治病之要，首辨药性。用药得当则救人，用药不当则杀人。若性味猛烈者，人易知之；
其间有极和平、泛常之品，几微之间，亦能偾事者，必须潜心研究，庶免致患。尝忆昔医治
虚痘，用四君子汤，平妥极矣，然亦间有枯毙者，以其白术之燥、茯苓之渗，即为大害；有阴
虚用四物汤尚能获咎，以芎、归辛窜耗阴。夫苓、术极平和之性味，芎、归体阴微辛之气，尚
能遗害，至于暑热、霍乱，服生姜汤立弊者，书载难以枚举耳。更有其药本不对症，因其能揠
苗助长，或治标病有小效，而其害过后方显者；或因病重药轻、药邪相拒，初服反觉不安，
患者不知，遂即更医，反致错乱者，凡此之类，尤属暗而难测。惟须细心讨论药、病，如何相
制、如何相反之理，而用之得宜者。譬如气虚者，只宜甘温极纯之剂，不能稍参克耗，间不
容发。若病久胃虚，仅宜参 、参地之品，若挟炒术、二陈、归、芎等，即觉不妥。又如阴极虚
而亡血者，只宜纯甘柔润，以三才复脉等法，然必去桂、姜。推而至于妇女之胎产，或血崩
过多，或郁勃日久，皆不得用升散之品。又有化燥、化热之证，不能夹丝毫辛温苦燥。每见
大泄之病，服胃苓而加剧，乃猪、泽渗利太过，反助下行之患。他如寒忌清凉，热忌辛温；虚
忌消耗，实忌涩滞；上逆者，宜降不宜升；下泄者，宜固不宜降；散乱者，宜收敛不宜辛散；郁
结者，宜宣达不宜涩滞。用药相当则病瘳，相忌则病进。
至于虚羸、年老，孕妇、产后，若患实症，攻邪宜早，乘其正未重伤，邪未深入，慎勿畏
攻，牵延正为邪伤，挽之莫及。当此危疑之际，有起死回生之法也。余治大病，必用大药，历
获奇效，如大散以麻黄、羌活为主，大攻以大黄、芒硝为要，大温以附子、干姜、肉桂为主，
大清以石膏、黄连为主，大补以人参、黄 为
主，大滋阴以熟地、二冬为主。每遇大实之症，必须大剂，大黄由五钱至一两；治大寒之症，
附子由三钱增至六钱者；大清之症，石膏由八钱增至五两者，方克捷效，转危为安。所以医
贵阅历、经验，非近世庸愚无识，每以轻药相代，或用数分至钱半，以希起死回生者，何异
痴人说梦耳。夫药性生成，各具专能，生克制化，用以补偏救弊，断非他物可代。
然用药之道，各有次序，凡邪犯上焦、心肺、头目、清窍，则宜轻清之品，不宜重味，药
过病所，反伤中下。郁结之病，治从轻宣柔润，不宜苦重、大热、补涩之品，非徒无效，而反增
病也。倘妇女崩漏，治宜重大之剂，方可胜任；若用轻小之剂，扬汤止沸，于病无济。大泻之
，汤剂直过病所，不能留恋，宜用末药以缓止之。至疯狂、淫疮、疫疠等患，皆宜重下，轻
微之品难于取效。所列各法，皆平日历验心得，用特录记，以备研究，作后进之模范也可。
澜按∶用药之道，言之精且详矣。大病用大剂，方克胜任，庶免正虚邪盛，更难挽救，是
平素经验阅历之言。论中石膏用至五两，大黄用至一两，桂、附等亦五六钱者，是《内经》有
故无损之遗法，然非有先生之才识则可，无先生之胆略则不可。学人尤当熟读深思，潜心推
测，自能心领神会而造精微，步良医之后尘，庶不负指归之教焉。
治病的关键，首先在于辨别药性。用药得当就能救人，用药不当就会杀人。那些性味猛烈的药物，人们容易知晓；其中有一些极其平和、寻常的药物，在细微之处也能导致失败（造成医疗事故），必须潜心研究，才能避免祸患。曾经回忆过去治疗虚证痘疮时，使用四君子汤，虽然平稳妥当，但偶尔也有干枯死亡的病例，这是因为白术的燥性和茯苓的渗利之性造成了大害；有阴虚患者使用四物汤尚且能招致过错，因为川芎、当归辛散走窜耗伤阴液。茯苓、白术是极平和的药性，川芎、当归是体阴而微辛的气，尚且能遗留危害，至于暑热、霍乱病，服用生姜汤立刻产生弊端的，书中记载难以枚举。更有那些药物本来不对症，却因其能拔苗助长（强行提升正气或症状），或者治疗标病有小效，而其危害在过后才显现的情况；或者因病重药轻、药邪相互抗拒，初服反而觉得不安，患者不知晓，随即更换医生，反而导致混乱的情况，凡此之类，尤其属于隐秘而难预测的。只有细心讨论药物与病症，如何相互制约、如何相互排斥的道理，从而用得适宜。譬如气虚者，只宜用甘温纯正的方剂，不能稍加克伐消耗的药物，时间紧迫不容发间。如果病久胃虚，仅宜用人参、人参地黄之类的药物，如果夹杂炒白术、二陈汤、当归、川芎等，就觉得不妥。又如阴极虚而亡血者，只宜纯甘柔润的方法，如三才复脉等法，但必须去掉桂枝、生姜。推及到妇女胎产方面，或是血崩过多，或是郁勃日久，都不得使用升散的药物。又有化燥、化热的证候，不能夹杂丝毫辛温苦燥的药物。常见大泄泻的病，服用胃苓汤反而加剧，乃是猪苓、泽泻渗利太过，反而帮助了下行造成的祸患。其他如寒证忌清凉，热证忌辛温；虚证忌消耗，实证忌涩滞；上逆者，宜降不宜升；下泄者，宜固涩不宜降泄；散乱者，宜收敛不宜辛散；郁结者，宜宣达不宜涩滞。用药相当则病愈，用药相忌则病进。
至于身体虚弱消瘦、年老体衰、孕妇、产后之人，如果患有实证，攻逐邪气应当尽早，趁着正气未受重伤，邪气未深入体内，千万不要畏惧攻法，拖延致使正气被邪气伤害，那时挽救就来不及了。在这危疑之际，是有起死回生之法的时候。我治疗大病，必定使用大剂量药物，屡次获得奇效，如大发散以麻黄、羌活为主，大攻下以大黃、芒硝为关键，大温补以附子、干姜、肉桂为主，大清解以石膏、黄连为主，大滋补以人参、黄芪为主，大滋阴以熟地黄、天冬、麦冬为主。每次遇到大实之症，必须用大剂量，大黄由五钱增至一两；治疗大寒之症，附子由三钱增至六钱的；大清之症，石膏由八钱增至五两的，才能取得快速疗效，转危为安。所以医学贵在阅历和经验，不是近代庸俗愚昧无识的人，每用轻药替代，或用几分至一钱半，希望起死回生的，这跟痴人说梦有什么区别呢。药物的性味生成，各具专门功能，通过生克制化，用来补救偏颇和弊端，绝对不是其他药物可以替代的。
然而用药之道，各有次序。凡是邪气侵犯上焦、心肺、头目、清窍，则宜用轻清的药物，不宜用重味的药物，否则药力超过病所，反而损伤中下焦。郁结的疾病，治疗宜从轻宣柔润，不宜用苦重、大热、补涩的药物，不仅无效，反而增加病情。倘若妇女崩漏，治疗宜用重大剂量的药物，方可胜任；如果用轻小剂量的药物，如同扬汤止沸，对病情没有帮助。大泻病的汤剂直接经过病所，不能停留，宜用散末药来缓慢止住。至于疯狂、淫疮、疫疠等疾病，都宜用重剂攻下，轻微的药物难于取效。所列的各种方法，都是平日经历验证的心得体会，特意记录在此，以备研究，作为后学的模范也可以。
澜按：用药之道，说得精辟且详细了。大病用大剂量，方能胜任，以免正气虚弱邪气强盛，更难挽救，这是平时经验和阅历的话。论中提到石膏用到五两，大黄用到一两，桂枝、附子等也用到五六钱的，这是《内经》“有故无损”（有病则病受之，不伤正气）的遗法，然而没有先生的才识是不行的，没有先生的胆略也是不行的。学人尤其应当熟读深思，潜心推测，自然能心领神会而达到精微境界，追随良医的步伐，才不辜负指归的教诲啊。
The key to treating disease lies first in distinguishing the properties of medicinal substances. When medicines are used appropriately, they save lives; when used inappropriately, they cause death. For those with fierce and pungent properties, people easily know them; however, among those that are extremely mild and ordinary, even subtle differences can lead to failure (medical mishaps), requiring profound study to avoid harm. I recall once treating acne vulgaris with deficiency patterns using Sijunzi Tang (Four Gentlemen Decoction); although it was very safe and