伤寒传变，邪热渐入，而六经以次受之，六经传尽，无出而再传之理也。欲知其传之始
先别人身六经。足太阳为三阳，最在外；阳明为二阳，在太阳内；少阳为一阳，在阳明内；
此三阳为表也，皆由内以数至外。故一二三之次第如此，伤寒由表入里，邪气渐以深，传六
七日厥阴也，此论其常耳。变则不可拘于次第，拘于日数。其传至厥阴，为传经尽，再不复
传。成氏曰∶六曰厥阴传经尽，七日当愈，七日不愈者，谓之再传，言再自太阳传至厥阴，
谓传经尽，十三日当愈，十三日不愈者，谓之过经。谓再过太阳经，以次而传也谬矣！马仲
化曰∶自太阳以至厥阴，犹人由户登堂入室，厥阴复出而传于太阳，奈有少阴太阴少阳阳明
以隔之，岂有遽出传于太阳之理？此斥再传之非，诚千古断案，惜乎释七日病衰，犹有未明
，使后人于传经不无障蔽耳。然则邪气之入，果无由里而出于表者乎？其在太阳篇曰∶欲自
解者，必当先烦，乃有汗而解。何以知之？脉浮故汗出欲解也，此以脉浮知邪气还表，知
是向安之地，不待更用汤药。邪自外散者，散则复何传焉？须知里邪不出则已，出则欲愈，
非欲传也。或曰∶太阳篇云∶太阳病头痛，七日以上自愈者，以行其经尽故也。若欲作再经
者，针足阳明，使经不传则愈，此非一日至六日传三阳三阳经，至七日当愈。不愈者，则太
阳之邪再传阳明者欤。曰∶伤寒始于太阳受病，以次而终，于厥阴为传经尽。诸经受病，凡
七日自愈者，
为行其经尽。太阳病至七日头痛自愈者，
以行太阳经尽也。邪气行来始终，则在太阳一经而
尽，其七日当愈之数也。太阳篇曰∶
发阳者七日愈，以阳数七故也。若七日以上不自愈，欲过太阳一经，当针足阳明经，迎而夺
之，使不传阳明则。愈玩其行经之句，不曰传经尽，则仲景之意昭然矣。成氏误以行其经尽
。为传（遍）六经，则厥阴之邪，再传太阳，太阳再传阳明，则宜厥阴未传太阳之前，预针太
阳矣，何必欲传阳明而后针阳明哉？或曰∶霍乱篇有曰十三日愈，所以然者，经尽故也。此
非伤寒传变三阳三阴。后六日再传经尽，十三日当愈者欤。太阳篇有曰∶伤寒十三日不解。
过经谵语者，以有热故也，当以汤下之。此非十二日再传经尽，十三日不愈者，谓之过经者
欤，如太阳行其经尽之谓也。由太阳受病于一日至七日，为行太阳经尽之理推之，则诸经皆
屈指而期矣。阳明受病于二日至八日自愈者，谓行阳明经尽。少阳受病于三日至九日自愈
者，为行少阳经尽，却四五日至三阴上，次第至十二日自愈者，为行厥阴经尽。十三日当大
气皆去，精神爽慧之期也，故曰若过十三日不间，尺寸陷者为大危。其曰十三日不解，过经
谵语者，正以当解之期，不解乃过于经，而入于里。此为内实，而热结于里也，当以汤下之
。此泛言过经，不专指何经者也，何尝有再传经尽谓之过经之旨哉？详考过经之意，或有言
过太阳经成里证者，或有专言过太阳经者，或有泛言过太阳经者，可引而证之。阳明篇曰∶
汗出谵语者，以有燥屎在胃中，此为风也，过经乃可下之。盖谓燥屎在胃中而谵语者，其风
邪在表而汗出，其燥屎在胃中而当下，须过太阳经，无表证而结于里，乃可下之，此言过太
阳经而成里病者也，果如成氏十三日再传经尽，谓之过经，则燥屎在胃，乃待十三日乃可下
之乎。于此则注曰∶须过太阳经无表证，乃可下之，则无再传经尽。谓之过经者，相矛盾也
。太阳篇曰∶太阳过十余日，及二三下之，后四五日，柴胡证仍在者，先与小柴胡汤。盖谓
太阳经无太阳表证也，然里证未具者，未如下。及二三下之，后四五日当有少阳柴胡证者，
须与小柴胡汤。此则专言过太阳经者也。霍乱篇曰∶下痢后，当便鞭能食者愈。今反不能食
，服则复过一经，过一经能食，过一日当愈，不愈则不属阳明也。此承上文言下痢霍乱后亡
津液而便硬。硬而能食者愈。属阳明胃气和也。今反不能食。传入后一经中，颇能食，是复
过一经能食矣，此暴热使之能食。非阳明胃气和也。此泛言过经者也。何尝有再传经尽谓之
过经之旨哉？况邪传六经，岂有三度之理。朱氏释仲景书。阐明奥旨。惠及后世多矣。犹于
传经少达，乃至穿凿之甚。蕴要祖成氏之注。其过经不解例注曰∶经言伤寒十三日不解谓之
过经，仲景焉有此话？是以成注为经矣。其六经传变论又曰∶过经不解，乃为坏病。夫仲景
所谓坏病者，言为逆犯所坏也。蕴要之说，讹上之讹也。陶尚文曰∶伤寒汗不愈而过经，其
证尚在而不除者，亦温病也。更不可晓。
