仲景之用桂枝，不独太阳病为然，即已见里症而表犹未罢者亦用之。故建中、复脉，虽
于
滋腻中，尚借一味桂枝以达余邪； 而桃仁承气汤、黄连汤、桂枝人参汤、柴胡姜桂汤、当
归四逆汤、乌梅丸诸方之用桂枝准此矣。其尤着者，阳明、太阴二篇，皆有浮脉者宜桂枝汤
之论，可见无表症而有表脉者，犹当用桂枝。所以然者，有表脉则气连于表，与未罢之表症
同；无表症则不得不随其所见之病以为隶。近人泥桂枝为太阳经者，究未明其例也。夫仲景
之用意虽深，能善读之，则义随文见，自有迹之可寻，此所以为医学中百世之师也。
任分则权分，任专则权专；权分则功分，权专则功专。分者我与人均，专者人由我使。
桂枝
汤桂、芍俱三两，则桂自驱风，芍自敛汗，各不相假，所谓任分权分而功分也。此方桂三两
，芍四两，则芍能使桂，桂虽有驱风之能，亦不过以辛温善达之气，助芍药宣已痹之血，而
不得独炫其长，所谓任专权专而功专也。加生姜之义，可以类推。此论身疼痛在发汗后，显
属汗后亡津，血气痹着之象。津血同类，故从血痹治。芍药、生姜皆治血痹，故独重其分。
亡津故加人参，与白虎加人参汤症义同。何以知此身疼痛为血痹也？以脉沉细知之。栝蒌桂
枝汤症，亦云脉沉细，而其病由于亡津，以彼例此昭然已。
张仲景使用桂枝，并不仅限于太阳病（太阳经受邪所致的病证），即使是已经出现里证（脏腑功能失调或邪气入里的病证）而表证尚未解除的情况，也使用桂枝。因此，小建中汤和大复脉汤，虽然在滋腻的药物中，还借助一味桂枝来透达残留的邪气；而桃仁承气汤、黄连汤、桂枝人参汤、柴胡姜桂汤、当归四逆汤、乌梅丸等方剂中使用桂枝，都是遵循这一原则。其中尤为显著的是，在《伤寒论》的阳明病篇和太阴病篇中，都有“若见浮脉者，适宜用桂枝汤”的论述，由此可见，即使没有明显的表证症状，但出现表证的脉象时，仍然应当使用桂枝。之所以这样，是因为出现表证的脉象，说明正气与体表相连，这与表证未解的情况相同；如果没有表证症状，就不得不根据所见的其他病症来灵活处理。近代人拘泥于认为桂枝仅属于太阳经药物，终究是没有明白其中的规律。张仲景的用意虽然深远，但只要善于研读，义理就会随着文句显现，自然有迹可循，这就是他成为医学中千秋万代老师的原因。
职责分担则权力分散，职责专一则权力集中；权力分散则功效分散，权力集中则功效专一。分散是指药力由我和他人（指方中其他药物）共同承担，集中是指他人（其他药物）由我（主药）指挥。桂枝汤中桂枝和白芍各用三两，那么桂枝自行驱散风邪，白芍自行收敛汗液，互不依赖，这就是所谓的职责分担、权力分散而功效分散。此方（新加汤）中桂枝用三两，白芍用四两，那么白芍能够驱使桂枝，桂枝虽然有驱散风邪的能力，也不过是利用其辛温善于通达的气性，帮助白芍宣通已经痹阻的血脉，而不能独自炫耀其长处，这就是所谓的职责专一、权力集中而功效专一。加入生姜的意义，可以由此类推。这段论述的是身体疼痛出现在发汗之后，显然属于发汗后津液耗伤，气血痹阻不通的现象。津液和血液同类，所以从血痹的角度治疗。白芍和生姜都能治疗血痹，所以特别加重它们的用量。因为津液耗伤所以加入人参，这与白虎加人参汤证的含义相同。怎么知道这种身体疼痛是血痹呢？通过脉象沉细来判断。栝楼桂枝汤证，也说脉象沉细，但其病因也是由于津液耗伤，用那个例子来比照这个，就非常清楚了。
Zhang Zhongjing's use of Guizhi (Cinnamon Twig) is not limited to Taiyang disease (diseases caused by pathogenic factors invading the Taiyang channel); even when interior syndromes are already present but the exterior syndrome has not yet resolved, Guizhi is still used. Therefore, in Xiaojianzhong Tang (Minor Construct the Middle Decoction) and Da Fumai Tang (Major Restore Pulse Decoction), despite the presence of cloying and greasy herbs, a single dose of Guizhi is borrowed to dispel residual pathogens; the use of Guizhi in formulas such as Tao Ren Cheng Qi Tang (Peach Kernel Drains the Lower Bowel Decoction), Huanglian Tang (Coptis Decoction), Guizhi Renshen Tang (Cinnamon Twig and Ginseng Decoction), Chaihu Jianggui Tang (Bupleurum, Ginger, and Cinnamon Twig Decoction), Danggui Sini Tang (Angelica Sinensis Cold-Reversal Decoction), and Wumei Wan (Mume Pill) all follow this principle. Most notably, in the chapters on Yangming disease and Taiyin disease, there are discussions stating that "if a floating pulse is present, Guizhi Tang should be appropriate." This shows that even in the absence of obvious exterior symptoms, if an exterior-type pulse appears, Guizhi should still be used. The reason for this is that an exterior-type pulse indicates that Qi is connected to the