太阳宜汗。少阳宜和。阳明宜下。太阴宜温。少阴宜补。厥阴宜清。
【秀按】此千古不易之法。但病有合并。方有离合。故治有先后缓急彼此之殊。须如星家之推命。纵同此八
字。而取用神有大不同者。取用或差。全不验矣。医家亦然。病不外此六经。治不外此六法。而错综变化之
间。倘取用不真。纵方能对证。往往先后倒施。缓急失机而贻祸。况方不对证乎。故能读古书。犹非难事。善
取用神。实医者之第一难也。
太阳、太阴、少阴。大旨宜温。少阳、阳明、厥阴。大旨宜清。
【荣斋按】根据文献记载，伤寒的六经∶太阳寒化，阳明兼燥化，少阳兼火化，太阴兼湿化，少阴兼热化，
厥阴兼风化。由于寒化，所以恶寒；燥化，所以渴不恶寒但恶热；湿化，所以腹满；火化，所以口苦咽干。而
少阴之热化，是虚热，所以须从治。此为用药宜温宜清的总方针。
吾四十余年阅历以来。凡病之属阳明、少阳、厥阴、而宜凉泻清滋者。十有七八。如太阳、太阴、少阴之宜温
散温补者。十仅三四。表里双解。三焦并治。温凉合用。通补兼施者。最居多数。
【秀按】时代不同。南北异辙。其大端也。且也受病有浅深。气体有强弱。天质有阴阳。性情有刚柔。筋骨
有坚脆。肢体有劳逸。年力有老少。风俗有习惯。奉养有膏粱藜藿之殊。心境有忧劳和乐之别。医必详辨其时
其地其人之种种不同。而后对证发药。一病一方。方方合法。法法遵古。医能是。是亦足以对病患而无愧矣。
阳道实。故风寒实邪。从太阳汗之。燥热实邪。从阳明下之。邪之微者。从少阳和之。阴道虚。故寒湿虚邪。
从太阴温之。风热虚邪。从厥阴清之。虚之甚者。从少阴补之。阳道虽实。而少阳为邪之微。故和而兼补。
阴道本虚。而少阴尤虚之极。故补之须峻。
【秀按】此六经证治。须用六法之原理也。故俗称伤寒无补法者谬。惟用补法下法。较汗和温清四法为尤
难。难在刚刚恰好耳。
伤寒证治。全藉阳明。邪在太阳。须藉胃汁以汗之。邪结阳明。须藉胃汁以下之。邪郁少阳。须藉胃汁以和之。
太阴以温为主。救胃阳也。厥阴以清为主。救胃阴也。由太阴湿胜而伤及肾阳者。救胃阳以护肾阳。由厥阴风胜而伤
及肾阴者。救胃阴以滋肾阴。皆不离阳明治也。
【秀按】伤寒虽分六经。而三阳为要。三阳则又以阳明为尤要。以胃主生阳故也。若三阴不过阳明甲里事
耳。未有胃阳不虚而见太阴证者。亦未有胃阴不虚而见厥阴证者。至于少阴。尤为阳明之底板。惟阳明告竭。
方致少阴底板外露。若阳明充盛。必无病及少阴之理。盖少阴有温清二法。其宜温者。则由胃阳偏虚。太阴湿
土偏胜而致。其宜清者。则由胃阴偏虚。厥阴风木偏胜而致。阳明偏虚。则见太阴厥阴。阳明中竭。则露少阴
底板。故阳明固三阴之外护。亦三阳之同赖也。如太阳宜发汗。少阳宜养汗。汗非阳明之津液乎。
风寒风湿。治在太阳。风温风火。治在少阳。暑热燥火。治在阳明。寒湿湿温。治在太阴。中寒治在少阴。
风热治在厥阴。
【秀按】六淫之邪。惟寒湿伤阳。风暑燥火。则无不伤阴。故治四时杂感。以存津液为要。
【廉勘】凡六淫邪气郁勃。既不得从表透达。则必向里而走空隙。而十二脏腑之中。惟胃为水谷之海。上下
有口。最虚而善受。故六经之邪。皆能入之。邪入则胃实。胃实则津液干。津液干则死。故有不传少阳及三阴
之伤寒。必无不犯阳明之伤寒。所以治法在二三日内。无论汗出不彻。或发汗不得。或未经发汗。但见口干烦
闷。舌苔白燥。或按之涩。纵有太阳表证。亦是邪从火化。此时急撤风药。惟宜轻清和解。以存津液。阴液既
充。则汗自涌出肌表而解。此发表时存津液之法也。若热既入里。邪从火化。火必就燥。张长沙承气诸方。皆
急下之以存津液。不使胃中津液。为实火燔灼枯槁而死。此攻里时存津液之法也。但今人肠胃脆薄者多。血气
充实者少。故后贤又制白虎承气。养荣承气。增液承气。参入润燥濡液之剂。频频而进。令胃中津液充足。实
邪自解。阴气外溢则得汗。阴液下润则便通。奏效虽迟。立法尤稳。
凡伤寒病。均以开郁为先。如表郁而汗。里郁而下。寒湿而温。火燥而清。皆所以通其气之郁也。病变不
同。一气之通塞耳。塞则病。通则安。无所谓补益也。补益乃服食法。非治病法。然间有因虚不能托邪者。亦须
略佐补托。
【秀按】病无补法。开其郁。通其塞而已。固也。但其中非无因病致虚。及病不因虚而人虚之证。自宜通补
