(直指本义起于分野，而广引以明之)
十二经之三阴三阳，其于脏腑不能执而强合也，前论详之矣。十二经之三阴三阳，其称
名起
于人身之分野，而分野则何为有三阴三阳也?曰∶象于天地之义也。南面而立，阳明在前，
阳之盛也，非燥气在前也；太阳在后，远而外之也，非寒气在后也；少阳在侧，前后之间也
，非火气在侧也。三阴同法。只因分野、方位、表
里以定名，非因风寒燥火暑湿六气以起义也。故人身之三阴三阳者，虚位也。或曰∶三阴三
阳为虚位，而《内经》每言燥病即曰阳明，寒病即曰太阳，火病即曰少阳，土病即曰太阴，
热病即曰少阴，风病即曰厥阴者，何也?曰∶此假其名也。阳明即燥金病假名，不必在身之
前也；金气通于肺，不专于胃与大肠之经矣。厥阴即风木病假名，不必在身之侧也；风气通
于肝，不及于包络之经矣。太阳、少阳、太阴、少阴，俱同此义。此气病而假其名也，亦有
经病而假其名者。胃经病曰足阳明，大肠经病曰手阳明，不必皆燥气为病也；肾经病曰足少
阴，心经病曰手少阴，不必皆火气为病也。夫人之中于邪也，中于面则于阳明，中于项则下
太阳，中于颊则下少阳，此所谓阳明、太阳、少阳者，皆以分野言，非以经络言也，非以六
气言也。邪之中人也，先中于皮毛分野之间，而经络脉管之中，未能即病也。脉管中血气不
盛，则邪气渗入脉中矣。有渗入阳经者，有渗入阴经者，有邪已至于三阴之分野，而犹未渗
入
脉管者。经脉之气通于脏腑，其机至捷。邪入经脉，则其入于脏腑也，不可御矣。故阳经亦
有里证，若邪至三阴分野，而未入脉管，是即三阴表证，犹可汗而愈也。昔人疑《伤寒论》
只言足经，不及手经者，论中所称三阴三阳，只是分野也。足经分野大，故见证多手经分野
小，故见证少。若邪入于脉管之中，则气行有道，脉络相引，手经亦自有手经之病矣。故《
伤寒论》有时及手经病证者，皆里证也。陶节庵曰∶足之六经，盖受伤之方分境界也。张景
岳曰∶足经脉长而远，自上及下，遍络四体，故可按之以察周身之病；手经脉短而近，皆出
入于足经之间，故伤寒但言足经，不及手经者。伤寒，表邪也，欲求外证，但当察之于周身
，而周身上下脉络，惟足六经尽之耳!(周身者，躯壳也，对脏腑言。)张石顽曰∶只传足经
者，邪气在身，未入脏腑也；若入脏腑，则不得独在足经矣。呜呼!观于诸家之论，不亦可
以恍然矣乎?独是邪在分野者，概于皮肤分肉之谓也，而病证竟分见某经，划然各有界畔者
，何谓也?(胀论曰∶五脏六腑各有界畔，其病各有形状。)曰∶邪之来也，必有其道。如中
于项，则下太阳，太阳分野，为邪所拥，则此分野中正气困矣；正气困，则不能与脉中之气
升降迟速相应，邪虽未入脉中，而脉中之正气已为所累矣，故周身上下，皆独见太阳证也。
累之日久，则里气亦虚，邪乃乘虚而内侵矣。总之，邪在分野，见证只在躯壳之外；邪入经
脉，见证必及脏腑之中。其有未入经脉而遽见里证者，必是邪气直中三焦也；直中三焦，则
其入脏腑也亦易矣。三焦者，内之分野也；三阴三阳者，外之分野也。分野者，卫之部也；
经脉者，荣之道也。
（直指本义起于分野，而广引以明之）
十二经脉中的三阴三阳，对于脏腑不能强行机械地对应，前文已有详细论述。十二经脉的三阴三阳，其名称起源于人体部位的划分（分野），那么这种划分为什么会有三阴三阳之分呢？回答说：这是取象于天地的道理。人面向南方站立时，阳明经位于前方，代表阳气最盛，并非指燥气在前；太阳经位于后方，代表远离体表之外，并非指寒气在后；少阳经位于侧面，处于前后之间，并非指火气在侧。三阴经也是同样的道理。只是根据部位、方位、表里来定名，并不是因为风寒燥火暑湿这六气来确立含义。所以人身上的三阴三阳，是虚设的位置概念。有人问：既然三阴三阳是虚设的位置，但《内经》中常说燥病就称为阳明，寒病就称为太阳，火病就称为少阳，土病就称为太阴，热病就称为少阴，风病就称为厥阴，这是为什么呢？回答说：这是借用其名罢了。阳明即借用了燥金之名，并不一定就在身体前方；金气通应于肺，并不专属于胃与大肠的经络。厥阴即借用了风木之名，并不一定就在身体侧面；风气通应于肝，并不涵盖心包络的经络。太阳、少阳、太阴、少阴，都遵循同样的道理。这是因气病而借用其名，也有因经络病而借用其名的情况。胃经发病称为足阳明，大肠经发病称为手阳明，并不一定是燥气致病；肾经发病称为足少阴，心经发病称为手少阴，并不一定是火气致病。大凡人感受邪气，邪气侵犯面部则归属于阳明，侵犯项部则归属于太阳，侵犯颊部则归属于少阳，这里所说的阳明、太阳、少阳，都是依据部位而言，不是依据经络而言，也不是依据六气而言。邪气侵袭人体，先侵犯皮毛所在的部位之间，此时经络脉管之中，尚未立即发病。如果脉管中的血气不旺盛，邪气就会渗入脉中。有渗入阳经的，有渗入阴经的，有邪气已经到达三阴的部位，却仍未渗入脉管的。经脉之气通应于脏腑，其传导机制非常迅速。邪气进入经脉，那么它传入脏腑也就无法抵御了。所以阳经也有里证，如果邪气到达三阴的部位，但未进入脉管，这就是三阴的表证，还可以用发汗法治愈。过去的人怀疑《伤寒论》只讲足经，不讲手经，其实论中所称的三阴三阳，只是指部位而已。足经的部位范围大，所以见证多；手经的部位范围小，所以见证少。如果邪气进入脉管之中，那么气运行有固定的道路，脉络相互牵引，手经自然也有手经的病证。所以《伤寒论》中有时涉及手经病证的，都是里证。陶节庵说：足的六经，大概是受伤的区域界限。张景岳说：足经脉长且远，从上到下，遍布四肢，所以可以通过诊察足经来了解周身疾病；手经脉短且近，都出入于足经之间，所以伤寒只讲足经，不讲手经。伤寒是表邪，想要寻求外证，应当诊察周身，而周身上下脉络，只有足六经能涵盖全部！（周身者，指躯壳，相对于脏腑而言。）张石顽说：只传变足经的，是因为邪气在身体表面，未入脏腑；如果进入脏腑，就不会只在足经了。唉！看了诸家的论述，不也可以恍然大悟了吗？只是邪气在部位之间，通常是指皮肤分肉之间，而病证竟然分别显现于某条经，界限分明各有边界，这是什么原因呢？（《胀论》说：五脏六腑各有边界，它们的病症各有形态。）回答说：邪气的到来，必有其道。如邪气侵犯项部，则归属于太阳，太阳部位被邪气占据，那么这个部位的正气就受困了；正气受困，就不能与脉中之气的升降迟速相应，邪气虽然未进入脉中，但脉中的正气已经被牵连了，所以周身上下，都单独显现太阳证。牵连日久，则里气也虚弱，邪气便乘虚内侵了。总之，邪气在部位之间，见证只在躯壳之外；邪气进入经脉，见证必涉及脏腑之中。那些未进入经脉却突然见到里证的，一定是邪气直中三焦；直中三焦，那么它进入脏腑也容易了。三焦，是内部的区域；三阴三阳，是外部的区域。区域，是卫气分布的部门；经脉，是营气运行的道路。
(Starting from the original meaning rooted in body regions, and extensively citing to clarify it)