exterior, which is similar to the state where the exterior syndrome has not resolved; in the absence of exterior symptoms, treatment must adapt to the specific pathology observed. Modern practitioners who rigidly confine Guizhi to the Taiyang channel ultimately fail to understand its principles. Although Zhang Zhongjing's intentions were profound, careful reading reveals the principles within the text, leaving traces to be followed; this is why he remains the teacher of medicine for all generations.
When responsibilities are shared, authority is divided; when responsibility is singular, authority is concentrated. When authority is divided, efficacy is dispersed; when authority is concentrated, efficacy is focused. "Shared" means the medicinal action is jointly undertaken by the primary herb and others; "concentrated" means other herbs are directed by the primary herb. In Guizhi Tang, both Guizhi (Cinnamon Twig) and Shaoyao (White Peony Root) are used in equal amounts of three liang; thus, Guizhi independently disperses wind, while Shaoyao independently consolidates sweat, without relying on each other. This is what is meant by shared responsibility, divided authority, and dispersed efficacy. In this formula (Xinjiasheng Tang/Modified New Addition Decoction), Guizhi is used in three liang, while Shaoyao is used in four liang. Here, Shaoyao directs Guizhi; although Guizhi possesses the ability to disperse wind, it merely utilizes its acrid-warm nature to facilitate penetration, assisting Shaoyao in unblocking blood stasis and bi-syndrome, rather than displaying its own strengths alone. This is what is meant by singular responsibility, concentrated authority, and focused efficacy. The rationale for adding Shengjiang (Fresh Ginger) can be inferred analogously. This discussion addresses body pain occurring after sweating, which clearly belongs to the pattern of fluid depletion following sweating, leading to blood and Qi stagnation and obstruction. Since fluids and blood share the same origin, treatment proceeds from the perspective of Blood Bi (Blood Obstruction). Both Shaoyao and Shengjiang treat Blood Bi, hence their dosages are specifically increased. Because fluids are depleted, Renshen (Ginseng) is added, consistent with the pathological meaning of Baihu Jia Renshen Tang (White Tiger Plus Ginseng Decoction). How do we know this body pain is due to Blood Bi? It is known through the deep and fine pulse. In the case of Gualou Guizhi Tang (Trichosanthes Root and Cinnamon Twig Decoction), a deep and fine pulse is also mentioned, and the etiology is likewise fluid depletion; using that case to illuminate this one makes it clear.