伤寒的传变，是邪热逐渐深入，六经依次受邪。当六经的传变过程全部完成，就没有再从太阳经开始再次传遍六经的道理了。想要了解传变的起始，必须先辨别人身六经的层次。足太阳经属于三阳之首，位置最表浅；阳明经属于二阳，位于太阳经之内；少阳经属于一阳，位于阳明经之内。这三阳经都属于表证，其排列顺序是由内向外数（即从深层向浅层数，但在解剖位置上太阳在最外）。所以一二三的次第是这样的：伤寒由表入里，邪气逐渐加深，经过六七天传到厥阴经，这是论述一般规律。如果病情变化，就不能拘泥于这种次第和日数。邪气传到厥阴，意味着传经已经完毕，不会再继续传变了。
成无己说：“第六天传到厥阴，传经已尽，第七天应当痊愈。如果第七天还不愈，叫做‘再传’，意思是再次从太阳经传到厥阴经，称为传经已尽，第十三日应当痊愈；如果十三日还不愈，叫做‘过经’，意思是再次经过太阳经，依次传下去。”这种说法是错误的。
马仲化说：“从太阳经到厥阴经，就像人从门口进入厅堂，再进入内室一样。如果厥阴经的病邪又要传出并传给太阳经，中间却有少阴、太阴、少阳、阳明等经络阻隔，怎么会有突然跳出传到太阳经的道理呢？”这是驳斥“再传”说法的错误之处，确实是千古定论。可惜他对“七日病势衰退”的解释还不够明白，导致后人在理解传经时仍有障碍。
那么，邪气侵入体内，真的没有从里出表的情况吗？在《伤寒论·太阳篇》中说：“想要自行解除病邪的，必定先出现心烦的症状，然后才有汗出而解。怎么知道呢？因为脉象浮，所以知道要汗出而病解。”这是通过脉浮判断邪气回归体表，知道这是趋向康复的地方，不需要再用汤药。邪气从外部散发的，散发之后还谈什么传变呢？必须知道，体内的邪气如果不出来就算了，一旦出来就是想要痊愈，而不是想要传变。
有人问：“《太阳篇》说：‘太阳病头痛，七天以上自愈的，是因为行完了本经的病程。’如果想要进行下一经的传变（作再经），针刺足阳明经，使经络不传变就能痊愈。这难道不是指第一天到第六天传遍三阳经，到第七天应当痊愈。如果不愈，则是太阳的邪气再次传给阳明经吗？”
回答说：“伤寒始于太阳经受病，依次传变，到厥阴经为传经完毕。各经受病，凡是七天自愈的，都是行完了本经的病程。太阳病到第七天头痛自愈，是因为行完了太阳经的病程。邪气从头到尾运行，只在太阳一经而尽，这就是七天应当痊愈的道理。《太阳篇》说：‘发于阳者七日愈，因为阳数的基数是七。’如果七天以上不自愈，想要超过太阳这一经，应当针刺足阳明经，迎头截夺邪气，使邪气不传入阳明经就能痊愈。仔细玩味‘行经’这句话，不说‘传经尽’（传遍六经），那么张仲景的本意就显而易见了。成无己错误地把‘行其经尽’解释为‘传遍六经’，认为厥阴的邪气再传太阳，太阳再传阳明，那么在厥阴还没传太阳之前，就应该预先针刺太阳经了，何必等到想要传阳明时才针刺阳明经呢？
又有人问：“《霍乱篇》中有说‘十三日愈’，之所以这样，是因为经气已尽的缘故。这难道不是指伤寒传变三阳三阴后，再过六天再次传经已尽，十三日应当痊愈吗？《太阳篇》中有说：‘伤寒十三日不解，过经谵语的，因为有热，应当用汤药攻下。’这难道不是指十二日再次传经已尽，十三日不愈，叫做‘过经’吗？就像太阳行完其经的意思一样。从太阳受病，第一天到第七天，是行完太阳经的道理来推断，那么其他各经也可以屈指计算日期了。阳明经受病，第二天到第八天自愈，是行完阳明经。少阳经受病，第三天到第九天自愈，是行完少阳经。接着第四五天传到三阴经，依次到第十二天自愈，是行完厥阴经。第十三日应该是大气（邪气）全部去除，精神清爽的时候，所以说如果过了十三日病情没好转，寸尺脉沉陷的是大危之症。所谓‘十三日不解，过经谵语’，正是因为在应当痊愈的时期没有痊愈，于是超过了本经的范围，而入于里。这是内实，热结在里，应当用汤药攻下。这是泛泛地说‘过经’，并不专门指哪一经，哪里有什么‘再次传遍六经叫做过经’的宗旨呢？
详细考察‘过经’的意思，有的说过太阳经而成里证的，有的专说过太阳经，有的泛说过太阳经，可以引用这些来证明。《阳明篇》说：‘汗出谵语的，是因为胃中有燥屎，这是风邪所致，过经才可以攻下。’意思是说，胃中有燥屎而谵语，风邪在表而汗出，燥屎在胃中应当攻下，但必须经过太阳经，没有表证且结聚在里，才可以攻下。这是说过太阳经而成为里病。如果真的像成无己说的十三日再次传经已尽叫做过经，那么胃中有燥屎，难道要等到十三日才可以攻下吗？在这里注释说：‘须过太阳经无表证，乃可下之’，这就与‘再次传经已尽叫做过经’的说法相矛盾了。