The Three Yin and Three Yang of the twelve meridians cannot be rigidly or forcibly matched with the Zang-Fu organs, as detailed in previous discussions. The names of the Three Yin and Three Yang of the twelve meridians originate from the division of body regions (Fenye). Why are there divisions into Three Yin and Three Yang? The answer is: this takes imagery from Heaven and Earth. When standing facing south, the Yangming meridian is in front, representing the peak of Yang Qi, not implying that Dryness Qi is in front; the Taiyang meridian is at the back, representing being distant and external, not implying that Cold Qi is at the back; the Shaoyang meridian is on the side, between front and back, not implying that Fire Qi is on the side. The same logic applies to the Three Yin meridians. Names are determined solely by region, orientation, and interior-exterior relationships, not by the Six Qi (Wind, Cold, Dryness, Heat, Dampness, Summer-Heat) to establish their meanings. Therefore, the Three Yin and Three Yang in the human body are empty positional concepts. One might ask: If the Three Yin and Three Yang are empty positions, why does the *Neijing* (Classic of Internal Medicine) often say that Dryness diseases are called Yangming, Cold diseases are called Taiyang, Fire diseases are called Shaoyang, Earth diseases are called Taiyin, Heat diseases are called Shaoyin, and Wind diseases are called Jueyin? The answer is: this is borrowing the names. Yangming borrows the name of Dryness Metal, but it does not necessarily have to be in front of the body; Metal Qi connects with the Lung, not exclusively with the Stomach and Large Intestine meridians. Jueyin borrows the name of Wind Wood, but it does not necessarily have to be on the side of the body; Wind Qi connects with the Liver, not extending to the Pericardium meridian. Taiyang, Shaoyang, Taiyin, and Shaoyin all follow this same principle. This is borrowing names due to Qi pathologies, and there are also cases where names are borrowed due to meridian pathologies. When the Stomach meridian is diseased, it is called Foot-Yangming; when the Large Intestine meridian is diseased, it is called Hand-Yangming; this does not necessarily mean Dryness Qi is causing the disease. When the Kidney meridian is diseased, it is called Foot-Shaoyin; when the Heart meridian is diseased, it is called Hand-Shaoyin; this does not necessarily mean Fire Qi is causing the disease. Generally, when a person is attacked by pathogens, if the attack is on the face, it falls under Yangming; if on the nape, it falls under Taiyang; if on the cheek, it falls under Shaoyang. Here, the terms Yangming, Taiyang, and Shaoyang refer to body regions, not to specific meridians, nor to the Six Qi. Pathogens attacking humans first invade the areas between skin and hair follicles; at this stage, the meridians and vessels have not yet immediately become diseased. If the Qi and Blood within the vessels are not robust, pathogens will seep into the vessels. Some pathogens seep into the Yang meridians, some into the Yin meridians, and some reach the regions of the Three Yin without yet entering the vessels. The Qi of the meridians connects with the Zang-Fu organs, and its transmission mechanism is extremely rapid. Once pathogens enter the meridians, their entry into the Zang-Fu organs becomes unstoppable. Therefore, Yang meridians can also present Interior syndromes. If pathogens reach the regions of the Three Yin but have not entered the vessels, this constitutes an Exterior syndrome of the Three Yin, which can still be cured by sweating. Ancients