或问汉张仲景立伤寒论。其中有三百九十七法。一百一十三方。以治风寒暑湿之邪。东有青龙汤。西有白
虎汤。更有北方之真武汤。中央虽无勾陈之名。而有建中理中之治。独无南方朱雀汤者。何也。意者南方
属火。太热而不可用欤。抑制方时遗失而未之有欤。曰非也。张仲景乃汉建安时人。举孝廉。官至长沙太守。
始受术于同郡张伯祖。盖儒而通于医者也。晋玄晏先生皇甫谧序甲乙经云。伊芳尹以元圣之才。撰用神农本
草以为汤液。汉张仲景论广汤液而为伤寒论。学贯天人。理穷精奥。凡阴阳消息。变化屈伸。靡所不通。
其所着之论。但默具其理于六经证治之中。而不显言其故者。盖以阴阳理数。奥妙难知。恐天下后世贤愚不等。
不能尽通其理故耳。此正显仁藏用之妙。非秘密而不宣也。后之读之者。又谁得其皮与其骨哉。今以子之问。
请试论之。夫青龙者。东方之神。属木而主疏泄。犹天地之阳气郁伏。至春木行令。则阳气上腾而为风。阳气
鼓动。雷雨满盈。而郁结之气得伸矣。白虎者。西方之神。属金而主清肃。天地之暑热郁蒸。至秋金行令。
则天气下降。凉风荐爽。玉露沛零。而郁热之邪解矣。真武者。北方之神。属水与火。故玄武之中。 蛇附焉。
即坎卦一阳居于二阴之象也。坎本坤体。以坤体之中。干阳居焉。所以专主闭藏其阳气于寒水之中。而为龙
蛇之蛰。故曰潜龙勿用。若夫失精泄汗。阳气外泄。真火虚衰。无根失守。亢害上炎。下焦虚冷。厥逆 惕。故以
真武汤救
之。导使归源。令龙火潜渊。然后波恬浪息。是北方治水之中。已具南方治火之法。不必朱雀汤也。然朱雀者。
南方之神。丙丁离火是也。乃后天之火。非前坎中之火也。然朱雀之用。能泻后天。能补先天。可寒可热。
所以能泻能补。随其所在。故不可有定名也。如论中之大黄黄连泻心汤竹叶石膏汤越婢一汤葛根黄连黄芩汤茵
陈蒿汤栀子柏皮汤大小调胃承气等汤。皆泻后天实火之剂也。而无朱雀之称者。盖有深意存焉。是故风寒暑
湿燥火者。天之六气也。水火木金土者。地之五行也。六气无形而五行有质。故易曰在天成象。在地成形。
所以日月星辰为天之四象而分阴阳。水火土石为地之四象而分刚柔。阴阳无形。而日月星则无形中之有形者也。
至辰则终无形也。刚柔有体。而水土石则成形中之有质者也。至于火则有形而无质矣。是以邵子皇极经世云。
天辰不见。地火常潜。彼苍苍者辰。初未尝有十二辰之分界也。不过推步家指画其经界耳。与九州之分野无异也。
即使大地原无界畔。亦无过积。算家分其畎亩阡陌耳。与天辰之分为十二无异也。至于火之一象。用之则有。
舍之则无。用时虽见其形。而实无体。灭之则形体全无矣。既无定形。又无实证。故不可有朱雀汤也。所以地理
家五行皆有峦头星体。而火星终不结穴。至理然也。夫火之为物。无处无之。或寓诸金石。或取诸钻燧。或藏诸
冰土。皎日之中。得之阳燧。幽阴之境。野烧如焚。至于积油生焰。照酒延烧。俱能无中生有。火虽不能独立形体。
必藉他物成形。然无往而不为妙用。使天地无火。则不能生长万物。人身无火。则不能常有其生。水无火之暖。
则凝结而不流通。木无火之暖。则郁遏而不条达。金无火之熔化。则不能成其器用。土无火之嘘培。则不能发育万类。
天地万物。无火不成。无往而不为用。故重于用而略于体也。是以仲景立方。在太阳经误治中。即有桂枝加桂汤。
桂枝加附子汤。真武四逆等汤之用。在阳明一经。俱属胃家实热。尚有吴茱萸汤。及阳明中寒例
中。有阳明脉迟。食难用饱。又阳明中寒。欲作固瘕。及脉浮而迟。表热里寒。下利清谷等条。亦有四逆汤之治。此皆
