因亢则害，下之以承真阴之气。我现在直接探求真阴之源而补之，如同亢旱之时甘霖一施，土木皆濡，顷刻变为清凉世界，有什么不可以呢？况且肾水既虚，再经过一次攻下，万无可生之理。慎之又慎，我为此恐惧，所以在《补天要论》中详细论述。
陶节庵也领悟到这个道理，他说：自气而至血，血而复之气的，用大承气汤下之；自血而之气，气而复之血的，用生地黄黄连汤主治。两者都大便不通，这是承气汤的对子，又与三黄石膏汤相表里，这都是三焦胞络虚火用的。病既危急，只得用此汤降血中之火。陶节庵以血为阴，所以有此论，可惜他不识真阴真阳的至理。
综合而言，真知其为阳虚，则用补中益气汤；真知其为阳虚直中，则用附子理中汤；真知其为阴虚，则用六味肾气汤；真知其为阴虚无火，则用八味肾气汤。其间有似阴似阳的假证，则用寒因热用的方法顺从其假象，不可稍有失误。惟以补正为主，不可攻邪。正气得力，自然推出寒邪，汗出而愈。攻字，是仁人所厌恶的。百战百胜，是作战中的善者；不战而屈人之兵，是善中之善者。所以说善于作战的人应受上刑。
Shanghan (Cold Damage) theory exclusively venerates Zhang Zhongjing. Anyone reading Zhang Zhongjing's works must distinguish between Shanghan (Cold Damage) and Zhonghan (Direct Strike of Cold) as two separate categories to facilitate understanding. Due to the passage of time, the original texts have suffered from fragmentation; those who added supplements and annotations often introduced chronological errors and mistakes. Fortunately, successive generations of scholars gradually clarified these issues. It was only after the publication of Tao Jie'an's *Liu Shu* (Six Books) and Wu Shou's *Yun Yao* (Essential Collection) that the principles of Shanghan became prominent. I do not have the leisure to debate the profound truths in detail at this moment; instead, I will first clarify Shanghan and Zhonghan one by one to prevent the confusion of Yin and Yang syndromes. Treating Shanghan is not difficult if one grasps the general outline; however, seeking too many divergent paths leads to a fragmented approach.
Let us first discuss Yang syndromes. Since it is called Shanghan, cold pathogenic factors enter from the exterior and damage the interior. The entry has degrees of depth and sequence: from the surface to the interior, first affecting the skin and hair, then muscles, and subsequently bones, sinews, stomach, and intestines. This is the gradual trend of deepening invasion. When wind-cold initially enters, it must first invade the Taiyang (Greater Yang) Bladder meridian, presenting symptoms such as aversion to wind, aversion to cold, headache, and spinal pain. Cold stagnating in the skin and hair constitutes an Exterior Syndrome. Other meridians would not present these specific symptoms. If the pulse is floating and tight without sweating, it is Shanghan, treated with Mahuang Tang (Ephedra Decoction) to induce sweating for resolution. If the pulse is floating and relaxed with sweating, it is Wind Injury, treated with Guizhi Tang (Cinnamon Twig Decoction) to disperse pathogens, resolving when sweating stops. If there is no headache or aversion to cold, and the pulse is not floating, this indicates the Exterior Syndrome has ceased and the pathogen is in the "Middle" (half-exterior/half-interior). What is the Middle? It is the boundary between exterior and interior, specifically the realms of Yangming (Stomach) and Shaoyang (Gallbladder). The pulse is neither floating nor sinking, located between the muscles, beneath the skin. There are two variations here: if the pulse is slightly flooding and long, it is a Yangming pulse; external signs include dry nose and insomnia, treated with Gegen Tang (Kudzu Decoction) to release the muscles. If the pulse is wiry and rapid, it is a Shaoyang pulse; symptoms include hypochondriac pain, deafness, alternating chills and fever, and bitter taste in the mouth, treated with Xiaochaihu Tang (Minor Bupleurum Decoction) to harmonize. This is because Yangming and Shaoyang do not follow the root or branch but are treated via the middle. If even a slight aversion to cold remains, indicating the pathogen is still on the exterior, even if entering the half-exterior/half-interior, dispersing methods should be combined. Beyond this point, the pathogen enters the interior, becoming Excess Heat. The pulse is neither floating nor sinking; if sinking, pressing reveals it between bones and sinews. If the pulse is sinking, solid, and forceful, and external signs show aversion to wind/cold is absent but aversion to heat, delirium, and extreme thirst are present, along with constipation for six to seven days, this clearly indicates heat entering the interior causing dryness and excess in the stomach and intestines. Mild cases use Dahuang Huanglian Xixin Tang (not explicitly named here but implied contextually as intermediate) or rather, mild cases use Da Chaihu Tang (Major Bupleurum Decoction), while severe cases use the Three Chengqi Decoctions (Tiaowei Chengqi Tang, Xiao Chengqi Tang, Da Chengqi Tang). Once stool passes, heat dissipates.
