按仲景自序云“虽未能尽愈诸病”，其留心诸病可知。故于诸病之表里阴阳，分为六经，令各得所司。清理
脉症之异同，寒热之虚实，使治病者只在六经下手，行汗吐下和解温补等法而无失也。夫一身之病，俱受六经范
围者，犹《周礼》分六官而百职举，司天分六气而万物成耳。伤寒不过是六经中一症，叔和不知仲景之六经，是
经界之经，而非经络之经，妄引《内经·热病论》作序例，以冠仲景之书，而混其六经之症治。六经之理因不明，
而仲景平脉辨症，能尽愈诸病之权衡废矣。夫热病之六经，专主经脉为病，但有表里之实热，并无表里之虚寒。
虽因于伤寒，而已变成热病，故竟称热病，而不称伤寒。要知《内经》热病，即温病之互名，故无恶寒症，但有
可汗可泄之法，并无可温可补之例也。观温病名篇，亦称评热病论，其义可知矣。夫叔和不于病根上讲求，但于
病名上分解，故序例所引《内经》，既背仲景之旨，亦舛岐伯之意也。夫仲景之六经，是分六区地面，所该者广，
虽以脉为经络，而不专在经络上立说。凡风寒温热内伤外感，自表及里，有寒有热，或虚或实，无乎不包。故以
伤寒杂病合为一书，而总名《伤寒杂病论》。所以六经提纲，各立一局，不为经络所拘，弗为风寒划定也。然仲
景既云撰用《素问》，当于《素问》之六经广求之。按《皮部论》云∶“皮有分部，脉有经纪。其生病各异，别
其部分，左右上下，阴阳所在，诸经始终。”此仲景创立六经部位之原。又曰∶“阳主外，阴主内。”故仲景以
三阳主外，三阴主内。又曰∶“在阳者主内，在阴者主出，以渗于内。”故仲景又以阳明主内。少阴亦有反发热
者，故仲景又于表剂中用附子，是固其渗也。又曰∶“少阴之阴，名曰枢儒。其入于经也，从阳部注于经，其出
者，从阴部注于骨。”故仲景制麻黄附子汤，治发热脉沉无里症者，是从阳部注经之义也；制附子汤治身体骨节
痛、手足寒、背恶寒、脉沉者，是从阴内注于骨之义也。又《阴阳离合论》“太阳为开。”故仲景以之主表，而
以脉浮、恶寒、头项强痛为提纲，立言与热病颇同，而立意自别。阳明为阖，故以之主里，而以胃实为
提纲，虽有目痛、鼻干等症，而所主不在是。少阳为枢，少阴亦为枢，故皆主半表半里症。少阳为阳枢，归重在
半表，故以口苦、目眩为提纲，而不及胸胁痛硬。少阴为阴枢，其欲寐不寐，欲吐不吐，亦半表半里症，虽有舌
干、口燥等症，而不入提纲，归重在半里也。岂惟阳明主里，三阴皆主里，而阴阳异位，故所主各不同。阳明主
里症之阳，阳道实，故以胃实属阳明。太阴主里症之阴，阴道虚，故以自利属太阴。太阴为开，又为阴中之至阴，
故主里寒自利。厥阴为阖，又为阴中之阳，故主里热而气逆。少阴为阴中之枢，故所主或寒或热之不同，或表或
里之无定，与少阳相似也。请以地理喻，六经犹列国也。腰以上为三阳地面，三阳主外而本乎里。心者三阳夹界
之地也。内由心胸，外自巅顶，前至额颅，后至肩背，下及于足，内合膀胱，是太阳地面。此经统领营卫，主一
身之表症，犹近边御敌之国也。内自心胸至胃及肠，外自头颅，由面至腹，下及于足，是阳明地面。由心至咽，
退场门颊，上耳目，斜至巅，外自胁内属胆，是少阳地面。此太阳差近阳明，犹京畿矣。腰以下为三阴地面，三阴
主里，而不及外。腹者三阴夹界之地也。自腹由脾及二肠魄门，为太阴地面。自腹至两肾及膀胱溺道，为少阴地
面。自腹由肝上膈至心，从胁肋下及于小腹宗筋，为厥阴地面。此经通行三焦，主一身之里症，犹近京夹辅之国
也。太阴阳明，同居异治，犹周、召分政之义。四经部位，有内外出入，上下牵引之不同，犹先王分土域民，犬
牙相制之理也。若经络之经，是六经道路，非六经地面矣。六经之有正邪客邪、合病并病、属脾属胃者，犹寇贼
充斥，或在本境，或及邻国，或入京师也。太阳地面最大，内邻少阴，外邻阳明，故病有相关。如小便不利，本
膀胱病，少阴病而亦小便不利者，是邪及太阳之界也。腰痛本肾病，太阳病而亦腰痛者，是邪及少阴之界也。六
七日不大便，及头痛身热者，是阳明热邪，侵入太阳之界也。头项强痛兼鼻鸣干呕者，是太阳风邪，侵及阳明之
界也。心胸是阳明地面，而为太阳之通衢。因太阳主营卫，心胸是营卫之本，营卫环周不休，犹边邑之吏民士卒，
会于京畿，往来不绝也。如喘而胸满者，是太阳外邪入阳明地面而骚扰，故称为太阳阳明合病。若头不痛，项不
强，胸中痞硬，气冲咽喉，不得息者，此邪不自太阳来，乃阳明实邪结于胸中，犹盗贼聚于本境而为患也。心为
六经之主，故六经皆有心烦证。如不头项强痛，则烦不属太阳；不往来寒热，则烦不
属少阳；不见三阴症，则烦不属三阴矣。故心愦愦，心怵惕，心中懊 ，一切虚烦，皆属阳明，以心居阳明之地
面也。阳明犹京师，故心腹皆居其地。邪在心为虚烦，在腹为实热，以心为阳而属无形，腹为阴而属有形也。夫
人身之病，动关心腹。阳邪聚于心，阴邪聚于腹。肝为阴中之阳，故能使阴邪之气撞于心。阳明主在里之阳，故
能使阳邪入聚于腹耳。更请以兵法喻，兵法之要，在明地形。必先明六经之路，才知贼寇所从来，知某方是某府
来路，某方是某郡去路。来路是边关，三阳是也；去路是内境，三阴是也。六经来路各不同，太阳是大路，少阳
是僻路，阳明是直路，太阴近路也，少阴后路也，厥阴斜路也。客邪多从三阳来，正邪多由三阴起，犹外寇自边
