伤寒邪气在表者。必渍形以为汗。邪气在里者。必荡涤以为利。其于不外不内。半
表半里。既非发汗之所宜。又非吐下之所对。是当和解则可矣。小柴胡为和解表
里之剂也。柴胡味苦平微寒。黄芩味苦寒。内经曰。热淫于内。以苦发之。邪在半表
半里。则半成熟矣。热气内传。攻之不可。则迎而夺之。必先散热。是以苦寒为主。故
以柴胡为君。黄芩为臣。以成彻然发表之剂。人参味甘温。甘草味甘平。邪气传里。
则里气不治。甘以缓之。是以甘物为之助。故用人参甘草为佐。以扶正气而复之
也。半夏味辛微温。邪初入里。则里气逆。辛以散之。是以辛物为之助。故用半夏为
佐。以顺逆气而散邪也。里气平正。则邪气不得深入。是以三味佐柴胡以和里。生
姜味辛温。大枣味甘温。内经曰。辛甘发散为阳。表邪未已。迤逦内传。既未作实。宜
当两解。其在外者必以辛甘之物发散。故生姜大枣为使。辅柴胡以和表。七物相
合。两解之剂当矣。邪气自表未敛为实。乘虚而凑。则所传不一。故有增损以御之。
胸中烦而不呕。去半夏人参。加栝蒌实。烦者热也。呕者气逆也。胸中烦而不呕。则
热聚而气不逆。邪气欲渐成实也。人参味甘为补剂。去之使不助热也。半夏味辛
为散剂。去之以无逆气也。栝蒌实味苦寒。除热必以寒。泄热必以苦。加栝蒌实以
通胸中郁热。若渴者去半夏。加人参栝蒌根。津液不足则渴。半夏味辛性燥。渗津
液物也。去之则津液易复。人参味甘而润。栝蒌根味苦而坚。坚润相合。津液生而
渴自已。若腹中痛者。去黄芩。加芍药。宜通而塞为痛。邪气入里。里气不足。寒气壅
之。则腹中痛。黄芩味苦寒。苦性坚而寒中。去之则中气易和。芍药味酸苦微寒。酸
性泄而利中。加之则里气得通。而痛自已。若胁下痞硬。去大枣。加牡蛎。内经曰。甘
者令人中满。大枣味甘温。去之则硬渐散。咸以软之。牡蛎味酸咸寒。加之则痞者
消。而硬者软。若心下悸。小便不利者。去黄芩。加茯苓。心下悸小便不利。水蓄而不
行也。内经曰。肾欲坚。急食苦以坚之。坚肾则水益坚。黄芩味苦寒。去之则蓄水浸
行。内经曰。淡味渗泄为阳。茯苓味甘淡。加之则津液通流。若不渴。外有微热。去人
参加桂。不渴则津液足。去人参。以人参为主内之物也。外有微热。则表证多。加桂
以取汗。发散表邪也。若咳者去人参大枣生姜。加五味子干姜。肺气逆则咳。甘补
中。则肺气愈逆。故去人参大枣之甘。五味子酸温。肺欲收。急食酸以收之。气逆不
收。故加五味子之酸。生姜干姜一物也。生者温而干者热。寒气内淫。则散以辛热。
盖诸咳皆本于寒。故去生姜。加干姜。是相假之。以正温热之功。识诸此者。小小变
通。独类而长焉。
柴胡（君半升） 黄芩（臣三两） 人参（佐一两） 甘草（佐三两炙）
半夏（佐半升洗） 生姜（使三两切） 大枣（使十二枚擘）
上七味。以水一斗二升。煮取六升。去渣再煎。取三升。温服一升。日三服。
伤寒病邪气在体表者，必定通过浸渍形体来发汗。邪气在体内者，必定通过荡涤肠胃来通便泻下。如果邪气既不在表也不在里，处于半表半里的位置，这就不适合用发汗法，也不适合用吐法或下法，此时应当采用和解的方法就可以了。小柴胡汤是用于和解表里的方剂。
柴胡味苦、平、微寒。《内经》说：“热邪内盛，用苦味药发散。”邪气在半表半里，已经接近成熟（化热），热气向内传入，攻伐它不可行，那就迎着病势而削弱它，必须先散热，所以以苦寒的药物为主。因此用柴胡作为君药，黄芩作为臣药，以构成彻底发表散热的方剂。
人参味甘、温；甘草味甘、平。邪气传入体内，则里气失调，用甘味药来缓和它，所以用甘味的药物作为辅助。因此用人参、甘草作为佐药，以扶持正气并恢复其功能。
半夏味辛、微温。邪气初入里，则里气上逆，用辛味药来散之，所以用辛味的药物作为辅助。因此用半夏作为佐药，以顺降逆气并驱散邪气。
