轻清成象，本乎天者亲上也；（味薄，茶之类。）重浊成形，本乎地者亲下也。（味浓，大黄之类。）
气味辛甘发散为阳，酸苦涌泻为阴。清中清者，清肺以助其天真；清中浊者，荣华腠理。浊中清
者，荣养于神；浊中浊者，坚强骨髓。
凡药之所用，皆以气味为主。补泻在味，随时而换。气薄为阳中之阴，气浓者为阳中之阳；
味薄为阴中之阳，味浓者为阴中之阴。辛、甘、淡之热者，为阳中之阳；辛、甘、淡之寒者，为
阳中之阴。酸、苦、咸之寒者，为阴中之阴；酸、苦、咸之热者，为阴中之阳。夫辛、甘、淡、
酸、苦、咸乃味之阴阳，又为地之阴阳也。温凉寒热，乃气之阴阳，又为天之阴阳也。气味生成，
而阴阳造化之机存焉。一物之内，气味兼有；一药之中，理性具焉。主对治疗，由是而出。
凡药苦平升，微寒平亦升，甘辛平降，甘寒泻火，苦寒泻湿热，苦甘寒泻血热。
茯苓淡，为在天之阳也。阳当上行，何谓利水而泄下？亦不离乎阳之体，故人手太阳。麻黄
苦，为在地之阴也，阴当下行，何谓发汗而升上？经云∶味之薄者，乃阴中之阳，所以麻黄发
汗而升上，然亦不离乎阴之体，故入手太阴。附子气之浓者，乃阳中之阳，故经云发热；大黄
味之浓者，乃阴中之阴，故经云泄下。粥淡，为阳中之阴，所以利小便；茶苦，为阴中之阳，所以
清头目。
凡药根之在土中者，中半以上，脉之上行也，以生苗者为根；中半以下，气脉之下行也，以
入土者为梢。病在中焦与上焦者，用根；在下焦者，用梢∶根升梢降。大凡药根有上、中、下，
人身半以上，天之阳也，用
头；在中焦者，用身半以下，地之阴也，用梢。述类象形者也。
凡药之五味，大抵随五脏所入之味而为补泻。甘入脾，酸入肝，咸入肾，苦入心，辛入肺。
所入之味，亦不过因其性而调治之。辛主散，酸主收，甘主缓，苦主坚，咸主软。辛能散结、
润燥，苦能燥湿、软坚，咸能软坚，酸能收缓，甘能缓急，淡能利窍。
肝苦急，急食甘以缓之。（甘草。）心苦缓，急食酸以收之。（五味子。）脾苦湿，急食苦以燥之。
（白术。）肺苦气上逆，急食苦以泻之。（诃子皮。）肾苦燥，急食辛以润之。（知母、黄柏。）
肾欲坚，急食苦以坚之。（知母。）肝欲散，急食辛以散之。（川芎。）心欲软，急食咸以软之。
（芒硝。）脾欲缓，急食甘以缓之。（甘草。）肺欲收，急食酸以收之。（白芍。）肝虚以陈皮、
生姜之类补之。经云∶虚则补其母。水能生木，肾乃肝之母，肾水也，若补其肾，熟地黄、黄柏
是也。如无他证，惟不足，钱氏地黄丸主之，实则白芍药泻之。如无他证，钱氏泻青丸主之，实
则泻其子，心乃肝之子，以甘草泻心。
心虚则炒盐补之，虚则补其母。木能生火，肝乃心之母，肝木也，心火也，以生姜补肝。如
无他证，钱氏安神丸是也。实则甘草泻之。如无他证，以钱氏方中重则泻心汤，轻则导赤散。
脾虚则甘草、大枣之类补之。实则以枳壳泻之。如无他证，虚则以钱氏益黄散，实则泻黄
散。心乃脾之母，以炒盐补心。肺乃脾之子，以桑白皮泻肺。
肺虚则五味子补之，实则桑白皮泻之。如无他证，实则用钱氏泻白散，虚则用阿胶散。虚则
以甘草补脾土，补其母也。实则以泽泻泻肾水，泻其子也。
肾虚则熟地黄、黄柏补之，泻以泽泻泻之。肾本无实，本不可泻，钱氏有补肾地黄丸，
无泻肾之药。肺乃肾之母，金生水故也，以五味子补肺而已。
Light and clear qi forms the image of Heaven; things originating from Heaven tend to move upward. (Taste is thin, such as tea.) Heavy and turbid qi forms the structure of Earth; things originating from Earth tend to move downward. (Taste is strong, such as Rhizoma et Radix Rhei, Dahuang.)