关至，盗贼自内地生也。明六经地形，始得握百病之枢机；详六经来路，乃得操治病之规则。如以证论，伤寒大
寇也，病从外来；中风流寇也，病因旁及；杂病盗贼也，病由中起。既认为何等之贼，又知为何地所起，发于其
境，便御之本境，移祸邻郡，即两路夹攻。如邪入太阳地面，即汗而散之，犹陈利兵于要害，乘其未定而击之也。
邪之轻者在卫，重者在营，尤重者在胸膈，犹寇之浅者在关外，其深者在关上，尤深者在关内也。麻黄为关外之
师，桂枝、葛根为关上之师，大小青龙为关内之师矣。凡外寇不靖，内地盗贼必起而应之，因立两解法，故有大
小青龙及桂枝、麻黄加减诸方。如前军无纪，致内乱蜂起，当重内轻外，因有五苓、十枣、陷胸、泻心、抵当等
汤也。邪入少阳地位，宜杂用表里寒热攻补之品，为防御解利之法。如偏僻小路，利于短兵，不利于矛戟，利于
守备，不利于战争也。邪之轻者入腠理，重者入募原，尤重者入脾胃。小柴胡腠理之剂也，大柴胡募原之剂也。
小建中、半夏泻心、黄芩、黄连四汤，少阳之脾剂也；柴胡加芒硝加龙蛎二方，少阳之胃剂也。如太阳少阳有合
并病，是一军犯太阳，一军犯少阳矣。用柴胡桂枝汤，是两路分击之师也。甚至三阳合并病，是三面受敌矣，法
在独取阳明。阳明之地整肃，则太、少两路之阳邪，不攻自解。但得内寇宁而外患自息，此白虎之所由奏捷耳。
若阳邪不戢于内地，用大承气以急下之，是攻贼以护主。若阴邪直入于中宫，用四逆汤以急救其里，是强主以逐
寇也。阳明为内地，阳明界上，即太阳少阳地面。邪入阳明之界，近太阳地面，虽不犯太阳，太阳之师，不得坐
视而不救。故阳明之营卫病；即假麻黄桂枝等方以汗之。邪近少阳地面，虽不入少阳，少阳之师，
不得高垒而无战。故阳明之腠理病，即假柴胡以解之。是阳明之失守，非太阳之不固，即少阳之无备，所以每每
两阳相合而为病也。若邪已在阳明地面，必出师奋击，以大逐其邪，不使少留，故用栀豉瓜蒂之吐法以迅扫之。
若深入内地，不可复驱，则当清野千里，使无所剽掠，是又白虎得力处也。若邪在内廷，又当清宫除盗，此三承
气所由取胜。如茵陈、猪苓辈，又为失纪之师立法矣。太阴亦内地，少阴厥阴是太阴之夹界也。太阴居中州，虽
外通三阳，而阴阳既已殊途，心腹更有膈膜之藩蔽。故寒水之邪，从太阳外属者轻，由少阴内授者重；风木之邪，
自少阳来侵者微，因厥阴上袭者甚。如本经正邪转属阳明而为实，犹师老势穷，可下之而愈。如阳明实邪转属本
经而成虚，则邪盛正衰，温补挽回者甚难。盖太阴阳明，地面虽分，并无阻隔。阳明犹受敌之通衢，甲兵所聚，
四战之地也。太阴犹仓廪重地，三军所根据，亦盗贼之巢穴也。故元气有余，则邪入阳明；元气不支，则邪入太阴。
在阳明地面，则陈师鞠旅，可背城一战，取胜须臾。在太阴地面，则焚劫积蓄，仓廪空虚，枵腹之士，无能御敌
耳。厥阴之地，相火游行之区也，其本气则为少火。若风寒燥湿之邪，一入其境，悉化为热，即是壮火。其少火
为一身之生机，而壮火为心腹之大患。且其地面通达三焦，邪犯上焦，则气上撞心，心中疼热，消渴口烂，咽痛
喉痹。逼入中焦，即手足厥冷，脉微欲绝，饥不欲食，食即吐蛔。移祸下焦，则热利下重，或便脓血，为害非浅，
犹跋扈之师矣。仲景制乌梅丸方，寒热并用，攻补兼施，通理气血，调和三焦，为平治厥阴之主方，犹总督内地
之大帅也。其与之水以治消渴，茯苓甘草汤以治水，炙甘草汤以复脉，当归四逆以治厥，是间出锐师，分头以救
上焦之心主，而安神明也。用白虎、承气辈，清胃而平中焦之热实，白头翁、四逆散，清脾而止下焦之热利，是
分头以救腹中之阴，而扶胃脘之元气耳。胃为一腑，而分阴阳二经，少阴一经，而兼阴阳两脏者，皆为根本之地
故也。邪有阴阳两途，脏分阴阳二气。如阳邪犯少阴之阳，反发热心烦，咳渴咽痛；阳邪犯少阴之阴，则腹痛自
利，或便脓血；阴邪犯少阴之阳，则身体骨节痛，手足逆冷，背恶寒，而身蜷卧；阴邪犯少阴之阴，则恶寒呕吐，
下利清谷，烦躁欲死。仲景制麻黄附子细辛、黄连阿胶、甘草、桔梗、猪肤、半夏、苦酒等汤，御阳邪犯少阴之
阳也；其制桃花、猪苓等汤，御阳邪入少阴之阴也；附子、吴茱萸、四逆等汤，御阴邪犯少阴之
阳也；通脉四逆、茯苓四逆、干姜附子等汤，御阴邪入少阴之阴也。少阴为六经之根本，而外通太阳，内接阳明。
故初得之而反发热，与八九日而一身手足尽热者，是少阴阳邪侵及太阳地面也；自利纯清水，心下痛，口燥舌干
者，少阴阳邪侵阳明地面也。出太阳则用麻黄为锐师，而督以附子，入阳明则全仗大承气，而不设监制，犹兵家
用向导与用本部不同法也。其阴邪侵入太阴，则用理中、白通加人尿猪胆等法，亦犹是矣。嗟乎！不思仲景之所
集，安能见病知源也哉？
柯琴按：张仲景在自序中说“虽然不能治愈所有的疾病”，由此可见他对各种疾病的关注。因此，他将各种疾病的表里、阴阳分为六经，使它们各自有所管辖。他辨析脉象和症状的异同，寒热、虚实的区别，使得治病的人只需在六经上着手，运用汗、吐、下、和解、温、补等方法而不出错。全身的疾病，都受六经范围的约束，就像《周礼》划分六官而百职得以执行，司天划分六气而万物得以生成一样。伤寒不过是六经中的一种病症，王叔和不知道仲景的六经是“经界”（区域界限）的经，而不是“经络”（经脉通道）的经，妄自引用《内经·热病论》作为序例，冠于仲景之书，从而混淆了六经的症治。六经的道理因此不明，而仲景通过平脉辨症以能治愈所有疾病的权衡标准也就废弛了。