并进。然通者自通其病。补者自补其虚。虽两相兼。仍两不相背也。其要诀。治寒病须察其有无热邪。治热病
须察其有无寒邪。治虚病须察其有无实邪。治实病须察其有无虚邪。留心久久。自能识病于病外。而不为病所欺弄矣。
【廉勘】邪实于表为表实。邪实于里为里实。既有实邪。断不宜补于邪实之时。表实者宜发表。里实者攻其
里而已。若遇有内伤宿病之人。适患外感时病。不得用峻汗峻攻之法。必参其人之形气盛衰。客邪微甚。本病
之新久虚实。向来之宜寒宜热。宜燥宜润。宜降宜升。宜补宜泻。其间或挟痰。或挟瘀。或挟水。或挟火。或
挟气。或挟食。务在审证详明。投剂果决。自然随手克应。故治外感或挟内伤。首必辨其虚中实、实中虚。
太阳病适宜用发汗法。少阳病适宜用和解法。阳明病适宜用攻下法。太阴病适宜用温里法。少阴病适宜用补益法。厥阴病适宜用清法。
【俞秀按】这是千古不变的治疗法则。但是疾病常有合并症，方剂也有组合与拆分的变化，因此治疗有先后缓急以及侧重点的不同。这就像算命先生推演命运一样，虽然都依据这八个字（指六经治法），但选取关键用药的原则有很大不同。如果选取用药稍有偏差，疗效就会完全不符预期。医生也是如此。疾病不外乎这六经，治疗不外乎这六种方法，但在错综复杂的变化之间，如果选取用药不精准，即使方剂对症，也往往因为先后顺序颠倒、缓急时机错失而留下祸患，更何况方剂不对症呢？所以，能读懂古书并非难事，善于选取关键用药，才是医生的第一难点。
太阳、太阴、少阴，大体原则适宜用温法；少阳、阳明、厥阴，大体原则适宜用清法。
【徐荣斋按】根据文献记载，伤寒的六经：太阳寒化，阳明兼燥化，少阳兼火化，太阴兼湿化，少阴兼热化，厥阴兼风化。由于寒化，所以出现恶寒症状；燥化，所以口渴且不恶寒只恶热；湿化，所以腹部胀满；火化，所以口苦咽干。而少阴的热化，属于虚热，所以必须从治（顺其性而治）。这是用药宜温宜清的总方针。
在我四十多年的临床阅历中，凡是属于阳明、少阳、厥阴，且适宜凉泻、清滋的病证，占十之七八。而属于太阳、太阴、少阴，适宜温散、温补的病证，仅占三四成。表里双解、三焦并治、温凉合用、通补兼施的情况，占据大多数。
【俞秀按】时代不同，南北地域差异，这是大趋势。况且受病的深浅不同，体质强弱不同，先天禀赋阴阳不同，性格刚柔不同，筋骨坚脆不同，肢体劳逸不同，年龄老少不同，风俗习惯不同，饮食供养有精细与粗劣的区别，心境有忧劳与和乐的区别。医生必须详细辨别时间、地点、人物的种种不同，然后对症用药。做到一病一方，方方合法，法法遵古。医生能做到这样，也就足以面对病患而无愧疚了。
阳道多实，所以风寒实邪，从太阳经用发汗法解除；燥热实邪，从阳明经用攻下法解除。邪气轻微的，从少阳经用和解法解除。阴道多虚，所以寒湿虚邪，从太阴经用温里法解除；风热虚邪，从厥阴经用清法解除。虚损严重的，从少阴经用补益法解除。阳道虽多实，但少阳是邪气轻微之处，所以和解兼以补益。阴道本虚，但少阴更是虚损至极，所以补益必须峻猛。
【俞秀按】这六经的证治，必须运用六法的原理。所以俗称“伤寒无补法”是错误的。只有使用补法和下法，比汗、和、温、清四法更为困难。难在掌握得恰到好处。
伤寒证的治理，全赖阳明胃气。邪气在太阳，须借助胃中津液来发汗；邪结在阳明，须借助胃中津液来攻下；邪郁在少阳，须借助胃中津液来和解。太阴以温为主，是为了挽救胃阳；厥阴以清为主，是为了挽救胃阴。由太阴湿胜而伤及肾阳的，通过救胃阳来保护肾阳；由厥阴风胜而伤及肾阴的，通过救胃阴来滋养肾阴。这些都不离开对阳明的治理。
【俞秀按】伤寒虽然分为六经，但以三阳为关键。三阳之中又以阳明尤为重要，因为胃主生发阳气。至于三阴，不过是阳明内部的事情罢了。没有胃阳不虚而出现太阴证的，也没有胃阴不虚而出现厥阴证的。至于少阴，更是阳明的基础底板。只有当阳明衰竭时，才会导致少阴底板外露。如果阳明充盛，必定没有病及少阴的道理。盖少阴有温、清两种治法，适宜温的，是因为胃阳偏虚，太阴湿土偏胜所致；适宜清的，是因为胃阴偏虚，厥阴风木偏胜所致。阳明偏虚，则出现太阴、厥阴证；阳明中竭，则显露少阴底板。所以阳明固然是三阴的外护，也是三阳共同依赖的根本。如太阳宜发汗，少阳宜养汗，汗不就是阳明的津液吗？
