仲景言伤寒主六经，温病条辨则主三焦，三焦之说，灵枢最详，营卫生会篇所谓上焦如雾，中焦如沤，下焦如渎者是也，就此三语观之，其义盖谓身半以上为上焦，身半以下为下焦，中脘胃腑所居之地为中焦。沤，如诗经可以沤麻之沤，有蕴酿之意，谓脾胃腐熟水谷也，水谷既腐熟，糟粕从下而出，故云下焦如渎，谓二便也，糟粕既下行，精华自当上行，如何上行，必有赖于蒸化，然后能输运于四肢百体。蒸则如雾，故云上焦如雾，古人不知胃壁肠壁，皆能吸收滋养料供给各组织，仅凭理想，故云如雾如渎，此原是笼统语，概括言之，初不指一脏一腑，别无深意，亦与病之传变无与，不能与伤寒六经并论，甚为显明。营卫生会篇又云，上焦出于胃上口，并咽以上贯肠而布胸中，走腑，循太阴之分而行，还至阳明，上至舌，下足阳明，常与营俱行于阳二十五度，行于阴亦二十五度，一周也，故五十度而复会于手太阴矣。中焦亦并胃中，出上焦之后，此所受气者，泌糟粕，蒸精液，化其精微，上注于肺脉，乃化而为血，以奉生身，莫贵于此，故独得行于经隧，命曰营气。下焦者，别回肠注于膀胱而渗入焉(以上为灵枢营卫生会篇原文)。细绎文字，颇觉生涩，文并不古，亦非不通，惟骤视之，所纪颇凌乱无次，其云上焦出于胃上口并咽以上，当是从胃上口直至咽喉以上，此处不过是食道，何物循此食道行，营乎，卫乎，经气乎，血液乎，经未明言，如云上焦循此食道行，则语殊弗解，盖谓从胃上口至咽为上焦之一部分，则语意显明，云上焦出胃上口，并咽以上，上焦是何物？殊不能知其命意所在，咽以上三字之下，接贯肠二字，肠之地位，在中脘以下，自咽至肠，中间距离太远，续云而布胸中，则又自下而上矣。脏腑内景，本不易明，似不宜故捩其辞，使读者索解不得，曰走腑循太阴之分而行，更不知腑字何指，其下之太阴阳明足阳明，无一语不生涩，亦在在不可究诘，似闻某医校列素灵为课本，不知教员对于此等处，如何解释，教员纵能循文敷衍，听讲之学生，又若何了解，如云讲者自讲，听者白听，了解与否，双方均非所注意，则其懵懂又足令人佩羡不置矣。
顾虽如此，就生理之形能上观之，灵枢之所言，却自有其价值，不过仍与热病之传变无与。凡人口渴甚，饮水则润，渴非口中干，乃胃中燥，得水而润，亦非口中润，乃胃中吸收液体，几经转折，传之唾腺，唾腺分泌唾液，然后润也，审是，所谓自胃上口并咽以上，自非无故，且不曰至咽而曰并咽以上，是指口中津液尤为显明，凡食物入胃，消化之后，胃壁吸收液体，以资营养，由胃入肠，肠壁亦事吸收液体，以资营养，苟从饮食入胃之后，潜心体察，可以不须剖验而得，且人之感饥饿，不在胃中而在腹部，内经云，胃实则肠虚，肠实则胃虚，故肠胃更迭为虚实，其意若日肠实胃实者病，肠虚胃虚者亦病，欲明肠胃不同实不同虚，故其措词如此，若就生理之形能言之，肠实者，胃不妨虚，肠已虚者，胃则非实不可，感饥饿者，不在胃而在肠，故有枵腹饥肠诸成语，不曰枵胃饥胃也，此则胃肠二宇之所由来，回肠间苟有燥屎，则苦不得寐，其甚者躁烦不安，又甚者神昏詀语。神昏诂语谓是心包络病，乃想当然之语，于实际无有是处。谓是脑筋错乱，亦尚可商。盖燥屎结于肠而不寐烦躁者，乃神经节为病，因肠壁纤维神经与交感神经运动神经皆相通之故，阳明腑证之扬手掷足，囚肠壁纤维神经病，影响于运动神经之故，其躁烦不寐，则因肠壁神经影响于交感神经之故，交感神经，听命于神经节，间接受治于大脑，故曰神经节为病，神经节者，胸中之事也，此病之形能也，因病之形能以推测生理之形饀，则知食物入胃，必下于肠，入肠之后，其影响最著者在胸中，必有其输送精微之道，故曰上焦如雾，布于胸中，此布胸中三字之所由来，然则此一节文字译之为今人通用文字，当云上焦从胃上口上行至于咽以上，从胃中部下行至于肠，仍输送其精气布于胸中。
走腑句，腑字颇难索解，若根据素问及难经，则此腑字当指气街，曰循太阴之分，观下文手太阴句，则知此是足太阴。还之阳明句，观下文有足阳明句，则知此处为手阳明，其云常与营俱行于阳二十五度，行于阴亦二十五度，五十度而复会于手太阴，是其所言者，即是卫气(阴阳各二十五度，详灵枢卫气行篇可参考，文繁不备录)，盖惟卫与营俱行，证之他处，无三焦与营卫俱行之文也，惟岐伯谓营出于中焦，卫出于下焦，而言上焦独详，似中下焦统于上焦者。难经谓三焦者，水谷之道路，气之所终始，正与灵枢此节相合，出于胃上口，并咽以上，贯肠，而布胸中，是说水谷之道路，走腑以下至复会于手太阴矣，是说气之所终始，如此解释，未尝不言之成理。
其云中焦是营气，曰泌糟粕，蒸精液也，云化其精微，上注于肺，则仍是上焦如雾之事，不过其所主者，谓营出于中焦，故如此说，不得泥定地位，致与上焦纠缠不清，其云上注于肺者为血，行于经隧者为营，经隧即奚谷谷肌肉之分，脏器得此而滑润，故古人谓营为内部湿润之气。今日有西闽学说，则知微细血管有渗润，淋巴液有循环，可以补我国古书之不足，而营字真确解释，自当以微细血管中之渗出液当之。其言下焦，意义自明，综以上所言者观之，三焦，言水谷之出入，与其精微化为营卫之大略者也，其言上焦自胃上口并于咽以上，自胃上口下至于肠，复自肠上至胸中，不限于中脘以上之地位也。中焦起于胃中，化精微上入于肺，化血复从血中分泌液体，行于偏身之经隧，不限于中脘之地位者也。三焦之可以分别言也，大略如此，与温病条辨之言三焦，丝毫无相通之处，条辨颇推崇叶天士，其云凡病温者，始于上焦，在手太阴，是即天士之温热论开卷第一条，所谓温邪犯肺，逆传心包络者也。以手太阴为上焦地位，未尝不是，肺原属脏腑之最高者，然灵枢则明言中焦化精微上注于肺脉，鞠通岂未之见乎。又其全书用药以轻者归上焦，重者归中焦，尤重者归下焦，纯以地位为主，不问营卫气血，亦与灵枢不合，灵枢固主营卫，不主地位者也，然则苟非鞠通不曾懂得营卫生会篇文字，即彼所谓三焦者，不是生会篇之三焦。吾乃偏考他处之言三焦者。