里气平和端正，则邪气不得深入。这三味佐药配合柴胡来调和里气。生姜味辛、温；大枣味甘、温。《内经》说：“辛味和甘味结合能发散属阳的邪气。”表邪尚未解除，逐渐向内传入，但尚未形成实证，应当表里双解。其中在表的邪气必须用辛甘的药物来发散，所以用生姜、大枣作为使药，辅佐柴胡来调和表气。
以上七味药相合，成为表里双解的方剂，是恰当的。邪气从体表而来，尚未收敛成实，乘虚侵入，传变不一，所以有加减变化来应对。
如果胸中烦闷但不呕吐，去掉半夏、人参，加栝蒌实。烦闷是因为热，呕吐是因为气逆。胸中烦闷而不呕吐，说明热邪聚集而气不逆，邪气将要逐渐成实。人参味甘属于补剂，去掉它以免助长热邪。半夏味辛属于散剂，去掉它因为这里没有气逆的情况。栝蒌实味苦、寒，除热必须用寒性药，泄热必须用苦味药，加入栝蒌实以疏通胸中的郁热。
如果有口渴症状，去掉半夏，加人参、栝蒌根。津液不足就会口渴，半夏味辛性燥，会渗耗津液，去掉它则津液容易恢复。人参味甘而润，栝蒌根味苦而质坚，苦坚与甘润相结合，津液生成而口渴自愈。
如果腹中疼痛，去掉黄芩，加芍药。应当通畅却闭塞导致疼痛，邪气入里，里气不足，寒气壅滞，就会导致腹中痛。黄芩味苦、寒，苦性坚燥且寒凉伤中，去掉它则中气容易调和。芍药味酸、苦、微寒，酸性泄利且通调中焦，加上它则里气得通，疼痛自愈。
如果胁下痞塞坚硬，去掉大枣，加牡蛎。《内经》说：“甘味使人中满。”大枣味甘、温，去掉它则硬结逐渐消散。咸味能软坚，牡蛎味酸、咸、寒，加上它则痞塞消除，硬结变软。
如果心下悸动、小便不利，这是水饮停蓄而不运行。去掉黄芩，加茯苓。《内经》说：“肾欲坚，急食苦以坚之。”坚固肾气则水更加固摄。黄芩味苦、寒，去掉它则蓄水得以流动。《内经》说：“淡味具有渗泄作用，属阳。”茯苓味甘、淡，加上它则津液通流。
如果不口渴，体表有轻微发热，去掉人参，加桂枝。不口渴说明津液充足，去掉人参，因为人参主要作用于内部。体表有轻微发热，说明表证较多，加桂枝以取汗，发散表邪。
如果咳嗽，去掉人参、大枣、生姜，加五味子、干姜。肺气上逆则咳嗽，甘味补中，会使肺气更加上逆，所以去掉人参、大枣的甘味。五味子味酸、温，肺喜收敛，急用酸味以收敛之，气逆不收，所以加五味子的酸味。生姜和干姜本是同一种植物，生姜性温，干姜性热。寒气内侵，则用辛热之品发散。大概各种咳嗽都本源于寒，所以去掉生姜，加干姜，这是借助干姜的正温热之功。
懂得这些道理的人，可以小小地变通运用，同类相推，举一反三。
柴胡（君药，半升） 黄芩（臣药，三两） 人参（佐药，一两） 甘草（佐药，三两，炙）
半夏（佐药，半升，洗） 生姜（使药，三两，切） 大枣（使药，十二枚，掰开）
以上七味药，用水一斗二升，煮取六升，去渣滓，再煎煮，取三升。每次温服一升，每日三次。
When pathogenic factors of cold damage are in the exterior, the body must be soaked to induce sweating. When pathogenic factors are in the interior, the bowels must be purged to promote defecation. If the pathogen is neither in the exterior nor in the interior, but in the half-exterior half-interior stage, it is not suitable for diaphoresis, nor for emesis or purgation; at this time, harmonization is appropriate. Xiao Chai Hu Tang (Minor Bupleurum Decoction) is a formula for harmonizing the exterior and interior.