风寒风湿，治疗在太阳；风温风火，治疗在少阳；暑热燥火，治疗在阳明；寒湿湿温，治疗在太阴；中寒，治疗在少阴；风热，治疗在厥阴。
【俞秀按】六淫邪气中，只有寒湿损伤阳气，风、暑、燥、火无不损伤阴液。所以治疗四季杂感病，以保存津液为要务。
【廉勘】凡六淫邪气郁结勃发，既然不能从体表透达，就必然向体内走窜空隙。而在十二脏腑之中，唯有胃是水谷之海，上下有口，最虚弱且善于受纳，所以六经的邪气都能进入胃中。邪气入胃则胃实，胃实则津液干枯，津液干枯则死亡。所以有不传变至少阳及三阴的伤寒，但没有不侵犯阳明的伤寒。因此治疗方法在发病二三日内，无论汗出不彻底，或发汗不当，或未经发汗，只要见到口干烦闷，舌苔白燥，或触之涩滞，纵有太阳表证，也是邪气从火化。此时急需撤去风药，只宜轻清和解，以保存津液。阴液既已充足，则汗自然涌出肌表而病解。这是发表时保存津液的方法。如果热邪已经入里，邪气从火化，火必就燥，张仲景的承气汤诸方，都是急下之以保存津液，不让胃中津液被实火燔灼枯槁而死。这是攻里时保存津液的方法。但现在人的肠胃大多脆薄，血气充实者少，所以后世医家又制定了白虎承气、养荣承气、增液承气等方，加入润燥濡液的药剂，频频进服，令胃中津液充足，实邪自然解除。阴气外溢则得汗，阴液下润则便通。奏效虽然稍慢，但立法尤为稳妥。
凡伤寒病，都以开郁为先。如表郁则发汗，里郁则攻下，寒湿则温化，火燥则清解，都是为了通畅气的郁结。病变不同，只是一气之通塞而已。塞则生病，通则安康，无所谓补益之说。补益是服食养生之法，不是治病之法。然而间或有因虚而不能托举邪气的，也必须略微佐以补托。
【俞秀按】病无补法，只是开通其郁结，疏通其闭塞罢了。固然如此。但其中并非没有因病致虚，以及病不因虚而人自虚的证候，自然应当通补并进。然而通者自通其病，补者自补其虚，虽然两者兼用，仍互不违背。其要领在于：治寒病须察其有无热邪，治热病须察其有无寒邪，治虚病须察其有无实邪，治实病须察其有无虚邪。留心观察久久，自然能在病之外识病，而不被病所欺骗玩弄了。
【廉勘】邪气实于表称为表实，邪气实于里称为里实。既然已有实邪，断不宜在邪实之时进补。表实者宜发表，里实者攻其里而已。如果遇到有内伤宿疾的人，恰好患上外感时病，不能使用峻汗、峻攻之法，必须参酌病人的形气盛衰，客邪微甚，本病的新久虚实，向来适宜寒热、燥润、升降、补泻的情况。其间或挟痰，或挟瘀，或挟水，或挟火，或挟气，或挟食，务必审证详明，投药果决，自然随手见效。所以治疗外感或挟内伤，首先必须辨别是虚中实、还是实中虚。
Taiyang (Sun) syndrome is suitable for diaphoresis (sweating method). Shaoyang (Gallbladder) syndrome is suitable for harmonization. Yangming (Stomach) syndrome is suitable for purgation (draining downward). Taiyin (Spleen) syndrome is suitable for warming. Shaoyin (Kidney/Heart) syndrome is suitable for tonification. Jueyin (Liver/Pericardium) syndrome is suitable for clearing.
[Commentary by Yu Xiu] This is an unchangeable therapeutic principle throughout history. However, diseases often have concurrent conditions, and formulas undergo combination and separation; thus, treatment varies in sequence, urgency, and focus. It is like a fortune