suspected that the *Shanghan Lun* (Treatise on Cold Damage) only discussed Foot meridians and ignored Hand meridians. In fact, the Three Yin and Three Yang mentioned in the treatise refer merely to body regions. The regions of the Foot meridians are large, hence they present more symptoms; the regions of the Hand meridians are small, hence they present fewer symptoms. If pathogens enter the vessels, Qi flows along fixed pathways, and meridians influence each other; thus, Hand meridians naturally have their own diseases. Therefore, when the *Shanghan Lun* mentions Hand meridian syndromes, these are always Interior syndromes. Tao Jian'an said: The six meridians of the foot represent the geographical boundaries of injury. Zhang Jingyue said: The Foot meridians are long and distant, extending from top to bottom and connecting all four limbs, so one can examine whole-body diseases by palpating them; the Hand meridians are short and proximal, intersecting among the Foot meridians, which is why Shanghan discusses only Foot meridians and ignores Hand meridians. Shanghan involves Exterior pathogens; to seek Exterior syndromes, one should examine the whole body, and among the meridians throughout the body, only the six Foot meridians encompass everything! ("Whole body" refers to the trunk/shell, contrasted with Zang-Fu organs.) Zhang Shiweng said: Transmission occurring only in Foot meridians means the pathogen is in the body surface and has not entered the Zang-Fu organs; if it enters the Zang-Fu organs, it cannot remain solely in the Foot meridians. Alas! Observing the arguments of various experts, can one not suddenly realize this? However, when pathogens are in the body regions, it generally refers to the skin and muscle layers, yet the syndromes clearly manifest in specific meridians with distinct boundaries. What is the reason for this? (*Zhang Lun* states: Each of the five Zang and six Fu organs has its boundaries, and their diseases have distinct shapes.) The answer is: The arrival of pathogens must follow a specific path. For example, if attacked on the nape, it falls under Taiyang. When the Taiyang region is occupied by pathogens, the healthy Qi in that region becomes constrained. When healthy Qi is constrained, it cannot coordinate with the rising, falling, slowing, and accelerating of Qi in the vessels. Although pathogens have not yet entered the vessels, the healthy Qi in the vessels is already affected. Thus, the entire body uniformly manifests Taiyang syndromes. After prolonged constraint, the Interior Qi also becomes deficient, allowing pathogens to invade internally due to deficiency. In summary, when pathogens are in the body regions, syndromes appear only outside the trunk; when pathogens enter the meridians, syndromes involve the Zang-Fu organs. Cases where Interior syndromes appear suddenly without pathogens entering the meridians must be due to pathogens directly striking the Sanjiao (Triple Burner); direct strike to the Sanjiao makes entry into Zang-Fu organs easier. The Sanjiao is the internal region; the Three Yin and Three Yang are the external regions. Regions are the departments of Wei Qi (Defensive Qi); meridians are the pathways of Ying Qi (Nutritive Qi).