人身从脐中分，上部为阳，下部为阴，面为阳，背为阴，左为阳，右为阴，表
为阳，里为阴，腑为阳，脏为阴，气为阳，血为阴，动为阳，静为阴，语为阳，默
为阴，寤为阳，寐为阴，呼为阳，吸为阴，魂为阳，魄为阴。《内经》言背为阳，是
对腹为阴说，非谓背为阳而面为阴也。盖腹处下，而背居上，故以上者为阳，下者
为阴耳。后人不明其说，以腹字当面字看，误矣。观《易》卦，阳盛于午，阴盛于
子。背，北也，北属阴，阴静阳动，背不动，属阴明矣。又溺水死者，女尸必仰，
女人阴气重也。男尸必仆，男人阳气重也。不更可验背之属阴，面之属阳哉？
夫阳盛于午，阴盛于子，此面阳背阴之义也。由复至干，左升为阳，由
至坤，右降为阴，此左阳右阴之义也。阳主气，阴主血，阳大而阴小。乃丹溪谓∶
左半血多，右半气多，人右手足大于左手足。何也？曰∶左右阴阳对待，本甚均平，
无偏多偏少。然阳盛于午，至酉而犹热，阴盛于子，至卯而犹寒，岂非极盛之势，
余气犹旺耶？然则左虽属阳，而阴反盛，右虽属阴，而阳反强，固可见矣。又何疑
于左半身血多，右半身气多，右手足之大于左手足乎。（《医贯》谓∶冬至一阳生，当渐向暖和，
乃腊月大寒，冰雪反甚，盖阳伏于下，逼阴于上，故井水气蒸而坚冰至。夏至一阴生，当
渐向清凉，乃三伏潺暑，酷热反炽，盖阴盛于下，逼阳于上，故井水寒而雷电合。可以互
证。）予尝病眼热，必右目先而甚，左目后而微，知左属血，火不易伤也。（所谓干柴者先
灼，湿者后燃也。）又病脚肿，必左先而甚，右后而微，知右属气，湿尚易运也。又尝掩
右目，用左目视月，则不如右目之明，以右目火盛，能远烛也。掩左目，用右目观书，
则不如左目之朗，以左目水盛，能近鉴也。然此犹各有所长也。若较其强弱，则右必强
于左。尝吹筒弋鸟，筒鸟相对若引绳，以为必中也，而不中，知二目之力有强弱不同也
。因闭右目，独用左目视筒鸟如引绳，乃开右目并用，则大异矣，是左目为右目所夺也
。又闭左目，独用右目，视筒鸟如引绳，乃开左目并视，其为如引绳者，亦无异也，是
右目不为左目所夺也。岂非右目强而左目弱哉？故《经》言右耳目不如左耳目明者，吾
不信也。腑为阳，脏为阴。细分之，则心肺处上部为阳，肝肾居下部为阴。又心与肺较，
则肺属金为阴，心属火为阳。肝与肾较，肾属水为阴，肝属木为阳。又肺与肝较，
则肺主降为阴，肝主升为阳。又肾有水有火，肾火为阳，肾水为阴。纷纭蕃变，无
有定名。医书动言阴阳，而不切指其为何项，甚属朦混，当细分之。（如言阴虚，则未知
其言血虚耶？肺虚耶？肾水虚耶？肾火虚耶？何不切指之曰血虚，曰肺虚，曰肾水虚，
曰肾火虚，之为明白也。本集一一分晰之。）
人体以肚脐为界，上部属阳，下部属阴；面部属阳，背部属阴；左侧属阳，右侧属阴；体表属阳，体内属阴；六腑属阳，五脏属阴；气属阳，血属阴；运动属阳，静止属阴；说话属阳，沉默属阴；清醒属阳，睡眠属阴；呼气属阳，吸气属阴；魂属阳，魄属阴。《黄帝内经》说背部属阳，是相对于腹部属阴而言的，并不是说背部属阳而面部属阴。大概是因为腹部处于下方，而背部居于上方，所以以上方者为阳，下方者为阴罢了。后人不明白这个说法，把“腹”字当作“面”字来看待，这是错误的。观察《易经》卦象，阳气在午时最盛，阴气在子时最盛。背对应北方，北方属阴，阴主静、阳主动，背部不动，显然属于阴。另外溺水而死的人，女尸必定仰面朝天，因为女人阴气重；男尸必定俯卧在地，因为男人阳气重。这不更可以验证背部属阴、面部属阳吗？
阳气在午时最盛，阴气在子时最盛，这就是面部属阳、背部属阴的道理。从复卦到乾卦，向左上升为阳；从姤卦到坤卦，向右下降为阴，这就是左侧属阳、右侧属阴的道理。阳主要主管气，阴主要主管血，阳体大而阴体小。但是朱丹溪却说：左半身血多，右半身气多，人的右手足比左手足大。为什么呢？回答说：左右阴阳相对，本来非常平衡，没有偏多偏少。然而阳气在午时极盛，到了酉时仍然热；阴气在子时极盛，到了卯时仍然寒，这难道不是极盛之势，残余之气依然旺盛吗？既然如此，那么左侧虽然属阳，但阴反而盛；右侧虽然属阴，但阳反而强，这已经很明显了。又何必怀疑左半身血多、右半身气多，以及右手足比左手足大呢？（《医贯》中说：冬至一阳生，应当逐渐趋向暖和，但腊月大寒时，冰雪反而更甚，这是因为阳气潜伏在下，逼迫阴气在上，所以井水气蒸腾而坚冰到来。夏至一阴生，应当逐渐趋向清凉，但三伏酷暑时，酷热反而炽盛，这是因为阴气盛于下，逼迫阳气在上，所以井水冷而雷电交合。这可以互相印证。）我曾经患眼热病，一定是右眼先发作且严重，左眼后发作且轻微，由此知道左侧属血，火邪不易伤害它。（所谓干柴先燃烧，湿柴后燃烧的道理。）又曾患脚肿病，一定是左脚先发作且严重，右脚后发作且轻微，由此知道右侧属气，湿邪尚易运化。又曾经遮住右眼，用左眼看月亮，则不如右眼明亮，因为右眼火气盛，能照得远。遮住左眼，用右眼看书，则不如左眼清晰，因为左眼水气盛，能看得近。然而这还算是各有所长。如果比较强弱，那么右眼一定强于左眼。曾经用吹筒射鸟，筒鸟相对像拉紧的绳子，以为一定能射中，结果没中，知道两只眼睛的力量有强弱不同。于是闭上右眼，只用左眼看筒鸟像拉紧的绳子，再睁开右眼同时看，情况就大不相同了，这是左眼被右眼所压制。又闭上左眼，只用右眼看筒鸟像拉紧的绳子，再睁开左眼同时看，那像拉紧绳子的景象也没有差异，这是右眼不被左眼所压制。这难道不是右眼强而左眼弱吗？所以《内经》说右耳目不如左耳目明亮，我不相信。
