太阳篇曰∶无热恶寒者，发于阴也。此言寒邪直中阴经之寒证也。始终则在一经非若热
证之
传经者也。人伤于寒者，自表而始，则皮肤受伤，阳气不能伸越，乃郁而成热，是为发于阳
之热证，表邪不解，则以次而传经。若夫非表始而直入于阴经，不由阳郁热而来，初起便手
足厥冷，或恶寒伴倦，成无热恶寒之证。始于阴经，是为发于阴之寒证，三阴所见，虽有吐
痢，语证稍异，如自利不渴属太阴，自痢而渴属少阴之类，皆起于无热恶寒，乃其常耳。惟
少阴有始得之反发热脉沉者，以罕有是证，故语其变而曰反也。然则发于阴经之寒证，岂可
与发于阳经之热证并论哉？热证属阳，寒证属阴，阴阳动静，造化自然。阴寒直入，只在一
经无传之理。何成氏昧于此，谓其从太阳始，亦以次而传变六经，且以再传三传推之，有是
理乎？《少阴篇》曰∶少阴病，脉微细，但欲寐者，阴主静也。乃注曰∶邪气传里深也。若
此之类，无始得便厥之文。盖误认为热证，无惑乎传里之说也。《厥阴篇》曰∶伤寒厥四日
，热反三日，复厥五日，其病为进，寒多热少，阳气退，故为凶也。夫先厥四日者，寒邪直
入厥阴阴胜也。热后三日，阳气欲复耳，非变为传经之热证也。复厥五日者，阴气胜阳，阳
不能复，故曰病进。乃注曰∶先厥四日，却热三日，七日传经尽当愈。若不愈而复厥者，再
作传经，盖再从太阳传里之谓也。阳经受病，必郁而成热，有先厥者乎？《灵枢》曰∶邪之
中人，或中于阴，或中于阳，何尝必自太阳始耶？盖因其或寒或热，不知始终。只是厥阴证
，亦无惑乎传经之失也。至若辨脉篇曰∶其脉沉而迟，不能食，身体重，大便反硬，名曰阴
结也，期十四日当剧。注曰∶沉迟阴结也，不能食，身体重，阴证也。阴病见阴脉则当下，
今大便硬者，为阴气结，阳不得而杂之，是名阴结。成氏知其寒证为纯阴矣，而复以传经至
再三释之。夫既为阴气结固，则结固于里者，能出而传之表乎？不可下编曰∶无阳阴强，大
便硬者，必清谷腹满，此即阴结之寒证也。成氏亦注曰∶阴强者寒多，阴结即里寒之证，其
有传经者哉。总由不知伤寒有直入三阴之寒证，又不知寒邪与热病大不相同，其意混谓中寒
则必传经。故虽知寒气胜而先厥者，概以自表而传论之。三阴注释，误者纷纷，立言垂训
之士，胡为若此，学人明于取舍，始得尚友之道矣。
《伤寒论·太阳篇》说：“没有发热而只有恶寒的，是发于阴经。”这是指寒邪直接侵入阴经所致的寒证。这种病始终停留在本经，不像热证那样会传变至其他经络。人受寒邪侵袭，通常是从体表开始，导致皮肤受损，阳气不能正常舒展升发，于是郁结而化热，这称为“发于阳”的热证；如果表邪不解，就会依次传变到其他经络。如果是从体表开始而非直接侵入阴经，也不是由阳气郁结化热而来，初起就出现手足厥冷，或者伴有畏寒和疲倦，形成无热恶寒的症状。因为起始于阴经，所以称为“发于阴”的寒证。三阴病（太阴、少阴、厥阴）虽然都有呕吐下痢等症状，言语表现略有不同，例如自利不渴属于太阴病，自利且口渴属于少阴病等，但都起源于无热恶寒，这是其常态。只有少阴病中有初起反而发热、脉象沉伏的情况，因为这种证候很少见，所以在论述其变化时称之为“反”。既然这样，那么发于阴经的寒证，怎么能与发于阳经的热证相提并论呢？热证属阳，寒证属阴，阴阳的动静关系，是自然造化的规律。阴寒之邪直中体内，只局限于一经，没有传变的道理。为什么成无己氏不明白这一点，却说它从太阳经开始，也依次传变六经，并且用再传、三传来推演，哪有这样的道理呢？
《伤寒论·少阴篇》说：“少阴病，脉象微细，只想睡觉的，是因为阴主静。”对此的注解却说：“这是邪气传入里部很深了。”像这类情况，原文并没有初起就四肢厥冷的记载。大概是误认为是热证，所以对于“传里”的说法也就不足为奇了。
《伤寒论·厥阴篇》说：“伤寒四肢厥冷四天，发热反而三天，又再次厥冷五天，病情加重，因为寒多热少，阳气衰退，所以预后不良。”先厥冷四天，是寒邪直接侵入厥阴，阴气偏胜。发热三天，是阳气试图恢复罢了，并不是变成了传经的热证。再次厥冷五天，是阴气胜过阳气，阳气无法恢复，所以说病情加重。然而注解却说：“先厥冷四天，后来发热三天，到第七天传经结束应当痊愈。如果不痊愈又再次厥冷，就是再次发生传经，大概是指再从太阳经传变到里部。”阳经受病，必然郁结而化热，哪里有先出现厥冷的呢？《灵枢》说：“邪气中人，有的侵犯阴经，有的侵犯阳经”，何尝一定从太阳经开始呢？大概是因为对寒热性质不清楚，不知道疾病的始终。即使是厥阴证，对于传经的错误理解也就不足为怪了。
至于《辨脉篇》说：“脉象沉而迟，不能进食，身体沉重，大便反而干硬，名叫阴结，预计十四天病情会加剧。”注解说：“沉迟脉是阴结，不能进食、身体沉重是阴证。阴病见到阴脉则应当用下法，现在大便干硬，是因为阴气凝结，阳气不能混杂其中，这叫做阴结。”成无己知道这种寒证是纯阴之证，却又用传经多次来解释。既然已经是阴气凝结坚固，那么在里的凝结坚固之物，能出来传变到表吗？不可能。《不可下编》说：“没有阳证而阴气强盛，大便干硬的，必定排出未消化的食物且腹部胀满，这就是阴结的寒证。”成无己也注解道：“阴气强盛则寒邪多，阴结就是里寒证，哪里会有传经的呢？”总归是因为不知道伤寒有直接侵入三阴的寒证，又不知道寒邪与热病大不相同，他的意思混淆地认为中寒就必须传经。所以即使知道寒气胜而先出现厥冷，也一概按照从体表传变来论述。三阴病的注释，错误的纷纷出现，作为立言垂训的人，为什么要这样做呢？学习者明白取舍之道，才能找到与古人交友的途径。