teller deducing fate: although the same eight characters (referring to the six-meridian treatments) are used, the selection of key medicinal principles differs greatly. If the selection of medication deviates even slightly, the efficacy will be completely inconsistent with expectations. Physicians are the same. Diseases fall within these six meridians, and treatments fall within these six methods. Yet, amidst complex variations, if the selection of medication is not precise, even if the formula matches the syndrome, errors in sequence and timing may lead to adverse consequences, let alone mismatched formulas. Therefore, reading ancient texts is not difficult; mastering the art of selecting key medications is the physician's greatest challenge.
Taiyang, Taiyin, and Shaoyin generally require warming methods; Shaoyang, Yangming, and Jueyin generally require clearing methods.
[Commentary by Xu Rongzhai] According to literature, the six meridians of Shanghan (Cold Damage): Taiyang involves cold transformation, Yangming involves dryness transformation, Shaoyang involves fire transformation, Taiyin involves dampness transformation, Shaoyin involves heat transformation, and Jueyin involves wind transformation. Due to cold transformation, there is aversion to cold; due to dryness transformation, there is thirst without aversion to cold but with aversion to heat; due to dampness transformation, there is abdominal fullness; due to fire transformation, there is bitter taste and dry throat. The heat transformation of Shaoyin is deficient heat, so it must be treated by following its nature (treating deficiency with warmth/nourishment). This is the general guideline for whether to use warming or clearing methods.