《太阳篇》说：‘太阳病过十余日，经过两三次攻下之后，过了四五天，柴胡证仍在的，先给小柴胡汤。’意思是太阳经已经没有太阳表证了，但是里证还不具备，不能直接攻下。经过两三次攻下后，过了四五天，应当出现少阳柴胡证，需要给予小柴胡汤。这是专说过太阳经的情况。
《霍乱篇》说：‘下痢后，大便变硬且能吃东西的会好。现在反而不能吃，吃了就会再经过一经，经过一经如果能吃东西，过一天应当痊愈，如果不愈则不属于阳明。’这是承接上文说下痢霍乱后亡失津液而导致大便硬。大便硬且能吃东西的好，是属阳明胃气和顺的表现。现在反而不能吃，病邪传入后一经中，稍微能吃一点，这是再次经过一经能吃东西，这是暴热导致的假性食欲，并不是阳明胃气和顺。这是泛泛地说‘过经’。哪里有什么‘再次传遍六经叫做过经’的宗旨呢？况且邪气传变六经，哪里有传变三次的道理？朱氏解释张仲景的书，阐明了深奥的主旨，惠及后世很多。但在传经方面稍显不足，以至于穿凿附会得很厉害。《医宗金鉴·蕴要》沿袭了成无己的注解，在‘过经不解’的例子中注释说：‘经文说伤寒十三日不解叫做过经，张仲景哪有这样的话？’因此把成无己的注当作经典。他在《六经传变论》中又说：‘过经不解，就是坏病。’张仲景所说的坏病，是指被误治所破坏的病。《蕴要》的说法，是错误之上的错误。陶尚文说：‘伤寒发汗后不愈而过经，症状还在而没有消除的，也是温病。’更是不明白的话。
The transmission of Shanghan (Cold Damage) involves pathogenic heat gradually penetrating deeper, with the Six Channels (Six Meridians) affected in sequence. Once the transmission through all Six Channels is completed, there is no mechanism for it to restart from Taiyang and transmit through again. To understand the beginning of this transmission, one must first distinguish the hierarchy of the Six Channels in the human body. Foot-Taiyang belongs to the "Three Yang" and is located most externally; Yangming belongs to the "Two Yang" and is internal to Taiyang; Shaoyang belongs to the "One Yang" and is internal to Yangming. These three Yang channels belong to the Exterior level, and their numerical order (3-2-1) reflects a counting from interior to exterior layers, though anatomically Taiyang is outermost. Thus, the sequence is as follows: Shanghan moves from the exterior to the interior, with pathogenic qi deepening gradually. By the sixth or seventh day, it reaches Jueyin. This describes the normal pattern. However, if variations occur, one cannot rigidly adhere to this sequence or specific day counts. When the pathogen reaches Jueyin, the transmission process is complete, and it will not continue further.
