寒者热之。热者寒之。微者逆之。甚者从之。坚者削之。客者除之。劳者温之。结者散之。留者攻之。燥者濡之。
急者缓之。散者收之。损者益之。逸者行之。惊者平之。
诸法以寒治热。以热治寒攻散补平。皆易知之。惟微者逆之甚者从之。此理极其微妙。盖微者如小贼。可以扑灭。
甚者如巨盗。巢穴深固。非诱之不为功。西医如治热证。则以冰压胸。此热者寒之之正法也。然热之微者。可以立除。
如热之甚者。反逼激其热。使内伏入心而死。香港疫症。如此治死者多矣。皆不知甚者从之也。比如被火伤甚重。则忌
用冷水浇。恐火毒伏心而死也。然则逆从之法。可不讲耶。
逆者正治。从者反治。热因寒用。寒因热用。塞因塞用。通因通用。其始则同其终则异可使破积。可使溃坚可使气
和可使必已。
逆者以寒治热。以热治寒。故为正治。从者热病从热。寒病从寒。故为反治又言反治之理。热药因寒而得其用。寒
药因热而得其用。即所谓反佐之治也。塞因塞用。如满逆不下从而吐越之。通因通用。如泻痢不止。从而润降之。其始
则与。病从同。所以诱之其终则与病各异所以敌之。也变幻莫测。故可破坚积。以期其必愈。
病在下。取之上。病在上。取之下。病在中。旁取之。
此又言治病不可逐末。当求其源委所在如小便大便不利。病在下也。然多是心肺传移之病。故当取之。上头目耳喉
间。病在上也。然多是肝肾之邪上犯。故当取之下。病在中。属脾胃。然多是少阳厥阴之邪所犯。故宜旁取之。
治法之详。当求各书。然能洞明内经大义。则各书治法。其理已具。西医言治多执着。故鲜神妙。
寒证用热性药物治疗。热证用寒性药物治疗。病情轻微的，采用逆其病势的正治法。病情严重的，采用顺其病势的反治法。坚积的，采用消削的方法。外邪侵袭的，采用祛除的方法。劳损虚弱的，采用温补的方法。气结郁滞的，采用消散的方法。留滞不行的，采用攻逐的方法。干燥的，采用滋润的方法。
拘急痉挛的，采用缓和的方法。涣散不收的，采用收敛的方法。虚损不足的，采用补益的方法。安逸停滞的，采用行散疏通的方法。惊恐不安的，采用平定安神的方法。
以上各种治法，以寒治热、以热治寒、攻邪、散结、补虚、平惊，都是容易理解的道理。只有“微者逆之，甚者从之”这一条，其原理极其微妙。大概轻微的病邪如同小贼，可以直接扑灭；严重的病邪如同大盗，巢穴深固，如果不加以诱导，就不能成功。西医治疗热证，往往用冰块压迫胸部，这是“热者寒之”的正治法。然而，对于轻微的热证，可以立即消除；但对于严重的热证，如果用冰强行压制，反而会激惹热邪，使其内陷侵犯心脏而导致死亡。香港发生的疫病中，因此治法而死者很多，这都是不懂得“甚者从之”的道理。比如被火烧伤非常严重，就忌讳用冷水浇淋，恐怕火毒内陷心脏导致死亡。那么，“逆治”和“从治”的方法，难道可以不研究吗？
所谓“逆”，就是正治；所谓“从”，就是反治。“热因寒用”、“寒因热用”、“塞因塞用”、“通因通用”。这些方法开始时看似与病势相同，最终却不同，能够破除积滞，瓦解坚结，使气血调和，必定能治愈疾病。
“逆治”是用寒药治热证，用热药治寒证，所以称为正治。“从治”是热证顺从其假热表现，寒证顺从其假寒表现，所以称为反治。这里又阐述了反治的原理：热性药物因为配合寒凉药（或用于热证中的特定情况）而发挥效用，寒性药物因为配合温热药（或用于寒证中的特定情况）而发挥效用，这就是所谓的“反佐”治法。“塞因塞用”，例如胀满气逆不能下行，反而采用催吐越气的方法来顺应它；“通因通用”，例如腹泻痢疾不止，反而采用润降的方法来顺应它。开始的时候与病症表面现象相同，以此来诱导病邪；最终则与病症不同，以此来对抗病邪。变化莫测，所以能够破除坚硬的积滞，以期达到必愈的效果。
病位在下部的，取上部的穴位或脏腑进行治疗；病位在上部的，取下部的穴位或脏腑进行治疗；病位在中部的，从旁侧进行取治。
这里又说明治病不可只追求末梢症状，应当探求疾病的根源所在。例如小便、大便不利，病位在下部，但大多是由于心肺功能失调传移所致，所以应当从上部的头、目、耳、喉等部位去调治。病位在上部，但大多是由于肝肾邪气上犯所致，所以应当从下部的肝肾去调治。病位在中部，属于脾胃，但大多是由于少阳、厥阴的邪气所侵犯，所以适宜从旁侧（肝胆等）进行取治。
关于治法的详细论述，应当查阅各医书。但如果能透彻明白《黄帝内经》的大义，那么各医书中的治法原理就已经包含其中了。西医言治疗多执着于表象，所以很少能达到神妙境界。
Cold conditions are treated with heat. Heat conditions are treated with cold. Minor conditions are treated by opposing them (Zheng Zhi, standard treatment). Severe conditions are treated by following them (Fan Zhi, reverse treatment). Solid accumulations are reduced. Exogenous pathogens are expelled. Debility from overwork is warmed. Stagnation is dispersed. Retention is attacked. Dryness is moistened.
