喻嘉言改秋伤于湿为伤燥，在喻氏不过借证秋燥之义，而擅改经文，则谬矣。夫湿非燥
之讹
也。《素问》水热穴论曰∶秋者，金始治，肺将收杀，阴气初胜，湿气及体。盖四时五行之
递嬗也，惟土湿与金清相递太急，湿令未衰，而清敛之令已至，故其始湿虽盛而气外散也；
及秋而湿乃敛入体中矣，及冬而阳气又入矣。阳湿相激，故咳嗽也。若是伤燥，秋即当嗽
，不待冬矣。其所制清燥救肺汤，亦治秋燥，非治冬咳之燥也。
燥为次寒，其气属金，其象为干，为坚，为降，为清析，为锋利，皆金之正令也。若热
燥
，是挟火在内，与寒燥相对待，不专于金也。喻专以热言燥，则水泽腹坚，又何以说之?
伤寒，非奇病也。《伤寒论》，非奇书也。仲景据其所见，笔之于书，非既有此书，而
天下
之人根据书而病也。其三阴三阳转变之处，前人往往词涉硬派，一似暗有鬼物，指使邪气，如
何传法，并不得如何传法。读者须消去此等臆见，每读一段，即设一病者于此，以揣其病机
、治法，而后借证于书，不得专在文本上安排。
第一须辨伤寒为何等病。此本四时皆有之病也，但三时多有挟温、挟湿、挟燥、挟风之
异，其
气不专于寒，其肤腠疏松，初伤即兼二三经，再传而六经已遍。惟冬时腠理固密，寒邪必先
伤皮肤，以渐深入，故谓三时伤寒治法不同则可，谓三时无伤寒则不可。仲景是专论冬时伤
寒，惟即病于冬，与迟病于春，中多相间错出，未曾分析。其迟病于春者，亦系专指寒病，
未及化热者，与《内经》冬伤于寒，春必病温之旨不同。前释发阴、发阳篇，可参看。伏气
二字，本不必过于深求，今日感寒，今日即病，固即病也；上月感寒，下月始病，亦常有之
事，谓之伏气可也，谓之即病可也。岂得一言伏气，便有许多奇怪?
第二须辨论中寒热二字为何等气。寒者、天地之邪气也；热者，人身之正气也，为寒邪
所束，不得宣发，郁结而成；与寒邪是两气，非寒能化热也，与温热病伤于天地之热邪者不
同
。寒邪既散，即当阳气伸而热解，其有不解者，正气久困，经脉凝滞，不能自运，抑或误治
使然。
第三须将“传”字看得活。非邪气有脚，能自国中转变，步伐正齐也。病证变见何象，
即为
邪伤何经。如少阳主行津液，津液灼干，即少阳证；阳明主运渣滓，渣滓燥结，即阳明证。
读者须思何以头痛、呕吐、晕眩、胁胀?何以大便秘结、潮热、自汗?不得浑之曰邪入少阳故
尔也，邪入阳明故尔也!当在气化上推求，不得专在部位上拘泥。
第四须辨初伤有三阳，有两感，有直中。太阳行身之后而主表，其时阳明、少阳决无不
伤。
《内经》曰∶中于项则下太阳，中于面则下阳明，中于颊则下少阳；中于阳则溜于经，中于
阴
则溜于腑。即仲景所叙太阳中风，鼻鸣，干呕，岂专太阳?但邪在大表，治法不外麻、桂、
葛根，故不必多立名色。两感、直中，皆因其人阳气之虚，或邪气之猛也。太阳少阴、阳明
太阴，皆有两感；少阳厥阴，两感殊少。直中亦然。少、厥两感，即阳气蔑矣。直中与两感
不同者，两感是一阴一阳同病，其邪相等；直中是邪甚于阴也，其阳亦断无不伤。但阴分之
病，校较感为急。
第五须识伤营伤卫，不能判然两途。仲景风则伤卫，寒则伤营，只略叙于麻黄证中，不
过分
析风、寒所伤之偏重如此。其意侧重在寒，是串说，非平说。况夫中风脉缓自汗，汗即营也
，营液外泄，桂枝汤是充助营气之剂；伤寒脉紧无汗，是卫气为寒所拘，麻黄轻迅，是过营
透卫以开表，其力正注于卫。何得谓风伤卫不伤营，寒伤营不伤卫?更何得以此劈分两大纲?
