有病因。有病名。有病形。辨其因。正其名。察其形。三者俱当。始可以言治矣。一或未明
。而曰不误于人。吾未之信也。且如
伤寒。此以病因。而为病名者也。温病热病。此以天时与病形。而为病名者也。由三者皆起
于感寒。或者通以伤寒称之。夫通称伤寒者。原其因之同耳。至于用药。则不可一例而施也
。何也。夫伤寒盖感于霜降后。春分前。然不即发。郁热。而发于春夏者也。伤寒即发于天
令寒冷之时。而寒邪在表。闭其腠理。故非辛甘温之剂。不足以散之。此仲景桂枝麻黄等汤
之所以必用也。温病热病后发于天令暄热之时。怫热自内而达于外。郁其腠理。无寒在表。
故非辛凉或苦寒或酸苦之剂。不足以解之。此仲景桂枝麻黄等汤。独治外者之所以不可用。
而后人所处水解散。大黄汤。千金汤。防风通圣散之类。兼治内外者之所以可用也。夫即病
之伤寒。有恶风恶寒之证者。风寒在表。而表气受伤故也。后发之温病热病。有恶风恶寒
之
证者。重有风寒新中。而表气亦受伤故也。若无新中之风寒。则无恶风恶寒之证。故仲景曰
。太阳病。发热。而渴。不恶寒者。为温病。温病如此。则知热病亦如此。是则不渴而恶寒者
。非温热病矣。然或有不因新中风寒。亦见恶风恶寒之证者。盖病患表气本虚。热达于表。
又重伤表气。故不禁风寒。非伤风恶风。伤寒恶寒也。但卫虚则恶风。荣虚则恶寒耳。且温
病
热病。亦有先见表证。而后传里者。盖怫热自内达外。热郁腠理。不得外泄。遂复还里。而
成可攻之证。非如伤寒从表而始也。或者不悟此理。乃于春夏温病热病。而求浮紧之脉。不
亦疏乎。殊不知紧为寒脉。有寒邪则见之。无寒邪则不见也。其温病热病。或见脉紧者。乃
重感不正之暴寒。与内伤过度之冷食也。岂其本然哉。又或者不识脉形。但见弦便呼为紧。
断为寒。而妄治。盖脉之盛而有力者。每每兼弦。岂可错认为紧。而断为寒。夫温病热病之
脉。多在肌肉之分。而不甚浮。且右手反盛于左手者。诚由怫热在内故也。其或左手盛或浮
者。必有重感之风寒。否则非温病热病。自是暴感风寒之病耳。凡温病热病。若无重感。表
证。虽间见。而里病为多。故少有不渴者。斯时也。法当治里热为主。而解表兼之。亦有治
里。而表自解者。余每见世人治温热病。虽误攻其里。亦无大害。误发其表。变不可言。此
足以明其热之自内达外矣。其间有误攻里。而致大害者。乃春夏暴寒所中之疫证。邪纯在表
。未入于里故也。不可与温病热病同论。夫惟世以温病热病混称伤寒。故每执寒字。以求浮
紧之脉。以用温热之药。若此者。因名乱实。而戕人之生。名其可不正乎。又书方多言四时
伤寒。故以春夏之温病热病。与秋冬之伤寒。一类视之。而无所别。夫秋冬之伤寒。真伤寒
也。春夏之伤寒。寒疫也。与温病热病自是两涂。岂可同治。吁。此弊之来。非一日矣。历
考方书。并无救弊之论。每每雷同。良可痛哉。虽然。伤寒与温病热病。其攻里之法。若果
是以寒除热。固不必求异。其发表之法。断不可不异也。况伤寒之直伤阴经。与太阳虽伤。
不及郁热即传阴经为寒证。而当温者。又与温病热病大不同。其可妄治乎。或者知一不知二
。
故谓仲景发表药。今不可用。而攻里之药。乃可用。呜呼。其可用不可用之理。果何在哉
。若能辨其因。正其名。察其形。治法其有不当者乎。彼时行不正之气所作。及重感异气而
变者。则又当观其何时何气。参酌伤寒温热病之法。损益而治之。尤不可例以仲景即病伤
寒药通治也。
有病因，有病名，有病状表现。辨别其病因，端正其病名，观察其病状表现。这三方面都弄清楚了，才可以谈论治疗了。如果有一方面还不明白，就声称不会误人，我是不相信的。
比如伤寒，这是以病因作为病名的。温病和热病，这是以天时气候和病状表现作为病名的。由于这三种病都起因于感受寒邪，有人便通称为伤寒。所谓通称伤寒，只是追溯其病因相同罢了。至于用药治疗，就不能一概而论地施用。为什么呢？
伤寒大概是在霜降之后、春分之前感受的，但当时不立即发病，而是郁积化热，等到春夏季节才发作。而典型的伤寒（即病之伤寒）是在天气寒冷的时候立即发病，寒邪在体表，闭塞腠理，所以非辛甘温的药物不足以发散它。这就是张仲景的桂枝汤、麻黄汤等方剂必须使用的缘故。
温病和热病是在天气温暖炎热的时候随后发作的，怫郁的热气从体内通达于体表，郁滞腠理，体表没有寒邪，所以非辛凉或苦寒或酸苦的药物不足以解除它。这就是张仲景的桂枝汤、麻黄汤等方剂，仅能治疗外感表证的情况之所以不可用的原因；而后人所开具的水解散、大黄汤、千金汤、防风通圣散等方剂，能够兼顾治疗内外病症的，之所以可用。
那种立即发病的伤寒，如果有恶风、恶寒的症状，是因为风寒在体表，导致表气受伤的缘故。那些随后发作的温病和热病，如果有恶风、恶寒的症状，是因为又新近遭受了风寒侵袭，导致表气也受伤的缘故。如果没有新近遭受的风寒，就不会有恶风、恶寒的症状。所以张仲景说：“太阳病，发热，而且口渴，不恶寒的，是温病。”温病是这样，那么热病也是这样。这样看来，如果不口渴且恶寒的，就不是温热病了。
