或问曰∶金石之药，埋之不腐，煮之不烂，用能固气，可以延年；草木之药，未免腐烂
，焉
有固驻之功？答曰∶金石之药，其性 悍，而无津液之润。人服金石，当壮盛时，未见其害
；及其衰弱，毒则发焉。夫壮年气盛则能制，血旺则能行，故不发也。及其气虚血衰，不能
行制，毒积于脏腑，大患生焉。何固驻之有？或问曰∶亦有未衰弱而石发，何也？答曰∶忧恚
在心，气血不宣畅，营卫涩滞，不能行石，热结不散，随其所积，发诸痈疮。又有服石之人
，倚石热而纵欲，恃石势而啖肥浓，以为奇效，而不知精液潜耗，猛热遂作，烈火燎原，罕
不焦土，问曰∶金石之为害若此，农皇何以标之于本经？答曰∶大虚积冷之人，不妨暂服，
疾愈即止，亦无害也。又问曰∶石性标悍，脏衰则发，今病者先虚而后服石，岂能制其势力
乎？且未见其害何也？答曰∶初服之人，石势未积，又乘虚冷之体，焉得发邪。又曰∶草木自
不能久，岂能益人载？答曰∶服之不倦，势力相接，积年之后，必获大益。夫攻之药，以疾
瘥见功；固驻之方，觉安为效。形神既宁，则寿命日永矣。
医贵适中，毋太过，毋不及。用药失于不及，譬如浅力之弓，取兽百步之外；又如升斗
之水
，救车薪之火，势必无济也。用药失于太过，譬如牮屋，用机过力，梁柱损裂；又如饮酒过
量
，呕吐委顿，有何益乎？徒见其害。二者似是而实谬，为医不可不知也。治病先表后里，先
攻后补，先本后标，先气后血，此一定之理也。然而有先里后表者，（如痘疮斑疹不起，用
承气下之。）有表里并治者，（如伤寒之用大柴胡汤。）有先补后攻者，（古人治大积大聚多用
先补后攻。）有攻补并施者，（如枳术丸、黄龙汤）有先标后本者，（所谓急则先治其标。）有
标本并顾者，（如参苏饮、人参白虎之类。）有先血后气者，（如用承气后用白虎等汤。）有
气血并治并补者。（如通圣散、八珍汤之类。）为医亦不可不知也。
有人问：“金石类药物，埋在地下不会腐烂，煮在水中不会烂掉，服用它们能固摄元气，可以延年益寿；而草木类药物，难免会腐烂，哪里有什么固驻（稳固身体、延缓衰老）的功效呢？”
回答说：“金石类药物的药性猛烈刚悍，缺乏津液的滋润。人如果在身体壮盛时服用金石药，看不出有什么害处；等到身体衰弱时，毒性就会发作。因为壮年时正气旺盛就能制约药性，血液充盈就能推动运行，所以毒邪不会发作。等到气虚血衰时，既不能制约也不能推动，毒邪积聚在脏腑中，大祸就产生了。这哪里谈得上什么固驻延年呢？”
又问：“也有人在身体尚未衰弱时就出现‘石发’（服石后产生的热毒病症），这是为什么呢？”
回答说：“如果心中充满忧愁愤怒，导致气血不宣畅，营卫之气涩滞，无法运化金石之药，热邪结聚不散，随着所积之处，就会引发各种痈疮。还有那些服用石药的人，倚仗石药的燥热而放纵性欲，凭借石药的势头而食用肥甘厚味，自以为有奇效，却不知道精液已在暗中耗损，猛烈的热邪随即产生，如同烈火燎原，很少有不烧成焦土的。
又问：“金石的危害如此严重，神农氏为什么在《本经》（《神农本草经》）中标注它呢？”
回答说：“对于体内积冷的大虚之人，不妨暂时服用，病愈后立即停止，也是没有害处的。”
又问：“石药性质标悍（猛烈），脏腑衰弱时就会发作。现在病人先虚弱而后服用石药，怎么能制约它的势力呢？况且并没有看到危害，这是为什么呢？”
回答说：“刚开始服药的人，石药的势力还没有积聚，再加上患者本身是虚冷的体质，怎么会发作呢？”
又问：“草木药物自己都不能长久保存，怎么能有益于人的寿命呢？”
回答说：“如果连续不断地服用，药力接连不断，积累多年之后，必定能获得巨大的益处。攻伐疾病的药物，以疾病痊愈为功效；固驻延年的方剂，以感觉安宁舒适为效果。形体和精神既然安宁，寿命就会日益长久。”
治病贵在适中，不要太过分，也不要不够。用药力度不够，就像用力量小的弓去射百步之外的野兽；又像用升斗那么少的水去救一车柴火的火灾，势必无济于事。用药力度太过，就像支撑房屋时用力过猛，导致梁柱损坏断裂；又像饮酒过量，导致呕吐疲惫，有什么好处呢？只看到了它的害处。这两者看似合理实则谬误，做医生的不可不知道。
治疗疾病通常遵循先解表后治里、先攻邪后补虚、先治本后治标、先调气后调血的固定原则。然而也有先治里后解表的，（例如痘疮斑疹不起发，使用承气汤攻下。）有表里同治的，（例如伤寒症使用大柴胡汤。）有先补后攻的，（古人治疗大的积聚病症多采用先补后攻的方法。）有攻补兼施的，（例如枳术丸、黄龙汤。）有先治标后治本的，（所谓急则先治其标。）有标本兼顾的，（例如参苏饮、人参白虎汤之类。）有先调血后调气的，（例如先用承气汤后用白虎汤等。）有气血并治并补的。（例如通圣散、八珍汤之类。）做医生的也不可不知道这些变通之法。
A question was asked: "Medicines of metals and stones, when buried, do not rot; when boiled, do not disintegrate. Their use can consolidate Qi (vital energy) and prolong life. However, herbal medicines from plants inevitably rot. How can they possess the power to consolidate and sustain?"