《内经》中热病的六经，专门主管经脉受邪，只有表里的实热，没有表里的虚寒。虽然起因于伤寒，但已经演变成热病，所以竟称为热病，而不称为伤寒。要知道，《内经》的热病，就是温病的互称，所以没有恶寒的症状，只有可发汗、可泄下的方法，并没有可温补的例子。看《内经》中名为“评热病论”的篇章，其中的含义就可以知道了。王叔和不从病根上探究，只在病名上分解，所以他引用的《内经》序例，既违背了仲景的宗旨，也错乱了岐伯的本意。
仲景的六经，是划分了六个区域的地面，所涵盖的范围很广，虽然以脉象为经络的依据，但并不专在经络上立论。凡是风寒温热、内伤外感，自表及里，有寒有热，或虚或实，无不包罗。所以将伤寒与杂病合为一书，总名为《伤寒杂病论》。因此，六经提纲，各立一局，不被经络所拘束，也不被风寒所划定。然而仲景既然说撰用《素问》，就应当在《素问》的六经中广泛寻求依据。
按《素问·皮部论》说：“皮肤有分部，脉有经纪。它们生病各异，辨别其部分，左右上下，阴阳所在，诸经始终。”这是仲景创立六经部位的原由。又说：“阳主外，阴主内。”所以仲景以三阳主外，三阴主内。又说：“在阳者主内，在阴者主出，以渗于内。”所以仲景又以阳明主内。少阴也有反发热者，所以仲景又在解表剂中使用附子，以固护其渗出的功能。又说：“少阴之阴，名曰枢儒。它进入经脉，是从阳部注入经脉；它外出，是从阴部注入骨骼。”所以仲景制定麻黄附子汤，治疗发热、脉沉、无里证者，这是从阳部注经的意义；制定附子汤治疗身体骨节痛、手足寒、背恶寒、脉沉者，这是从阴内注于骨的意义。
又《素问·阴阳离合论》说：“太阳为开。”所以仲景以它主表，而以脉浮、恶寒、头项强痛为提纲，立言与热病颇为相同，但立意自不同。阳明为阖，所以以它主里，而以胃实为提纲，虽然有目痛、鼻干等症状，但所主的不在这些。少阳为枢，少阴也为枢，所以都主半表半里症。少阳为阳枢，归重在半表，所以以口苦、目眩为提纲，而不及胸胁痛硬。少阴为阴枢，其欲寐不寐、欲吐不吐，也是半表半里症，虽然有舌干、口燥等症状，但不入提纲，归重在半里。岂止阳明主里，三阴皆主里，而阴阳位置不同，所以所主各不相同。阳明主里症之阳，阳道实，所以以胃实属阳明。太阴主里症之阴，阴道虚，所以以自利属太阴。太阴为开，又为阴中之至阴，所以主里寒自利。厥阴为阖，又为阴中之阳，所以主里热而气逆。少阴为阴中之枢，所以所主或寒或热不同，或表或里不定，与少阳相似。
姑且用地理来比喻，六经就像列国。腰以上为三阳地面，三阳主外而本乎里。心是三阳夹界之地。内由心胸，外自巅顶，前至额颅，后至肩背，下及于足，内合膀胱，这是太阳地面。此经统领营卫，主一身之表症，就像靠近边境抵御敌人的国家。内自心胸至胃及肠，外自头颅，由面至腹，下及于足，这是阳明地面。由心至咽，退至颊车，上耳目，斜至巅顶，外自胁内属胆，这是少阳地面。这太阳差近阳明，就像京畿之地。腰以下为三阴地面，三阴主里，而不及外。腹是三阴夹界之地。自腹由脾及二肠魄门，为太阴地面。自腹至两肾及膀胱溺道，为少阴地面。自腹由肝上膈至心，从胁肋下及于小腹宗筋，为厥阴地面。此经通行三焦，主一身之里症，就像靠近京城辅佐的国家。
太阴和阳明，同居而异治，就像周公、召公分政的意义。四经部位，有内外出入、上下牵引的不同，就像先王分土域民，犬牙相制的道理。如果说是经络的经，那是六经的道路，不是六经的地面。六经中有正邪客邪、合病并病、属脾属胃的情况，就像寇贼充斥，或在本地，或波及邻国，或进入京师。
太阳地面最大，内邻少阴，外邻阳明，所以病有关联。如小便不利，本是膀胱病，少阴病也出现小便不利，这是邪气波及太阳的边界。腰痛本是肾病，太阳病也出现腰痛，这是邪气波及少阴的边界。六七日不大便，及头痛身热，是阳明热邪侵入太阳的边界。头项强痛兼鼻鸣干呕，是太阳风邪侵及阳明的边界。心胸是阳明地面，却是太阳的通衢。因为太阳主营卫，心胸是营卫之本，营卫环周不休，就像边邑的吏民士卒，汇聚于京畿，往来不绝。如喘而胸满，是太阳外邪进入阳明地面而骚扰，所以称为太阳阳明合病。若头不痛，项不强，胸中痞硬，气冲咽喉，不得息，此邪气不自太阳来，乃阳明实邪结于胸中，就像盗贼聚于本地而为患。
心为六经之主，所以六经都有心烦证。如不头项强痛，则烦不属太阳；不往来寒热，则烦不属少阳；不见三阴症，则烦不属三阴。所以心愦愦、心怵惕、心中懊憹，一切虚烦，皆属阳明，因为心居阳明地面。阳明犹京师，所以心腹皆居其地。邪在心为虚烦，在腹为实热，因为心为阳而属无形，腹为阴而属有形。人身之病，动关心腹。阳邪聚于心，阴邪聚于腹。肝为阴中之阳，所以能使阴邪之气撞于心。阳明主在里之阳，所以能使阳邪入聚于腹。
更请用兵法来比喻，兵法的要领，在于明了地形。必须先明六经之路，才知道贼寇从哪里来，知道某方是哪府的来路，某方是哪郡的去路。来路是边关，即三阳；去路是内境，即三阴。六经来路各不相同，太阳是大路，少阳是僻路，阳明是直路，太阴是近路，少阴是后路，厥阴是斜路。客邪多从三阳来，正邪多由三阴起，就像外寇自边关至，盗贼自内地生。明六经地形，始得握百病之枢机；详六经来路，乃得操治病之规则。
