成无己注伤寒论。有云。四逆者。四肢不温也。厥者。手足冷也。伤寒邪在三阳。则手足必
热。传到太阴。手足自温。至少阴。则邪热渐深。故四肢逆而不温。及至厥阴。则手足厥冷
。是又甚于逆。经曰。少阴病。四逆。其人或咳。或悸。或小便不利。或腹中痛。或泄痢下
重者。四逆散主之。方用柴胡枳实芍药甘草。四者皆寒冷之物。而专主四逆之疾。是知四逆
非虚寒之证也。四逆与厥相近而非。经曰诸四逆厥者。不可下。是四逆与厥有异也。吁。斯
言也。所谓弥近理而大乱真者欤。窃尝考之。仲景言四逆与厥者非一。或曰四逆。或曰厥。
或曰厥逆。或曰厥冷。或曰厥寒。或曰手足逆冷。
或曰手足厥逆。或曰手足厥冷。或曰手足厥逆冷。细详其义。俱是言寒冷耳。故厥逆二字。
每每互言。未尝分逆为不温。厥为冷也。然四肢与手足却
有所分。其以四字加于逆字之上者。是通指手足臂胫以上言也。其以手足二字加于厥逆厥冷
等之上。及无手足二字者。是独指手足言也。既曰不温。即为冷矣。尚何异乎。仲景所谓诸
四逆厥者。不可下。盖以四逆。为四肢通冷。厥为手足独冷。而臂与胫以上不冷耳。不谓逆
厥。有不温与冷之别也。故又曰。厥者手足逆冷是也。以逆冷二字释厥字。足见逆即厥。厥
即逆也。故字书曰。厥者逆也。虽然。逆厥虽俱为寒冷。而却有阴阳之殊焉。热极而成逆
厥者。阳极似阴也。寒极而成逆厥者。独阴无阳也。阳极似阴。固用寒药。独阴无阳。固用
热药。仲景以四逆散寒药治四逆一条。此阳极似阴之四逆也。其无四逆汤热药治四逆之条者
。安知其非本有而失之乎。且四逆汤之名。由四肢之冷而立也。今以四逆汤治手足厥冷。岂
非逆厥之不异乎。既以四逆为四肢不温。厥为手足独冷。何故不名治厥之药为四厥汤乎。成
氏于四逆散治四逆条下。谓。四逆为热邪所为。及于明理论。谓。四逆非虚寒之证矣。至于
少阴病死证二条下。却谓。四逆为寒甚。君此者得不自悖其说乎。是知四逆亦犹厥之有寒有
热。固不可谓四逆。专为热邪所作也。但四肢通冷。比之手足独冷。则有间尔。故仲景曰。
少阴病。吐利。躁烦。四逆者。死。又曰。少阴病。四逆。恶寒而身蜷。脉不至。不烦而躁
者。死。又曰。少阴病。吐利。手足厥冷。烦躁欲死者。吴茱萸汤主之。此三条者。二为死
。一为可治。虽通由诸证兼见而然。然死者以四逆言。可治者以厥冷言。则亦可见。四逆
与
手足厥冷之有轻重浅深矣。夫四肢通冷。其病为重。手足独冷。其病为轻。虽妇人小子亦能
知之。成氏乃谓厥甚于逆。何邪。若能知四逆厥之所以异者。在于独指手足言。与兼指臂胫
以上言。则不劳创为不温与冷之曲说。而自然贯通矣。
成无己在注释《伤寒论》时说：“四逆，是指四肢不温暖；厥，是指手足寒冷。”他认为伤寒邪气在三阳经时，手足必然发热；传到太阴经时，手足自然温暖；到了少阴经，邪热逐渐深入，所以四肢逆冷而不温暖；等到厥阴经，则手足完全冰冷。这比“逆”更严重了。经文说：“少阴病，出现四逆，病人有的咳嗽，有的心悸，有的小便不利，有的腹中疼痛，有的腹泻且肛门有下坠感，用四逆散主治。”方剂由柴胡、枳实、芍药、甘草组成。这四味药都是寒凉性质的药物，却专门主治四逆这种病症。由此可知，四逆并不是虚寒证候。“四逆”与“厥”名称相近但实质不同。经文说：“凡是出现四逆或厥的，不可使用泻下法。”这说明四逆与厥是有区别的。唉！这种说法，正是所谓“看似有理实则大乱真理”的典型例子。
我曾仔细考证过，张仲景提到四逆和厥的情况不止一次。有时说“四逆”，有时说“厥”，有时说“厥逆”，有时说“厥冷”，有时说“厥寒”，有时说“手足逆冷”，有时说“手足厥逆”，有时说“手足厥冷”，有时说“手足厥逆冷”。仔细推敲其含义，都是在描述寒冷而已。因此，“厥逆”二字常常互换使用，从未将“逆”解释为不温、“厥”解释为冷。然而，“四肢”与“手足”的概念确实有所区分。凡是在“逆”字前加上“四”字的（如四逆），是泛指包括手、足、臂、胫在内的整个肢体以上部位；凡是在“厥逆”、“厥冷”等词前加上“手足”二字的，以及没有加“手足”二字的，则是专指手和足而言。既然已经说了“不温”，那就是冷了，还有什么区别呢？
张仲景所说的“诸四逆厥者，不可下”，大概是因为“四逆”指的是四肢整体发冷，而“厥”仅指手足单独发冷，手臂和小腿以上部位并不冷。他并不是说“逆”和“厥”有不温暖和寒冷的区别。所以他又说：“所谓的厥，就是手足逆冷。”他用“逆冷”二字来解释“厥”字，足以证明“逆”就是“厥”，“厥”就是“逆”。所以字书也说：“厥，就是逆。”虽然如此，逆和厥虽然都表现为寒冷，却有阴阳的区别。热极导致的逆厥，是阳极似阴的表现；寒极导致的逆厥，是独阴无阳的表现。阳极似阴，固然要用寒药；独阴无阳，固然要用热药。张仲景用四逆散（寒药）治疗四逆这一条，这是阳极似阴类型的四逆。而没有用四逆汤（热药）治疗四逆的条文，怎么能知道不是原本有而失传了呢？况且“四逆汤”这个名字，是由四肢寒冷而立名的。现在用四逆汤治疗手足厥冷，难道不是说逆和厥没有区别吗？如果认为四逆是四肢不温，厥是手足独冷，为什么不用治疗厥的药物命名为“四厥汤”呢？
