病在表则发汗；病在里则清下；病在半表半里则宜和解；病有表复有里则宜和解。和解之法，
视某经有某邪，用某经发表药一二味以散邪。视某经有里热者，用某经退热之药一二味以清
里，和解表里，内外分消而病愈矣。仲景以桂枝五苓散，和解太阳里多表少之症；越婢汤，
和解太阳表多里少之症。干葛汤，和解阳明表多里少之症；干葛石膏汤，和解阳明里多表少
之症。小柴胡汤，和解少阳半表半里之症。推而广之，二阳合病有表复有里者，二味表药以
解表，二味凉药以清里；三阳合病有表复有里者，三味以解表，三味以清里。大凡和解之法，
散表清里又加和中之药，助其胃气，和其表里。例如小柴胡汤，和解少阳症，以柴胡散表邪
而治恶寒，以黄芩清里热而治发热，再加人参，甘草、广皮以和中气，而和解之义始彰，和
解之名始称耳。
忌和解者，以和解之药发表清里，杂合互用者也。若表邪未散，误用和解，内有一半寒药，
恐表汗不出。若热邪在里，误用和解，内有一半辛散之药，里热不宜。即遇一半表一半里之
症，仲景未尝概以和解施治。故曰表症急者，先发其表，后攻其里。与夫里症悉具，若有一
些恶寒头痛之症，即当从太阳施治。故仲景于太阳症中，虽立和解之方而不明言和解，惟少
阳症中，乃明言和解治法，深恐太阳表症居多，难于和解耳。少阳经络，已具半表半里，故
宜和解，然亦必始太阳而后传少阳乃可。若初起即见少阳，又兼太阳恶寒者，即为太阳少阳
症，尚从太阳施治，亦不从少阳和解，方中惟加柴胡耳。
病邪在体表，则采用发汗法治疗；病邪在体内，则采用清热或攻下法治疗；病邪在半表半里之间，则适宜采用和解法治疗；病情既有表证又有里证时，也适宜采用和解法治疗。和解的方法，是观察哪一经脉受何种邪气侵袭，就选用该经脉的解表药一至两味来疏散邪气；观察哪一经脉有里热，就选用该经脉的清退里热的药物一至两味来清除内热，从而调和表里，使内外之邪分消，疾病得以痊愈。张仲景使用桂枝五苓散，来调和太阳经中里证多而表证少的症状；使用越婢汤，来调和太阳经中表证多而里证少的症状。使用干葛汤，来调和阳明经中表证多而里证少的症状；使用干葛石膏汤，来调和阳明经中里证多而表证少的症状。使用小柴胡汤，来调和少阳经半表半里的症状。以此类推并推广开来，如果是阳明与太阳二经合病，且既有表证又有里证，就用两味解表药来解除表邪，用两味寒凉药来清泄里热；如果是三阳经合病，且既有表证又有里证，就用三味药来解表，用三味药来清里。大凡和解之法，是在发散表邪、清泄里热的基础上，再加入调和脾胃的药物，以资助胃气，调和表里。例如小柴胡汤，用于调和少阳病症，其中柴胡用于疏散表邪并治疗恶寒，黄芩用于清泄里热并治疗发热，再加上人参、甘草、广皮（陈皮）来调和中焦之气，这样和解的意义才能彰显，和解的名称才名副其实。
所谓“忌用和解”，是因为和解类药物兼具发表和清里的作用，是将不同性质的药物混合使用。如果表邪尚未消散，误用和解法，方中含有半数寒凉药物，恐怕会导致汗液无法排出。如果热邪在体内，误用和解法，方中含有半数辛温发散药物，则会加重里热。即使遇到一半在表、一半在里的病症，张仲景也未曾一概使用和解法进行治疗。所以说，表证急重的，应当先发散表邪，然后再攻逐里邪。如果里证已经完全具备，但仅有一点恶寒、头痛的症状，就应当从太阳经的角度进行治疗。因此，张仲景在太阳病的论述中，虽然设立了和解的方剂，但并不明确称之为“和解”；只有在少阳病的论述中，才明确指出这是和解治法，这是深怕太阳病多为表证，难以单纯通过和解法治愈的缘故。少阳经络的病位已经具备半表半里的特征，所以适宜采用和解法，但这通常必须是病邪先从太阳传入少阳才可以。如果疾病初起即出现少阳症状，又兼有太阳病的恶寒症状，这就属于太阳少阳合病，仍然应当从太阳经进行治疗，而不从少阳进行和解，方剂中仅仅加入柴胡罢了。
When the pathogen is in the exterior, diaphoresis (sweating method) should be employed; when the pathogen is in the interior, clearing heat or purging should be employed; when the pathogen is in the half-exterior and half-interior, harmonizing is appropriate; when the disease presents with both exterior and interior symptoms, harmonizing is also appropriate. The method of harmonizing involves observing which meridian is affected by which pathogen and using one or two exterior-releasing herbs from that meridian to disperse the pathogen. It also involves observing which meridian has interior heat and using one or two heat-clearing herbs from that meridian to clear the interior. By harmonizing the exterior and interior, the pathogens are dispersed internally and externally, and the disease is cured. Zhang Zhongjing used Guizhi Wuling San (Cinnamon Twig and Five-Ingredient Poria Decoction) to harmonize Shaoyang syndrome where the interior aspect predominates over the exterior aspect; Yu Bi Tang (Yarbrella Soup) to harmonize Shaoyang syndrome where the exterior aspect predominates over the interior aspect. Gan Ge Tang (Pueraria Decoction) to harmonize Yangming syndrome where the exterior aspect predominates over the interior aspect; Gan Ge Shi Gao Tang (Pueraria and Gypsum Decoction) to harmonize Yangming syndrome where the interior aspect predominates over the exterior aspect. Xiao Chai Hu Tang (Minor Bupleurum Decoction) to harmonize Shaoyang