补先天火虚之剂也。阳经用之。可谓有经有权。能变能化。况三阴篇之阴寒证治乎。是仲景虽不立朱雀汤。而
朱雀已无往而不用之矣。其屡用之而不立汤名者。盖亦重其用而略其体也。其深明羲皇之四象。而预得康节地火常
潜之义乎。呜呼。苟非洞彻阴阳。深知理数。而能如是乎。
有人问：汉代张仲景撰写《伤寒论》，其中包含三百九十七法，一百一十三首方剂，用来治疗风、寒、暑、湿等邪气。东方有青龙汤，西方有白虎汤，更有北方的真武汤。中央虽然没有名为“勾陈”的方剂，但有建中汤、理中汤等治疗方法。唯独没有南方的朱雀汤，这是为什么呢？猜想是因为南方属火，过于炎热而不可使用吗？还是因为方剂在时代流传中遗失了而没有留存下来呢？
回答说：不是这样的。张仲景是汉建安年间的人，被举荐为孝廉，官至长沙太守。他最初向同郡的张伯祖学习医术。他是儒者而通晓医学。晋代玄晏先生皇甫谧在《甲乙经》序言中说：伊尹凭借圣人的才能，撰写了《神农本草》作为汤液的依据；汉代张仲景论述并扩充了汤液理论，写成《伤寒论》。他的学问贯通天人与事理，穷尽了精微深奥的道理。凡是阴阳的消长变化、屈伸往来，没有不通晓的。他所撰写的理论，只是默默地将道理蕴含在六经证治之中，而不显明地说出其中的缘由。这是因为阴阳的道理和数理，奥妙难以知晓，恐怕天下后世贤者与愚者资质不同，不能全部通晓其中的道理罢了。这正是彰显仁德、隐藏功用的微妙之处，并非秘密而不宣示。后来阅读它的人，又有谁能得到它的皮毛与骨骼呢？现在针对你的问题，请让我试着论述一下。
所谓青龙，是东方的神，属木而主疏泄。就像天地间的阳气郁结潜伏，到了春季木行当令，阳气便上升化为风。阳气鼓动，雷雨充满，郁结之气得以舒展。所谓白虎，是西方的神，属金而主清肃。天地间的暑热郁蒸，到了秋季金行当令，天气下降，凉风清爽，玉露充沛，郁热的邪气得以解除。所谓真武，是北方的神，属水与火，所以在玄武（龟蛇合体）之中，蛇附于龟上。这即是坎卦（☵）中一阳爻居于两个阴爻之中的象意。坎卦本源于坤体（纯阴），但在坤体之中，乾阳居焉。所以专门主持在寒水之中闭藏其阳气，如同龙蛇的蛰伏。所以说“潜龙勿用”。如果是出现失精、泄汗，导致阳气外泄，真火虚衰，无根失守，亢盛害事而上炎，下焦虚冷，四肢厥逆且心中惊惕不安，所以用真武汤来救治它。引导阳气回归本源，使龙火潜藏于深渊，然后波涛平静，浪息风止。这是在北方治水之中，已经具备了南方治火的方法，不需要朱雀汤了。
然而，朱雀是南方的神，对应丙丁离火（☲）。这是后天的火，不是前坎（☵）中的火。然而朱雀的作用，能泻后天之火，能补先天之火，可寒可热，所以能泻能补，随着病情的所在而变化，因此不能有固定的名称。比如《伤寒论》中的大黄黄连泻心汤、竹叶石膏汤、越婢汤、葛根黄连黄芩汤、茵陈蒿汤、栀子柏皮汤、大小调胃承气汤等方剂，都是泻除后天实火的药剂，而没有称为朱雀汤。这大概是有深意在里面。
因此，风、寒、暑、湿、燥、火，是天之六气；水、火、木、金、土，是地之五行。六气无形而五行有质。所以《易经》说：“在天成象，在地成形。”所以日月星辰是天的四象，分为阴阳；水、火、土、石是地的四象，分为刚柔。阴阳是无形的，而日月星则是无形中的有形之物。至于辰（时间/方位），则最终归于无形。刚柔是有体的，而水土石则是有形中的有质之物。至于火这一象，使用时则有，舍弃时则无。使用时虽然见到其形，但实际上没有实体。熄灭后形体全无。既然没有固定的形状，又没有具体的实证，所以不能有朱雀汤。这也是风水地理家中，五行皆有峦头星体，而火星终究不结穴的原因，这是至理所在。