Spasm is relaxed. Scattering is consolidated. Deficiency is tonified. Idleness/stagnation is moved. Fright is calmed.
All these methods—treating heat with cold, cold with heat, attacking, dispersing, tonifying, and calming—are easily understood. Only the principle of "minor conditions are opposed, severe conditions are followed" is extremely subtle. Generally, minor pathogenic factors are like small thieves, which can be extinguished directly. Severe pathogenic factors are like great robbers, with deep and solid nests; unless they are lured out, success cannot be achieved. Western medicine, when treating heat syndromes, often presses ice on the chest. This is the orthodox method of "treating heat with cold." However, for minor heat, it can be eliminated immediately. But for severe heat, forcing it down with ice may instead provoke the heat, driving it inward to invade the Heart and cause death. Many died in the epidemic diseases in Hong Kong due to such treatments, because they did not understand "severe conditions are followed." For example, if one suffers severe burns, one must avoid pouring cold water on them, fearing that the fire toxin will penetrate into the Heart and cause death. Therefore, must we not study the methods of opposition and following?
Opposition refers to Standard Treatment (Zheng Zhi); Following refers to Reverse Treatment (Fan Zhi). Treating heat by using cold agents (in a specific context), treating cold by using heat agents, treating obstruction with obstructive methods, treating discharge with purgative methods. At first they seem similar, but at the end they differ; thus, they can break up accumulations, dissolve hardness, harmonize Qi, and ensure recovery.
Opposition means treating heat with cold and cold with heat, hence it is called Standard Treatment. Following means allowing heat syndromes to follow their apparent heat nature and cold syndromes to follow their apparent cold nature, hence it is called Reverse Treatment. This further explains the logic of reverse treatment: Hot herbs achieve their effect when used in conjunction with cold (or in heat syndromes appropriately), and cold herbs achieve their effect when used in conjunction with heat (or in cold syndromes appropriately); this is what is known as Counter-adjuvant Treatment (Fan Zuo). "Treating obstruction with obstructive methods," for instance, in cases of fullness and rebellious Qi failing to descend, one follows the trend by inducing vomiting to vent the Qi. "Treating discharge with purgative methods," for instance, in cases of persistent diarrhea or dysentery, one follows the trend by using moistening and descending methods. At first, they align with the disease's manifestation to lure it; ultimately, they differ from the disease to combat it. Their changes are unpredictable, thus they can break hard accumulations, aiming for certain cure.
For diseases located below, treat from above. For diseases located above, treat from below. For diseases located in the middle, treat from the sides.
This further states that treating disease should not focus merely on the symptoms (the branches) but should seek the root cause. For example, difficulty in urination or defecation is a disease located below, but it is often caused by transmission from the Lung and Heart; therefore, one should treat from above, such as points around the head, eyes, ears, and throat. Diseases located above are often caused by evil qi from the Liver and Kidney invading upward; therefore, one should treat from below. Diseases located in the middle belong to the Spleen and Stomach, but are often invaded by evil qi from the Shaoyang and Jueyin channels; therefore, one should treat from the sides.
Detailed descriptions of treatment methods should be sought in various medical texts. However, if one thoroughly understands the major principles of the *Huangdi Neijing* (Yellow Emperor's Inner Canon), then the principles of treatment in all other texts are already contained within. Western medicine tends to be rigid in its approach to treatment, and thus rarely achieves miraculous results.