The *Taiyang Chapter* states: "Those without fever but with aversion to cold originate from the Yin." This refers to Cold syndromes where Cold pathogenic factors directly invade the Yin meridians. Such conditions remain confined to a single meridian throughout, unlike Heat syndromes which undergo transmission (Chuan Jing) to other meridians. When humans are injured by Cold, it typically begins at the exterior, damaging the skin and muscles. Yang Qi fails to extend and transcend, leading to stagnation and transformation into Heat; this is termed "originating from Yang" (Fa Yu Yang), a Heat syndrome. If the exterior pathogen is not resolved, it transmits sequentially through the meridians. However, if the invasion does not begin at the exterior but directly enters the Yin meridians, and does not arise from Yang stagnation transforming into Heat, the initial presentation involves cold extremities or aversion to cold accompanied by fatigue, forming a syndrome of aversion to cold without fever. Starting in the Yin meridians, this is called "originating from Yin" (Fa Yu Yin), a Cold syndrome. Although the Three Yin syndromes (Taiyin, Shaoyin, Jueyin) present with vomiting and diarrhea, their specific manifestations vary slightly; for instance, spontaneous diarrhea without thirst belongs to Taiyin, while spontaneous diarrhea with thirst belongs to Shaoyin. All these originate from aversion to cold without fever, which is their normal course. Only in Shaoyin disease is there an exception where fever appears initially despite a deep pulse; because this presentation is rare, it is described as "counterfeit" (Fan) when discussing its variations. Given this, how can Cold syndromes originating from the Yin meridians be discussed on par with Heat syndromes originating from the Yang meridians? Heat syndromes belong to Yang, Cold syndromes belong to Yin; the movement and stillness of Yin and Yang follow the natural order of creation. When Yin-Cold invades directly, it remains confined to one meridian with no rationale for transmission. Why did Cheng Wuji fail to understand this, claiming that it starts from the Taiyang meridian and transmits sequentially through the Six Meridians, and deducing further transmissions? Is such reasoning valid?