Chai Hu (Bupleuri Radix) has a bitter, neutral, and slightly cold taste. The *Nei Jing* (Classic of Internal Medicine) states: "For excessive heat within, use bitter substances to disperse." When pathogens are in the half-exterior half-interior, they have nearly matured into heat. As heat transmits inward, direct attack is contraindicated; instead, one should intercept and weaken the pathogen by first dissipating heat. Therefore, bitter-cold herbs are used as the main component. Thus, Chai Hu (Bupleuri Radix) is used as the Sovereign herb, and Huang Qin (Scutellariae Radix) as the Minister herb, to form a formula that thoroughly disperses heat from the exterior.
Ren Shen (Ginseng Radix et Rhizoma) has a sweet and warm taste; Gan Cao (Glycyrrhizae Radix et Rhizoma) has a sweet and neutral taste. When pathogens transmit to the interior, the interior Qi becomes dysfunctional. Sweet substances are used to moderate this dysfunction. Therefore, sweet herbs serve as assistants. Thus, Ren Shen (Ginseng Radix et Rhizoma) and Gan Cao (Glycyrrhizae Radix et Rhizoma) are used as Assistant herbs to support healthy Qi and restore its function.
Ban Xia (Pinelliae Rhizoma) has a pungent and slightly warm taste. When pathogens initially enter the interior, interior Qi rebels upward. Pungent substances are used to scatter this rebellion. Therefore, pungent herbs serve as assistants. Thus, Ban Xia (Pinelliae Rhizoma) is used as an Assistant herb to smooth rebellious Qi and scatter pathogens.
When interior Qi is peaceful and upright, pathogens cannot penetrate deeply. These three Assistant herbs work with Chai Hu (Bupleuri Radix) to harmonize the interior. Sheng Jiang (Zingiberis Rhizoma Recens) has a pungent and warm taste; Da Zao (Jujubae Fructus) has a sweet and warm taste. The *Nei Jing* states: "Pungent and sweet combinations disperse Yang." Since exterior pathogens remain unresolved and gradually transmit inward without yet forming excess, both exterior and interior should be addressed simultaneously. Pathogens in the exterior must be dispersed using pungent and sweet substances. Thus, Sheng Jiang (Zingiberis Rhizoma Recens) and Da Zao (Jujubae Fructus) are used as Envoy herbs to assist Chai Hu (Bupleuri Radix) in harmonizing the exterior.
The combination of these seven ingredients forms an appropriate formula for simultaneous resolution of exterior and interior conditions. Pathogens coming from the exterior have not yet consolidated into excess; invading due to deficiency, their transmission varies. Therefore, modifications are made to address them.
If there is irritability in the chest without vomiting, remove Ban Xia (Pinelliae Rhizoma) and Ren Shen (Ginseng Radix et Rhizoma), and add Gua Lou Shi (Trichosanthis Fructus). Irritability indicates heat; vomiting indicates rebellious Qi. Chest irritability without vomiting means heat is concentrated but Qi is not rebelling, suggesting pathogens are gradually becoming excess. Ren Shen (Ginseng Radix et Rhizoma) is sweet and tonifying; removing it prevents aiding heat. Ban Xia (Pinelliae Rhizoma) is pungent and dispersing; removing it is appropriate because there is no Qi rebellion. Gua Lou Shi (Trichosanthis Fructus) is bitter and cold; clearing heat requires cold nature, and draining heat requires bitter flavor. Adding Gua Lou Shi (Trichosanthis Fructus) unblocks stagnant heat in the chest.