火这种事物，无处不有。有的寄托在金石中，有的通过钻燧取得，有的藏在冰土中。在皎洁的日光中，通过阳燧可以取火；在幽暗阴冷的环境中，野火烧得如焚。至于积聚的油产生火焰，借着酒引燃蔓延，都能无中生有。火虽然不能独立形成形体，必须借助其他物体来成形，然而无处不为妙用。如果天地没有火，就不能生长万物；人身如果没有火，就不能维持生命。水没有火的温暖，就会凝结而不能流通；木没有火的温暖，就会郁遏而不能条达；金没有火的熔化，就不能成为器具；土没有火的嘘培（温养培育），就不能发育万类。天地万物，没有火就不能成就，无处不为有用。所以重视其作用而略去其形体。
因此，张仲景创立方剂，在太阳经误治中，就有桂枝加桂汤、桂枝加附子汤、真武汤、四逆汤等的应用。在阳明一经，虽然都属于胃家实热，尚有吴茱萸汤，以及在阳明中寒的例子中，有“阳明脉迟，食难用饱”，以及“阳明中寒，欲作固瘕”，还有“脉浮而迟，表热里寒，下利清谷”等条文，也有用四逆汤治疗的。这些都是补益先天火虚的方剂。在阳经中使用，可以说是既有常规又有权变，能够变化转化，何况是三阴篇中的阴寒证治呢？所以张仲景虽然没有设立朱雀汤，但朱雀（火法）已无处不使用了。他屡次使用却不设立汤名，大概是重视其作用而略去其形体吧。这是否是他深刻明了伏羲、皇极的四象，并预先得到了康节先生“地火常潜”的含义呢？唉！如果不是透彻洞察阴阳，深知理数，怎么能做到这样呢？
A question was asked: Han Dynasty's Zhang Zhongjing compiled the *Shanghan Lun* (Treatise on Cold Pathogenic Diseases), which contains 397 methods and 113 prescriptions to treat pathogens of wind, cold, summerheat, and dampness. In the East, there is Qinglong Tang (Azure Dragon Decoction); in the West, there is Baihu Tang (White Tiger Decoction); and further north, there is Zhenwu Tang (True Warrior Decoction). Although there is no prescription named "Gouchen" (Black Tortoise/Gou Chen) for the Central region, there are treatments like Jianzhong Tang (Middle-Boosting Decoction) and Lizhong Tang (Regulate the Middle Decoction). Why is there uniquely no Zhuque Tang (Vermilion Bird Decoction) for the South? Is it because the South belongs to Fire, is excessively hot, and thus unusable? Or has the prescription been lost through the ages and not preserved?