如以证论，伤寒是大寇，病从外来；中风是流寇，病因旁及；杂病是盗贼，病由中起。既认为是何等之贼，又知为何地所起，发于其境，便御之本境，移祸邻郡，即两路夹攻。如邪入太阳地面，即汗而散之，就像陈设精兵于要害，乘其未定而击之。邪之轻者在卫，重者在营，尤重者在胸膈，就像寇之浅者在关外，其深者在关上，尤深者在关内。麻黄为关外之师，桂枝、葛根为关上之师，大小青龙为关内之师。凡外寇不靖，内地盗贼必起而应之，因此立两解法，故有大小青龙及桂枝、麻黄加减诸方。如前军无纪，致内乱蜂起，当重内轻外，因此有五苓、十枣、陷胸、泻心、抵当等汤。
邪入少阳地位，宜杂用表里寒热攻补之品，为防御解利之法。如偏僻小路，利于短兵，不利于矛戟，利于守备，不利于战争。邪之轻者入腠理，重者入募原，尤重者入脾胃。小柴胡是腠理之剂，大柴胡是募原之剂。小建中、半夏泻心、黄芩、黄连四汤，是少阳之脾剂；柴胡加芒硝、加龙蛎二方，是少阳之胃剂。如太阳少阳有合并病，是一军犯太阳，一军犯少阳。用柴胡桂枝汤，是两路分击之师。甚至三阳合并病，是三面受敌，法在独取阳明。阳明之地整肃，则太、少两路之阳邪，不攻自解。但得内寇宁而外患自息，这就是白虎汤之所以奏捷的原因。
若阳邪不戢于内地，用大承气汤以急下之，是攻贼以护主。若阴邪直入于中宫，用四逆汤以急救其里，是强主以逐寇。阳明为内地，阳明界上，即太阳少阳地面。邪入阳明之界，近太阳地面，虽不犯太阳，太阳之师，不得坐视而不救。所以阳明之营卫病，即假借麻黄桂枝等方以汗之。邪近少阳地面，虽不入少阳，少阳之师，不得高垒而无战。所以阳明之腠理病，即假借柴胡以解之。这是阳明之失守，非太阳之不固，即少阳之无备，所以每每两阳相合而为病。
若邪已在阳明地面，必出师奋击，以大逐其邪，不使少留，所以用栀豉瓜蒂之吐法以迅扫之。若深入内地，不可复驱，则当清野千里，使无所剽掠，这又是白虎汤得力之处。若邪在内廷，又当清宫除盗，这是三承气汤之所以取胜的原因。如茵陈、猪苓辈，又为失纪之师立法。
太阴亦内地，少阴厥阴是太阴之夹界。太阴居中州，虽外通三阳，而阴阳既已殊途，心腹更有膈膜之藩蔽。所以寒水之邪，从太阳外属者轻，由少阴内授者重；风木之邪，自少阳来侵者微，因厥阴上袭者甚。如本经正邪转属阳明而为实，就像师老势穷，可下之而愈。如阳明实邪转属本经而成虚，则邪盛正衰，温补挽回者甚难。盖太阴阳明，地面虽分，并无阻隔。阳明犹受敌之通衢，甲兵所聚，四战之地。太阴犹仓廪重地，三军所根据，亦盗贼之巢穴。所以元气有余，则邪入阳明；元气不支，则邪入太阴。在阳明地面，则陈师鞠旅，可背城一战，取胜须臾。在太阴地面，则焚劫积蓄，仓廪空虚，枵腹之士，无能御敌耳。
厥阴之地，是相火游行之区，其本气则为少火。若风寒燥湿之邪，一入其境，悉化为热，即是壮火。其少火为一身之生机，而壮火为心腹之大患。且其地面通达三焦，邪犯上焦，则气上撞心，心中疼热，消渴口烂，咽痛喉痹。逼入中焦，即手足厥冷，脉微欲绝，饥不欲食，食即吐蛔。移祸下焦，则热利下重，或便脓血，为害非浅，就像跋扈之师。仲景制乌梅丸方，寒热并用，攻补兼施，通理气血，调和三焦，为平治厥阴之主方，就像总督内地的大帅。其与之水以治消渴，茯苓甘草汤以治水，炙甘草汤以复脉，当归四逆以治厥，是间出锐师，分头以救上焦之心主，而安神明。用白虎、承气辈，清胃而平中焦之热实，白头翁、四逆散，清脾而止下焦之热利，是分头以救腹中之阴，而扶胃脘之元气耳。
胃为一腑，而分阴阳二经，少阴一经，而兼阴阳两脏者，皆为根本之地故也。邪有阴阳两途，脏分阴阳二气。如阳邪犯少阴之阳，反发热心烦，咳渴咽痛；阳邪犯少阴之阴，则腹痛自利，或便脓血；阴邪犯少阴之阳，则身体骨节痛，手足逆冷，背恶寒，而身蜷卧；阴邪犯少阴之阴，则恶寒呕吐，下利清谷，烦躁欲死。仲景制麻黄附子细辛、黄连阿胶、甘草、桔梗、猪肤、半夏、苦酒等汤，御阳邪犯少阴之阳也；其制桃花、猪苓等汤，御阳邪入少阴之阴也；附子、吴茱萸、四逆等汤，御阴邪犯少阴之阳也；通脉四逆、茯苓四逆、干姜附子等汤，御阴邪入少阴之阴也。少阴为六经之根本，而外通太阳，内接阳明。故初得之而反发热，与八九日而一身手足尽热者，是少阴阳邪侵及太阳地面也；自利纯清水，心下痛，口燥舌干者，少阴阳邪侵阳明地面也。出太阳则用麻黄为锐师，而督以附子，入阳明则全仗大承气，而不设监制，犹兵家用向导与用本部不同法也。其阴邪侵入太阴，则用理中、白通加人尿猪胆等法，亦犹是矣。嗟乎！不思仲景之所集，安能见病知源也哉？