The answer was: "The nature of metal and stone medicines is fierce and harsh, lacking the moistening quality of body fluids. When a person takes such medicines during their prime, no harm is seen; but when they become weak, the toxicity manifests. In youth, abundant Qi can control it, and vigorous Blood can circulate it, so it does not manifest. However, when Qi becomes deficient and Blood declines, neither control nor circulation is possible. Toxicity accumulates in the Zang-Fu organs, giving rise to major disasters. Where is there any consolidation or longevity?"
Another question arose: "There are cases where 'stone eruption' (toxic heat reactions caused by taking mineral drugs) occurs even before weakness sets in. Why is this?"
The answer was: "If sorrow and anger reside in the heart, causing Qi and Blood to fail to flow smoothly, and Ying (Nutritive) and Wei (Defensive) energies to become stagnant, the mineral substances cannot be metabolized. Heat knots and fails to dissipate, manifesting as various sores and abscesses at the site of accumulation. Furthermore, those who take stone medicines may rely on the drug's heat to indulge in sexual activity, or depend on the drug's momentum to consume rich and fatty foods, believing these to be miraculous effects. Unaware that their essence and fluids are secretly depleted, fierce heat arises like a prairie fire, rarely leaving anything but scorched earth."
Another question was posed: "Given such severe harms from metals and stones, why did Shennong (the Divine Farmer) list them in the *Shennong Bencao Jing* (Divine Farmer's Materia Medica)?"
The answer was: "For individuals with extreme deficiency and accumulated cold, temporary use is permissible. Once the illness is cured, one should stop, and there will be no harm."
Another question followed: "Stone medicines have a fierce nature and manifest toxicity when Zang-Fu organs decline. If a patient is first deficient and then takes stone medicines, how can they control the drug's potency? Moreover, why is no harm observed?"
The answer was: "When a person first takes the medicine, the drug's potency has not yet accumulated. Additionally, since the patient's constitution is already deficient and cold, how could it manifest?"
Another question was raised: "Plant-based herbs cannot last long themselves; how can they benefit human lifespan?"
The answer was: "If taken continuously without fatigue, the medicinal forces connect and accumulate over years, surely yielding great benefits. Medicines for attacking pathogens achieve merit through the resolution of disease; formulas for consolidation and sustenance achieve efficacy through a sense of peace and comfort. With both form and spirit tranquil, lifespan will daily increase."
In medicine, balance is prized; one must avoid excess and deficiency. Using medication insufficiently is like using a weak bow to hunt beasts beyond a hundred paces, or like trying to extinguish a fire on a cartload of firewood with water from a small measure; it will certainly be of no help. Using medication excessively is like shoring up a house with too much force, damaging the beams and pillars; or like drinking to excess, resulting in vomiting and prostration, offering no benefit—only harm is seen. These two approaches seem plausible but are actually erroneous; physicians must understand this.
Treating diseases generally follows fixed principles: exterior before interior, attack before tonify, root before branch, Qi before Blood. However, there are exceptions: treating interior before exterior (e.g., using Chengqi Decoction to purge downward when measles/rash fails to erupt); treating exterior and interior simultaneously (e.g., using Da Chaihu Decoction for Shaoyang-Taiyang combined syndrome); tonifying before attacking (ancients often used this for large accumulations); combining attack and tonification (e.g., Zhizhu Wan, Huanglong Tang); treating branch before root (as in 'in acute conditions, treat the branch first'); addressing both root and branch simultaneously (e.g., Renshen Suxin Yin, Renshen Baitu Tang); treating Blood before Qi (e.g., using Chengqi Decoction followed by Baitu Tang); and treating and tonifying both Qi and Blood simultaneously (e.g., Tongsheng San, Bazhen Tang). Physicians must also be aware of these variations.