六腑属阳，五脏属阴。细分起来，心、肺位于上部属阳，肝、肾位于下部属阴。再者，心与肺相比，肺属金为阴，心属火为阳。肝与肾相比，肾属水为阴，肝属木为阳。再者，肺与肝相比，肺主降为阴，肝主升为阳。再者，肾中有水有火，肾火为阳，肾水为阴。纷繁变化，没有固定的名称。医书中动不动就说阴阳，却不具体指明是哪一项，非常含糊，应当细分清楚。（比如说到阴虚，却不知道是说血虚呢？还是肺虚？还是肾水虚？还是肾火虚？为什么不具体指明说是血虚、肺虚、肾水虚、肾火虚，这样才明白呢。本集中已一一分析清楚。）
The human body is divided by the navel: the upper part is Yang, the lower part is Yin; the face is Yang, the back is Yin; the left side is Yang, the right side is Yin; the exterior is Yang, the interior is Yin; the Fu organs (Six Intestines/Gallbladder/Bladder) are Yang, the Zang organs (Five Viscera) are Yin; Qi is Yang, Blood is Yin; movement is Yang, stillness is Yin; speaking is Yang, silence is Yin; being awake is Yang, sleeping is Yin; exhaling is Yang, inhaling is Yin; Hun (Ethereal Soul) is Yang, Po (Corporeal Soul) is Yin. The *Huangdi Neijing* states that the back is Yang, which is said in contrast to the abdomen being Yin; it does not mean the back is Yang and the face is Yin. This is because the abdomen is situated below, while the back is positioned above; thus, what is above is considered Yang, and what is below is considered Yin. Later generations did not understand this explanation and misinterpreted "abdomen" as "face," which was an error. Observing the hexagrams of the *I Ching*, Yang Qi peaks at Wu hour (noon), and Yin Qi peaks at Zi hour (midnight). The back corresponds to the North; the North belongs to Yin. Yin is still, Yang is active; since the back is immobile, it clearly belongs to Yin. Furthermore, among those who drown, female corpses always float on their backs, indicating that women have heavy Yin Qi; male corpses always lie prone, indicating that men have heavy Yang Qi. Does this not further verify that the back belongs to Yin and the face belongs to Yang?