Ke Qin notes: Zhang Zhongjing stated in his preface, "Although I may not be able to cure all diseases," which reveals his concern for various ailments. Therefore, he categorized the exterior-interior and yin-yang of all diseases into the Six Channels (Liu Jing), assigning each its specific jurisdiction. He analyzed the similarities and differences in pulse and symptoms, as well as cold-heat and deficiency-excess patterns, enabling physicians to treat diseases by focusing on the Six Channels, employing methods such as sweating, vomiting, purging, harmonizing, warming, and tonifying without error. Diseases of the entire body are encompassed within the scope of the Six Channels, just as the *Rites of Zhou* divided officials into six categories to manage myriad duties, or as the Heavenly Stems divided Qi into six types to allow all things to flourish. Cold damage (Shanghan) is merely one type of condition among the Six Channels. Wang Shuhe failed to understand that Zhongjing's "Jing" (Channels) referred to "Jingjie" (territorial boundaries/regions) rather than "Jingluo" (meridian pathways). He recklessly cited the *Neijing*'s "Treatise on Heat Diseases" as a preface to Zhongjing's work, thereby confusing the diagnosis and treatment principles of the Six Channels. Consequently, the principles of the Six Channels remained unclear, and Zhongjing's standard of diagnosing through pulse differentiation to cure all diseases was abandoned.
The Six Channels of heat diseases in the *Neijing* specifically govern pathogenic invasion of the meridians, involving only excess heat in the exterior and interior, with no deficiency-cold. Although originating from cold damage, it has transformed into a heat disease; thus, it is called "Heat Disease" rather than "Cold Damage." It must be understood that the "Heat Disease" of the *Neijing* is synonymous with "Warm Disease" (Wenbing); hence, there are no aversion-to-cold symptoms, only methods for inducing sweating or purging, with no examples of warming or tonifying. This meaning is evident in the *Neijing*'s chapter titled "Evaluation of Heat Diseases." Wang Shuhe did not investigate the root of diseases but merely dissected disease names. Thus, the *Neijing* citations in his preface both violated Zhongjing's intent and distorted Qibo's original meaning.