The *Shaoyin Chapter* states: "In Shaoyin disease, with a faint and thin pulse and only a desire to sleep, this is because Yin governs stillness." The commentary notes: "This indicates the pathogenic factor has transmitted deeply into the interior." In cases like this, there is no text describing initial cold extremities. Presumably, mistaking it for a Heat syndrome makes the theory of "transmission to the interior" unsurprising.
The *Jueyin Chapter* states: "In cold damage, cold extremities last four days, fever lasts three days, then cold extremities return for five days; the disease progresses because Cold is predominant and Heat is scarce, causing Yang Qi to retreat, thus indicating a ominous prognosis." The initial four days of cold extremities indicate Cold pathogenic factors directly invading Jueyin, with Yin excess. The subsequent three days of fever represent an attempt by Yang Qi to recover, not a transformation into a transmitting Heat syndrome. The return of cold extremities for five days signifies Yin overcoming Yang, preventing Yang recovery, hence stating the disease progresses. However, the commentary claims: "After four days of cold extremities and three days of fever, by the seventh day, the transmission cycle should complete and healing should occur. If not healed and cold extremities return, it constitutes another round of transmission, implying transmission again from Taiyang to the interior." When Yang meridians are affected, they must stagnate and transform into Heat; how could cold extremities appear first? The *Ling Shu* states: "Pathogenic factors attacking humans may strike Yin meridians or Yang meridians," questioning why it must necessarily start from Taiyang. Due to confusion between Cold and Heat and ignorance of the disease's beginning and end, even in Jueyin syndromes, errors regarding transmission are understandable.
Regarding the *Bian Mai Pian* (Chapter on Pulse Differentiation): "If the pulse is deep and slow, the patient cannot eat, feels heavy-bodied, and the stool is paradoxically hard, it is named Yin Knot (Yin Jie), expected to worsen on the fourteenth day." The commentary explains: "Deep and slow pulses indicate Yin Knot; inability to eat and heaviness indicate Yin syndromes. When Yin diseases present with Yin pulses, purgatives should be used. Now, hard stool indicates Yin Qi knotting, excluding Yang Qi interference, hence named Yin Knot." Cheng Wuji recognized this Cold syndrome as pure Yin, yet explained it via multiple rounds of transmission. If Yin Qi is firmly knotted internally, can this internal knotting transmit outward to the exterior? It is impossible. The *Bu Ke Xia Bian* states: "Without Yang, with strong Yin and hard stool, there must be undigested food in stools and abdominal fullness; this is the Cold syndrome of Yin Knot." Cheng Wuji also commented: "Strong Yin implies much Cold; Yin Knot is a Interior-Cold syndrome, where would transmission come from?" Ultimately, this stems from not knowing that cold damage includes Cold syndromes directly entering the Three Yin meridians, and failing to recognize that Cold pathogens differ significantly from Heat diseases. His intent conflates mid-Cold with inevitable transmission. Thus, even recognizing that excessive Cold causes initial cold extremities, he generally attributes it to transmission from the exterior. The commentaries on the Three Yin meridians are rife with errors. Why do those establishing doctrines act thus? Learners must discern what to accept and reject to achieve the way of befriending the ancients.