按冬月腠理闭密，寒邪以渐而深。初伤皮肤，只在气分，此时发之，不必得汗，其邪自
散；
次伤肌肉，乃在津液，邪与汗俱，汗出邪退；次伤经脉，乃入血分，即入经脉，则或窜筋骨
，或溃三焦而据脏腑，亦有已及筋骨，而仍未入经脉之中者，故三阴亦有表证可汗也；既入
经脉，必连脏腑，非可专恃汗法矣。其未入经脉时，所称太阳病、阳明病、少阳病及三阴病
者，只是三阳三阴之部，非经也。与第二卷《三阴三阳名义》篇参看。
第六须辨寒热传化之机。初伤固总是寒，日久有寒邪内陷者，是其人本内寒也；有寒去
热不
解者，是其人阴不足也。寒邪内陷必下利，即所谓阴传太阴也，其实即阳明之下陷耳!继即
少阳之气陷，继即少阴之气陷，至厥阴肝气亦陷，无复生机矣。始终总不离乎下利，若利早
止于厥阴未陷之前，即不得死；止于厥阴已陷之后，息高时冒，阴气竭矣。热气不解，必秘
结，必自汗，即所谓阳传阳明也。此时太阴之津液，必已亏矣，治之失法，而少阴之精又亏
，厥阴之血又亏，始终总不离乎秘结。非邪至阳明，即无复传也，总不离乎阳明耳!
第七须识伤寒、温病，始异终同之说不可执也。此只说得热传阳明一边，其寒传太阴，
迥乎
不同。伤寒有寒死证，无热死证。阳明内实，非死证也；其有死者，皆由误治。若温热病，
则有自然一成不变之热死证。
第八须识合病、并病之中，有真假之不同。前人分别合病、并病，语多牵强。当是两阳
同感
，谓之合病；由此连彼，谓之并病。更有邪气未及彼经，而彼经为之扰动者，其见证必有虚
实之不同。如素胃寒者，一伤于寒，即口淡，即便滑；素阴虚者，一伤于寒，热气内菀，即
喘喝，即口渴。岂真邪传阳明太阴耶?但散其寒，诸证即瘳；亦有略须兼顾者，必其内虚之
甚，预杜邪气内陷之路也。
第九须求寒热气化之真际。六经传次，本不必根据仲景篇次也。无如前人越经传、表里传
等语
，说得过泥，并未靠定各经，切发其所以然。如少阳主经脉之津液，经脉灼干，即见少阳证
；太阴主肠胃之津液，肠胃灼干，即见太阴证；阳明主肠胃之渣滓，渣滓燥结，即见阳明证
；厥阴主筋膜之津液，筋膜枯索，即见厥阴证；少阴主下焦之气化津液，津竭气散，即见少
阴证。此从热化也；从寒化者，阳气不足而下泄，寒水淫溢而上逆，总是何脏受伤，即何经
见证。
第十寒化热化，各视本体之阴阳虚实。此语浅而极真。论中误汗后，有为内寒者，有为
内热
者；误下后，亦有内寒者，有内热者。若执过汗亡阳、过下亡阴之例，便不可通。故读者以
随文生义为贵。夫六经乘虚而传，寒热随偏而化也。
第十一须知表里之说。有形层之表里，有经络之表里，有脏腑之表里，有气化之表里。
形层
即前所谓皮肤、肌肉、筋骨，所谓部分也。邪在三阴之部，里而仍表，仍宜汗解；邪入三阳
之经，表而已里，只有清化，即和解也。少阳半表半里，亦有数解∶以部位言，则外在经络
则内连三焦也；以气化言，则表里未清，而里热已盛也，总是气化燥结之象。
与第四卷《少阳三禁》篇参看。
第十二须知手经足经，并无分别。足经部位大，邪气在表，尚在经脉之外，其气是一大
片，
故见足经证；邪入经脉之中，反多见手经证矣。大抵足经证见者，多在躯壳之外；手经证见
者，多关脏腑之中。足证有在经者，手证绝少在经也。经者，身形之事也；脏腑者，神明气
化之事也。
第十三须知三阴三阳，只是经络表里之雅名，于脏腑气血之阴阳，不相涉也。若谓邪入
三阳
，即为伤阳；邪入三阴，即为伤阴，则差矣。《内经》心为太阳，肝为少阳，肺为少阴，肾
为太阴，脾与六腑为至阴。此以气血清浊言之，今人已不讲。其实各经各脏各腑之中，各有
阴阳。此说甚长，细读《内经》，自能辨之。
第十四读书须知阙疑。论中叙证，有极简者，有极繁者，有方证不合者，有上下文义不
贯者。一
经设身处境，实在难以遵行，安知非错简、脱简耶?不必枉费心机，以俟将来之阅历。即如
少阳、阳明合病，自下利者，黄芩汤；太阳误下，利不止者，此协热利也，承气汤。此必内
有伏热，三焦肠胃秽气郁浊，颇似温病之发于伏邪者，于伤寒自利，及误下而利者，殊不合
格。又太阳误下结胸，正宜兼开兼降，以宣内陷之阳，而开邪气之结，乃反用甘遂、巴豆以
重泄之，是以一误为不足，而又益之也。又太阳、阴明合病，自利者，葛根汤；不下利，但
呕者，葛根汤加半夏。既不下利，何以仍用原方?是原方只治合病，并非治下利也，前文何
必特署下利字样?此类宜详思之。前人只说三阳合病，皆有下利，绝不说合病所以下利之故
。此之谓半截学问。
总之，读《伤寒论》，只当涵泳白文。注家无虑数十，以予所见二十余种，皆不免穿凿
附会
，言似新奇，莫能见之行事。鄙见只当分作四层∶曰伤寒初起本证治法∶曰伤寒初起兼证
治法；曰伤寒日久化寒，并误治化寒证治，曰伤