Zhongjing's Six Channels refer to six territorial regions, covering a broad scope. Although based on pulses and meridians, the theory does not rely exclusively on meridian anatomy. It encompasses wind-cold, warm-heat, internal injuries, and external invasions, from exterior to interior, cold to heat, deficiency to excess—nothing is excluded. Therefore, cold damage and miscellaneous diseases were combined into one book, titled *Treatise on Cold Damage and Miscellaneous Diseases*. The outlines of the Six Channels stand independently, unconstrained by meridians or limited to wind-cold. Since Zhongjing claimed to utilize the *Suwen*, we should seek the origin of the Six Channels within the *Suwen*.
According to the *Suwen·Pibu Lun*: "Skin has divisions, vessels have connections. Diseases manifest differently; distinguishing parts, left-right, upper-lower, and yin-yang locations marks the beginning and end of the channels." This is the origin of Zhongjing's creation of Six Channel locations. It further states: "Yang governs the exterior, Yin governs the interior." Hence, Zhongjing assigned the Three Yang channels to the exterior and the Three Yin channels to the interior. It also says: "What is in Yang governs entering inward; what is in Yin governs exiting outward, seeping inward." Thus, Zhongjing assigned Yangming to govern the interior. Shaoyin sometimes presents with fever; therefore, Zhongjing used Aconite (Fuzi) in exterior-releasing formulas to secure this seepage. The text states: "The Yin of Shaoyin is named Shuru. Entering the channels, it flows from the Yang aspect into the channels; exiting, it flows from the Yin aspect into the bones." Accordingly, Zhongjing formulated Mahuang Fuzi Tang to treat fever, deep pulse, and absence of interior syndromes, reflecting the principle of flowing from the Yang aspect into the channels; he formulated Fuzi Tang to treat body and joint pain, cold hands and feet, aversion to cold on the back, and deep pulse, reflecting the principle of flowing from the Yin aspect into the bones.
Furthermore, the *Suwen·Yinyang Lilun* states: "Taiyang acts as the opening." Thus, Zhongjing used it to govern the exterior, establishing floating pulse, aversion to cold, and stiffness/pain in the head and neck as the outline. While similar in wording to heat diseases, the intent differs. Yangming acts as the closing, governing the interior, with stomach excess as the outline; although eye pain and dry nose occur, they are not the primary focus. Shaoyang acts as the pivot, and so does Shaoyin; thus, both govern half-exterior/half-interior syndromes. Shaoyang, as the Yang pivot, emphasizes the half-exterior, using bitter taste and dizziness as the outline, excluding chest/flank pain/stiffness. Shaoyin, as the Yin pivot, includes desire to sleep but inability, desire to vomit but inability, which are also half-exterior/half-interior syndromes; although dry tongue and mouth occur, they are not in the outline, emphasizing the half-interior. Not only does Yangming govern the interior, but all Three Yin channels do as well; however, due to different yin-yang positions, their focuses differ. Yangming governs the Yang aspect of interior syndromes; the Yang pathway is excess, so stomach excess belongs to Yangming. Taiyin governs the Yin aspect of interior syndromes; the Yin pathway is deficiency, so spontaneous diarrhea belongs to Taiyin. Taiyin is the opening and the extreme Yin within Yin, governing interior cold and spontaneous diarrhea. Jueyin is the closing and the Yang within Yin, governing interior heat and rebellious Qi. Shaoyin is the pivot within Yin, so its manifestations vary between cold/heat and exterior/interior, resembling Shaoyang.
Let us use geography as an analogy: the Six Channels are like feudal states. The area above the waist is the territory of the Three Yang channels, which govern the exterior but originate from the interior. The Heart is the borderland of the Three Yang. Internally from the heart/chest, externally from the vertex, anteriorly to the forehead, posteriorly to the shoulders/back, inferiorly to the feet, and internally connecting to the Bladder—this is the Taiyang territory. This channel commands Ying and Wei, governing exterior syndromes of the whole body, akin to a border state defending against enemies. Internally from the heart/chest to the stomach/intestines, externally from the head, face to abdomen, down to the feet—this is the Yangming territory. From the heart to the throat, retreating to the cheekbone, ascending to eyes/ears, obliquely to the vertex, externally from the hypochondrium internally connecting to the Gallbladder—this is the Shaoyang territory. Taiyang is close to Yangming, akin to the capital region.
The area below the waist is the territory of the Three Yin channels, governing the interior and not extending to the exterior. The Abdomen is the borderland of the Three Yin. From the abdomen via the Spleen to the intestines and anus—this is the Taiyin territory. From the abdomen to the kidneys and bladder urethra—this is the Shaoyin territory. From the abdomen via the Liver up through the diaphragm to the Heart, from the hypochondrium down to the lower abdomen and tendons—this is the Jueyin territory. This channel circulates through the Sanjiao, governing interior syndromes of the whole body, akin to a state assisting the capital near the center.
Taiyin and Yangming reside together but are treated differently, analogous to the governance of Duke of Zhou and Duke of Shao. The four channels' locations involve different internal/external movements and upper/lower pullings, similar to the ancient kings' division of land and people, interlocking like dog teeth. If referring to meridians, these are the roads of the Six Channels, not the territories themselves. Conditions in the Six Channels include righteous vs. pathogenic factors, combined diseases, and involvement of spleen/stomach, akin to bandits filling the land, either in their own territory, neighboring states, or the capital.