Among flavors and aromas, pungent and sweet flavors have a dispersing action and belong to Yang; sour and bitter flavors have a vomiting and purging action and belong to Yin. Among the clear substances, those that are purely clear clear the Lungs to assist Tianzhen Qi (Innate True Qi); those that are clear yet turbid nourish the Couli (interstitial spaces). Among the turbid substances, those that are turbid yet clear nourish the Shen (Spirit); those that are purely turbid strengthen the Marrow and Bones.
The application of all herbs primarily depends on their flavor and aroma. Tonification and Purging depend on the flavor and change with time. Aroma that is thin belongs to Yin within Yang; aroma that is strong belongs to Yang within Yang. Flavor that is thin belongs to Yang within Yin; flavor that is strong belongs to Yin within Yin. Pungent, sweet, and bland flavors that are hot belong to Yang within Yang; pungent, sweet, and bland flavors that are cold belong to Yin within Yang. Sour, bitter, and salty flavors that are cold belong to Yin within Yin; sour, bitter, and salty flavors that are hot belong to Yang within Yin. The pungent, sweet, bland, sour, bitter, and salty flavors constitute the Yin-Yang of flavors, which also correspond to the Yin-Yang of Earth. Warm, cool, cold, and hot properties constitute the Yin-Yang of aromas, which also correspond to the Yin-Yang of Heaven. Once flavors and aromas are generated, the mechanism of Yin-Yang creation exists within them. Within a single substance, both flavor and aroma are present; within a single herb, its nature and property are complete. Treatment targeting specific conditions arises from this.
Generally, herbs with a bitter taste and neutral temperature ascend; those with slightly cold temperature and neutral balance also ascend; those with sweet and pungent tastes and neutral temperature descend; sweet and cold herbs purge Fire; bitter and cold herbs purge Damp-Heat; bitter and sweet cold herbs purge Blood Heat. Fuling (Poria) has a bland taste and belongs to the Yang of Heaven. Since Yang should ascend, why does it promote urination and drain downward? This is because it remains true to its Yang nature, thus entering the Taiyang Channel. Mahuang (Ephedrae Herba) has a bitter taste and belongs to the Yin of Earth. Since Yin should descend, why does it induce sweating and ascend? The Classic states: "Flavors that are thin are Yin containing Yang." Therefore, Mahuang induces sweating and ascends, yet it remains true to its Yin nature, thus entering the Taiyin Channel. Fuzi (Radix Aconiti Lateralis Preparata) has a strong aroma and is Yang within Yang, hence the Classic states it generates heat. Dahuang (Rhizoma et Radix Rhei) has a strong flavor and is Yin within Yin, hence the Classic states it purges downward. Congee has a bland taste and is Yang within Yin, thus promoting urination. Cha (Tea) has a bitter taste and is Yin within Yang, thus clearing the head and eyes.
For herbal roots growing in the soil, the upper half has ascending pulse energy and is considered the root where shoots emerge; the lower half has descending pulse energy and is considered the tip (shao). For diseases in the Middle Jiao and Upper Jiao, use the root; for diseases in the Lower Jiao, use the tip: roots ascend, tips descend. Generally, herbal roots have upper, middle, and lower parts. The upper part of the human body corresponds to the Yang of Heaven, so use the head of the herb; the middle part corresponds to the Middle Jiao, so use the body of the herb; the lower part corresponds to the Yin of Earth, so use the tip of the herb. This follows the principle of taking analogies based on form.
The five flavors of herbs generally perform tonification and purging according to the flavors entering the Five Zang Organs. Sweet enters the Spleen, sour enters the Liver, salty enters the Kidney, bitter enters the Heart, and pungent enters the Lung. The entering flavors simply regulate treatment based on their nature. Pungent governs dispersion, sour governs astringency, sweet governs moderation, bitter governs firmness, and salty governs softening. Pungent can dissipate nodules and moisten dryness; bitter can dry dampness and soften hardness; salty can soften hardness; sour can collect and moderate; sweet can relieve urgency; bland can open orifices.