寒日久化热，并误治化热证治。其霍乱、风湿、食复、劳复，以杂证附之。再参之陶节庵书
，及各家论温热书，互相考证，庶于读书有条理，而临诊亦可有径途矣。盖经脉部位，与夫
形层表里浅深之事，固不可不讲，而究不可过执也，着力仍在气化上。此书在唐以前，已非
一本，其章节离合，本无深意，读者只应各就本文思量，不必牵扯上下文，积久自能融会贯
通。
喻嘉言将“秋伤于湿”改为“伤燥”，在喻氏看来不过是借秋季燥证的意义，但擅自更改经文，则是错误的。湿气并非燥气的讹误。《素问·水热穴论》说：秋天，金气开始主事，肺脏即将收敛肃杀，阴气初胜，湿气侵袭人体。这是四季五行更替的结果，只是土湿与金清交替得太快，湿令尚未消退，而清凉收敛的时令已经到来，所以起初湿气虽盛，但气机向外发散；到了深秋，湿气才收敛进入体内；到了冬天，阳气又向内入藏。阳气和湿气相互激荡，所以产生咳嗽。如果是伤了燥气，秋天就应该咳嗽，不需要等到冬天。他所制作的清燥救肺汤，也是治疗秋燥的，不是治疗冬季咳嗽的燥症。
燥气属于次寒，其气属金，其象表现为干燥、坚硬、下降、清明析理、锋利，这些都是金的正常特性。如果是热燥，那是夹带着火气在内，与寒燥相对立，不单纯属于金了。喻氏专门从热的角度论述燥，那么“水泽腹坚”（水面结冰，腹部坚硬）这种现象又怎么解释呢？
伤寒，并不是奇特的病。《伤寒论》，也不是奇特的书。张仲景是根据他看到的病情，记录在书上，并不是因为已经有了这本书，天下的人才依据这本书生病。其中三阴三阳转变的地方，前人往往措辞生硬刻板，好像暗中有什么鬼物驱使邪气，按照某种方法传变，让人搞不清楚到底是怎么传的。读者必须消除这种臆测之见，每读一段，就设想有一个病人就在这里，揣摩他的病机、治法，然后再参考书中的条文，不能只在文本字面上做安排。
第一，必须辨别伤寒是什么性质的病。这本来是四季都有的病，但其他三个季节多有挟带温、湿、燥、风的不同，其气不专属于寒，皮肤腠理疏松，初次受伤就兼涉两三条经脉，再传变则六经都已遍及。只有冬天时腠理固密，寒邪必须先伤害皮肤，逐渐深入，所以说三个季节的伤寒治法不同是可以的，说三个季节没有伤寒就不对了。张仲景是专门论述冬天的伤寒，只是即发于冬季和迟发于春季的病症，中间多相间错出，未曾详细分析。那些迟发于春季的，也专门指寒病，未及化热的，这与《内经》中“冬伤于寒，春必病温”的宗旨不同。前面解释发阴、发阳篇的内容，可以参考。伏气这两个字，本来不必过于深究，今天感受寒邪，今天就发病，固然是即病；上个月感受寒邪，下个月才发病，也常有这种事，称之为伏气可以，称之为即病也可以。怎么能一说伏气，就变得很奇怪呢？
第二，必须辨别书中“寒”、“热”二字代表什么气。寒，是天地的邪气；热，是人身的正气，被寒邪束缚，不能宣发，郁结而成；它与寒邪是两种气，不是寒能化热，这与温热病伤害于天地热邪的情况不同。寒邪既然消散，就应当阳气伸展而热解，有不解的，是因为正气久受困顿，经脉凝滞，不能自行运转，或者是误治造成的。
第三，要把“传”字看活络。不是邪气有脚，能从身体内部转变，步伐整齐划一。病证变成什么样子，就是邪气伤害了哪条经脉。比如少阳主管运行津液，津液被灼干，就是少阳证；阳明主管运化渣滓，渣滓燥结，就是阳明证。读者必须思考为什么头痛、呕吐、晕眩、胁胀？为什么大便秘结、潮热、自汗？不能笼统地说邪入少阳所以这样，邪入阳明所以这样！应当在气化上推求，不能只在部位上拘泥。
第四，必须辨别初伤有三阳证，有两感证，有直中证。太阳行于身背而主表，此时阳明、少阳决无不受伤的道理。《内经》说：中于项部则传入太阳，中于面部则传入阳明，中于颊部则传入少阳；中于阳经则流注于经脉，中于阴经则流注于腑。就像张仲景所叙述的太阳中风，鼻鸣，干呕，难道只伤太阳吗？只是邪气在大表，治法不外乎麻黄、桂枝、葛根，所以不必多立名目。两感、直中，都是由于人的阳气虚弱，或邪气猛烈所致。太阳少阴、阳明太阴，都有两感；少阳厥阴，两感很少。直中也是如此。少阳、厥阴两感，就是阳气微绝了。直中与两感不同之处在于，两感是一阴一阳同病，邪气相当；直中是邪气甚于阴分，其阳分也断无不伤。但阴分的病，比较起来比感邪更为急迫。
第五，必须认识伤营、伤卫，不能截然分为两条路。张仲景说风则伤卫，寒则伤营，只是在麻黄证中略作叙述，并没有过分分析风、寒所伤的偏重如此。他的意思侧重于寒，是连贯的说法，不是平铺直叙。况且中风脉缓自汗，汗即是营，营液外泄，桂枝汤是充助营气的方剂；伤寒脉紧无汗，是卫气被寒邪拘束，麻黄轻迅，是过营透卫以开表，其力正注于卫。怎么能说风伤卫不伤营，寒伤营不伤卫？又怎么能以此劈分为两大纲领？