成无己在四逆散治疗四逆的条文下说：“四逆是由热邪引起的。”到了《明理论》中，又说：“四逆不是虚寒证候。”但在少阴病死证的两个条文下，却又说：“四逆是由于寒气极盛。”这样做难道不是自相矛盾吗？由此可知，四逆也像厥一样，有寒证也有热证，固不能说四逆完全是由热邪引起的。只是四肢整体发冷，比起手足单独发冷，病情程度有所不同罢了。所以张仲景说：“少阴病，呕吐腹泻，烦躁不安，出现四逆的，预后不良（死）。”又说：“少阴病，出现四逆，恶寒且身体蜷缩，脉搏摸不到，不烦躁但躁动的，预后不良（死）。”又说：“少阴病，呕吐腹泻，手足厥冷，烦躁得快要死的，用吴茱萸汤主治。”这三条中，两条是死证，一条是可治之证。虽然这都是因为各种症状兼见所致，但死证是用“四逆”来描述的，可治之证是用“厥冷”来描述的，这也可见四逆与手足厥冷在轻重深浅上的差异。四肢整体发冷，病情较重；手足单独发冷，病情较轻。即使是妇女小孩也知道这一点。成无己却说“厥比逆更严重”，这是什么道理呢？如果能明白四逆和厥的区别在于：前者兼指手臂和小腿以上部位，后者专指手足，就不需要牵强附会地创造“不温”与“冷”的区别之说，自然就能贯通理解了。
Cheng Wuji, in his commentary on the *Shanghan Lun* (Treatise on Cold Damage), stated: "Si Ni (Four Extremities Reversal/Coldness) refers to the limbs being not warm; Jue (Reversal/Extremity Coldness) refers to the hands and feet being cold." He believed that when pathogenic factors of cold damage are in the Three Yang meridians, the hands and feet must be hot; when transmitted to the Taiyin meridian, the hands and feet naturally become warm; upon reaching the Shaoyin meridian, the pathogenic heat deepens gradually, thus causing the four extremities to reverse and become not warm; arriving at the Jueyin meridian, the hands and feet become completely cold. This is more severe than "Ni" (Reversal). The classic states: "In Shaoyin disease, if Si Ni occurs, and the patient experiences cough, palpitations, difficulty in urination, abdominal pain, or dysentery with a sensation of heaviness in the anus, Si Ni San (Four Extremities Reversal Powder) should be used as the primary treatment." The formula consists of Chai Hu (Bupleuri Radix), Zhi Shi (Aurantii Fructus Immaturus), Shao Yao (Paeoniae Radix Alba), and Gan Cao (Glycyrrhizae Radix et Rhizoma). These four herbs are all cold-natured substances, yet they specifically treat the condition of Si Ni. From this, it can be known that Si Ni is not a deficiency-cold syndrome. "Si Ni" and "Jue" are similar in name but different in essence. The classic states: "For those presenting with various forms of Si Ni or Jue, purgation methods should not be used." This indicates that Si Ni and Jue are distinct. Alas! This statement is precisely what is meant by "appearing plausible yet fundamentally distorting the truth."