steady, there were occasional cases of drying up and death because the dryness of Baizhu Rhizoma Atractylodis Macrocephalae and the leaching nature of Poria (Fu Ling) caused great harm; for patients with Yin deficiency, using Siwu Tang (Four Substances Decoction) could still incur blame because Xiong (Chuanxiong Rhizoma) and Gui (Danggui Radix Angelicae Sinensis) are acrid and dispersing, consuming Yin. Fu Ling and Baizhu have extremely mild properties, while Xiong and Gui have a Yin-nourishing yet slightly acrid nature, yet they can still leave behind harm. As for summerheat-heat or cholera, taking Shengjiang Tang (Fresh Ginger Decoction) causing immediate detriment is recorded in books innumerable. Furthermore, there are cases where the medicine does not match the syndrome, but due to its ability to "pull seedlings to help them grow" (forcing improvement), or having minor effects on superficial symptoms, while its harm manifests only later; or where the disease is severe but the medication is light, leading to resistance between medicine and pathogen, causing initial discomfort upon ingestion. If the patient, unaware of this, changes doctors, it leads to confusion. Such cases are particularly obscure and unpredictable. One must carefully discuss the relationship between medicine and disease, understanding how they constrain or oppose each other, to use them appropriately. For instance, Qi deficiency requires purely sweet-warm formulas without any draining or consuming agents, as time is of the essence. If chronic illness has led to Stomach deficiency, only Ren Shen (Ginseng Radix et Rhizoma) or Renshen Dihuang preparations should be used; adding Chao Baizhu (Stir-fried Rhizoma Atractylodis Macrocephalae), Erchen Tang (Two-Cured Decoction), Danggui, or Chuanxiong would be inappropriate. Similarly, for extreme Yin deficiency with blood loss, purely sweet and moistening methods like Sancai Fumai (Three Immortals Pulse-Replenishing Method) should be used, but Guizhi Ramulus Cinnamomi and Shengjiang must be removed. Extending this to women's pregnancy and postpartum conditions, whether from excessive uterine bleeding or long-standing stagnation, ascending and dispersing agents must not be used. In syndromes transforming into dryness or heat, no acrid-warm or bitter-dry agents should be included. It is common to see severe diarrhea worsened by Weiling Tang (Weiling Decoction) because Zhuling Polyporus and Zexia Alisma excessively promote drainage, inadvertently assisting downward flow. Generally, cold syndromes forbid cooling agents, heat syndromes forbid acrid-warm agents; deficiency forbids draining, excess forbids astringing; upward rebellion requires descending rather than ascending; downward leakage requires securing rather than descending; scattering requires converging rather than dispersing; stagnation requires venting rather than astringing. When medicines correspond to the condition, the disease heals; when they conflict, the disease progresses.