Cheng Wuji stated: "On the sixth day, transmission reaches Jueyin, completing the cycle. On the seventh day, recovery should occur. If not recovered by the seventh day, it is called 'secondary transmission' (Zai Chuan), meaning it transmits again from Taiyang to Jueyin. This completion is termed 'transmission exhausted.' Recovery should occur on the thirteenth day. If not recovered by the thirteenth day, it is called 'passing the channel' (Guo Jing), implying passing through the Taiyang channel again and transmitting sequentially." This view is erroneous.
Ma Zhonghua argued: "Moving from Taiyang to Jueyin is like entering a house from the gate, then to the hall, and finally to the inner room. For Jueyin to transmit back to Taiyang, it would have to bypass Shaoyin, Taiyin, Shaoyang, and Yangming. How could it suddenly jump out to transmit to Taiyang?" This refutation of 'secondary transmission' is indeed a definitive judgment for the ages. Unfortunately, his explanation of 'pathogenic decline on the seventh day' remains unclear, causing confusion among later practitioners regarding channel transmission.
So, is it true that pathogenic qi never exits from the interior to the exterior? In the Taiyang Chapter, it is stated: "For self-resolution, vexation (Fan) must precede sweating, which leads to resolution. How do we know this? Because the pulse is floating, indicating that sweating and resolution are imminent." This uses the floating pulse to identify that pathogenic qi has returned to the exterior, signaling a trend toward health, requiring no further herbal decoctions. Pathogens dispersing from the exterior have nowhere else to transmit once dispersed. One must understand that interior pathogens, if they do not exit, remain static; if they exit, they seek resolution, not transmission.
Some ask: "The Taiyang Chapter states: 'Taiyang disease with headache resolves spontaneously after seven days because the channel's course is completed.' If it is about to enter the next stage ('Zuo Zai Jing'), needling the Foot-Yangming channel prevents transmission and ensures cure. Does this not imply that from day 1 to 6, the Three Yang channels are transmitted through, and by day 7, recovery is expected? If not cured, does the Taiyang pathogen transmit again to Yangming?"
The response is: "Shanghan begins in Taiyang and proceeds sequentially until Jueyin, marking the completion of transmission. Any channel disease resolving within seven days indicates the completion of that specific channel's cycle. Headache in Taiyang resolving on day 7 signifies the completion of the Taiyang channel's course. The pathogen's journey starts and ends within Taiyang alone, accounting for the seven-day recovery period. The Taiyang Chapter states: 'Diseases originating in Yang resolve in seven days because seven is the number of Yang.' If symptoms persist beyond seven days, intending to exceed the Taiyang channel, one should needle the Foot-Yangming channel to intercept and prevent transmission to Yangming. Examining the phrase 'moving through the channel,' without using 'transmission exhausted' (referring to all six channels), Zhang Zhongjing’s intent becomes clear. Cheng Wuji mistakenly interpreted 'completing its own channel' as 'transmitting through all six channels,' suggesting Jueyin transmits to Taiyang, then Taiyang to Yangming. If this were true, one should needle Taiyang before Jueyin transmits to it, rather than waiting until transmission to Yangming is anticipated to needle Yangming.