按冬天月份腠理闭密，寒邪逐渐深入。初伤皮肤，只在气分，此时发散它，不必出汗，邪气自然消散；次伤肌肉，乃在津液，邪与汗俱出，汗出邪退；次伤经脉，乃入血分，既入经脉，则或窜入筋骨，或溃散三焦而占据脏腑，也有已及筋骨，却仍未入经脉之中的，所以三阴也有表证可以发汗；既入经脉，必然连及脏腑，就不能专恃汗法了。在未入经脉时，所称的太阳病、阳明病、少阳病及三阴病者，只是三阳三阴的部位，不是经脉。可与第二卷《三阴三阳名义》篇参看。
第六，必须辨别寒热传化的机理。初伤固总是寒，日久有寒邪内陷的，是其人本体内寒；有寒去热不解的，是其人阴不足。寒邪内陷必致下利，即所谓阴传太阴，其实也就是阳明之下陷！接着就是少阳之气陷，接着就是少阴之气陷，至厥阴肝气亦陷，就没有生机了。始终总不离乎下利，如果利早止于厥阴未陷之前，就不会死；止于厥阴已陷之后，息高头昏，阴气竭尽了。热气不解，必致秘结，必致自汗，即所谓阳传阳明。此时太阴的津液，必定已亏损，治法失当，而少阴的精又亏，厥阴的血又亏，始终总不离乎秘结。不是邪至阳明，就没有再传的了，总不离乎阳明罢了！
第七，必须认识伤寒、温病，始异终同的说法不可固执。这只说了热传阳明一边，其寒传太阴，迥然不同。伤寒有寒死证，无热死证。阳明内实，不是死证；其中有死的，都是由误治造成。若温热病，则有自然一成不变的热死证。
第八，必须认识合病、并病之中，有真假的不同。前人分别合病、并病，言语多牵强。应当是两阳同感，称为合病；由此连彼，称为并病。更有邪气未及彼经，而彼经为之扰动的，其见证必有虚实不同。如素来胃寒的人，一伤于寒，即口淡，即便溏滑；素来阴虚的人，一伤于寒，热气内郁，即喘喝，即口渴。难道是真正邪传阳明太阴吗？只要散其寒，诸证即愈；也有略须兼顾的，必是其内虚甚严重，预先杜绝邪气内陷的路径。
第九，必须探求寒热气化的真实情况。六经传次，本来不必根据张仲景的篇章次序。无奈前人越经传、表里传等语，说得过于拘泥，并未靠定各经，切发其所以然。如少阳主管经脉的津液，经脉灼干，即见少阳证；太阴主管肠胃的津液，肠胃灼干，即见太阴证；阳明主管肠胃的渣滓，渣滓燥结，即见阳明证；厥阴主管筋膜的津液，筋膜枯索，即见厥阴证；少阴主管下焦的气化津液，津竭气散，即见少阴证。这是从热化；从寒化的，阳气不足而下泄，寒水淫溢而上逆，总是何脏受伤，即何经见证。
第十，寒化热化，各自视本体之阴阳虚实。这话浅显而极真。论中误汗后，有为内寒者，有为内热者；误下后，亦有内寒者，有内热者。若执守过汗亡阳、过下亡阴的例子，便不可通融。所以读者以随文生义为贵。夫六经乘虚而传，寒热随偏而化也。
第十一，必须知道表里的说法。有形层的表里，有经络的表里，有脏腑的表里，有气化的表里。形层即前所谓皮肤、肌肉、筋骨，所谓部分也。邪在三阴之部，里而仍表，仍宜汗解；邪入三阳之经，表而已里，只有清化，即和解也。少阳半表半里，亦有数解：以部位言，则外在经络则内连三焦也；以气化言，则表里未清，而里热已盛也，总是气化燥结之象。与第四卷《少阳三禁》篇参看。
第十二，必须知道手经足经，并无分别。足经部位大，邪气在表，尚在经脉之外，其气是一片大的，故见足经证；邪入经脉之中，反多见手经证矣。大抵足经证见者，多在躯壳之外；手经证见者，多关脏腑之中。足证有在经者，手证绝少在经也。经者，身形之事也；脏腑者，神明气化之事也。
第十三，必须知道三阴三阳，只是经络表里的美称，于脏腑气血之阴阳，不相涉也。若谓邪入三阳，即为伤阳；邪入三阴，即为伤阴，那就错了。《内经》心为太阳，肝为少阳，肺为少阴，肾为太阴，脾与六腑为至阴。这是以气血清浊言之，今人已不讲。其实各经各脏各腑之中，各有阴阳。此说甚长，细读《内经》，自能辨之。
第十四，读书须知阙疑。论中叙证，有极简者，有极繁者，有方证不合者，有上下文义不贯者。一经设身处境，实在难以遵行，安知非错简、脱简耶？不必枉费心机，以俟将来之阅历。即如少阳、阳明合病，自下利者，黄芩汤；太阳误下，利不止者，此协热利也，承气汤。此必内有伏热，三焦肠胃秽气郁浊，颇似温病之发于伏邪者，于伤寒自利，及误下而利者，殊不合格。又太阳误下结胸，正宜兼开兼降，以宣内陷之阳，而开邪气之结，乃反用甘遂、巴豆以重泄之，是以一误为不足，而又益之也。又太阳、阴明合病，自利者，葛根汤；不下利，但呕者，葛根汤加半夏。既不下利，何以仍用原方？是原方只治合病，并非治下利也，前文何必特署下利字样？此类宜详思之。前人只说三阳合病，皆有下利，绝不说合病所以下利之故。此之谓半截学问。