The answer is: No. Zhang Zhongjing was a person of the Jian'an era of the Han Dynasty. He was recommended as a Xiaolian (Filial and Incorrupt Candidate) and served as the Governor of Changsha. He initially received his medical arts from Zhang Bozu, a fellow townsman. He was a Confucian scholar who was also proficient in medicine. Huangfu Mi, courtesy name Xuan'yan, in his preface to the *Jiayi Jing* (Systematic Classic of Acupuncture and Moxibustion), stated: Yi Yin, with the talent of a sage, composed the *Shennong Bencao Jing* (Divine Farmer's Materia Medica) as the basis for decoctions. Zhang Zhongjing of the Han Dynasty discussed and expanded upon these decoctions to create the *Shanghan Lun*. His learning penetrated heaven and humanity, exhausting the subtle and profound principles. Regarding the waxing and waning of Yin and Yang, and changes of flexion and extension, there was nothing he did not understand. The theories he wrote merely silently embedded their logic within the syndrome differentiation and treatment of the Six Channels (Liu Jing), without explicitly stating the reasons. This is because the principles and numerology of Yin and Yang are profound and difficult to comprehend; fearing that the wise and the foolish of future generations would differ in capacity and fail to fully grasp these principles, he chose this approach. This precisely demonstrates the subtlety of manifesting benevolence while concealing utility, rather than keeping secrets. How could later readers attain even its skin and bones? Now, regarding your question, let me attempt to discuss it.
Qinglong (Azure Dragon) is the deity of the East, belonging to Wood and governing dispersion and drainage. It is akin to the Qi of Heaven and Earth being stagnant and latent; when Spring arrives and Wood governs, the Yang Qi ascends and transforms into Wind. As Yang Qi stirs, thunder and rain fill the air, and stagnant Qi is released. Baihu (White Tiger) is the deity of the West, belonging to Metal and governing clarity and肃ness (astringency/clearing). When the summer heat of Heaven and Earth stagnates, Autumn arrives and Metal governs; then Heavenly Qi descends, cool breezes refresh, and jade-like dew falls abundantly, resolving the stagnant Heat pathogen. Zhenwu (True Warrior) is the deity of the North, belonging to Water and Fire. Thus, in Xuanwu (Black Tortoise, symbolized by a turtle and snake intertwined), the Snake is attached. This corresponds to the image of the Kan hexagram (☵), where one Yang line resides between two Yin lines. Kan originates from Kun (pure Yin), but within Kun, Qian Yang resides. Therefore, it specifically governs the storage of Yang Qi within Cold Water, similar to the hibernation of dragons and snakes. Hence, the phrase "Hidden Dragon does not act." If there is loss of essence or sweating, leading to the leakage of Yang Qi, deficiency of True Fire, rootlessness, loss of control, hyperactivity harming upwards, cold deficiency in the Lower Jiao, cold extremities, and palpitations/fear, then Zhenwu Tang is used to rescue the condition. It guides the Qi back to its source, allowing the Dragon Fire to submerge in the abyss, so that waves calm and tides cease. This means that within the method of treating Water in the North, the method of treating Fire in the South is already contained; there is no need for Zhuque Tang.
However, Zhuque (Vermilion Bird) is the deity of the South, corresponding to Bing-Ding Li Fire (☲). This is Post-Heaven Fire, not the Fire within Pre-Heaven Kan (☵). Yet, the function of Zhuque can purge Post-Heaven Fire and tonify Pre-Heaven Fire; it can be cold or hot, thus capable of purging or tonifying according to the location of the pathology. Therefore, it cannot have a fixed name. For instance, in the *Shanghan Lun*, formulas such as Dahuang Huanglian Xiexin Tang (Rhubarb and Coptis Decoction to Drain the Heart), Zhuye Shigao Tang (Bamboo Leaf and Gypsum Decoction), Yuespi Tang (Dispersing Confinement Decoction), Gegen Huanglian Huangqin Tang (Kudzu, Coptis, and Scutellaria Decoction), Yinchen Hao Tang (Artemisia Capillaris Decoction), Zhizi Baipi Tang (Gardenia and Phellodendron Bark Decoction), and Da/Xiao Tiaowei Chengqi Tang (Major/Minor Regulating the Stomach and Bowels Decoctions) are all agents that purge Post-Heaven Excess Fire. They are not called Zhuque Tang. This likely harbors a deep meaning.
