经也者。分野之谓也。犹孟子所谓经界。在人身谓之部位。无专物而命物者也。部位既定。于是筋与脉之行于
太阳少阴之部者。命曰太阳之筋。太阳之脉。少阴之筋。少阴之脉。行于阳明太阴之部者。命曰阳明之筋。阳明之
脉。太阴之筋。太阴之脉。行于少阳厥阴之部者。命曰少阳之筋。少阳之脉。厥阴之筋。厥阴之脉。故灵枢经脉经
筋两篇。并冠以经者。以筋之与脉。皆分经而行。非筋脉之外。别有所为经也。大者为经。支者为络。以脉之大者。
各据专部。故得独被以经之名。非以经络相对。屹然二物也。然则三阴三阳。果本于何义而有此名也。曰本于天地
四象也。阴阳离合论曰。圣人南面而立。前曰广明。后曰太冲。太冲之地。名曰少阴。少阴之上。名曰太阳。中身
而上。名曰广明。广明之下。名曰太阴。太阴之前。名曰阳明。厥阴之表。名曰少阳。太阴之后。名曰少阴。少阴
之前。名曰厥阴。由此观之。前曰阳明者。阳者。表也。明者。盛也。耳目之精。手足之用。皆聚于前。故曰阳明。
其里太阴。人身背为阳。腹为阴。居腹之里。故曰至阴。后曰太阳者。太者。至也。阳者。表也。居背之表。而又
为耳目手足之所不及。在人身为至远。故曰太阳。远之也。其里少阴。少者。小也。居背之里。稍近于前。故曰少
阴。两侧曰少阳者。分据两侧。部位狭隘。故曰少阳。其里厥阴。厥者。逆也。前后之交。两气相触故也。是故阴
阳者。表里之雅名。太少厥阴者。前后两侧之雅名耳。三阳经之气血。亦营运于三阴。三阴经之气血。亦营运于三
阳。不得以表里分经之阴阳。为气血本性之阴阳也。气血之阴阳。当各从其脏腑之本体求之。与分经之阴阳。两不
相涉者也。故至真要大论曰。以名命气。以气命处。而言其病。谓以四象阴阳之名。命于六气。以六气阴阳之名。
命于人身上下表里之处。处即经之义也。盖天下无无名之物也。必分立诸名。而后便于讨论病机焉。言者。讨论之
谓也。由是推之。命燥金曰阳明。湿土曰太阴。特假其名而已。非燥金之气属阳。湿土之气属阴。而居前也。命寒
水曰太阳。君火曰少阴。亦假其名而已。非寒水属阳。君火属阴。而居后也。命相火曰少阳。风木曰厥阴。亦假其
名而已。非相火属阳。风木属阴。而居两侧也。总之三阴三阳分经。只是人身分野之空名。非如筋脉之有专物也。
邪在分野。是为腠理。是为表病。故无论三阴三阳。当其邪在分野。见证只在躯壳之外。必其邪入经脉。见证乃及
脏腑之中。其有未入经脉。遽见里证者。是邪气直中三焦也。三焦者。里之分野也。三阴三阳者。外之分野也。分
野者。卫之部也。经脉者。营之道也。
此义诸家发明。不一而足。西医解剖。见无所为六经者。便诮中医诞妄。而不自知其疏陋也。略看医书小本。
便肆狂吠。中国士子且然。于西医乎何责。易曰。圣人有以见天下之赜。而拟诸其形容。象其物宜。是故谓之象。
至哉言乎。圣人通于天地万象之本。无不可以阴阳者也。如高下之升降浮沉也。前后之向背表里也。往来之顺逆也。
清浊寒热也。牝牡雌雄也。凡属对待之象。皆可命以阴阳之名。岂特分经而已哉。即心肺为阳。肝肾为阴。脾胃六
腑为至阴。亦阳清阴浊之一端耳。清者多静而居里浊者多动而居表。故又有阳浊阴清之说。若不开拓心胸。洞见本
原。而欲执一义以印万象。亦安往而不窒乎。万象可通于一义而不能拘于一义者也。有体之阴阳。有性之阴阳。有
气之阴阳。有象之阴阳。有数之阴阳。有部位之阴阳。有功用之阴阳。有角立之阴阳。有相生之阴阳。有交变杂错
之阴阳。故曰。阴阳者。数之可十。推之可百。引之可千。推之可万。然其要。一也。知其要者。一言而终不知其
要。流散无穷。
The meridians (Jingmai, 经络) refer to the territorial divisions of the human body. Just as Mencius spoke of "jingjie" (field boundaries), in the human body these are called "buiwei" (body regions). They do not possess a specific physical object but are named concepts to designate specific areas. Once these regions are established, the sinews and vessels running through the Taiyang (Greater Yang) and Shaoyin (Lesser Yin) regions are named the sinews and vessels of Taiyang and Shaoyin, respectively; those running through the Yangming (Bright Yang) and Taiyin (Greater Yin) regions are named accordingly; and those running through the Shaoyang (Lesser Yang) and Jueyin (Terminal Yin) regions are named the sinews and vessels of Shaoyang and Jueyin. Therefore, the chapters "Meridian Vessels" (Jingmai) and "Meridian Sinews" (Jingjin) in the *Lingshu* (Spiritual Pivot) both bear the title "Meridian" because sinews and vessels all run along their respective meridians; there is no separate "meridian" existing outside of sinews and vessels. The main trunks are called meridians, while the branches are called collaterals (Luojing, 络脉). Because the larger vessels each occupy a specific region, they alone receive the name "meridian." This does not imply that meridians and collaterals are two distinct, opposing entities.
