《内经》曰∶“人受气于谷。谷入于胃，以传于肺；五脏六腑，
皆以受气；清者为营，浊者为卫；营行脉中，卫行脉外。”（此明胃气为脉道之
根，脏腑之本，气血之所由出也。凡人之生，皆受气于谷，万物资生之本也。凡谷之
入，必先至于胃，万物归土之义也。坤土不敢自专，精微上输于肺，盖地道卑而上
行也。肺为干金，所受精微，下溉脏腑，盖天道下济而光明也。金土互输，地天交
泰，清而上升者为营血，阴生于阳也；浊而下降者为卫气，阳根于阴也。营血为阴，
故行脉中；卫气为阳，故行脉外也。）
【按】审病察脉，以决死生，非指下了然，将安所凭借乎！深慨世医
不知脉为何物。若以为气乎，而气为卫，卫行脉外，则知非气矣。若以为
血乎，而血为营，营行脉中，则知非血矣。若以为经隧乎，而经隧实繁，则
知非经隧矣。然则脉果何物耶？余尝于此深思，久而始悟其微。古之脉
字，从血从HT ，谓气血流行，各有分派而寻经络也。今之脉字，从肉从永，
谓胃主肌肉，气血资生而永其天年也。夫人之生，惟是精与神而已。精
气即血气，而神则难见也。人非是神，无以主宰血气，保合太和，流行三
焦，灌溉百骸，故脉非他，即神之别名也。神超乎气血之先，为气血之根
蒂，善乎华元化曰∶“脉者，气血之先也”，气血之先，非神而何！然神根据于
气，气根据于血，血资于谷，谷本于胃，所以古之论脉者云∶“有胃气则生，
无胃气则死。”东垣亦曰∶“脉贵有神，正指胃气言也。”是知谷气充则血
旺，血旺则气强，气强则神昌，神之昌与否，皆以脉为征兆。故脉也者，实
气血之先也。先也者，主宰乎气血之神也。脉即神之别名，此千古未剖之疑义也，特表而出之。
《黄帝内经》说：“人从谷物中获取精气。谷物进入胃中，进而传输到肺；五脏六腑，都由此获得精气；其中清轻的部分成为营气，重浊的部分成为卫气；营气运行在脉管之中，卫气运行在脉管之外。”（这段文字阐明胃气是脉道的根本，脏腑的本源，也是气血产生的源头。大凡人的生存，都是从谷物中获取精气，这是万物赖以生存的根本。凡是谷物进入人体，必定先到达胃，这符合万物归于土的道理。坤土（脾胃）不敢专断，将精微物质向上输送给肺，这正是地道卑微而向上的道理。肺属金，接受精微物质后，向下灌溉滋养脏腑，这正是天道下济而光明的道理。金与土相互输转，天地交泰，清轻而上升的成为营血，这是阴生于阳；重浊而下降的成为卫气，这是阳根于阴。营血属于阴，所以运行在脉管之中；卫气属于阳，所以运行在脉管之外。）
【按语】审察病情、诊察脉象，以此判断生死预后，如果不是指下感觉了然分明，那凭借什么呢？我深深感慨当今医生不知道脉究竟是什么东西。如果认为脉就是气，但气表现为卫气，卫气运行在脉外，那么就知道脉不是气。如果认为脉就是血，但血表现为营气，营气运行在脉中，那么就知道脉不是血。如果认为脉就是经络隧道，但经络隧道众多繁杂，那么就知道脉不是经络隧道。既然如此，脉究竟是什么呢？我曾经对此深思，很久之后才领悟其中的奥妙。古时候的“脉”字，由“血”和“永”（此处原文为HT，推测为“永”或类似结构，意指水流长远）组成，意思是气血流行，各有分派并循行于经络。现在的“脉”字，由“肉”和“永”组成，意思是胃主肌肉，气血资生从而延长寿命。人的生存，只有精与神罢了。精气即血气，而神则是难以看见的。人如果没有神，就无法主宰血气，保持太和之气，使气血流行于三焦，灌溉全身百骸。所以脉并不是其他什么东西，它就是神的别名。神超出于气血之前，是气血的根本。华佗（华元化）说得好：“脉，是气血的先导”，既然是气血的先导，除了神还能是什么呢！然而神依附于气，气依附于血，血依赖于谷物，谷物根本在于胃。所以古人论述脉时说：“有胃气就能生存，无胃气就会死亡。”李东垣也说：“脉贵在有神，正是指胃气而言。”由此可知，谷气充足则血旺盛，血旺盛则气强盛，气强盛则神昌盛，神是否昌盛，都以脉作为征兆。所以脉，确实是气血的先导。所谓先导，就是主宰气血的神。脉就是神的别名，这是千古以来未曾剖析清楚的疑难问题，特此提出并阐明。
The *Huangdi Neijing* (Yellow Emperor's Inner Canon) states: "Humans derive Qi from grain. Grain enters the stomach and is transmitted to the lungs; the Zang and Fu organs all receive Qi from it. The clear portion becomes Ying Qi (Nutritive Qi), and the turbid portion becomes Wei Qi (Defensive Qi); Ying Qi circulates within the vessels, while Wei Qi circulates outside the vessels." (This clarifies that Stomach Qi is the root of the pulse channels and the foundation of the Zang-Fu organs, from which Qi and Blood originate. All living beings derive Qi from grain, which is the fundamental basis for their existence. When grain enters the body, it must first reach the stomach, reflecting the principle that all things return to Earth. Kun Earth [Spleen/Stomach] does not act arbitrarily but transports the essence upward to the Lungs, embodying the principle that the earthly path is humble yet ascends. The Lung belongs to Metal; having received the essence, it irrigates the Zang-Fu organs downward, embodying the principle that the heavenly path descends to bring illumination. Metal and Earth exchange transmission, Heaven and Earth interact in harmony. The clear ascending portion becomes Ying Blood, where Yin is born from Yang; the turbid descending portion becomes Wei Qi, where Yang is rooted in Yin. Since Ying Blood is Yin, it circulates within the vessels; since Wei Qi is Yang, it circulates outside the vessels.)