Thus, Wind, Cold, Summerheat, Dampness, Dryness, and Fire are the Six Qi of Heaven; Water, Fire, Wood, Metal, and Earth are the Five Elements of Earth. The Six Qi are formless, while the Five Elements have substance. Hence, the *I Ching* states: "In Heaven they form images, on Earth they take shape." Therefore, the Sun, Moon, Stars, and Constellations are the Four Images of Heaven, dividing Yin and Yang; Water, Fire, Earth, and Stone are the Four Images of Earth, dividing Rigidity and Flexibility. Yin and Yang are formless, yet the Sun, Moon, and Stars are form-within-formlessness. As for Chen (Time/Direction), it ultimately returns to formlessness. Rigidity and Flexibility have body, while Earth, Water, and Stone are substance-within-shape. As for the image of Fire, it exists when used and ceases when abandoned. When used, although its form is seen, it actually lacks substance. When extinguished, both form and substance vanish. Since it has no fixed shape and no concrete evidence, there cannot be a Zhuque Tang. This is why, in Feng Shui geography, the Five Elements all have landscape forms (Luantou) and star bodies, but Huo Xing (Fire Star) never forms a grave site (Jiexue); this is the ultimate truth.
Fire as a thing is everywhere. It may reside in metals and stones, be obtained through drilling and friction, or hidden in ice and earth. In bright sunlight, fire can be drawn using a Yang mirror (Yangsui); in dark, yin environments, wild fires burn fiercely. Accumulated oil generates flames; wine extends burning. All can create something from nothing. Although Fire cannot exist independently as a body, it must rely on other objects to take shape, yet it performs miraculous functions everywhere. If Heaven and Earth lacked Fire, myriad things could not grow; if the human body lacked Fire, life could not be sustained. Without the warmth of Fire, Water would congeal and fail to circulate; without the warmth of Fire, Wood would be stifled and fail to flourish; without the melting power of Fire, Metal could not become vessels; without the nurturing warmth of Fire, Earth could not develop all categories. Heaven, Earth, and all things cannot be accomplished without Fire, and nowhere is it not useful. Therefore, its function is emphasized while its physical form is neglected.
Thus, when Zhang Zhongjing established his formulas, in cases of mismanagement of the Taiyang Channel, there were applications of Guizhi Jia Gui Tang (Cinnamon Twig Plus Cinnamon Twig Decoction), Guizhi Jia Fuzi Tang (Cinnamon Twig Plus Aconite Decoction), Zhenwu Tang, and Sini Tang (Recover the Extremities Decoction). In the Yangming Channel, although mostly pertaining to Stomach-Fullness Heat, there is still Wuzhuyu Tang (Evodia Decoction). In examples of Yangming Middle-Jiao Cold, there are clauses such as "Yangming pulse is slow, food cannot be consumed to fullness," "Yangming middle-jiao cold, intending to form Gujia (stubborn accumulation)," and "pulse floating and slow, exterior heat interior cold, diarrhea with undigested food," all of which also employ Sini Tang for treatment. These are all agents that tonify Pre-Heaven Fire Deficiency. Using them in Yang channels demonstrates both standard practice and flexible adaptation, ability to change and transform. How much more so for the Yin-Cold syndromes in the Three Yin chapters? Therefore, although Zhang Zhongjing did not establish a Zhuque Tang, Zhuque (the principle of Fire) was utilized everywhere. The reason he frequently used it without naming the decoction is precisely because he valued its function over its form. Did he profoundly understand the Four Images of Fuxi and Huangdi, and anticipate Kangjie's (Shao Yong's) meaning that "Earth Fire often remains latent"? Alas! Unless one thoroughly penetrates Yin and Yang and deeply understands principle and numerology, how could one achieve such mastery?