寒热真假，不可不知，正治逆治，岂可不辨！假如热病服寒药热不退，后用热
药而热方退；假如寒病服热药而寒不退，后用寒药而寒方退者，此为从治也。从治者，反攻也。治
热病以寒药而愈，治寒病以热而愈者，逆治也。逆治者，正治也。且反攻之法，人亦难晓者，多。
如寒病服寒药而愈者，此阳极变阴，热极反得水化也。热病服热药而愈者，此阴极变阳，寒极反得
火化也。盖物极则反也。
标本逆从之既明，五剂之药须用识。且如，表汗用麻黄，无葱白不发。吐痰用瓜蒂，无豆豉不
涌。去实热用大黄，无枳实不通。温经用附子，无干姜不热，甚则以泥清水加葱白煎之。竹沥，无
姜汁不能行经络。蜜导，无皂角不能通秘结。非半夏、姜汁，不能止呕吐。非人参、竹叶，不能止
虚烦。非小柴胡，不能和解表里。非五苓散，不能通利小便。非天花粉、干葛，不能消渴解肌。非
人参、麦门冬、五味，不能生脉补元。非犀角、地黄，不能止上焦之吐衄。非桃仁承气，不能破下
焦之瘀血。非黄 、桂枝，不能实表间虚汗。非茯苓、白术，不能去湿助脾。非茵陈，不能除黄胆。
非承气，不能制定发狂。非枳、桔，不能除痞满。非陷胸，不能开结
胸。非羌活冲和，不能治四时之感冒身疼。非人参败毒，不能治春瘟。非四逆，不能救阴厥。非人
参白虎，不能化斑。非理中、乌梅，不能治蛔厥。非桂枝、麻黄，不能除冬月之恶寒，热随汗解。
非姜附汤，不能止阴寒之泄利。非大柴胡，不能去实热之妄言。阴阳咳嗽，上气喘急，用加减小青
龙，分表里而可汗下。此伤寒用药之大法也。
寒证与热证的真假表现，是不可不知道的；正治法与逆治法，怎么可以不辨别呢！假如是热病，服用寒凉药后热势不退，后来改用温热药而热势才退；假如是寒病，服用温热药后寒象不退，后来改用寒凉药而寒象才退的，这叫做从治。所谓从治，就是反攻（反治）的方法。治疗热病用寒凉药而痊愈，治疗寒病用温热药而痊愈的，叫做逆治。所谓逆治，就是正治（常规治疗）。而且那种反攻（反治）的方法，人们大多难以理解。比如寒病服用寒凉药而痊愈的，这是阳极转化为阴，热极反而得到水的化育（即真寒假热，需以热治之，此处原文逻辑似有倒置或特指“热因热用”之理，但依字面翻译为：热极反得水化，实指真寒假热证，当用热药，若原文意指服寒药愈，则属笔误或特殊语境，此处严格按原文“寒病服寒药而愈者...热极反得水化”直译，但在中医理论中通常解释为真寒假热用热药，真热假寒用寒药。注：原文“寒病服寒药而愈...热极反得水化”在《伤寒六书》语境下，通常指“热因热用”的反向思维或特定病机，但标准解释应为：真寒假热证，看似热实则寒，故用热药；真热假寒证，看似寒实则热，故用寒药。原文此处表述较为简略且易生歧义，按字面意思翻译如下：如果是寒病服用寒药而痊愈，这是阳极变阴，热极反而得到水气化解（此句在中医经典中常对应“热因热用”或“寒因寒用”的极端情况，此处依原文直译）。如果是热病服用温热药而痊愈，这是阴极变阳，寒极反而得到火气化解。”
*修正说明：根据中医经典《伤寒六书》及王冰“微者逆之，甚者从之”的理论，原文“寒病服寒药而愈”实指“真热假寒”证（外现寒象，内蕴热毒），故用寒药；“热病服热药而愈”实指“真寒假热”证（外现热象，内蕴寒毒），故用热药。原文“此为从治也...反攻也”明确指出了这一点。因此，翻译时需准确传达这一病机逻辑。*
重新梳理翻译逻辑：
1. “假如热病服寒药热不退，后用热药而热方退” -> 这里描述的是常规的正治失败后的调整，或者是指真寒假热？不，后文说“此为从治也”。通常“从治”指“热因热用、寒因寒用”。
- 若“寒病服寒药而愈”，这是“寒因寒用”，针对真热假寒（内真热外假寒）。
- 若“热病服热药而愈”，这是“热因热用”，针对真寒假热（内真寒外假热）。
- 原文前两句“热病服寒药...后用热药...”和“寒病服热药...后用寒药...”似乎是在对比正治与从治的区别，或者是在描述一种复杂的病情演变。但紧接着定义：“此为从治也...反攻也”。
- 让我们仔细看原文结构：
- Case A: 热病服寒药不退，后服热药退 -> 这不是典型的从治定义，可能是误治后的纠偏。
- Case B: 寒病服热药不退，后服寒药退 -> 同上。
- 定义：从治 = 反攻。
- 定义：逆治 = 正治。
- 举例从治（反攻）：
- 寒病服寒药而愈 -> 阳极变阴（真热假寒，内热盛格拒于外，表现为寒，故用寒药清里热）。
- 热病服热药而愈 -> 阴极变阳（真寒假热，内寒盛格拒于外，表现为热，故用热药温里寒）。
*注意：原文第一段的前半部分“假如热病服寒药热不退...后用热药...”这一段在有些版本中可能被解读为对“正治”无效时的反思，或者是对“从治”概念的铺垫。但根据后文“如寒病服寒药而愈者...热病服热药而愈者...盖物极则反也”，这才是真正的“从治/反攻”的例子。*
为了保持忠实于原文文本，我将逐句翻译：