[Commentary] To examine the disease and palpate the pulse in order to determine life and death, if one does not have a clear perception under the fingers, what can one rely upon? I deeply lament that contemporary physicians do not know what the pulse actually is. If one considers the pulse to be Qi, yet Qi manifests as Wei Qi, which circulates outside the vessels, then one knows the pulse is not Qi. If one considers the pulse to be Blood, yet Blood manifests as Ying Qi, which circulates within the vessels, then one knows the pulse is not Blood. If one considers the pulse to be the meridians and collaterals, yet there are numerous and complex meridian pathways, then one knows the pulse is not the meridians. Then, what exactly is the pulse? I once pondered this deeply and only after a long time did I comprehend its subtlety. In ancient times, the character for "pulse" (Mai) consisted of "Blood" and "Yong" [permanence/flow], meaning that Qi and Blood flow, each having distinct distributions and following the meridians. In modern times, the character for "pulse" consists of "Flesh" and "Yong", meaning that the Stomach governs the muscles, and the generation of Qi and Blood prolongs one's natural lifespan. Human life consists solely of Essence and Spirit. Essence-Qi is identical to Blood-Qi, whereas Spirit is difficult to perceive. Without Spirit, humans cannot govern Qi and Blood, maintain Great Harmony, allow circulation through the San Jiao (Triple Burner), and irrigate the entire body. Therefore, the pulse is nothing other than an alias for Spirit. Spirit transcends Qi and Blood, serving as their root. As Hua Tuo (Hua Yuanhua) said beautifully: "The pulse is the precursor of Qi and Blood." Being the precursor of Qi and Blood, who else could it be but Spirit! However, Spirit relies on Qi, Qi relies on Blood, Blood depends on Grain, and Grain originates from the Stomach. Thus, ancients discussing the pulse stated: "With Stomach Qi, there is life; without Stomach Qi, there is death." Li Dongyuan also said: "The pulse values Spirit, which precisely refers to Stomach Qi." From this, we know that sufficient Grain Qi leads to abundant Blood, abundant Blood leads to strong Qi, and strong Qi leads to flourishing Spirit. Whether the Spirit flourishes or not is signaled by the pulse. Therefore, the pulse is indeed the precursor of Qi and Blood. The so-called precursor is the Spirit that governs Qi and Blood. The pulse is an alias for Spirit. This is a doubt unresolved for millennia, which I hereby highlight and elucidate.