Another query: "The Huoluan Chapter mentions recovery on the thirteenth day due to 'channel exhaustion.' Does this refer to the transmission of Three Yin and Three Yang, followed by another six days of transmission, totaling thirteen days? The Taiyang Chapter also says: 'Shanghan unresolved for thirteen days, with delirium after passing the channel, is due to heat and requires purgative decoctions.' Does this mean twelve days of secondary transmission exhausted, and non-recovery on day thirteen is 'passing the channel'? Similar to the concept of Taiyang completing its course? Inferring from Taiyang (day 1 to 7 completes Taiyang), other channels follow suit. Yangming disease (day 2 to 8) resolves as Yangming's course is completed. Shaoyang disease (day 3 to 9) resolves as Shaoyang's course is completed. Then, moving to the Three Yin channels around days 4-5, reaching day 12 resolves as Jueyin's course is completed. Day 13 is when vital qi fully recovers and spirit clarifies; thus, if unresolved past day 13 with sunken pulses at Cun and Chi, it is critical. 'Unresolved after thirteen days, delirium after passing the channel' means failing to resolve at the expected time causes the pathogen to exceed the channel and enter the interior, creating interior excess with heat binding internally, requiring purgatives. This is a general term for 'exceeding the channel,' not specific to any single channel. There is no principle stating 'secondary transmission exhausted is called passing the channel.'
Examining 'Guo Jing' (Passing/Exceeding the Channel): Some refer to exceeding Taiyang to form interior syndromes; some specify Taiyang; others use it generally. The Yangming Chapter states: 'Sweating and delirium indicate dry feces in the stomach due to wind. Purging is only appropriate after passing the channel.' This means if dry feces cause delirium and wind-pathogen causes sweating, purging is permissible only after the Taiyang channel phase has passed, exterior signs are absent, and the pathogen is bound in the interior. This refers to becoming an interior syndrome after exceeding Taiyang. If Cheng’s view (13 days = secondary transmission exhausted = Guo Jing) were correct, one would wait until day 13 to purge dry feces. However, the note says 'must pass Taiyang, no exterior signs, then purge,' contradicting the 'secondary transmission' theory.
The Taiyang Chapter states: 'After more than ten days of Taiyang disease, following two or three purgations, if four to five days later Shaoyang symptoms persist, administer Xiao Chaihu Tang first.' This implies Taiyang exterior signs are gone, but interior signs are insufficient for direct purgation. After purgations, Shaoyang symptoms emerge, requiring Xiao Chaihu Tang. This specifically discusses exceeding Taiyang.
The Huoluan Chapter states: 'After dysentery, hard stool with appetite indicates recovery. Inability to eat suggests transmission to the next channel. Appetite returning after passing a channel indicates recovery in one day; otherwise, it is not Yangming.' This follows the previous text on fluid loss causing hard stool. Hard stool with appetite indicates harmonious Yangming Stomach Qi. Inability to eat suggests transmission to the subsequent channel. Slight appetite here is due to sudden heat, not Yangming harmony. This is a general use of 'passing the channel.' Where is the idea of 'secondary transmission exhausted equals passing the channel'? Moreover, pathogen transmission through Six Channels logically allows only one cycle, not three. Zhu’s commentary elucidates profound principles but falls short on transmission, leading to forced interpretations. *Yiyong Zuyao* inherits Cheng’s errors, annotating 'unresolved after passing the channel' by claiming Zhang Zhongjing never said 'thirteen days unresolved is passing the channel,' thereby elevating Cheng’s notes to classic status. His 'Six Channel Transmission Theory' claims 'unresolved after passing the channel is a damaged disease (Huai Bing).' Zhang Zhongjing defined 'Huai Bing' as damage caused by improper treatment. *Yiyong Zuyao*’s view is error upon error. Tao Shangwen claimed: 'Shanghan unresolvable after sweating and passing the channel, with persistent symptoms, is also Warm Disease.' This is equally incomprehensible.