In my forty years of clinical experience, cases belonging to Yangming, Shaoyang, and Jueyin that require cooling, purging, clearing, and nourishing account for seventy to eighty percent. Cases belonging to Taiyang, Taiyin, and Shaoyin requiring warming dispersion and warming tonification account for only thirty to forty percent. Cases involving simultaneous resolution of exterior and interior, treatment of all three jiaos, combined use of warming and clearing, and simultaneous application of draining and tonifying constitute the majority.
[Commentary by Yu Xiu] Differences in era and geographical location between North and South are major factors. Moreover, depth of pathogenic invasion, constitution strength, innate yin-yang balance, personality rigidity/flexibility, bone/tendon durability, physical labor/rest, age, local customs, dietary habits (rich vs. plain), and mental state (worry/stress vs. peace/joy) vary. Physicians must carefully distinguish these temporal, spatial, and individual differences before prescribing. Achieving "one disease, one formula," where every formula is lawful and every method follows antiquity, allows a physician to face patients without guilt.
The Yang pathway tends toward excess; thus, wind-cold excess pathogens are resolved via diaphoresis from Taiyang, and dry-heat excess pathogens are resolved via purgation from Yangming. Minor pathogens are resolved via harmonization from Shaoyang. The Yin pathway tends toward deficiency; thus, cold-damp deficiency pathogens are resolved via warming from Taiyin, and wind-heat deficiency pathogens are resolved via clearing from Jueyin. Severe deficiency is resolved via tonification from Shaoyin. Although Yang tends toward excess, Shaoyang involves minor pathogens, so harmonization is combined with tonification. Although Yin tends toward deficiency, Shaoyin represents extreme deficiency, so tonification must be vigorous.
[Commentary by Yu Xiu] The treatment of these six meridians requires applying the principles of the six methods. Thus, the common saying "Shanghan has no tonification method" is erroneous. Using tonification and purgation methods is more difficult than using diaphoresis, harmonization, warming, and clearing methods because precision is paramount.
The management of Shanghan relies entirely on the Yangming Stomach Qi. When pathogens are in Taiyang, stomach fluids are needed for diaphoresis; when pathogens bind in Yangming, stomach fluids are needed for purgation; when pathogens stagnate in Shaoyang, stomach fluids are needed for harmonization. Taiyin focuses on warming to rescue Stomach Yang; Jueyin focuses on clearing to rescue Stomach Yin. When Taiyin dampness excess injures Kidney Yang, rescuing Stomach Yang protects Kidney Yang; when Jueyin wind excess injures Kidney Yin, rescuing Stomach Yin nourishes Kidney Yin. All these revolve around managing Yangming.
[Commentary by Yu Xiu] Although Shanghan is divided into six meridians, the Three Yang are critical, with Yangming being particularly important because the Stomach generates Yang Qi. The Three Yin are merely internal matters of Yangming. There is no Taiyin syndrome without Stomach Yang deficiency, nor Jueyin syndrome without Stomach Yin deficiency. Shaoyin is the foundation plate of Yangming. Only when Yangming collapses does the Shaoyin foundation become exposed. If Yangming is robust, illness rarely reaches Shaoyin. Shaoyin has two methods: warming (due to Stomach Yang deficiency and Taiyin dampness excess) and clearing (due to Stomach Yin deficiency and Jueyin wind excess). Yangming deficiency leads to Taiyin/Jueyin syndromes; Yangming collapse exposes Shaoyin. Thus, Yangming protects the Three Yin and supports the Three Yang. For example, Taiyang requires diaphoresis, Shaoyang requires nourishing sweat; isn't sweat the fluid of Yangming?