When the Liver suffers from tension, urgently consume sweet flavors to moderate it. (Gancao, Glycyrrhizae Radix et Rhizoma.) When the Heart suffers from laxity, urgently consume sour flavors to astringe it. (Wuweizi, Schisandrae Fructus.) When the Spleen suffers from dampness, urgently consume bitter flavors to dry it. (Baizhu, Atractylodis Macrocephalae Rhizoma.) When the Lung suffers from rebellious Qi, urgently consume bitter flavors to purge it. (Heqipi, Pericarpium Arecae Semen Preparatum.) When the Kidney suffers from dryness, urgently consume pungent flavors to moisten it. (Zhimu, Anemarrhenae Rhizoma; Huangbai, Phellodendri Cortex.) When the Kidney desires firmness, urgently consume bitter flavors to firm it. (Zhimu, Anemarrhenae Rhizoma.) When the Liver desires dispersion, urgently consume pungent flavors to disperse it. (Chuanxiong, Ligustici Chuanxiong Rhizoma.) When the Heart desires softness, urgently consume salty flavors to soften it. (Mangxiao, Natrii Sulfas.) When the Spleen desires moderation, urgently consume sweet flavors to moderate it. (Gancao, Glycyrrhizae Radix et Rhizoma.) When the Lung desires astringency, urgently consume sour flavors to astringe it. (Baishao, Paeoniae Radix Alba.) For Liver deficiency, use Chenpi (Pericarpium Citri Reticulatae) and Shengjiang (Zingiberis Rhizoma Recens) to tonify. The Classic states: "Deficiency requires tonifying the Mother." Water generates Wood; the Kidney is the Mother of the Liver. The Kidney belongs to Water. To tonify the Kidney, use Shudihuang (Rehmanniae Radix Preparata) and Huangbai (Phellodendri Cortex). If there are no other symptoms, only insufficiency, Qian Shi Dihuang Wan (Qian's Rehmannia Pill) is indicated. If excess, Baishao (Paeoniae Radix Alba) purges it. If there are no other symptoms, Qian Shi Xieqing Wan (Qian's Draining Green Pill) is indicated. If excess, purge the Child; the Heart is the Child of the Liver, so use Gancao (Glycyrrhizae Radix et Rhizoma) to purge the Heart.
For Heart deficiency, use fried salt to tonify; deficiency requires tonifying the Mother. Wood generates Fire; the Liver is the Mother of the Heart. The Liver belongs to Wood, the Heart to Fire. Use Shengjiang (Zingiberis Rhizoma Recens) to tonify the Liver. If there are no other symptoms, Qian Shi Anshen Wan (Qian's Calming Spirit Pill) is indicated. If excess, use Gancao (Glycyrrhizae Radix et Rhizoma) to purge it. If there are no other symptoms, for severe cases use Qian Shi Xie Xin Tang (Qian's Purging Heart Decoction), and for mild cases use Dao Chi San (Guide Out Red Powder).
For Spleen deficiency, use Gancao (Glycyrrhizae Radix et Rhizoma) and Dazao (Jujubae Fructus) to tonify. If excess, use Zhike (Aurantii Fructus Immaturus) to purge it. If there are no other symptoms, for deficiency use Qian Shi Yihuang San (Qian's Strengthening Yellow Powder), and for excess use Xiehuang San (Draining Yellow Powder). The Heart is the Mother of the Spleen; use fried salt to tonify the Heart. The Lung is the Child of the Spleen; use Sangbaipi (Mori Cortex) to purge the Lung.
For Lung deficiency, use Wuweizi (Schisandrae Fructus) to tonify; if excess, use Sangbaipi (Mori Cortex) to purge it. If there are no other symptoms, for excess use Qian Shi Xiebai San (Qian's Purging White Powder), and for deficiency use Ejiao San (Donkey-Hide Gelatin Powder). For deficiency, use Gancao (Glycyrrhizae Radix et Rhizoma) to tonify Spleen Earth, which is tonifying the Mother. For excess, use Zexie (Alismatis Rhizoma) to purge Kidney Water, which is purging the Child.
For Kidney deficiency, use Shudihuang (Rehmanniae Radix Preparata) and Huangbai (Phellodendri Cortex) to tonify, and Zexie (Alismatis Rhizoma) to purge. The Kidney essentially has no excess and should not be purged. Qian Shi has Bushen Dihuang Wan (Tonifying Kidney Rehmannia Pill) but no formula for purging the Kidney. The Lung is the Mother of the Kidney because Metal generates Water; therefore, only Wuweizi (Schisandrae Fructus) is used to tonify the Lung.