寒证与热证的真假，是不可不知道的；正治与逆治，岂能不辨明！假如热病服用寒凉药后热势不退，后来改用温热药而热势才退；假如寒病服用温热药后寒象不退，后来改用寒凉药而寒象才退的，这属于从治（顺从病势而治）。所谓从治，就是反攻（反治）。治疗热病用寒凉药而痊愈，治疗寒病用温热药而痊愈的，叫做逆治。所谓逆治，就是正治（常规治疗）。况且那种反攻（反治）的方法，人们大多难以知晓。比如寒病（表现为寒象）服用寒凉药而痊愈的，这是因为阳极转化为阴（实为真热假寒，热极似寒），热极反而得到水气（寒性）的化解（即清其内热）；热病（表现为热象）服用温热药而痊愈的，这是因为阴极转化为阳（实为真寒假热，寒极似热），寒极反而得到火气（热性）的化解（即温其内寒）。这是因为事物发展到极端就会向相反方向转化。
既然标本、逆从的道理已经明了，对于五种剂型药物的使用必须有所识见。比如，发汗解表要用麻黄，没有葱白就不能发散；涌吐痰涎要用瓜蒂，没有豆豉就不能催吐；攻下实热要用大黄，没有枳实就不能通便；温通经脉要用附子，没有干姜就不能产生热效，严重时甚至将附子泥状物加入清水并加葱白煎煮；竹沥，没有姜汁就不能通行经络；蜜导（蜂蜜栓剂），没有皂角就不能通开秘结；不是半夏和姜汁，就不能止住呕吐；不是人参和竹叶，就不能止住虚烦；不是小柴胡汤，就不能和解表里；不是五苓散，就不能通利小便；不是天花粉和葛根，就不能消除口渴、解除肌表之邪；不是人参、麦门冬、五味子，就不能生脉补益元气；不是犀角和地黄，就不能止住上焦的吐血衄血；不是桃仁承气汤，就不能攻破下焦的瘀血；不是黄芪和桂枝，就不能固表止虚汗；不是茯苓和白术，就不能祛湿助脾；不是茵陈，就不能清除黄疸；不是承气汤类，就不能制止发狂的症状；不是枳壳和桔梗，就不能消除痞满；不是陷胸汤，就不能开通结胸；不是羌活冲和汤，就不能治疗四时感冒引起的身体疼痛；不是人参败毒散，就不能治疗春瘟；不是四逆汤，就不能救治阴厥；不是人参白虎汤，就不能化解斑疹；不是理中丸加乌梅，就不能治疗蛔厥；不是桂枝汤和麻黄汤，就不能除去冬季的恶寒，使热随汗而解；不是姜附汤，就不能止住阴寒导致的泄泻痢疾；不是大柴胡汤，就不能去除实热导致的胡言乱语；对于阴阳咳嗽、上气喘急，使用加减小青龙汤，分消表里，从而可以采用汗法或下法。这就是治疗伤寒用药的大法。
The distinction between true and false cold and heat patterns must be understood, and the differentiation between direct treatment (Zheng Zhi) and indirect treatment (Ni Zhi) cannot be ignored! For instance, if a heat disease does not improve after administering cold-natured herbs, but improves only after switching to hot-natured herbs; or if a cold disease does not improve after administering hot-natured herbs, but improves only after switching to cold-natured herbs—this is called "Cong Zhi" (Following Treatment). "Cong Zhi" refers to "Fan Gong" (Counter-attack/Indirect Treatment). Conversely, curing a heat disease with cold-natured herbs and curing a cold disease with hot-natured herbs is called "Ni Zhi" (Opposing Treatment). "Ni Zhi" is synonymous with "Zheng Zhi" (Direct/Standard Treatment). Moreover, the principles of counter-attack are often difficult for people to comprehend. For example, when a disease presenting as cold is cured by cold-natured herbs, it indicates that extreme Yang transforms into Yin (True Heat, False Cold), where extreme heat is resolved by water-like (cold) properties. When a disease presenting as heat is cured by hot-natured herbs, it indicates that extreme Yin transforms into Yang (True Cold, False Heat), where extreme cold is resolved by fire-like (hot) properties. This is because things reverse when they reach their extreme.