Then, on what basis do the Three Yin and Three Yang derive their names? The answer is: they originate from the Four Images (Sixiang, 四象) of Heaven and Earth. The *Suwen: Treatise on the Separation and Union of Yin and Yang* states: "When the sage stands facing south, the front is called Guangming (Broad Brightness), and the back is called Taichong (Great Surge). The land of Taichong is named Shaoyin; above Shaoyin is named Taiyang. The upper part of the mid-body is called Guangming; below Guangming is named Taiyin; before Taiyin is named Yangming; the exterior of Jueyin is named Shaoyang; behind Taiyin is named Shaoyin; before Shaoyin is named Jueyin." From this, we see that the front is called Yangming because Yang represents the exterior, and Ming represents abundance. The essence of the eyes and ears, and the functions of the hands and feet, all gather at the front; hence it is called Yangming. Its interior counterpart is Taiyin. Since the back of the body is Yang and the abdomen is Yin, and Taiyin resides within the abdomen, it is called Zhiyin (Ultimate Yin). The back is called Taiyang because Tai means ultimate, and Yang means exterior. Situated at the exterior of the back, and being the area least reached by the eyes, ears, hands, and feet, it is the furthest point in the body; thus it is called Taiyang, meaning extreme distance. Its interior counterpart is Shaoyin. Because Shao means small, and it resides within the back, slightly closer to the front, it is called Shaoyin. The sides are called Shaoyang because they occupy the lateral positions, which are narrow; hence Shaoyang. Its interior counterpart is Jueyin. Because Jue means reversal, this arises from the intersection of front and back, where the two Qi interact. Thus, Yin and Yang are elegant terms for the exterior and interior, while Tai, Shao, and Jue are elegant terms for the back, front, and sides. The Qi and Blood of the Three Yang meridians also circulate within the Three Yin meridians, and vice versa. One must not confuse the Yin-Yang of meridian distribution (i.e., exterior-interior positioning) with the inherent Yin-Yang nature of Qi and Blood. The Yin-Yang of Qi and Blood should be sought in the本体 (ben ti, essential substance) of the respective Zang-Fu organs, which is unrelated to the Yin-Yang of meridian distribution.