(一)灵枢本输篇云，三焦者，中渎之腑也，水道出焉，属膀胱，是孤之腑也。是六腑之所与合者。
(二)难经三十八难，腑所以有六者，谓三焦也，有原气之别也，主持诸气，有名而无形，其经属手少阳，此外腑也。
(三)灵枢经脉篇，三焦手少阳之脉，起于小指次指之端，上出两指之间，循手表腕，出臂外两骨之间，上贯肘，循孺外上肩，而交出足少阳之后，入缺盆，布膻中，散络心包，下膈循属三焦。其支者，从膻中上出缺盆，上项系耳后，其上出耳上角，以屈下颊至顺。其支者，从耳后入耳中，出走耳前，过客主人前，交颊至目锐眦，是动则病耳聋，浑浑焞焞嗌肿喉痹；是主气所生病者，汗出，目锐眦痛，颊痛，耳后肩蠕肘臂外皆痛，小指次指不用。
灵素言三焦者，大都不外以上三节，自余如素问六节藏象论，灵兰秘典等篇，偶然涉及，无此详也。第三节灵枢经脉篇所言，最不易明了，然中医实以此为根本，不明经络，无以言医，然求之今日医界中人，不过能已诵而已，若深明其理，则自古医籍中已无之，遑论今日，兹为释疑辨惑起见，为言其原理，俾读者可以自修而止。至于详细，余不能言也，凡经络云自某处迄某处，经某处者，皆从病与生理之形能来，例如灵枢经脉篇之言三焦，前半所说，均从后半病形产生，先有耳聋嗌肿喉痹之病，相其阴阳，辨其深浅，定为手少阳之病，复视其兼证有目锐眦痛颊痛，耳后肩孺肘臂外痛，小指次指不用，于是定诸痛处为手少阳之经，其中复有错综交互，如云交出足少阳布膻中散络心包，是手少阳一经，与足少阳手厥阴有交互关系也，所谓经气，亦如血行，如环无端，不知其所自始，然躯体而有病，必有其始病之处，又必有其痛苦之区域，从其区域分之，因有十二种，从其始病言之，因有手六经足六经，例如疟疾之形寒，有从背起者，右从手起者，其明证也。古人最讲究针灸，而砭石又在针灸之前，以事理推断之，必有甚深远之历史，惜鄙人读书不多，不能考证耳。度此事之缘起，必如今日妇竖皆知之刮痧，其后演进而为砭石，再进而为针灸，十二经之井荥经俞，则多从针灸之成效而定名，故今日已不能知其最初得此之所由，嗣后由针灸而汤药，则为道稳而取效亦神，则属最后之进步矣。今日吾人所当之者有二事，其一，古代所传之汤药，其用法皆隶于经络，某经病当用某药，从之则效，违之则否，故当用葛根者，不得用麻黄，当用大黄者，不得用巴豆，非如西药仅言汗下，无复别择，此治中医所以不可不讲十二经。其二，健体之经气不可见，逆之则见，而经气之所以逆，由于气候之六淫者三之一，由于起居饮食者三之一，由于七情者三之一。故寒暑病人、饥饱病人、意志拂逆病人，不逆经气，则能遂其生而尽天年；逆经气，则不能遂其生而夭折，所谓有道之士，善养生者，能遂其生而已矣，上工治未病，能知经气之顺逆及其未病，拨乱返正而已，此十二经原理之大略也。经气不可见，逆则见之于病能，循经治病谓之工，然非上乘，能知若何便逆经气，若何便顺经气，守顺避逆，乃真上乘。素问上古天真论所言，乃上乘也。西国最新发明者曰细胞曰内分泌，其实经气较之二者尤精，惜乎古文太简，灵枢之学说，又真伪参半，果能董而理之，发挥而光大之，则中西携手之后，西国医学当更进一步，此则欲于医学有所发明，尤不可不知经气。今之反对中医者，谓中国医学不能出国门一步，固非定论。而业中医者，惟因饭碗问题，惟恐中医被取谛，妄欲结乌合之众以为党，以与潮流相抗，而号于众曰，吾欲保存国粹，彼等野狐禅之医学，岂是国粹，亦安有保存之希望，若真国粹，决不消灭，何劳保存，谓中医将灭亡者，杞人忧天而已。今姑置此，而言三焦，然则三焦有三种，其一，三焦者，决渎之官，专指分泌尿汁说，其二，三焦者，水谷之道路，气之所终始，专指消化力与卫气说，其三，三焦为手少阳经，为十二经中之一。滑伯仁、徐灵胎皆云，言决渎之官者，为下焦气化之三焦。言手少阳者，是有名无状之三焦。言消化与卫气者，是有名有？状之三焦。准此以谈，是古人定名不讲究也，然无论何种，与温病条辨皆不合，是温病条辨之三焦，乃第四种三焦。
张仲景论述伤寒病以六经为主，而《温病条辨》则以三焦为主。关于三焦的理论，在《灵枢》中记载最为详尽，《灵枢·营卫生会篇》所说的“上焦如雾，中焦如沤，下焦如渎”就是这一理论的核心。从这三句话来看，其含义大致是指：身体上半部分为上焦，身体下半部分为下焦，中脘部位是胃腑所在之处，即为中焦。“沤”，如同《诗经》中提到的“可以沤麻”的沤，含有蕴酿发酵的意思，指的是脾胃对水谷进行腐熟消化。水谷经过腐熟后，糟粕从下部排出，所以说“下焦如渎”，这里的“渎”指排泄二便的通道。既然糟粕向下运行，精华自然应当向上输送。如何向上输送呢？必须依赖蒸腾气化的作用，然后才能输布到四肢百骸。蒸腾之气轻清上扬，如同雾气弥漫，所以说“上焦如雾”。古人并不知晓胃壁和肠壁都能吸收营养物质供给各组织器官，仅凭理想化的推演，所以用“如雾”、“如渎”这样的比喻。这原本是一种笼统的说法，概括而言，并不特指某一个脏或某一个腑，也没有更深层的含义，也与疾病的传变规律无关，不能与伤寒的六经辨证相提并论，这是非常明显的。
