如仲景治表虚，制桂枝汤方，桂枝味辛热，发散、助阳、体轻，本乎天者亲上，
故桂枝为君，芍药、甘草佐之。〔如〕阳脉涩，阴脉弦，法当腹中急痛，制小建中
〔汤〕方，芍药为君，桂枝、甘草佐之。一则治其表虚，一则治其里虚，是各言其主
用也。后人之用古方者，触类而长之，则知其本，而不致差误矣。
黄连泻心火，黄芩泻肺火，白芍药泻肝火，知母泻肾火，木通泻小肠火，黄芩泻大
肠火，石膏泻胃火。柴胡泻三焦火，〔须用〕黄芩佐之；柴胡泻肝火，须用黄连佐之，
胆经亦然。黄柏泻膀胱火，又曰龙火，膀胱〔乃〕水之府，〔故曰龙火〕也。
以上诸药，各泻各经之火，不惟止能如此，更有治病，合为君臣，处详其宜而用
之，不可执而言也。
太阳经，羌活；在下者黄柏，小肠、膀胱也。少阳经，柴胡；在下者青皮，胆、三焦
也。阳明经，升麻、白芷；在下者，石膏，胃、大肠也。太阴经，白芍药，脾、肺也。少阴
经，知母，心、肾也。厥阴经，青皮；在下者，柴胡，肝、包络也。以上十二经之的药也。
Just as Zhang Zhongjing treated exterior deficiency syndrome and formulated the Guizhi Tang (Cinnamon Twig Decoction), where Guizhi (Cinnamon Twig) is acrid and hot in nature, possessing dispersing and yang-assisting properties, and is light in texture, following the heavenly qi to ascend; thus, Guizhi serves as the Sovereign herb, with Shaoyao (White Peony Root) and Gancao (Licorice Root) acting as Assistant herbs. [If] the Yang pulse is choppy and the Yin pulse is string-taut, according to the principles, there should be acute pain in the abdomen; therefore, the Xiaojianzhong Tang (Minor Construct the Middle Decoction) was formulated, where Shaoyao (White Peony Root) is the Sovereign herb, and Guizhi (Cinnamon Twig) and Gancao (Licorice Root) are Assistants. The former treats exterior deficiency, while the latter treats interior deficiency; this illustrates their respective primary applications. When later generations use ancient formulas, by extending knowledge through analogy, they can grasp the fundamental principles and avoid errors.
Huanglian (Coptis Rhizome) clears Heart Fire; Huangqin (Scutellaria Root) clears Lung Fire; Baishao (White Peony Root) clears Liver Fire; Zhimu (Anemarrhena Rhizome) clears Kidney Fire; Mutong (Akebia Stem) clears Small Intestine Fire; Huangqin (Scutellaria Root) clears Large Intestine Fire; Shigao (Gypsum Fibrosum) clears Stomach Fire. Chaihu (Bupleurum Root) clears Sanjiao (Triple Burner) Fire, requiring Huangqin (Scutellaria Root) as an Assistant; Chaihu (Bupleurum Root) clears Liver Fire, requiring Huanglian (Coptis Rhizome) as an Assistant; the same applies to the Gallbladder Meridian. Huangbai (Phellodendron Bark) clears Bladder Fire, also referred to as Dragon Fire; since the Bladder is the mansion of water, it is called Dragon Fire.
The aforementioned drugs each clear the fire of their respective meridians. They do not merely perform this function but also treat diseases by forming Sovereign-Minister-Assistant-Envoy structures; one must carefully consider the appropriateness for use and apply them accordingly, without being dogmatic.
For the Taiyang (Greater Yang) Meridian, Qianghuo (Notopterygium Rhizome); for the lower part, Huangbai (Phellodendron Bark), corresponding to the Small Intestine and Bladder. For the Shaoyang (Lesser Yang) Meridian, Chaihu (Bupleurum Root); for the lower part, Qingpi (Aurantii Fructus Pericarpium), corresponding to the Gallbladder and Sanjiao (Triple Burner). For the Yangming (Yang Brightness) Meridian, Shengma (Cimicifugae Rhizome) and Baizhi (Angelicae Dahuricae Radix); for the lower part, Shigao (Gypsum Fibrosum), corresponding to the Stomach and Large Intestine. For the Taiyin (Greater Yin) Meridian, Baishao (White Peony Root), corresponding to the Spleen and Lung. For the Shaoyin (Lesser Yin) Meridian, Zhimu (Anemarrhena Rhizome), corresponding to the Heart and Kidney. For the Jueyin (Terminal Yin) Meridian, Qingpi (Aurantii Fructus Pericarpium); for the lower part, Chaihu (Bupleurum Root), corresponding to the Liver and Pericardium. These are the specific guiding herbs for the twelve meridians.
Bitter flavor is used to purge; Sweet flavor is used to moderate and to disperse; examine its appropriate application; Sour flavor is used to astringe; Acrid flavor is used to disperse; Salty flavor is used to soften hardness; Bland flavor is used to promote diuresis and leach out dampness.
The number of Sovereign herbs is the greatest, Ministers are next, and Assistants/Envoys are least. Regarding the correspondence between herbs and syndromes, for the stagnation or location primarily addressed, equal parts are taken.