If thirst occurs, remove Ban Xia (Pinelliae Rhizoma), and add Ren Shen (Ginseng Radix et Rhizoma) and Gua Lou Gen (Trichosanthis Radix). Insufficiency of body fluids causes thirst. Ban Xia (Pinelliae Rhizoma) is pungent and drying, depleting fluids; removing it allows fluids to recover easily. Ren Shen (Ginseng Radix et Rhizoma) is sweet and moistening; Gua Lou Gen (Trichosanthis Radix) is bitter and firm/astringent. The combination of bitter-firmness and sweet-moisture generates fluids, resolving thirst.
If abdominal pain occurs, remove Huang Qin (Scutellariae Radix) and add Bai Shao (Paeoniae Radix Alba). Pain results from obstruction where flow is required. Pathogens entering the interior cause insufficiency of interior Qi; cold qi stagnation leads to abdominal pain. Huang Qin (Scutellariae Radix) is bitter and cold; bitterness is drying and cold damages the middle. Removing it helps harmonize middle Qi. Bai Shao (Paeoniae Radix Alba) is sour, bitter, and slightly cold; sourness drains and benefits the middle. Adding it promotes circulation of interior Qi, relieving pain.
If fullness and hardness occur under the ribs, remove Da Zao (Jujubae Fructus) and add Mu Li (Ostreae Concha). The *Nei Jing* states: "Sweet substances cause fullness in the center." Da Zao (Jujubae Fructus) is sweet and warm; removing it allows hardness to gradually dissipate. Salty substances soften hardness. Mu Li (Ostreae Concha) is sour, salty, and cold; adding it resolves fullness and softens hardness.
If palpitations below the heart and difficult urination occur, this indicates water retention without movement. Remove Huang Qin (Scutellariae Radix) and add Fu Ling (Poria). The *Nei Jing* states: "The Kidney desires firmness; urgently consume bitter substances to firm it." Firming the Kidney makes water more secure. Huang Qin (Scutellariae Radix) is bitter and cold; removing it allows retained water to flow. The *Nei Jing* states: "Bland substances have permeating and draining actions, belonging to Yang." Fu Ling (Poria) is sweet and bland; adding it promotes the flow of fluids.
If there is no thirst but slight external heat, remove Ren Shen (Ginseng Radix et Rhizoma) and add Gui Zhi (Cinnamomi Ramulus). No thirst indicates sufficient fluids; removing Ren Shen (Ginseng Radix et Rhizoma) is appropriate as it primarily acts internally. Slight external heat indicates predominant exterior symptoms; adding Gui Zhi (Cinnamomi Ramulus) induces sweating to disperse exterior pathogens.
If coughing occurs, remove Ren Shen (Ginseng Radix et Rhizoma), Da Zao (Jujubae Fructus), and Sheng Jiang (Zingiberis Rhizoma Recens), and add Wu Wei Zi (Schisandrae Fructus) and Gan Jiang (Zingiberis Rhizoma). Rebellious Lung Qi causes coughing. Sweet substances tonify the middle, causing further Lung Qi rebellion; thus, the sweetness of Ren Shen (Ginseng Radix et Rhizoma) and Da Zao (Jujubae Fructus) is removed. Wu Wei Zi (Schisandrae Fructus) is sour and warm. The Lung desires consolidation; urgently consume sour substances to consolidate it. Since Qi rebels and does not consolidate, add the sourness of Wu Wei Zi (Schisandrae Fructus). Sheng Jiang (Zingiberis Rhizoma Recens) and Gan Jiang (Zingiberis Rhizoma) come from the same plant; fresh ginger is warm, dried ginger is hot. For internal invasion of cold qi, pungent-hot substances are used to disperse. Generally, all coughs originate from cold. Thus, Sheng Jiang (Zingiberis Rhizoma Recens) is removed and Gan Jiang (Zingiberis Rhizoma) is added to utilize the proper warming and heating effects.
Those who understand these principles can make minor adjustments, applying logic by analogy.
Chai Hu (Sovereign, half sheng) Huang Qin (Minister, 3 liang) Ren Shen (Assistant, 1 liang) Gan Cao (Assistant, 3 liang, honey-fried)
Ban Xia (Assistant, half sheng, washed) Sheng Jiang (Envoy, 3 liang, sliced) Da Zao (Envoy, 12 pieces, split)
Take the above seven ingredients, add 12 dou of water, boil to obtain 6 sheng, remove dregs, and decoct again to obtain 3 sheng. Take 1 sheng warm, three times daily.