I have carefully examined the texts, and Zhang Zhongjing mentions Si Ni and Jue on numerous occasions. Sometimes he says "Si Ni," sometimes "Jue," sometimes "Jue Ni," sometimes "Jue Leng," sometimes "Jue Han," sometimes "Shou Zu Ni Leng," sometimes "Shou Zu Jue Ni," sometimes "Shou Zu Jue Leng," and sometimes "Shou Zu Jue Ni Leng." Upon detailed examination of their meanings, they all refer to coldness. Therefore, the terms "Jue Ni" are often used interchangeably, never distinguishing "Ni" as merely not warm and "Jue" as cold. However, there is indeed a distinction between "Si Zhi" (four limbs) and "Shou Zu" (hands and feet). When the character "Si" (four) is placed before "Ni" (as in Si Ni), it generally refers to the entire limb region, including hands, feet, arms, and calves. When "Shou Zu" (hands and feet) is added before terms like "Jue Ni" or "Jue Leng," or when "Shou Zu" is omitted entirely, it specifically refers only to the hands and feet. Since "not warm" implies coldness, what difference remains?
Zhang Zhongjing's statement that "various cases of Si Ni and Jue should not be purged" likely stems from the understanding that "Si Ni" refers to coldness throughout the four limbs, whereas "Jue" refers specifically to coldness isolated to the hands and feet, while the arms and calves above remain uncold. He did not intend to distinguish between "Ni" and "Jue" based on degrees of warmth versus cold. Thus, he further clarified: "What is called Jue is precisely the reversal coldness of the hands and feet." By using the term "reversal coldness" (Ni Leng) to explain "Jue," it is evident that "Ni" is equivalent to "Jue," and "Jue" is equivalent to "Ni." Hence, dictionaries state: "Jue means Ni." Although both Ni and Jue manifest as coldness, they differ in Yin and Yang nature. Reversal coldness caused by extreme heat represents "Yang extreme resembling Yin"; reversal coldness caused by extreme cold represents "Yin extreme without Yang." Cases of Yang extreme resembling Yin naturally require cold-natured medicines; cases of Yin extreme without Yang naturally require hot-natured medicines. Zhang Zhongjing’s use of Si Ni San (a cold-natured formula) to treat Si Ni in one instance refers to Si Ni of the "Yang extreme resembling Yin" type. Regarding the absence of clauses where Si Ni Tang (a hot-natured formula) treats Si Ni, how can we know if such clauses originally existed but were lost? Moreover, the name "Si Ni Tang" is derived from the coldness of the four limbs. If Si Ni Tang is now used to treat hand-foot Jue Leng (coldness), does this not imply that Ni and Jue are indistinguishable? If Si Ni is defined as coldness of the four limbs and Jue as isolated coldness of the hands and feet, why is the medicine for treating Jue not named "Si Jue Tang"?
Cheng Wuji, under the clause for Si Ni San treating Si Ni, claimed that "Si Ni is caused by heat pathogens." In his *Ming Li Lun* (Discussion on Principles), he stated that "Si Ni is not a deficiency-cold syndrome." Yet, under the two clauses regarding fatal Shaoyin diseases, he asserted that "Si Ni is due to extreme cold." Is this not self-contradictory? From this, it is known that Si Ni, like Jue, can involve either cold or heat; it cannot be said that Si Ni is exclusively caused by heat pathogens. There is merely a difference in severity: coldness of the four limbs is more severe than isolated coldness of the hands and feet. Therefore, Zhang Zhongjing stated: "In Shaoyin disease, if vomiting, diarrhea, restlessness, and Si Ni occur, the prognosis is fatal." He also stated: "In Shaoyin disease, if Si Ni occurs accompanied by aversion to cold, body curling up, absent pulse, and restlessness without irritability, the prognosis is fatal." Furthermore: "In Shaoyin disease, if vomiting, diarrhea, hand-foot Jue Leng, and severe irritability occur, Wu Zhu Yu Tang (Evodia Decoction) should be used." Among these three clauses, two indicate fatality, and one indicates treatability. Although this depends on the combination of symptoms, the fatal cases are described using "Si Ni," while the treatable case uses "Jue Leng." This demonstrates the difference in severity and depth between Si Ni and hand-foot Jue Leng. Coldness of the four limbs indicates a heavier disease state; isolated coldness of the hands and feet indicates a lighter disease state. Even women and children understand this. Why did Cheng Wuji claim that "Jue is more severe than Ni"? If one understands that the distinction between Si Ni and Jue lies in whether the reference includes the arms and calves (Si Ni) or is restricted to the hands and feet (Jue), there would be no need to force explanations distinguishing "not warm" from "cold," and the concepts would naturally align.