For the emaciated, the elderly, pregnant women, and postpartum women, if they present with excess syndromes, attacking pathogens should be done early, while healthy Qi is not yet severely damaged and pathogens have not deeply penetrated. Do not fear attack therapies; delaying allows pathogens to damage healthy Qi, making rescue impossible. In such critical moments, there are methods to revive the dying. When I treat major diseases, I invariably use large doses of potent medicines, repeatedly achieving miraculous effects: for major dispersion, Ephedrae Herba (Mahuang) and Notopterygii Rhizoma et Radix (Qianghuo) are primary; for major purgation, Rhei Radix et Rhizoma (Dahuang) and Natrii Sulfas (Mangxiao) are essential; for major warming, Aconiti Lateralis Radix Praeparata (Fuzi), Zingiberis Rhizoma (Ganjiang), and Cinnamomi Cortex (Rougui) are primary; for major clearing, Gypsum Fibrosum (Shigao) and Coptidis Rhizoma (Huanglian) are primary; for major tonification, Ginseng Radix et Rhizoma (Renshen) and Astragali Radix (Huangqi) are primary; for major Yin nourishment, Rehmanniae Radix Praeparata (Shudihuang), Asparagi Tuber (Tian Dong), and Ophiopogonis Tuber (Mai Dong) are primary. Whenever encountering major excess syndromes, large doses are necessary: Dahuang from 5 qian to 1 liang; for major cold syndromes, Fuzi increased from 3 qian to 6 qian; for major clearing syndromes, Shigao increased from 8 qian to 5 liang. Only then can rapid efficacy be achieved, turning danger into safety. Therefore, medicine values experience and observation. It is not for modern mediocre and ignorant practitioners who substitute light medicines or use mere fen to half a qian, hoping for revival—this is akin to a fool talking about dreams. Medicinal properties arise from their specific natures, possessing unique functions, utilizing generation and restriction to correct imbalances; they cannot be replaced by other substances.
However, the way of using medicines follows a sequence. When pathogens invade the Upper Jiao, Heart, Lung, head, eyes, or clear orifices, light and clear agents are suitable, not heavy ones; otherwise, the medicine may exceed the site of disease and damage the Middle and Lower Jiao. For stagnation syndromes, treatment should start with light venting and moistening, avoiding bitter-heavy, hot, or astringent-tonic agents, which are not only ineffective but also aggravate the disease. Conversely, for women with metrorrhagia and metrostaxis, heavy doses are required to be effective; using light doses is like stirring soup to stop boiling, benefiting nothing. For severe diarrhea, decoctions pass through the site quickly and do not linger, so powdered medicines should be used for slow cessation. For madness, venereal sores, and epidemics, heavy purgative doses are appropriate; light agents are difficult to effect. The methods listed above are all personal experiences verified over time, recorded here for study and as models for successors.
Lan notes: The principles of using medicine are stated precisely and in detail. Using large doses for major diseases ensures effectiveness, preventing situations where healthy Qi is weak and pathogens are strong, making rescue difficult; these are words born of daily experience. Mentioning Shigao up to 5 liang, Dahuang up to 1 liang, and Rougui/Fuzi up to 5-6 qian reflects the legacy method from *Neijing*: "If there is pathology, there is no harm [to healthy Qi]" (pathogens bear the brunt). However, this requires the practitioner's talent and insight, and their courage and decisiveness. Students must read carefully, think deeply, and speculate profoundly to understand intuitively and reach subtlety, following in the footsteps of good physicians, thereby honoring the guidance provided.