然而，也有并非因为新近感受风寒，却也出现恶风、恶寒症状的情况。这是因为患者表气本来虚弱，热气通达于体表，又重伤了表气，所以禁受不住风寒，这并不是伤风导致的恶风、伤寒导致的恶寒，仅仅是卫气虚则恶风，营气虚则恶寒罢了。
况且温病和热病，也有先表现出表证，然后传变入里的。这是因为怫郁的热气从内通达于外，热气郁滞在腠理，不能向外宣泄，于是又返回体内，形成可以攻下的证候。这不像伤寒那样从体表开始传变。
有人不明白这个道理，竟然在春夏季的温病和热病中，去寻求浮紧的脉象，这不也太疏忽了吗？殊不知“紧”脉是寒脉，有寒邪才会出现，没有寒邪就不会出现。那些温病和热病，如果出现紧脉，那是重新感受了不正的暴寒，以及内伤过度食用冷食所致。难道这是它们本来的脉象吗？
又或者有人不认识脉象形态，只要见到弦脉就称之为紧脉，断定为寒证，从而胡乱治疗。脉象盛大而有力量时，常常兼带弦象，怎么能错认为是紧脉而断定为寒证呢？
温病和热病的脉象，多在肌肉之分，而不甚浮起，并且右手脉反而盛于左手脉，这确实是因为怫郁的热气在体内的缘故。如果左手脉盛或者浮起，那必定是重新感受了风寒，否则这就不是温病或热病，而是突然感受风寒的疾病了。
凡是温病和热病，如果没有重新感受风寒，虽然间或见到表证，但里证居多，所以很少有不口渴的。在这个时候，治法应当以治疗里热为主，兼以解表。也有只治疗里证，而表证自然解除的情况。
我常常见到世人治疗温热病，即使错误地攻下里证，也没有大害；但如果错误地发汗解表，产生的变证就无法言说了。这足以证明热气是从内部通达于外部的。其中也有错误攻下里证而导致大害的情况，那是春夏季被暴寒所中的疫病，邪气纯粹在体表，未进入体内，所以不能与温病和热病混为一谈。
正因为世人将温病和热病混称为伤寒，所以往往执着于“寒”字，去寻找浮紧的脉象，使用温热的药物。像这样的情况，是因为名称混乱了实质，从而残害人的性命，病名怎么可以不端正呢？
另外，医书中多提到“四时伤寒”，因此将春夏季的温病和热病与秋冬季的伤寒视为一类，不加区别。其实，秋冬季的伤寒，才是真正的伤寒；春夏季的伤寒，属于寒疫，这与温病和热病本是两条不同的路径，怎么可以同样治疗呢？唉，这种弊端的由来，不是一天了。遍查各方书，并没有纠正弊端的论述，每每雷同，实在令人痛心啊。
虽然如此，伤寒与温病、热病，在治疗里证的方法上，如果确实是用寒凉药来清除热邪，固然不必强求不同；但在治疗表证的方法上，绝对不可以不相同。何况伤寒直接损伤阴经，以及虽损伤太阳经但未郁积化热就传入阴经成为寒证，需要温补的情况，又与温病和热病大不相同，怎么可以胡乱治疗呢？
有人知其一不知其二，所以说张仲景的发表药现在不可用，而攻里的药才可用。唉，这可用与不可用的道理，究竟在哪里呢？如果能辨别其病因，端正其病名，观察其病状表现，治疗方法会有不当的吗？
至于那些由时行不正之气所作，以及因重感异气而发生变化的疾病，则应当观察是何时、何种气机，参照伤寒和温热病的治疗方法，加以增减变化后进行治疗。尤其不可以简单地用张仲景治疗即病伤寒的药物来通治。
There are disease causes, disease names, and disease manifestations. One must distinguish the cause, rectify the name, and observe the manifestation. Only when all three aspects are clear can one discuss treatment. If any one of them is unclear, yet one claims not to mislead others, I do not believe it.
Take *Shanghan* (Cold Damage) as an example; this is a disease named after its cause. *Wenbing* (Warm Disease) and *Rebing* (Heat Disease) are diseases named after the seasonal climate and their manifestations. Since all three originate from contracting cold pathogenic factors, some people generally refer to them all as *Shanghan*. The general term "Shanghan" merely traces back to the similarity in their causes. However, regarding medication, one cannot apply a uniform treatment. Why?