总之，读《伤寒论》，只当涵泳白文。注家无虑数十，以予所见二十余种，皆不免穿凿附会，言似新奇，莫能见之行事。鄙见只当分作四层：曰伤寒初起本证治法；曰伤寒初起兼证治法；曰伤寒日久化寒，并误治化寒证治；曰伤寒日久化热，并误治化热证治。其霍乱、风湿、食复、劳复，以杂证附之。再参之陶节庵书，及各家论温热书，互相考证，庶于读书有条理，而临诊亦可有径途矣。盖经脉部位，与夫形层表里浅深之事，固不可不讲，而究不可过执也，着力仍在气化上。此书在唐以前，已非一本，其章节离合，本无深意，读者只应各就本文思量，不必牵扯上下文，积久自能融会贯通。
Yu Jiayan changed "autumn injury by dampness" (Qiushangyu Shi) to "injury by dryness" (Shangzao). For Yu, this was merely borrowing the meaning of autumn dryness syndromes, but arbitrarily altering the classic text is erroneous. Dampness (Shi) is not a textual error for dryness (Zao). The *Suwen* (Plain Questions), chapter "Shui Re Xue Lun" (Discussion on Water and Heat Acupoints), states: "In autumn, Metal Qi begins to govern; the Lung prepares to gather and kill; Yin Qi initially prevails, and dampness invades the body." This is the sequential transition of the Four Seasons and Five Phases. It is only because the transition between Earth's dampness and Metal's clarity is too rapid, that the command of dampness has not faded while the command of coolness and gathering has already arrived. Thus, initially, although dampness is abundant, its Qi scatters outward; by late autumn, dampness gathers and enters the interior of the body; by winter, Yang Qi enters again. The interaction of Yang and dampness causes coughing. If it were an injury by dryness, coughing would occur in autumn, without waiting for winter. His prepared formula, Qingzao Jiufei Tang (Clear Dryness Rescue Lung Decoction), also treats autumn dryness, not the dryness associated with winter coughs.
Dryness is secondary cold; its Qi belongs to Metal; its manifestations are dryness, hardness, descent, clarity and analysis, and sharpness—all are the proper commands of Metal. If it is hot dryness, it carries fire within, standing in opposition to cold dryness, and does not exclusively belong to Metal. If Yu speaks of dryness solely in terms of heat, how then should one explain "water surfaces freeze, bellies become hard"?