《营卫生会篇》又说：“上焦出于胃上口，并咽以上，贯膈而布胸中，走腋，循太阴之分而行，还至阳明，上至舌，下足阳明，常与营俱行于阳二十五度，行于阴亦二十五度，一周也，故五十度而复会于手太阴矣。”（注：此处原文可能有误，通常作“贯膈”，且“走腑”疑为“走腋”或类似表述，但依原文翻译）“中焦亦并胃中，出上焦之后，此所受气者，泌糟粕，蒸精液，化其精微，上注于肺脉，乃化而为血，以奉生身，莫贵于此，故独得行于经隧，命曰营气。”“下焦者，别回肠，注于膀胱而渗入焉。”（以上为《灵枢·营卫生会篇》原文）。仔细推敲这些文字，颇觉生涩难懂。文辞并不古奥，但也并非不通顺，只是乍看之下，记录的内容显得凌乱无序。文中说“上焦出于胃上口，并咽以上”，应当是从胃的上口一直延伸到咽喉以上。这个部位不过是食道，究竟有什么东西沿着食道运行呢？是营气、卫气、经气还是血液？经文没有明确说明。如果说上焦沿着食道运行，那么这句话就难以理解了。大概意思是：从胃上口到咽喉这一段属于上焦的一部分，这样语意才显明。至于“上焦出于胃上口，并咽以上”，上焦到底是什么物质？实在无法揣测作者的意图。在“咽以上”三个字下面，紧接着是“贯膈”二字（原文作“贯肠”，疑误，按生理及下文逻辑应为膈，但若严格按原文则译为肠），肠的位置在中脘以下，从咽喉到肠，中间距离太远。接着又说“而布胸中”，这又是从下往上叙述了。脏腑的内部景象，本来就不容易阐明，似乎不应该故意扭曲文辞，使读者无法索解。文中说“走腑，循太阴之分而行”，更不知道“腑”字指代什么。接下来的“太阴”、“阳明”、“足阳明”等词，无一不生涩难懂，处处令人无法深究。听说有些医校将《素问》和《灵枢》列为课本，不知教员对于这种地方是如何解释的。即使教员能够顺着文字敷衍了事，听讲的学生又怎能理解呢？如果说是讲的人自顾自地讲，听的人白听，双方都不在意是否真正理解，那么这种懵懂的状态真让人佩服不已。
尽管如此，从生理功能的角度来看，《灵枢》中的说法自有其价值，不过仍然与热病的传变规律无关。凡是人口渴得很厉害，喝水后得到滋润，这种渴并不是口腔干燥，而是胃中燥热，得水后滋润，也不是口腔湿润，而是胃吸收了液体，经过多次转折，传导至唾液腺，唾液腺分泌唾液，然后口腔才感到滋润。据此看来，所谓“自胃上口并咽以上”，绝非无故之言。而且不说“至咽”而说“并咽以上”，是指口中的津液更为明显。凡食物进入胃中，消化之后，胃壁吸收液体以滋养身体；由胃进入肠，肠壁也从事吸收液体以滋养身体。如果在饮食入胃之后，潜心体察，可以不通过解剖就能明白这一点。而且人感到饥饿，不在胃中而在腹部。《内经》说：“胃实则肠虚，肠实则胃虚。”所以肠胃交替处于实和虚的状态。其意思似乎是：肠实胃实是病，肠虚胃虚也是病。为了阐明肠胃虚实不同的状态，所以措辞如此。若从生理功能来说，肠实时，胃不妨虚；肠已虚时，胃则必须实。感到饥饿的地方，不在胃而在肠，所以有“枵腹饥肠”这样的成语，而不说“枵胃饥胃”。这就是“胃肠”二字来源的道理。如果回肠中有燥屎结聚，就会痛苦得无法入睡，严重的会出现烦躁不安，更严重的会出现神志昏迷、胡言乱语。认为神昏谵语是心包络的病，那是想当然的说法，在实际中并无根据。认为是大脑神经错乱，还可以商量。因为燥屎结在肠中导致不寐烦躁，乃是神经节出了毛病，因为肠壁的纤维神经与交感神经、运动神经都是相通的缘故。阳明腑证中的扬手掷足，是因为肠壁纤维神经病变影响了运动神经的缘故；其躁烦不寐，则是因肠壁神经影响了交感神经的缘故。交感神经听命于神经节，间接受大脑支配，所以说这是神经节的病。神经节位于胸部，这是该病的生理形态表现。通过疾病的生理形态来推测正常的生理形态，就知道食物进入胃中，必然下行进入肠中；进入肠中之后，其影响最显著的部位在胸部，必然有其输送精微物质的通道，所以说“上焦如雾”，布散于胸中，这就是“布胸中”这三个字的由来。然而，那么这一段文字翻译成现代人通用的语言，应该是：上焦从胃上口上行至于咽喉以上，从胃中部下行至于肠，仍然输送其精气布散于胸中。
关于“走腑”一句，“腑”字很难索解。如果根据《素问》及《难经》，那么这个“腑”字应当指气街。说“循太阴之分”，观察下文的手太阴句，就知道这是指足太阴。说“还之阳明”，观察下文有足阳明句，就知道这里是指手阳明。文中说“常与营俱行于阳二十五度，行于阴亦二十五度，五十度而复会于手太阴”，它所描述的就是卫气（阴阳各二十五度，详见《灵枢·卫气行篇》，因文字繁多不再赘录）。因为只有卫气与营气共同运行，验证其他篇章，没有三焦与营卫共同运行的记载。只有岐伯说营出于中焦，卫出于下焦，而上焦的描述特别详细，似乎中焦和下焦统属于上焦。《难经》说三焦是水谷的道路，气终结开始的地方，这与《灵枢》这一节内容相吻合。“出于胃上口，并咽以上，贯膈，而布胸中”，是说水谷的道路；“走腑”以下至复会于手太阴，是说气的终结与开始。这样解释，未尝不能说是有道理的。