syndrome located in the half-exterior and half-interior. Extending this principle, in cases of combined diseases of two Yang meridians with both exterior and interior symptoms, two exterior-releasing herbs are used to resolve the exterior, and two cooling herbs are used to clear the interior; in cases of combined diseases of the three Yang meridians with both exterior and interior symptoms, three herbs are used to resolve the exterior, and three herbs are used to clear the interior. Generally speaking, the method of harmonizing involves dispersing the exterior, clearing the interior, and adding herbs that harmonize the middle jiao to support stomach qi and harmonize the exterior and interior. For example, Xiao Chai Hu Tang is used to harmonize Shaoyang syndrome: Chai Hu (Bupleuri Radix) disperses exterior pathogens and treats aversion to cold; Huang Qin (Scutellariae Radix) clears interior heat and treats fever; additionally, Ren Shen (Ginseng Radix et Rhizoma), Gan Cao (Glycyrrhizae Radix et Rhizoma), and Guang Pi (Citri Reticulatae Pericarpium) are added to harmonize the middle qi, thereby making the meaning of harmonization manifest and justifying its name.
The term "avoid harmonizing" refers to the fact that harmonizing formulas combine exterior-releasing and interior-clearing actions by mixing different types of herbs. If exterior pathogens have not yet been dispersed, mistakenly using harmonizing methods—which contain half cold-natured herbs—may prevent sweating. If heat pathogens are in the interior, mistakenly using harmonizing methods—which contain half acrid-warm dispersing herbs—is unsuitable as it may aggravate interior heat. Even when encountering symptoms that are half-exterior and half-interior, Zhang Zhongjing did not uniformly apply harmonizing treatments. Therefore, it is stated that when exterior symptoms are urgent, the exterior should first be released, followed by attacking the interior. If interior symptoms are fully present but there is even a slight symptom of aversion to cold or headache, treatment should proceed according to the Taiyang (Greater Yang) meridian. Thus, although Zhang Zhongjing established harmonizing formulas within the context of Taiyang syndrome, he did not explicitly label them as "harmonizing"; only in Shaoyang (Lesser Yang) syndrome did he explicitly state harmonizing treatment methods. This was likely due to the fear that Taiyang syndrome mostly consists of exterior symptoms, which are difficult to treat solely through harmonizing. The Shaoyang meridian's pathology inherently involves the half-exterior and half-interior, so harmonizing is appropriate; however, this typically requires the pathogen to transmit from Taiyang to Shaoyang. If Shaoyang symptoms appear at the onset of the disease, accompanied by Taiyang aversion to cold, it constitutes a combined Taiyang-Shaoyang syndrome. Treatment should still follow the Taiyang approach rather than harmonizing via Shaoyang, with only Chai Hu (Bupleuri Radix) added to the formula.