Shaoyang disease (Taiyang Bing) is not a rare disease. The *Shanghan Lun* (Treatise on Cold Damage) is not a rare book. Zhang Zhongjing recorded what he observed in writing; it is not that people worldwide fell ill based on the existence of this book. In the sections describing the transitions of the Three Yin and Three Yang, predecessors often used rigid and dogmatic language, as if dark spirits were directing the pathogenic factors, dictating transmission methods, leaving readers unable to understand how transmission actually occurs. Readers must eliminate such speculative views. When reading each section, one should imagine a patient present there, deduce their pathogenesis and treatment methods, and then reference the text. One should not merely arrange interpretations based on the text itself.
First, one must distinguish what kind of disease Shaoyang disease is. This is a disease present in all four seasons, but in the other three seasons, it often involves complications with warmth, dampness, dryness, or wind. Its Qi is not exclusively cold; the skin and pores are loose; initial injury involves two or three meridians simultaneously, and upon further transmission, all six meridians are affected. Only in winter are the pores solid and dense; cold pathogens must first injure the skin and gradually penetrate deeper. Therefore, it is correct to say that treatment methods for cold damage differ across the three non-winter seasons, but incorrect to say there is no cold damage in those seasons. Zhang Zhongjing specifically discussed winter cold damage. However, cases occurring immediately in winter and those delayed until spring are often intermixed and not clearly analyzed. The delayed cases in spring specifically refer to cold diseases that have not yet transformed into heat, which differs from the principle in the *Neijing*: "Winter injury by cold leads to warm disease in spring." Refer to the previous explanation of the Fa Yin and Fa Yang chapters. The term "latent qi" (Fuqi) need not be sought too deeply. Contracting cold today and falling ill today is indeed immediate illness; contracting cold last month and falling ill next month is also common. It can be called latent qi, or it can be called immediate illness. Why must mentioning latent qi make it seem strange?
Second, one must distinguish what "cold" and "heat" represent in the treatise. Cold is the pathogenic Qi of heaven and earth; heat is the righteous Qi of the human body, constrained by cold pathogens, unable to diffuse, and becoming stagnant due to constraint. They are two distinct Qis; cold does not transform into heat. This differs from warm-heat diseases caused by heavenly and earthly heat pathogens. Once cold pathogens dissipate, Yang Qi should extend and heat resolve. If it does not resolve, it is because righteous Qi has been trapped for a long time, meridians are stagnant, and cannot move freely, or it is due to mis-treatment.
Third, one must view the character "transmission" (Chuan) flexibly. Pathogens do not have feet to walk neatly from the interior to change positions. Whatever manifestation the syndrome presents indicates which meridian the pathogen has injured. For example, Shaoyang governs the movement of fluids; if fluids are scorched and dried, it is a Shaoyang syndrome; Yangming governs the transport of residues; if residues become dry and bound, it is a Yangming syndrome. Readers must ponder why there is headache, vomiting, dizziness, and hypochondriac distension? Why constipation, tidal fever, and spontaneous sweating? Do not simply say "because pathogen entered Shaoyang" or "because pathogen entered Yangming!" One must seek explanations in Qi transformation, not be confined to anatomical locations.
Fourth, one must distinguish initial injuries involving the Three Yang, simultaneous infection of Yin and Yang (Lianggan), and direct invasion (Zhizhong). Taiyang runs along the back and governs the exterior; at this time, Yangming and Shaoyang are inevitably involved. The *Neijing* states: "Injury at the nape transmits to Taiyang; injury at the face transmits to Yangming; injury at the cheek transmits to Shaoyang; injury at Yang flows into meridians; injury at Yin flows into fu organs." Even the Taiyang wind-strike described by Zhang Zhongjing, with nasal congestion and dry retching, is not exclusive to Taiyang. Since the pathogen is at the great exterior, treatment does not go beyond Mahuang Tang, Guizhi Tang, or Gegen Tang, so there is no need to establish many new categories. Lianggan and Zhizhong both result from deficiency of the person's Yang Qi or ferocity of the pathogen. Taiyang-Shaoyin and Yangming-Taiyin both have Lianggan; Shaoyang-Jueyin Lianggan is rare. Zhizhong is similar. Shaoyang-Jueyin Lianggan implies Yang Qi is negligible. The difference between Zhizhong and Lianggan is that Lianggan involves simultaneous disease of one Yin and one Yang with equal pathogen strength; Zhizhong involves pathogen overwhelming the Yin, though Yang is undoubtedly also injured. However, Yin branch diseases are comparatively more urgent than simple infections.