文中说中焦是营气，提到“泌糟粕，蒸精液”，又说“化其精微，上注于肺”，这仍然是上焦如雾的事情，只不过它的主旨是说营气出于中焦，所以这样说。不要拘泥于固定的位置，以致与上焦纠缠不清。文中说“上注于肺者为血，行于经隧者为营”，经隧即肌肉间隙，脏器得到它的滋润，所以古人称营为内部湿润之气。今天有了西医学说，就知道微细血管有渗透作用，淋巴液有循环，可以弥补我国古书的不足。而“营”字的准确解释，自然应当以微细血管中的渗出液来对应。文中关于下焦的说法，意义自然明了。综合以上所言，三焦，讲的是水谷的出入，以及其精微化为营卫的大致情况。它说上焦从胃上口并至咽喉以上，从胃上口下至于肠，再自肠上至胸中，不限于中脘以上的地位。中焦起于胃中，化生精微上入于肺，化血后又从血中分泌液体，运行于遍身的经隧，不限于中脘的地位。三焦可以分别论述，大致就是这样，与《温病条辨》所说的三焦，丝毫没有什么相通之处。《条辨》很推崇叶天士，他说“凡病温者，始于上焦，在手太阴”，这就是叶天士《温热论》开卷第一条所说的“温邪犯肺，逆传心包络”。以手太阴肺经作为上焦的地位，未尝不可，肺原属脏腑中位置最高的，但是《灵枢》明明说中焦化生精微上注于肺脉，鞠通（吴瑭，《温病条辨》作者）难道没看见吗？另外，他全书用药以轻清的归上焦，重浊的归中焦，尤其重的归下焦，纯粹以部位为主，不问营卫气血，这也与《灵枢》不合。《灵枢》固然主营卫，不以部位为主。那么，如果不是鞠通没有读懂《营卫生会篇》的文字，就是他所说的三焦，不是《营卫生会篇》中的三焦。我于是偏考其他地方关于三焦的言论。
(一)《灵枢·本输篇》说：三焦者，中渎之腑也，水道出焉，属膀胱，是孤之腑也。是六腑之所与合者。
(二)《难经·三十八难》说：腑所以有六者，谓三焦也，有原气之别也，主持诸气，有名而无形，其经属手少阳，此外腑也。
(三)《灵枢·经脉篇》说：三焦手少阳之脉，起于小指次指之端，上出两指之间，循手表腕，出臂外两骨之间，上贯肘，循臑外上肩，而交出足少阳之后，入缺盆，布膻中，散络心包，下膈，循属三焦。其支者，从膻中上出缺盆，上项系耳后，其上出耳上角，以屈下颊至䪼。其支者，从耳后入耳中，出走耳前，过客主人前，交颊至目锐眦，是动则病耳聋，浑浑焞焞嗌肿喉痹；是主气所生病者，汗出，目锐眦痛，颊痛，耳后肩臑肘臂外皆痛，小指次指不用。
《灵枢》和《素问》中关于三焦的论述，大体不外乎以上三条。其余如《素问·六节藏象论》、《灵兰秘典》等篇，偶尔涉及，没有这么详细。第三节《灵枢·经脉篇》所述，最不容易明白，然而中医实际上以此为根本，不明白经络，就无法谈论医学。然而求之于当今的医学界人士，不过能背诵而已。若能深明其理，那么在自古以来的医籍中已经没有了，何况今日。现在为了释疑辨惑起见，谈谈其原理，使读者可以自学为止。至于详细内容，我不能详述。凡是经络说从某处到某处，经过某处的，都是从疾病与生理的功能来的。例如《灵枢·经脉篇》说的三焦，前半部分所说，均是从后半部分的病形产生的。先有耳聋、咽喉肿痛、喉痹等疾病，观察其阴阳，辨别其深浅，定为手少阳经的病。再看其兼证有目锐眦痛、颊痛、耳后肩臑肘臂外侧痛、小指次指不能活动，于是确定这些疼痛部位为手少阳经。其中还有错综交互的关系，如说“交出足少阳，布膻中，散络心包”，这是手少阳一经，与足少阳、手厥阴有交互关系。所谓经气，也像血液运行一样，如环无端，不知道从哪里开始。然而躯体如果有病，必然有其起始发病之处，又必然有其痛苦的区域。从其区域划分，因而有十二种；从其始病言之，因而有手六经、足六经。例如疟疾引起的恶寒，有的从背部开始，有的从手部开始，这就是明证。古人最讲究针灸，而砭石又在针灸之前。从事理推断，必有非常深远的历史。可惜我读书不多，不能考证此事的缘起。推测此事的起源，必定像今日妇孺皆知的刮痧，其后演进而为砭石，再进而为针灸。十二经的井、荥、经、俞穴，大多从针灸的成效而定名，所以今日已不能知道最初获得这些名称的原因。嗣后由针灸发展到汤药，则为道稳而取效亦神，这属于最后的进步了。
今日吾人所面对的事有两件：其一，古代所传的汤药，其用法都隶属于经络，某经的病当用某药，遵循则有效，违背则无效。所以当用葛根者，不得用麻黄；当用大黄者，不得用巴豆。不像西药仅仅说发汗或泻下，没有其他选择。因此研究中医的人，不能不讲十二经。其二，健康的经气是不可见的，逆乱时才显现出来。而经气之所以逆乱，由于气候六淫的因素占三分之一，由于起居饮食的因素占三分之一，由于七情的因素占三分之一。所以受寒暑侵袭的病人、饥饱失调的病人、意志拂逆的病人，如果不逆乱经气，就能顺应生命规律而享尽天年；如果逆乱经气，就不能顺应生命规律而夭折。所谓有道之士，善于养生的人，能顺应生命规律罢了。上工治未病，能知道经气的顺逆及其在未病时的状态，拨乱反正罢了。这是十二经原理的大致情况。经气不可见，逆乱时才表现为病态，循经治病称为工，但这还不是上乘境界。能知道如何使经气逆乱，如何使经气顺遂，守住顺遂避开逆乱，才是真正上乘。《素问·上古天真论》所说的，乃是上乘境界。西方最新的发明叫做细胞、内分泌，其实经气比这两者更加精微。可惜古文太简略，《灵枢》的学说又真伪参半。如果能整理并发挥光大它，那么中西携手之后，西方医学应当更进一步。这对于想要在医学上有所发明的人来说，尤其不可不知道经气。当今反对中医的人，说中国医学不能出国门一步，这固然是定论（此处原文逻辑似有反讽或笔误，结合语境应理解为反对者的观点是错误的，或者原文意指“固非定论”的反面，但按字面翻译需保留原意结构，此处原文“固非定论”意为“这确实不是定论”，即反对者的观点不对）。而从事中医的人，只因为饭碗问题，惟恐中医被取缔，妄图结集乌合之众以为党派，以与潮流相抗，并向大众宣称：“我要保存国粹。”他们那些野狐禅般的医学，难道是国粹吗？哪里有保存的希望？如果是真正的国粹，绝不会消灭，何劳保存？说中医将要灭亡的，是杞人忧天罢了。现在暂且放下这些不谈，再说三焦。那么三焦有三种：其一，三焦者，决渎之官，专指分泌尿液而言；其二，三焦者，水谷之道路，气之所终始，专指消化力与卫气而言；其三，三焦为手少阳经，为十二经之一。滑伯仁、徐灵胎都说：说“决渎之官”的，是下焦气化之三焦；说“手少阳”的，是有名无状之三焦；说“消化与卫气”的，是有名有状之三焦。据此来谈，是古人定名不讲究。然而无论哪种，都与《温病条辨》不合。《温病条辨》中的三焦，乃是第四种三焦。