Now let us discuss Yin syndromes. If from the onset there is fear of cold, cold limbs, or shivering and curling up without thirst, accompanied by abdominal pain, vomiting, diarrhea, salivation, a face pale as if scraped by a knife, no fever, and a sinking, slow, and weak pulse, this is a Yin Syndrome. It does not follow the treatment examples of heat syndromes transmitted from Yang meridians. One must further observe external signs. Mild cases use Lizhong Tang (Regulate the Middle Decoction); severe cases use Jiangfu Tang (Ginger and Aconite Decoction) or Sini Tang (Recover the Extremities Decoction) to warm. From this, we see that Shanghan proceeds from skin/hair to organs/viscera. Initially虽有 aversion to cold and fever, it ultimately becomes a heat syndrome; such individuals must inherently possess Fire. Zhonghan (Direct Strike of Cold), however, goes directly into the viscera, maintaining constant aversion to cold without fever, etc.; such individuals lack Fire. One approach releases the exterior and attacks the interior; the other warms the middle and dispels cold. The two categories are distinct. How could they be mixed, causing confusion for later generations?
Cold damages Ying (Nutritive Blood); Wind damages Wei (Defensive Qi). Wei is Yang; Wind is also Yang. Like attracts like, so Wind damages Wei. Blood is Yin; Cold is also Yin. Like attracts like, so Cold damages Ying. Pungent and Sweet flavors that disperse belong to Yang. Wind should be dispersed with Pungent herbs; Cold should be released with Sweet herbs. Guizhi (Cinnamon Twig) is pungent and hot, thus dispersing Wind pathogens in the Wei level. Mahuang (Ephedra) is sweet and hot, thus dispersing Cold pathogens in the Ying/Blood level. Furthermore, Guizhi and Mahuang have light aromas and flavors, representing Yang within Yang, allowing them to enter the Taiyang meridian and disperse wind-cold in the skin. These two formulas are the precise prescriptions for treating Zheng Shanghan (True Cold Damage) in winter. From Frost Descent to Spring Equinox, the Taiyang Cold Water phase is dominant. Individuals who engage in sexual activity excessively or endure hard labor have deficient Taiyang Cold Water Qi, which allows pathogens to enter the Taiyang meridian due to resonance of similar energies, making injury easy. Zhang Zhongjing detailed this because the killing energy of cold is heaviest then. In other seasons, there is no Shanghan, and these two formulas should not be used. Today, medical signs often claim treatment for "Four Seasons Shanghan," which is improper nomenclature. The *Huoren Shu* states that for headache like splitting, use Lianxu Congbai Tang (Green Onion White Decoction); do not immediately give Shengma Gegen Tang, lest Taiyang pathogens flow into Yangming, pulling Taiyang pathogens into Yangming where they cannot be resolved. Before reaching Shaoyang, do not immediately give Chaihu Tang. If aversion to cold exists, add Mahuang to the base formula; if aversion to wind, add Guizhi. For true Yangming Fu organ disease, with no aversion to cold, sweating, and thirst, use Baihu Tang (White Tiger Decoction).
Taiyang meridian governs the exterior of the body, running along the back. Yangming meridian governs the interior of the body, running along the front. Shaoyang meridian governs half-exterior/half-interior, running along the sides of the ribs. Beyond these, Shaoyin, Taiyin, and Jueyin all enter the Zang organs, becoming Interior.