Fifth, one must recognize that injuring Ying and Wei cannot be strictly separated into two paths. Zhang Zhongjing stated wind injures Wei and cold injures Ying, briefly mentioned in Mahuang patterns, without overly analyzing the bias of wind versus cold injury. His intent focused on cold; it is a connected argument, not a flat statement. Moreover, wind-strike features slow pulse and spontaneous sweating; sweat is Ying fluid, and Ying fluid leaking externally means Guizhi Tang is a formula to replenish Ying Qi. Cold-damage features tight pulse and absence of sweating; this is Wei Qi constrained by cold. Mahuang is light and swift, penetrating Ying to open Wei and release the exterior, with force directed at Wei. How can one say wind injures Wei but not Ying, and cold injures Ying but not Wei? How can this be split into two major outlines?
According to winter months when pores are closed and dense, cold pathogens penetrate gradually. Initial injury to skin stays in the Qi level; dispersing it then does not require sweating, and the pathogen dissipates naturally. Secondary injury to muscles affects Jin-Ye (body fluids); pathogen exits with sweat, and sweat releases the pathogen. Tertiary injury to meridians enters the Blood level; once in meridians, it may窜 (creep) into sinews and bones, or disperse through Sanjiao to occupy Zang-Fu organs. There are also cases reaching sinews and bones without entering meridians, hence Three Yin also have exterior patterns suitable for sweating. Once in meridians, it necessarily connects to Zang-Fu organs, and one cannot rely solely on sweating methods. Before entering meridians, the so-called Taiyang, Yangming, Shaoyang, and Three Yin diseases refer only to the regions of the Three Yin and Three Yang, not the meridians themselves. Refer to Volume 2, "Meaning of Three Yin and Three Yang."
Sixth, one must distinguish the mechanism of cold-heat transmission and transformation. Initial injury is always cold. Over time, some cold pathogens sink inward, indicating the person originally had internal cold. Some cold leaves but heat remains unresolved, indicating Yin insufficiency. Cold sinking inward必然 (necessarily) causes diarrhea, known as Yin transmitting to Taiyin, which is essentially Yangming sinking. Subsequently, Shaoyang Qi sinks, then Shaoyin Qi sinks, until Jueyin Liver Qi sinks, leaving no vitality. It always revolves around diarrhea. If diarrhea stops early, before Jueyin sinking, death is avoided; if it stops after Jueyin sinking, with high breathing and vertigo, Yin Qi is exhausted. Unresolved heat必然 leads to constipation and spontaneous sweating, known as Yang transmitting to Yangming. At this point, Taiyin fluids are depleted; improper treatment depletes Shaoyin essence and Jueyin blood. It always revolves around constipation. Unless the pathogen reaches Yangming, there is no further transmission; it always centers on Yangming!
Seventh, one must recognize that the theory "Shaoyang and Warm diseases start differently but end similarly" is inflexible. This only covers the side of heat transmitting to Yangming; cold transmitting to Taiyin is completely different. Shaoyang disease has cold-death patterns, but no heat-death patterns. Internal excess in Yangming is not a death pattern; deaths there are due to mis-treatment. Warm-heat diseases, however, have natural, unchanging heat-death patterns.
Eighth, one must recognize that among Hebing (combined disease) and Bingbing (concurrent disease), there are true and false differences. Predecessors' distinctions between Hebing and Bingbing were often forced. Two Yang meridians infected simultaneously is Hebing; spreading from one to another is Bingbing. Furthermore, if pathogens have not reached another meridian but disturb it, the manifestations will differ in deficiency and excess. For instance, someone with chronic stomach cold who contracts cold will have bland taste and loose stools; someone with chronic Yin deficiency who contracts cold will have internal heat stagnation, leading to wheezing and thirst. Is this truly pathogen transmitting to Yangming and Taiyin? Simply dispersing the cold cures the symptoms; sometimes slight attention to underlying deficiency is needed to preemptively block the path from internal sinking.
Ninth, one must seek the true reality of cold-heat Qi transformation. The sequence of Six Meridian transmission need not follow Zhang Zhongjing's chapter order. Unfortunately, predecessors spoke too rigidly about "transmission across meridians" and "interior-exterior transmission," failing to anchor in each meridian to explain the rationale. For example, Shaoyang governs meridian fluids; scorching leads to Shaoyang signs; Taiyin governs intestinal fluids; scorching leads to Taiyin signs; Yangming governs intestinal residues; drying leads to Yangming signs; Jueyin governs fascia fluids; withering leads to Jueyin signs; Shaoyin governs lower Jiao Qi transformation and fluids; exhaustion leads to Shaoyin signs. This is transformation from heat. Transformation from cold involves insufficient Yang Qi causing downward leakage and overflowing cold water causing upward rebellion. Regardless, whichever Zang is injured, that meridian shows signs.