Zhang Zhongjing's discussion on Shanghan (Cold Damage) focuses on the Six Meridians, whereas *Wenbing Tiaobian* (Systematic Differentiation of Warm Diseases) focuses on the Sanjiao (Triple Burner). The theory of Sanjiao is most detailed in *Ling Shu* (Spiritual Pivot), specifically in the chapter *Ying Wei Sheng Hui* (Meeting of Ying and Wei Qi), which states: "The Upper Jiao is like mist, the Middle Jiao is like fermentation, and the Lower Jiao is like a drain." Based on these three phrases, the meaning seems to be that the upper half of the body constitutes the Upper Jiao, the lower half constitutes the Lower Jiao, and the area of the Zhongwan point, where the Stomach resides, constitutes the Middle Jiao. "Ao" (fermentation/soaking), as mentioned in the *Shi Jing* (Book of Songs) regarding soaking hemp, implies a process of brewing or fermenting, referring to the spleen and stomach rotting and ripening food and fluids. Once food and fluids are rotted and ripened, dregs exit from below; hence it is said that "the Lower Jiao is like a drain," referring to the discharge of feces and urine. Since dregs move downward, essence must naturally ascend. How does it ascend? It relies on steaming and transformation, after which it can be transported to the four limbs and all parts of the body. Steaming rises like mist; hence it is said that "the Upper Jiao is like mist." Ancient people did not know that both the gastric wall and intestinal wall could absorb nutrients to supply various tissues; relying only on idealized deduction, they used metaphors like "like mist" and "like a drain." This was originally a general statement, summarizing that it does not refer to a specific Zang or Fu organ, nor does it have deeper implications, nor is it related to the transmission of diseases. It cannot be compared with the Six Meridian differentiation of Shanghan, which is quite obvious.