Generally, when Shanghan pathogenic heat transmits to the interior and forms accumulation, one must judge the depth of heat to prescribe medication. Current physicians fail to distinguish between cases requiring urgent purgation and those needing only mild regulation of Stomach Qi, indiscriminately using Dahuang (Rhubarb) and Mangxiao (Mirabilite) in decoctions, leading to many wrongful deaths. I argue that Shanghan pathogens transmit in various ways, requiring different treatments. If pathogens injure all three Jiaos, resulting in fullness, distension, dryness, excess, and hardness, Da Chengqi Tang (Major Order the Qi Decoction) is appropriate. Houpo (Magnolia Bark) is bitter and warm to remove distension; Zhishi (Immature Bitter Orange) is bitter and cold to drain fullness; Mangxiao is salty and cold to moisten dryness and soften hardness; Dahuang is bitter and cold to drain excess and clear heat. The disease resolves. If pathogens are in the Middle Jiao, presenting dryness, excess, and hardness, Tiaowei Chengqi Tang (Regulate the Stomach Order the Qi Decoction) is used. Gancao (Licorice) harmonizes the middle; Mangxiao moistens dryness; Dahuang drains excess. Zhishi and Houpo are omitted to avoid damaging Upper Jiao Yuan Qi; hence the name "Regulate the Stomach." If the Upper Jiao is injured, presenting distension and excess, Xiao Chengqi Tang (Minor Order the Qi Decoction) is used. Zhishi and Houpo remove distension; Dahuang drains excess. Mangxiao is omitted to avoid damaging Lower Jiao True Yin, preserving the root. As for Da Chaihu Tang, it is used when exterior signs remain unresolved but interior signs are urgent, requiring simultaneous resolution of exterior and interior. It is also suitable for the elderly, weak, and those with dual deficiency of Qi and Blood. Thus, the classics state: regarding the urgency of medication transformation, those containing Mangxiao are most urgent. Da Chengqi is most urgent, Xiao Chengqi is next, Chaihu Tang is next. Da Chaihu Tang plus Mangxiao qualifies as transforming medication, intended for milder illnesses. Zhang Zhongjing stated that to sweep away Shanghan heat accumulation, decoctions must be used; pills are unsuitable. This must be known. To use these three Chengqi formulas, one must press the patient's abdomen from chest to lower abdomen; if there is hardness that cannot be touched, then one dares to administer. However, the subtlety lies in examining the tongue coating for dryness or slipperiness. The *Jing Jian Lu* (Record of Tongue Mirrors) describes thirty-six tongue types, which must be studied carefully.
If initial illness presents no fever but cold limbs, or chest/abdominal fullness, vomiting, abdominal pain, and diarrhea, with a fine and weak pulse, this is Cold contracted from a Yin syndrome, i.e., True Yin Syndrome, not transmitted from Yang meridians. Immediate warming is required, without delay. The classics state: Fever with aversion to cold originates in Yang; no fever with aversion to cold originates in Yin. Treatment should use Sini Tang. Abdominal fullness and pain are Yin syndromes, differing only in severity, making treatment non-uniform. Abdominal pain with constipation uses Guizhi Shaoyao Tang (Cinnamon Twig and Peony Decoction); severe abdominal pain uses Guizhi Dahuang Tang (Cinnamon Twig and Rhubarb Decoction). If spontaneous diarrhea with abdominal pain and clear urine, warm the middle using Lizhong Tang or Sini Tang based on severity. Mild cases use Wuji San (Five Accumulations Powder); severe cases use Sini Tang. Pulseless conditions use Tongmai Sini Tang (Pulse-Returning Sini Decoction) to make Yin retreat and Yang recover.
Yin Du (Yin Toxin) disease presents with blue fingernails/toenails, sinking, fine, and rapid pulse; treat with Sini Tang. Pulseless: Tongmai Sini Tang. Also consider Yindu Gancao Tang (Yin Toxin Licorice Decoction), moxa application on the navel with scallion, and moxibustion on Qihai and Guanyuan acupoints (200-300 moxa cones), followed by mild Qi-tonifying herbs to open interior/exterior and restore Yang Qi. If ineffective, it is a death case.
Above are True Yin Syndromes, which people know. Anomalous cases are harder to understand. Some present with fever, red face, restlessness, removing clothes/blankets, drinking cold fluids, and large pulse, mistaken for Yang syndrome and treated with cold herbs, leading to many deaths. One must rely on pulse diagnosis. Regardless of floating/sinking or large/small, if the pulse feels weak under the finger and completely powerless when pressed to bone/sinew, there must be hidden Yin. Do not give cooling herbs. If cooling herbs were already taken, the pulse may become forceful and striking, making pulse diagnosis unreliable. If all teas and medicines are vomited, this is Yin Excess repelling Yang. Urgently use Baotong Tang (Unblock the Yang Decoction) with human urine and pig bile to overcome the repelling cold. Thus, Zhang Zhongjing discusses both transmitted and direct-strike patterns in *Shanghan Lun* precisely because Yang syndromes can resemble Yin, and Yin syndromes can resemble Yang, requiring careful differentiation. Due to textual corruption over time, later compilations