Wind-cold and wind-damp are treated in Taiyang; wind-warmth and wind-fire in Shaoyang; summer-heat, dryness, and fire in Yangming; cold-damp and damp-warmth in Taiyin; middle-cold in Shaoyin; wind-heat in Jueyin.
[Commentary by Yu Xiu] Among the Six Excesses (pathogens), only cold and damp damage Yang; wind, summer-heat, dryness, and fire all damage Yin. Therefore, treating miscellaneous seasonal infections prioritizes preserving body fluids.
[Commentary by Lian Kan] When Six Excess pathogens are stagnant and cannot vent through the exterior, they move inward to empty spaces. Among the twelve zang-fu organs, the Stomach is the sea of water and grain, open at both ends, most vulnerable and receptive, so pathogens from all six meridians can enter it. Pathogen entry causes Stomach excess; Stomach excess dries up fluids; dried-up fluids lead to death. Thus, there is Shanghan that does not transmit to Shaoyang or the Three Yin, but no Shanghan that does not invade Yangming. Therefore, within two to three days of onset, regardless of incomplete sweating, improper sweating, or no sweating, if dry mouth, restlessness, white dry tongue coating, or rough palpation appear—even with Taiyang exterior signs—the pathogen has transformed into fire. At this stage, wind-dispersing herbs must be withdrawn immediately; only light, clear harmonization should be used to preserve fluids. Once yin fluids are replenished, sweat naturally emerges from the muscle layer, resolving the disease. This is the method of preserving fluids during exterior release. If heat enters the interior and transforms into fire, fire seeks dryness. Zhang Zhongjing’s Chengqi Decoctions urgently purge to preserve fluids, preventing stomach fluids from being scorched and dried by excess fire. This is the method of preserving fluids during interior purgation. However, modern people often have fragile intestines and weak blood/qi. Later physicians developed Baohu Chengqi, Yangrong Chengqi, and Zengye Chengqi, adding moistening agents, administered frequently to ensure sufficient stomach fluids, allowing excess pathogens to resolve naturally. Yin qi overflowing externally produces sweat; yin fluids moistening internally promotes bowel movement. Although effects are slower, the methodology is stable.
All Shanghan diseases prioritize opening stagnation. Exterior stagnation requires diaphoresis; interior stagnation requires purgation; cold-damp requires warming; fire-dryness requires clearing. These all aim to unblock qi stagnation. Variations in pathology are merely blockage or flow of qi. Blockage causes disease; flow brings health. Tonification is irrelevant here. Tonification is for dietary nourishment, not disease treatment. However, in cases where deficiency prevents expelling pathogens, slight tonifying support is necessary.
[Commentary by Yu Xiu] Disease treatment does not rely on tonification but on opening stagnation and unblocking obstruction. True. Yet, some cases involve deficiency caused by disease, or deficiency unrelated to disease etiology. In such cases, unblocking and tonifying should proceed together. Unblocking addresses the disease; tonifying addresses the deficiency. Though combined, they do not contradict. The key is: when treating cold diseases, check for heat pathogens; when treating heat diseases, check for cold pathogens; when treating deficiency diseases, check for excess pathogens; when treating excess diseases, check for deficiency pathogens. With long-term attention, one can discern the disease beyond its symptoms and avoid deception by the disease.
[Commentary by Lian Kan] Pathogen excess at the exterior is exterior excess; pathogen excess at the interior is interior excess. Given excess pathogens, tonification is contraindicated during excess phases. Exterior excess requires releasing the exterior; interior excess requires purging the interior. For patients with chronic internal injuries contracting external epidemic diseases, harsh diaphoresis or purgation is inappropriate. One must assess the patient’s constitutional strength, pathogen severity, duration and nature of the underlying condition, and previous responses to cold/heat, dry/moist, descending/ascending, tonifying/draining therapies. Complications may include phlegm, blood stasis, water retention, fire, qi stagnation, or food retention. Diagnosis must be detailed, and prescription decisive for immediate effect. Thus, treating external infections with internal injury complications requires first distinguishing between deficiency-with-excess and excess-with-deficiency patterns.