Tenth, cold and heat transformation depend on the individual's constitutional Yin-Yang and deficiency-excess. This statement is shallow yet profoundly true. After mis-sweating in the treatise, some develop internal cold, others internal heat; after mis-purging, similarly, some have internal cold, others internal heat. Rigidly applying examples of excessive sweating destroying Yang or excessive purging destroying Yin makes the text incomprehensible. Thus, readers should prioritize deriving meaning from the context. The Six Meridians transmit via deficiency, and cold/heat transform according to bias.
Eleventh, one must understand the concept of Exterior and Interior. There is structural exterior-interior, meridian exterior-interior, Zang-Fu exterior-interior, and Qi-transformation exterior-interior. Structural refers to skin, muscle, sinew, bone, i.e., parts. Pathogen in the Three Yin regions is interior yet still exterior, suitable for sweating; pathogen in Three Yang meridians is exterior yet already interior, requiring clearing and transforming, i.e., harmonizing. Shaoyang is half-exterior half-interior, which has several interpretations: structurally, external meridians connect internally to Sanjiao; in Qi transformation, exterior-interior is unclear, but interior heat is abundant, always showing signs of Qi transformation dryness-binding. Refer to Volume 4, "Three Prohibitions of Shaoyang."
Twelfth, one must know there is no distinction between Hand and Foot meridians. Foot meridians cover large areas; when pathogen is at the exterior, outside the meridians, its Qi is broad, hence Foot meridian signs appear; when pathogen enters the meridians, Hand meridian signs often appear instead. Generally, Foot meridian signs appear mostly outside the body shell; Hand meridian signs relate mostly to the interior of Zang-Fu organs. Foot signs can be in meridians; Hand signs rarely are. Meridians concern the physical form; Zang-Fu concerns spirit and Qi transformation.
Thirteenth, one must know Three Yin and Three Yang are merely elegant names for meridian exterior-interior relationships, unrelated to Zang-Fu and Qi-Blood Yin-Yang. To say pathogen entering Three Yang injures Yang, and entering Three Yin injures Yin, is wrong. The *Neijing* states Heart is Taiyang, Liver is Shaoyang, Lung is Shaoyin, Kidney is Taiyin, Spleen and Six Fu organs are Supreme Yin. This discusses clear and turbid Qi-Blood, a concept moderns ignore. Actually, each meridian, Zang, and Fu contains Yin and Yang. This topic is lengthy; careful study of the *Neijing* allows one to discern it.
Fourteenth, reading requires acknowledging doubts. The treatise describes syndromes simply or complexly; some formulas do not match syndromes; some contexts lack coherence. Placing oneself in the situation makes strict adherence difficult. Could these be misplaced or missing bamboo slips? Do not waste effort; wait for future experience. For example, Shaoyang-Yangming Hebing with spontaneous diarrhea uses Huangqin Tang; Taiyang mis-purged with unremitting diarrhea is協熱利 (Xiere Li), treated with Chengqi Tang. This implies latent internal heat, turbid Qi stagnation in Sanjiao and intestines, resembling warm diseases from latent pathogens, which does not fit standard Shaoyang spontaneous diarrhea or mis-purged diarrhea. Also, Taiyang mis-purged chest binding should involve opening and descending to vent sunk Yang and resolve pathogen binding, yet Gan Sui and Ba Dou are used for heavy purgation, compounding the error. Sun-Yangming Hebing with diarrhea uses Gegen Tang; without diarrhea but with vomiting, Gegen Tang plus Banxia. If no diarrhea, why use the original formula? The original formula treats Hebing, not specifically diarrhea; why specify diarrhea earlier? Such points require deep thought. Predecessors only said Three Yang Hebing all have diarrhea, never explaining why. This is half-baked scholarship.
In summary, reading the *Shanghan Lun* should focus on absorbing the plain text. There are dozens of commentators; over twenty I have seen are all forced and associative, sounding novel but ineffective in practice. My view divides it into four layers: Treatment of primary patterns of early Shaoyang disease; Treatment of accompanying patterns of early Shaoyang disease; Treatment of cold transformation and mis-treatment-induced cold patterns of prolonged Shaoyang disease; Treatment of heat transformation and mis-treatment-induced heat patterns of prolonged Shaoyang disease. Cholera, wind-dampness, food relapse, and labor relapse are attached as miscellaneous diseases. Cross-reference with Tao Jian'an's works and various warm-heat treatises for mutual verification. This ensures organized reading and clinical pathways. While meridian locations and structural exterior-interior depth must be studied, one must not cling to them excessively; effort should lie in Qi transformation. Before the Tang Dynasty, this book was not a single volume; chapter divisions had no profound meaning. Readers should contemplate the text itself, not force connections with context; over time, integration will occur naturally.