caused confusion. For example, Taiyang syndrome headache/fever should have a floating pulse but presents sinking, resembling Shaoyin; thus, Mahuang Fuzi Xixin Tang (Ephedra, Aconite, and Asarum Decoction) is used. Shaoyin syndrome pulse sinking should have no fever but presents fever, resembling Taiyang; thus, Ganjiang Fuzi Gancao Tang (Dried Ginger, Aconite, and Licorice Decoction) is used. Yin syndrome cold limbs vs. Yang syndrome cold limbs differ: Sini Tang vs. Sini San (Bupleurum Powder). Yin syndrome diarrhea vs. Yang syndrome leakage (undigested food): Lizhong Tang vs. Huanglong Tang (Yellow Dragon Decoction). Such ambiguities were clarified by Tao Jie'an's *Liu Shu*. I have another point: Reading Shanghan books without Li Dongyuan's works leaves Internal Injury unclear, causing many deaths. Reading Li Dongyuan without Zhu Danxi's works leaves Yin Deficiency unclear, causing many deaths. Reading Zhu Danxi without Xue Ji's works leaves True Yin/True Yang unclear, causing many deaths. Li Dongyuan said: Where pathogenic factors gather, Qi is necessarily deficient. Internal injuries are common; external contractions are rare. The word "rare" implies "one in five hundred years," emphasizing the absence of external contractions. Li Dongyuan's *Pi Wei Lun* (Treatise on Spleen and Stomach) and *Nei Shang Wai Gan Bian* (Differentiation of Internal Injury and External Contraction) clarify that fevers from hunger/fullness or fatigue are internal injuries, similar to Shanghan, forbidding sweating and purging. He argued internal injuries are common, external few; thus, warm tonification is needed, not dispersion. If external contraction is common and internal injury rare, add mild dispersion to warm tonification, primarily using Buyi Zhongqi Tang (Tonify the Middle and Augment the Qi Decoction), modified. For internal injury with Shanghan, add Mahuang; with Wind, add Guizhi; with Summerheat, add Huanglian; with Dampness, add Qianghuo. This offers eternal benefit. Li Dongyuan elucidated Yang Deficiency Fever. However, 60-70% of fevers in the world are due to True Yin Deficiency, indistinguishable from Shanghan, yet rarely discussed. People see fever and assume Shanghan requiring dispersion; if dispersion kills, they say Shanghan treatment is exhausted. Do they not know Zhu Danxi's deeper insights? I once treated Yin Deficiency fever with high doses of Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia), curing it instantly. For lower body cold/cold feet with upper body extreme thirst/dryness or vomiting upon drinking, I added Rougui (Cinnamon Bark) and Wuweizi (Schisandra) to Liuwei Dihuang Tang, or Fuzi (Aconite) in severe cases, served cold, curing instantly. I saved many with this method. Why keep it secret? I wrote *Bu Tian Yao Lun* (Essential Discourse on Supplementing Heaven) to supplement predecessors' shortcomings, hoping for expert review. Consider thirst in Shanghan: Pathogenic heat in Stomach consumes fluids, causing thirst. To save Stomach juice, urgent purging preserves fluids. For mild thirst, give water but not much, with no specific formula. Those who treat it use Huangqin, Huanglian, Zhimu, Huangbai, Maidong, Wuweizi, Tianguafen, or Shigao/Zhimu to stop thirst. These are tangible waters trying to extinguish intangible fire, unable to nourish Kidney True Yin. High-dose Liuwei Dihuang Tang cures thirst instantly, preventing transmission to Shaoyin and formation of dryness/excess/hardness. If formed, Zhang Zhongjing reluctantly uses Chengqi Tang, a temporary measure, warning against use in weak/elderly, substituting Da Chaihu Tang. Tao substituted Liuyi Shunqi Tang. Did he think these were mild? Even if effective, losses are great; 80-90% fail. If Liuwei Dihuang Yin was used heavily, effect might be slower but benefits infinite. Yin Deficiency fever presents scant urine and constipation, with thirst/restlessness like Shanghan. Their Chengqi Tang acts to descend rebellious Qi to support True Yin. I explore the source of True Yin and tonify it, like rain in drought, instantly cooling. Why not? After purging deficient Kidney Water, survival is impossible. Be cautious. I elaborate in *Bu Tian Yao Lun*.
Tao Jie'an understood this: From Qi to Blood, Blood to Qi: Da Chengqi Tang. From Blood to Qi, Qi to Blood: Shengdihuang Huanglian Tang. Both with constipation are counterparts to Chengqi Tang, related to Sanhuang Shigao Tang, treating Empty Fire in Three Jiao and Bao Luo. In critical illness, these cool blood-fire. Tao viewed Blood as Yin, hence his theory, but missed True Yin/True Yang principles.
In summary: True Yang Deficiency -> Buyi Zhongqi Tang. True Yang Deficiency Direct Strike -> Fuzi Lizhong Tang. True Yin Deficiency -> Liuwei Shenqi Tang. True Yin Deficiency without Fire -> Bawei Shenqi Tang (Eight-Ingredient Pill with Rehmannia). For pseudo-Yin/Yang signs, use "treat cold with hot" method following the false appearance, never erring. Focus on tonifying Righteous Qi, never attacking Evil. Strong Righteous Qi expels Cold naturally, inducing sweat and cure. "Attack" is abhorrent to benevolent men. Winning every battle is good; winning without fighting is best. Thus, skilled warriors deserve punishment.