Taiyang territory is largest, adjacent internally to Shaoyin and externally to Yangming, so diseases relate. For example, difficulty urinating is originally a Bladder disease; if Shaoyin disease also presents with difficulty urinating, the pathogen has reached the boundary of Taiyang. Lower back pain is originally a Kidney disease; if Taiyang disease also presents with lower back pain, the pathogen has reached the boundary of Shaoyin. Constipation for 6-7 days, headache, and fever indicate Yangming heat invading Taiyang's boundary. Stiffness/pain in head/neck with nasal congestion and dry vomiting indicates Taiyang wind invading Yangming's boundary. The chest/heart is Yangming territory but serves as a thoroughfare for Taiyang. Since Taiyang manages Ying and Wei, and the chest/heart is the root of Ying and Wei, which circulate endlessly, it is like border officials and soldiers gathering at the capital. Wheezing and chest fullness indicate Taiyang exterior pathogens entering Yangming territory and causing disturbance, termed Taiyang-Yangming combined disease. If there is no headache or neck stiffness, but chest oppression, Qi rushing to the throat, and dyspnea, the pathogen did not come from Taiyang but is Yangming excess knotting in the chest, like bandits causing trouble in their own territory.
The Heart is the master of the Six Channels, so all channels can present with vexation. If there is no head/neck stiffness, vexation does not belong to Taiyang; if there is no alternating chills/fever, it does not belong to Shaoyang; if there are no Three Yin symptoms, it does not belong to Three Yin. Therefore, mental confusion, palpitations, and intra-cardiac restlessness (Ao Nao), all forms of deficiency vexation, belong to Yangming because the Heart resides in Yangming territory. Yangming is like the capital, so both Heart and Abdomen are within its domain. Pathogen in the Heart causes deficiency vexation; pathogen in the Abdomen causes excess heat. The Heart is Yang and formless; the Abdomen is Yin and formed. Diseases of the human body often involve the Heart and Abdomen. Yang pathogens gather in the Heart; Yin pathogens gather in the Abdomen. The Liver is Yang within Yin, so it can cause Yin pathogenic Qi to strike the Heart. Yangming governs interior Yang, so it allows Yang pathogens to gather in the Abdomen.
Using military strategy as another analogy: the key to strategy is understanding terrain. One must first know the paths of the Six Channels to know where bandits come from. The approach is the border (Three Yang); the retreat is the interior (Three Yin). The approaches differ: Taiyang is the main road, Shaoyang is the obscure path, Yangming is the direct road, Taiyin is the nearby road, Shaoyin is the rear road, and Jueyin is the diagonal road. External pathogens usually come from the Three Yang; internal pathogens often arise from the Three Yin, like foreign invaders from borders or domestic thieves from the interior. Understanding Six Channel terrain allows grasping the pivot of all diseases; detailing the approaches provides rules for treatment.
Regarding syndromes: Cold Damage is a major invasion from outside; Wind Strike is a roaming bandit affecting from the side; Miscellaneous Diseases are thieves arising from within. Once identified as a certain type of thief and knowing its origin, if it attacks its own territory, defend there; if it moves to a neighbor, attack from two routes. If pathogens enter Taiyang territory, release them via sweating, like positioning elite troops at key points to strike before they settle. Light pathogens are in the Wei level, heavy in the Ying level, and most severe in the chest/diaphragm, like bandits shallow outside the pass, deep at the pass, and deepest inside. Mahuang represents troops outside the pass; Guizhi and Gegen represent troops at the pass; Da Qing Long and Xiao Qing Long represent troops inside the pass. When external threats persist, internal unrest follows; thus, dual-release methods were created, leading to formulas like Da/Xiao Qing Long and modified Guizhi/Mahuang formulas. If the vanguard lacks discipline causing internal chaos, prioritize the interior over the exterior, leading to formulas like Wu Ling San, Shi Zao Tang, Xuan Xiong Tang, Xie Xin Tang, and Di Dang Tang.
If pathogens enter Shaoyang territory, mix exterior/interior, cold/heat, attacking/tonifying agents for defense and resolution. Like a narrow path, short weapons are better than spears; defense is better than offense. Light pathogens enter the Couli (pores); heavy ones enter the Muyuan (membranes); most severe enter Spleen/Stomach. Xiao Chai Hu Tang treats Couli; Da Chai Hu Tang treats Muyuan. Xiao Jian Zhong Tang, Ban Xia Xie Xin Tang, Huang Qin, and Huang Lian treat the Spleen aspect of Shaoyang; Chai Hu Jia Mang Xiao Tang and Chai Hu Jia Long Gu Mu Li Tang treat the Stomach aspect. If Taiyang and Shaoyang have combined disease, it is one army attacking Taiyang and another Shaoyang; Chai Hu Gui Zhi Tang divides the attack. Even Triple Yang combined disease means facing enemies on three fronts; the method is to focus solely on Yangming. If Yangming territory is secured, Yang pathogens from Tai and Shao resolve spontaneously. Calming internal rebels stops external threats; this is why Bai Hu Tang achieves victory.
If Yang pathogens are not contained internally, use Da Cheng Qi Tang for urgent purging to attack thieves and protect the host. If Yin pathogens directly enter the central palace, use Si Ni Tang to urgently rescue the interior, strengthening the host to expel thieves. Yangming is the interior; its boundary is Taiyang/Shaoyang territory. If pathogens enter Yangming's boundary near Taiyang, even if not attacking Taiyang, Taiyang forces cannot ignore it. Thus, for Yangming Ying/Wei disease, borrow Guizhi/Mahuang formulas to sweat. If near Shaoyang territory, even if not entering Shaoyang, Shaoyang forces cannot remain passive. Thus, for Yangming Couli disease, borrow Chai Hu to resolve. This shows Yangming's failure is not due to Taiyang's weakness or Shaoyang's lack of preparation, but often results in Two Yang combining.