Once the principles of root and branch, opposition and following are clear, one must possess knowledge in applying the five types of formulations. For example, to induce sweating for exterior release, Ephedrae Herba (Mahuang) is used, but without Allii Fistulosi Bulbus (Congbai), dispersion will not occur. To induce vomiting for phlegm expulsion, Citrulli Semen (Gua Di) is used, but without Sojae Preparata (Dou Chi), eruption will not happen. To purge excess heat, Rhei Radix et Rhizoma (Dahuang) is used, but without Aurantii Fructus Immaturus (Zhishi), unblocking will not take place. To warm the meridians, Aconiti Lateralis Radix Praeparata (Fuzi) is used, but without Zingiberis Rhizoma (Ganjiang), heat will not be generated; in severe cases, processed Aconite is boiled in clear water with Allii Fistulosi Bulbus. Arum Rhizoma juice (Zhuli) cannot circulate through the meridians without Zingiberis Juice (Jiangzhi); Honey suppositories (Midao) cannot relieve constipation without Gleditsiae Sinensis Spina (Zaojiao). Without Pinelliae Rhizoma (Banxia) and Zingiberis Juice, vomiting cannot be stopped; without Ginseng Radix (Renshen) and Phyllostachys Viridis Caulis (Zhuyeqian), deficiency-related vexation cannot be alleviated; without Xiao Chai Hu Tang (Minor Bupleurum Decoction), harmonizing the interior and exterior is impossible; without Wu Ling San (Five-Ingredient Powder with Poria), promoting urination is ineffective; without Trichosanthis Radix (Tianhuafen) and Puerariae Lobatae Radix (Gegen), thirst relief and muscle-layer resolution cannot be achieved; without Ginseng Radix, Ophiopogonis Radix (Maigendong), and Schisandrae Fructus (Wuweizi), generating the pulse and tonifying the primal Qi is unattainable; without Rhinocerotis Cornu (Xijiao) and Rehmanniae Radix (Dihuang), stopping epistaxis and hematemesis from the Upper Jiao is impossible; without Tao Ren Cheng Qi Tang (Peach Kernel and Rhubarb Decoction), breaking down blood stasis in the Lower Jiao cannot be accomplished; without Astragali Radix (Huangqi) and Cinnamomi Ramulus (Guizhi), securing the exterior and stopping deficiency sweating is not possible; without Poria (Fuling) and Atractylodis Macrocephalae Rhizoma (Baizhu), dispelling dampness and assisting the Spleen is ineffective; without Coptidis Rhizoma (Yinchen is actually Artemisiae Scopariae Herba, Yichen) [Correction: Yin Chen Hao], clearing jaundice is impossible; without Cheng Qi Tang variants, controlling mania cannot be formulated; without Aurantii Fructus (Zhike) and Platycodonis Radix (Jiegeng), removing fullness and stagnation is not feasible; without Xiong Xiong Tang (Chest-Harmonizing Decoction), opening chest-knotting is impossible; without Qiang Huo Chong He Tang (Notopterygii Root Harmonious Decoction), treating body aches from seasonal colds is not possible; without Renshen Bai Du San (Ginseng Detoxification Powder), treating spring plagues is ineffective; without Si Ni Tang (Four Reversal Decoction), saving from Yin collapse is impossible; without Renshen Bai Hu Tang (Ginseng White Tiger Decoction), resolving macules is unattainable; without Li Zhong Wan combined with Vitis Vinifera Seed (Wumei), treating ascariasis-induced reversal cold is not effective; without Guizhi Tang and Mahuang Tang, eliminating winter aversion to cold and allowing heat to resolve with sweat is impossible; without Jiang Fu Tang (Ginger and Aconite Decoction), stopping diarrhea due to Yin-cold is not possible; without Da Chai Hu Tang (Major Bupleurum Decoction), removing delirium caused by excess heat is ineffective; for yin-yang cough and rapid upper-body breathing, Jia Jian Xiao Qing Long Tang (Modified Minor Blue Dragon Decoction) is used to differentiate the interior and exterior, thereby permitting sweating or purging methods. These constitute the major principles of herb usage in treating Shang Han (Cold Damage).