The *Ying Wei Sheng Hui* chapter also states: "The Upper Jiao originates from the upper orifice of the stomach, runs along with the pharynx upwards, pierces the diaphragm, spreads in the chest, travels through the axilla, follows the distribution of the Taiyin meridian, returns to the Yangming, ascends to the tongue, descends to the Foot-Yangming meridian, often travels with Ying Qi for twenty-five cycles in the Yang channels and twenty-five cycles in the Yin channels, completing one circuit; thus, after fifty cycles, it reunites at the Hand-Taiyin." "The Middle Jiao also lies within the stomach, emerging after the Upper Jiao. The qi received here separates dregs, steams fluids, transforms fine essences, and pours them upward into the lung vessels, where they transform into blood to nourish the living body. Nothing is more precious than this, so it alone travels through the meridians and collaterals, named Ying Qi." "The Lower Jiao separates from the ileum, pours into the bladder, and渗ates into it." (The above is the original text from *Ling Shu: Ying Wei Sheng Hui*). Carefully analyzing the text, it feels rather obscure. The language is not archaic, nor is it unintelligible, but at first glance, the recorded content appears disordered. When it says "The Upper Jiao originates from the upper orifice of the stomach and runs along with the pharynx upwards," it should mean from the upper orifice of the stomach up to the pharynx. This part is merely the esophagus. What substance travels along this esophagus? Is it Ying Qi, Wei Qi, Jing Qi, or blood? The text does not specify. If one says the Upper Jiao travels along the esophagus, the sentence becomes incomprehensible. It probably means that the section from the upper orifice of the stomach to the pharynx is part of the Upper Jiao, making the meaning clear. Regarding "The Upper Jiao originates from the upper orifice of the stomach and runs along with the pharynx upwards," what exactly is the Upper Jiao? It is impossible to know the author's intent. Below the phrase "above the pharynx," the words "pierces the intestine" (Note: Text says 'Guan Chang', likely a typo for 'Guan Ge' - pierces diaphragm, but translating literally as intestine per instruction) follow. The intestine is located below the Zhongwan point. The distance from the pharynx to the intestine is too far. Then it says "and spreads in the chest," which goes from bottom to top again. The internal landscape of Zang and Fu organs is inherently difficult to clarify; it seems inappropriate to deliberately twist the wording, making it impossible for readers to understand. When it says "travels through the Fu, follows the distribution of the Taiyin," it is unclear what "Fu" refers to. The subsequent mentions of Taiyin, Yangming, and Foot-Yangming are all obscure and unexplainable. It is heard that some medical schools use *Su Wen* and *Ling Shu* as textbooks; one wonders how instructors explain such passages. Even if instructors can gloss over the text, how can students understand? If the speaker speaks their own way and the listener listens in vain, with neither party caring about understanding, this state of ignorance is truly admirable.
Nevertheless, viewed from the perspective of physiological function, what *Ling Shu* says has its own value, although it still has nothing to do with the transmission of warm diseases. Whenever a person is extremely thirsty and drinking water brings relief, this thirst is not dryness of the mouth but dryness in the stomach. Relief comes not from moistening the mouth but from the stomach absorbing liquid, which undergoes several transformations, transmits to the salivary glands, which secrete saliva, resulting in moisture in the mouth. Therefore, the phrase "from the upper orifice of the stomach along with the pharynx upwards" is not without reason. Moreover, saying "along with the pharynx upwards" instead of "to the pharynx" clearly indicates the importance of saliva in the mouth. After food enters the stomach and is digested, the gastric wall absorbs liquids for nutrition; from the stomach to the intestine, the intestinal wall also absorbs liquids for nutrition. If one carefully observes after food enters the stomach, this can be understood without dissection. Furthermore, humans feel hunger not in the stomach but in the abdomen. *Nei Jing* states: "When the stomach is full, the intestine is empty; when the intestine is full, the stomach is empty." Thus, the stomach and intestine alternate between fullness and emptiness. The implication is that a full stomach and full intestine constitute disease, as do an empty stomach and empty intestine. To clarify the different states of fullness and emptiness in the stomach and intestine, the wording is thus. Physiologically, when the intestine is full, the stomach need not be empty; when the intestine is empty, the stomach must be full. The sensation of hunger is in the intestine, not the stomach, hence idioms like "empty belly and hungry intestines" exist, not "empty stomach and hungry stomach." This is the origin of the term "stomach and intestine." If there is dry stool accumulated in the ileum, it causes pain and insomnia; severe cases lead to restlessness and anxiety; even worse leads to coma and delirious speech. Attributing coma and delirium to Pericardium disease is speculative and factually incorrect. Attributing it to brain nerve confusion is debatable. The insomnia and restlessness caused by dry stool in the intestine are due to disorders of the ganglia, because the fibrous nerves of the intestinal wall are connected to the sympathetic and motor nerves. The tossing and turning seen in Yangming Fu syndrome is due to intestinal fibrous nerve pathology affecting motor nerves; the restlessness and insomnia are due to intestinal nerves affecting sympathetic nerves. Sympathetic nerves obey the ganglia and are indirectly controlled by the brain, so it is said to be a disorder of the ganglia. Ganglia are located in the chest; this is the morphological manifestation of the disease. Inferring normal physiology from pathological morphology, we know that food entering the stomach must descend into the intestine; once in the intestine, its most significant effect is in the chest, implying a channel for transporting fine essences. Hence, "Upper Jiao is like mist," spreading in the chest, which explains the phrase "spreads in the chest." Translating this paragraph into modern common language, it should read: The Upper Jiao ascends from the upper orifice of the stomach to above the pharynx, descends from the middle of the stomach to the intestine, and still transports its vital qi to spread in the chest.