Therefore, the *Suwen: Treatise on the Most Essential Requirements* states: "Name the Qi by its designation, name the location by the Qi, and thereby discuss the disease." This means using the names of the Four Images and Yin-Yang to designate the Six Qi (Liuqi, 六气), and using the names of the Yin-Yang of the Six Qi to designate the locations of the upper/lower and exterior/interior of the human body. "Location" is the meaning of "Meridian." Generally, nothing in the world exists without a name; only by establishing various names can one conveniently discuss pathogenesis. "Speech" here refers to discussion. By extension, designating Dry Metal as Yangming and Damp Earth as Taiyin is merely borrowing names; it does not mean Dry Metal Qi belongs to Yang and Damp Earth Qi belongs to Yin such that they are positioned at the front. Designating Cold Water as Taiyang and Ministerial Fire as Shaoyin is also merely borrowing names; it does not mean Cold Water belongs to Yang and Ministerial Fire belongs to Yin such that they are positioned at the back. Designating Ministerial Fire as Shaoyang and Wind-Wood as Jueyin is also merely borrowing names; it does not mean Ministerial Fire belongs to Yang and Wind-Wood belongs to Yin such that they are positioned on the sides. In summary, the division of Three Yin and Three Yang into meridians is merely an abstract name for bodily territories, unlike sinews and vessels which have concrete physical counterparts. When pathogens reside in these territories, they constitute the Couli (pores/cutaneous spaces, 腠理) and represent exterior diseases. Thus, whether involving Three Yin or Three Yang, when pathogens are in the territory, symptoms manifest only on the exterior of the body shell. Only when pathogens enter the meridians do symptoms affect the interior of the Zang-Fu organs. If there are interior symptoms appearing suddenly before the pathogens have entered the meridians, this indicates that the pathogenic factor has directly struck the Sanjiao (Triple Burner, 三焦). The Sanjiao is the interior territory, while the Three Yin and Three Yang are the exterior territories. The territory is the domain of Wei Qi (Defensive Qi, 卫气); the meridians are the pathways of Ying Qi (Nutritive Qi, 营气).
This principle has been elucidated by numerous scholars throughout history. Western anatomy, failing to identify the so-called "Six Meridians," mocks Traditional Chinese Medicine as absurd and delusional, unaware of their own superficiality. Those who glance at brief medical texts proceed to bark wildly; even Chinese scholars do this, so what blame can be placed on Western medicine? The *I Ching* (Book of Changes) states: "The sage perceives the profound complexity of the world under heaven, simulates its forms, and symbolizes its appropriateness; therefore it is called 'Xiang' (Image/Symbol)." These words are truly profound. The sage understands the root of all phenomena in heaven and earth, wherein nothing cannot be encompassed by Yin and Yang. Such as the rising and falling of high and low, the facing and turning of front and back, the smoothness and reversal of movement, clarity and turbidity, cold and heat, male and female—any phenomenon involving duality can be named with Yin and Yang. Is it merely limited to meridian division? Even regarding the Heart and Lungs as Yang, the Liver and Kidneys as Yin, and the Spleen, Stomach, and Six Fu organs as Zhiyin (Ultimate Yin), these are merely aspects of clear/turbid and Yin/Yang. Clear Qi tends to be static and resides internally; Turbid Qi tends to be active and resides externally; hence there is also the concept of "Yang Turbidity and Yin Clarity." If one does not broaden their mind and perceive the origin, yet attempts to apply a single theory to all phenomena, one will inevitably encounter obstruction everywhere. Phenomena can be connected by a single principle but cannot be confined by it. There is the Yin-Yang of form, of nature, of Qi, of image, of number, of location, of function, of opposition, of generation, and of complex transformation. Thus it is said: "The numbers of Yin and Yang can extend to ten, be pushed to a hundred, drawn to a thousand, and extended to ten thousand." Yet their essence remains one. He who knows the essence needs only one word to conclude; he who does not know the essence will scatter infinitely.