If pathogens are already in Yangming territory, launch a vigorous attack to purge them completely, using Zhi Chi or Gua Di for vomiting to sweep quickly. If they penetrate deep into the interior and cannot be driven out, practice scorched earth tactics to prevent plundering; this is where Bai Hu Tang excels. If pathogens are in the inner court, clear the palace and remove thieves; this is why the Three Cheng Qi formulas succeed. Agents like Yin Chen and Zhu Ling legislate for undisciplined troops.
Taiyin is also interior; Shaoyin and Jueyin are Taiyin's borderlands. Taiyin occupies the Central Plain; though connected externally to Three Yang, Yin and Yang have diverged, and the Heart/Abdomen are separated by the diaphragm barrier. Thus, Cold-Water pathogens attaching from Taiyang externally are mild; those transmitted internally from Shaoyin are severe. Wind-Wood pathogens invading from Shaoyang are slight; those袭 (attacking) from Jueyin are severe. If the channel's righteous pathogen transforms to Yangming becoming excess, it is like an exhausted army that can be cured by purging. If Yangming excess transforms to the channel becoming deficiency, pathogen is strong and righteousness weak, making recovery via warming/tonifying very difficult. Taiyin and Yangming territories are distinct but unobstructed. Yangming is a thoroughfare under attack, a gathering place for troops, a land of four battles. Taiyin is a granary, a base for armies, and a nest for thieves. If Yuan Qi is sufficient, pathogens enter Yangming; if insufficient, they enter Taiyin. In Yangming territory, one can deploy troops and fight behind the city walls, winning quickly. In Taiyin territory, granaries are burned empty, starving soldiers cannot resist enemies.
Jueyin territory is a zone where Ministerial Fire travels; its fundamental Qi is Lesser Fire. If wind-cold-dryness-dampness enters, it transforms into heat, becoming Flaming Fire. Lesser Fire is the life force of the body; Flaming Fire is a major disaster for the Heart/Abdomen. Its territory connects to the Sanjiao. Pathogens attacking the Upper Jiao cause Qi rushing to the Heart, burning pain in the chest, thirst, oral ulcers, sore throat, and bi obstruction. Pressing into the Middle Jiao causes cold extremities, faint pulse, hunger without appetite, and vomiting roundworms upon eating. Spreading to the Lower Jiao causes hot diarrhea with heaviness or pus/blood in stool, causing significant harm, like a rebellious army. Zhongjing formulated Wu Mei Wan, using cold/heat simultaneously, attacking/tonifying together, regulating Qi/Blood, and harmonizing Sanjiao, as the main formula for pacifying Jueyin, like a Grand Commander of the interior. Giving water for thirst, Fu Ling Gan Cao Tang for water retention, Zhi Gan Cao Tang for pulse restoration, and Dang Gui Si Ni Tang for cold extremities are sending out elite troops to save the Upper Jiao Heart Master and calm the Spirit. Using Bai Hu and Cheng Qi families clears Stomach heat and calms Middle Jiao excess; Bai Tou Weng Tang and Si Ni San clear Spleen heat and stop Lower Jiao hot diarrhea, saving the Yin in the Abdomen and supporting Stomach Qi.
The Stomach is one Fu organ but divided into Yin/Yang channels; Shaoyin is one channel but combines Yin/Yang Zang organs, both being roots of foundation. Pathogens have Yin/Yang paths; Zang organs have Yin/Yang Qi. If Yang pathogens attack Shaoyin-Yang, there is counter-fever, vexation, cough/thirst/sore throat. If Yang pathogens attack Shaoyin-Yin, there is abdominal pain, spontaneous diarrhea, or pus/blood in stool. If Yin pathogens attack Shaoyin-Yang, there is body/joint pain, cold extremities, back aversion to cold, and curling up. If Yin pathogens attack Shaoyin-Yin, there is aversion to cold, vomiting, clear diarrhea, and irritability desiring death. Zhongjing formulated Mahuang Fuzi Xi Xin, Huang Lian E Jiao, Gan Cao, Jie Geng, Zhu Fu, Ban Xia, Ku Jiu, etc., to defend against Yang pathogens attacking Shaoyin-Yang; Tao Hua and Zhu Ling Tang to defend against Yang pathogens entering Shaoyin-Yin; Fu Zi, Wu Zhu Yu, Si Ni, etc., to defend against Yin pathogens attacking Shaoyin-Yang; Tong Mai Si Ni, Fu Ling Si Ni, Gan Jiang Fu Zi, etc., to defend against Yin pathogens entering Shaoyin-Yin.
Shaoyin is the root of the Six Channels, connecting externally to Taiyang and internally to Yangming. Thus, initial counter-fever or fever of whole body/extremities after 8-9 days indicates Shaoyin-Yang pathogens invading Taiyang territory; spontaneous pure water diarrhea, epigastric pain, dry mouth/tongue indicates Shaoyin-Yang pathogens invading Yangming territory. Exiting Taiyang uses Mahuang as elite troops supervised by Fuzi; entering Yangming relies entirely on Da Cheng Qi without supervision, like using guides vs. native troops. If Yin pathogens invade Taiyin, use Li Zhong, Bai Tong with Urine/Pig Bile, etc., similarly. Alas! Without contemplating Zhongjing's collection, how can one see the disease and know its source?