*Shanghan* is generally contracted between the Frost's Descent (*Shuangjiang*) solar term and the Spring Equinox (*Chunfen*), but it does not manifest immediately. Instead, heat becomes stagnant and manifests during spring and summer. In contrast, typical *Shanghan* (immediate-onset Cold Damage) occurs immediately during cold weather. The cold pathogen resides on the exterior, closing the *Couli* (pores/cutaneous interspaces). Therefore, only pungent, sweet, and warm agents are sufficient to disperse it. This is why Zhang Zhongjing's *Guizhi Tang* (Cinnamon Twig Decoction) and *Mahuang Tang* (Ephedra Decoction) must be used.
*Wenbing* and *Rebing* manifest later during warm and hot weather. Stagnant heat reaches from the interior to the exterior, obstructing the *Couli*, with no cold pathogen on the exterior. Therefore, only pungent-cool, bitter-cold, or sour-bitter agents are sufficient to resolve it. This explains why Zhang Zhongjing's *Guizhi Tang* and *Mahuang Tang*, which treat only external conditions, are contraindicated, while later formulas such as *Shuijie San* (Water-Resolving Powder), *Dahuang Tang* (Rhubarb Decoction), *Qianjin Tang* (Thousand Gold Decoction), and *Fangfeng Tongsheng San* (Saposhnikovia Universal Benefit Powder), which treat both internal and external conditions, are applicable.
In immediate-onset *Shanghan*, symptoms of aversion to wind and aversion to cold occur because wind-cold is on the exterior, injuring the exterior qi. In subsequently manifesting *Wenbing* and *Rebing*, symptoms of aversion to wind and aversion to cold occur because there is a new contraction of wind-cold, also injuring the exterior qi. Without new wind-cold contraction, there would be no aversion to wind or cold. Thus, Zhang Zhongjing stated: "In *Taiyang* disease (disease of the Bladder/Large Intestine channel system characterized by exterior syndrome), if there is fever, thirst, and no aversion to cold, it is *Wenbing*." If *Wenbing* is like this, then *Rebing* is also like this. Therefore, those who are not thirsty and have aversion to cold are not suffering from warm-heat diseases.