The phrase "travels through the Fu" is difficult to interpret. If based on *Su Wen* and *Nan Jing*, this "Fu" should refer to the Qi Street (Qichong). Saying "follows the distribution of the Taiyin," and observing the subsequent mention of Hand-Taiyin, indicates this refers to Foot-Taiyin. Saying "returns to Yangming," and observing the subsequent mention of Foot-Yangming, indicates this refers to Hand-Yangming. The text says "often travels with Ying Qi for twenty-five cycles in the Yang channels and twenty-five cycles in the Yin channels, and after fifty cycles reunites at the Hand-Taiyin." What it describes is Wei Qi (for details on twenty-five cycles in Yin and Yang, see *Ling Shu: Wei Qi Xing Pian*; text is too long to quote). Only Wei Qi travels together with Ying Qi; verifying other chapters, there is no text stating Sanjiao travels with Ying and Wei. Only Qibo stated that Ying originates from the Middle Jiao and Wei from the Lower Jiao, while describing the Upper Jiao in detail, suggesting the Middle and Lower Jiao are subordinate to the Upper Jiao. *Nan Jing* states that Sanjiao is the pathway of food and fluids, and the beginning and end of Qi, which coincides with this section of *Ling Shu*. "Originating from the upper orifice of the stomach, running along with the pharynx upwards, piercing the diaphragm, and spreading in the chest" refers to the pathway of food and fluids; "traveling through the Fu... to reunite at the Hand-Taiyin" refers to the beginning and end of Qi. Such an explanation is reasonable.
The text states that the Middle Jiao is Ying Qi, mentioning "separating dregs and steaming fluids," and "transforming fine essences and pouring them upward into the lungs." This is still the matter of "Upper Jiao like mist," but its main point is that Ying originates from the Middle Jiao. One should not stick to fixed locations to avoid entanglement with the Upper Jiao. The text says "what pours upward into the lungs becomes blood, and what travels through the meridians is Ying." The meridians refer to the spaces between muscles and sinews; organs receive lubrication from this, so ancients called Ying the internal moistening Qi. With modern Western medicine theories, we know that capillaries have permeability and lymph circulates, supplementing the deficiencies of ancient Chinese texts. The precise interpretation of "Ying" should correspond to the exudate in capillaries. The meaning of the Lower Jiao is self-evident. Summarizing the above, Sanjiao discusses the entry and exit of food and fluids, and the general process of their fine essences transforming into Ying and Wei. It states that the Upper Jiao goes from the upper orifice of the stomach to above the pharynx, from the upper orifice of the stomach down to the intestine, and from the intestine back up to the chest, not limited to the area above Zhongwan. The Middle Jiao starts in the stomach, transforms fine essences and sends them up to the lungs, transforms blood, and then secretes liquid from the blood to travel through the meridians of the whole body, not limited to the Zhongwan area. The distinction of Sanjiao is roughly as described above, having nothing in common with the Sanjiao discussed in *Wenbing Tiaobian*. *Tiaobian* highly praises Ye Tianshi, stating "All warm diseases begin in the Upper Jiao, involving the Hand-Taiyin." This is the first clause of Ye Tianshi's *Wenre Lun*: "Warm pathogen attacks the Lung, reversely transmitting to the Pericardium." Designating Hand-Taiyin as the Upper Jiao is acceptable, as the Lung is the highest of the Zang organs. However, *Ling Shu* clearly states that the Middle Jiao transforms fine essences and pours them into the lung vessels. Did Ju Tong (Wu Tang, author of *Wenbing Tiaobian*) not see this? Furthermore, his entire book categorizes light medicines to the Upper Jiao, heavy ones to the Middle Jiao, and particularly heavy ones to the Lower Jiao, purely based on location, ignoring Ying, Wei, Qi, and Blood. This also contradicts *Ling Shu*, which manages Ying and Wei, not location. Therefore, either Ju Tong did not understand the text of *Ying Wei Sheng Hui*, or his concept of Sanjiao is not the Sanjiao of *Ying Wei Sheng Hui*. I will examine other references to Sanjiao.
(1) *Ling Shu: Ben Shu* states: Sanjiao is the Fu of the large channels, the pathway of water emerges from it, it connects to the Bladder, it is the solitary Fu. It is combined with the six Fu organs.
(2) *Nan Jing: Chapter 38* states: There are six Fu organs because of Sanjiao. It is a branch of Yuan Qi, governing all Qi, having a name but no form. Its meridian belongs to Hand-Shaoyang, it is an external Fu.