However, there are cases where, without new wind-cold contraction, aversion to wind and cold still appear. This is because the patient's exterior qi was originally deficient; as heat reaches the exterior, it further injures the exterior qi, making it unable to withstand wind-cold. This is not the aversion to wind caused by wind injury or the aversion to cold caused by cold injury; rather, deficiency of *Wei Qi* (Defensive Qi) leads to aversion to wind, and deficiency of *Ying Qi* (Nutritive Qi) leads to aversion to cold.
Furthermore, *Wenbing* and *Rebing* may initially show exterior syndromes before transmitting inward. This is because stagnant heat reaches from the interior to the exterior, obstructing the *Couli* and preventing outward release, causing it to return inward and form syndromes suitable for purgation. This differs from *Shanghan*, which begins at the exterior.
Some, failing to understand this principle, seek a floating-tight pulse in spring and summer *Wenbing* and *Rebing*, which is indeed negligent. The tight pulse is a cold pulse; it appears only when cold pathogens are present and disappears when they are absent. If a tight pulse appears in *Wenbing* or *Rebing*, it is due to a secondary contraction of violent cold or excessive consumption of cold food internally. Is this their natural state?
Others, failing to recognize pulse morphology, mistake a wiry pulse for a tight pulse, diagnose it as cold, and treat recklessly. A vigorous and forceful pulse often accompanies a wiry quality; how can it be mistaken for a tight pulse and diagnosed as cold?
The pulses of *Wenbing* and *Rebing* are mostly located at the muscle level and are not very floating. Moreover, the right hand pulse is often stronger than the left, truly due to stagnant heat within. If the left hand pulse is strong or floating, it indicates a secondary contraction of wind-cold; otherwise, it is not *Wenbing* or *Rebing*, but a sudden contraction of wind-cold.
Generally, in *Wenbing* and *Rebing*, without secondary contraction, although exterior signs may occasionally appear, interior syndromes predominate. Thus, thirst is rarely absent. At this time, the method should focus on treating interior heat, accompanied by releasing the exterior. There are also cases where treating the interior resolves the exterior spontaneously.
I often see that when people treat warm-heat diseases, mistakenly purging the interior causes little harm, whereas mistakenly sweating the exterior leads to untellable complications. This sufficiently proves that heat originates from the interior and reaches the exterior. Cases where mistaken purging causes great harm usually involve epidemics contracted from violent cold in spring and summer, where the pathogen is purely exterior and has not entered the interior; these cannot be discussed together with *Wenbing* and *Rebing*.
Because the world conflates *Wenbing* and *Rebing* with *Shanghan*, people often cling to the character "cold," seeking floating-tight pulses and using warm-hot medicines. Such practices confuse the name with reality and endanger lives; thus, disease names must be rectified.
Additionally, medical texts often mention "Four Seasons Shanghan," viewing spring/summer *Wenbing* and *Rebing* as identical to autumn/winter *Shanghan* without distinction. Autumn/winter *Shanghan* is true *Shanghan*; spring/summer *Shanghan* is cold epidemic (*Han Yi*). These are distinct paths from *Wenbing* and *Rebing* and cannot be treated identically. Alas, this malpractice has existed for a long time. Reviewing various texts, I find no discussions correcting this error; they merely repeat each other, which is truly lamentable.
Nevertheless, regarding the method of treating the interior for *Shanghan* versus *Wenbing*/*Rebing*, if the goal is indeed to remove heat with cold agents, there is no need to seek difference. However, the method for releasing the exterior must absolutely differ. Furthermore, direct injury to the Yin meridians in *Shanghan*, or *Taiyang* injury that does not stagnate into heat but transmits to Yin meridians becoming a cold syndrome requiring warming, is vastly different from *Wenbing* and *Rebing*. How can one treat them recklessly?
Some know one aspect but not the other, claiming that Zhang Zhongjing's exterior-releasing medicines are now unusable, while interior-purging medicines are usable. Alas, where exactly lies the logic of what is usable and what is not? If one can distinguish the cause, rectify the name, and observe the manifestation, can the treatment method be inappropriate?
For diseases caused by epidemic abnormal qi or those transformed by secondary contraction of different qi, one must observe the timing and nature of the qi, reference the methods of *Shanghan* and warm-heat diseases, and adjust the treatment accordingly. It is especially inadvisable to simply use Zhang Zhongjing's immediate-onset *Shanghan* medicines for universal treatment.