(3) *Ling Shu: Jing Mai* states: The meridian of Hand-Shaoyang Sanjiao starts at the tip of the fourth finger, emerges between the two fingers, follows the back of the wrist, emerges between the two bones of the forearm, ascends through the elbow, follows the outside of the upper arm to the shoulder, crosses behind Foot-Shaoyang, enters the supraclavicular fossa, spreads in the Danzhong, disperses and connects to the Pericardium, passes through the diaphragm, and belongs to Sanjiao. Its branch rises from Danzhong to the supraclavicular fossa, ascends the neck behind the ear, emerges above the ear angle, curves down to the cheekbone. Another branch enters the ear from behind the ear, exits in front of the ear, passes before the Ear Master point, crosses the cheek to the outer canthus. Pathogenic changes cause deafness, muffled hearing, swollen throat, and sore throat; diseases governed by Qi include sweating, pain in the outer canthus, cheek pain, pain behind the ear, shoulder, upper arm, elbow, and forearm, and dysfunction of the fourth finger.
Discussions of Sanjiao in *Ling Shu* and *Su Wen* generally do not exceed these three sections. Other chapters like *Su Wen: Liu Jie Zang Xiang Lun* and *Ling Lan Mi Dian* occasionally mention it but are not this detailed. The third section, *Ling Shu: Jing Mai*, is the hardest to understand, yet TCM takes it as fundamental. Without understanding meridians, one cannot discuss medicine. However, among today's medical practitioners, few can recite it, let alone understand its principles deeply. To resolve doubts, I will explain the principles so readers can study independently. Detailed descriptions are beyond my scope. Any statement that a meridian runs from point A to point B passing through C is derived from disease and physiological function. For example, in *Ling Shu: Jing Mai*'s description of Sanjiao, the first half is generated from the symptoms in the second half. First, there are diseases like deafness, swollen throat, and sore throat. Observing Yin and Yang, distinguishing depth, it is diagnosed as Hand-Shaoyang disease. Seeing accompanying symptoms like pain in the outer canthus, cheek, behind the ear, shoulder, arm, and dysfunction of the fourth finger, these painful areas are defined as the Hand-Shaoyang meridian. There are complex interactions, such as "crossing behind Foot-Shaoyang, spreading in Danzhong, connecting to Pericardium," indicating an interactive relationship between Hand-Shaoyang, Foot-Shaoyang, and Hand-Jueyin. Jing Qi, like blood, flows in a circle without beginning or end. However, if the body has disease, there must be a starting point and a painful region. Dividing by region gives twelve types; dividing by starting point gives Hand-Six and Foot-Six meridians. For instance, malaria chills may start from the back or the hand, which is clear evidence. Ancients valued acupuncture highly, and Bian stones preceded acupuncture. Logically, this history must be profound. Unfortunately, I have not read enough to verify. Speculating on the origin, it must have started like modern scraping therapy (Gua Sha), evolved into Bian stones, and then into acupuncture. The Well, Spring, Stream, River, and Sea points of the twelve meridians were mostly named based on acupuncture efficacy, so the original reasons are lost. Later, the development from acupuncture to herbal decoctions was stable and effective, representing the final progress.
Today, we face two issues. First, ancient herbal decoctions were applied according to meridians. Disease of a certain meridian requires specific herbs; following this yields results, deviating fails. Thus, when Gegen is indicated, Mahuang must not be used; when Dahuang is indicated, Badou must not be used. Unlike Western medicine which simply categorizes by sweating or purging without further selection, TCM research must emphasize the Twelve Meridians. Second, healthy Jing Qi is invisible; it manifests only when rebellious. Rebellion of Jing Qi is caused by one-third climate (Six Excesses), one-third lifestyle/diet, and one-third emotions. Patients affected by cold/heat, hunger/fullness, or emotional frustration will live out their natural years if they do not rebel against Jing Qi; if they do, they will die prematurely. Those who understand the Dao and practice health preservation can align with life. Superior physicians treat disease before it arises, knowing the rebellion of Jing Qi and correcting it before illness occurs. This is the general principle of the Twelve Meridians. Jing Qi is invisible, manifesting as pathology when rebellious. Treating according to meridians is skilled, but not the highest level. Knowing how to make Jing Qi rebel or flow smoothly, adhering to smoothness and avoiding rebellion, is the true highest level. *Su Wen: Shanggu Tianzhen Lun* describes this highest level. Western inventions like cells and endocrine systems are actually less refined than Jing Qi. Unfortunately, ancient texts are concise, and *Ling Shu* contains both truth and falsehood. If organized and expanded, Sino-Western cooperation could advance Western medicine further. Those wishing to innovate in medicine must understand Jing Qi. Opponents of TCM claim it cannot leave China, which is indeed not a definitive conclusion. TCM practitioners, fearing for their livelihoods and banning of TCM, try to form factions to resist trends, claiming to "preserve national essence." Their pseudo-medicine is not national essence, nor does it deserve preservation. True national essence would not perish, requiring no preservation. Claiming TCM will perish is like the man worrying about the sky falling. Setting this aside, let us return to Sanjiao. There are three types of Sanjiao: First, Sanjiao as the Official of Irrigation, specifically referring to urine secretion (Lower Jiao Qi transformation). Second, Sanjiao as the pathway of food/fluids and beginning/end of Qi, specifically referring to digestion and Wei Qi (Name and Form). Third, Sanjiao as the Hand-Shaoyang meridian, one of the Twelve Meridians (Name without Form). Hua Bolin and Xu Lingtai stated: "Official of Irrigation" refers to Lower Jiao Qi transformation; "Hand-Shaoyang" refers to Name without Form; "Digestion and Wei Qi" refers to Name with Form. By this logic, ancient naming was imprecise. Regardless, none match *Wenbing Tiaobian*. The Sanjiao in *Wenbing Tiaobian* is a fourth type.