Yang Qi is most abundant at Wu hour, and Yin Qi is most abundant at Zi hour; this is the meaning behind the face being Yang and the back being Yin. From the Fu hexagram to the Qian hexagram, rising to the left constitutes Yang; from the Gou hexagram to the Kun hexagram, descending to the right constitutes Yin; this is the meaning behind the left being Yang and the right being Yin. Yang primarily governs Qi, and Yin primarily governs Blood; Yang is large, and Yin is small. However, Zhu Danxi stated: "There is more Blood in the left half and more Qi in the right half, hence a person's right hand and foot are larger than the left." Why is this? The answer is: Left and Right Yin and Yang are mutually opposing and originally very balanced, with no excess or deficiency. Yet, when Yang Qi peaks at Wu hour, it remains hot until You hour; when Yin Qi peaks at Zi hour, it remains cold until Mao hour. Is this not evidence that even after reaching peak intensity, residual energy remains vigorous? Therefore, although the left belongs to Yang, Yin actually prevails there; although the right belongs to Yin, Yang actually dominates there. This is evident. So why doubt that there is more Blood in the left half-body and more Qi in the right half-body, and that the right hand and foot are larger than the left? (*Yi Guan* states: "At Winter Solstice, one Yang Qi arises, so warmth should gradually increase; yet during the Great Cold of the twelfth lunar month, ice and snow become even more severe. This is because Yang Qi hides below, forcing Yin Qi upward, causing well water to steam while solid ice forms. At Summer Solstice, one Yin Qi arises, so coolness should gradually increase; yet during the Sanfu extreme heat, scorching heat becomes intense. This is because Yin Qi is abundant below, forcing Yang Qi upward, causing well water to be cold while thunder and lightning combine. These can corroborate each other.") I once suffered from eye heat; my right eye would always be affected first and severely, while the left eye was affected later and mildly. Thus, I knew the left belongs to Blood, and Fire pathogenic factors do not easily injure it. (This is like dry wood burning first and wet wood burning later.) I also once suffered from leg edema; my left foot swelled first and severely, while the right foot swelled later and mildly. Thus, I knew the right belongs to Qi, and Dampness pathogenic factors are relatively easy to transform. I once covered my right eye and used my left eye to view the moon, but it was not as clear as with my right eye, because the right eye has abundant Fire Qi and can illuminate distant objects. I covered my left eye and used my right eye to read books, but it was not as bright as with my left eye, because the left eye has abundant Water Qi and can inspect near objects. However, these cases show that each has its strengths. If comparing strength, the right eye must be stronger than the left. I once used a blowpipe to shoot at birds; aiming at a bird through the pipe seemed like pulling a tight rope, leading me to believe I would hit it, but I missed. This showed that the two eyes have different levels of power. Then, closing my right eye and using only my left eye to aim at the bird as if pulling a tight rope, and then opening both eyes to look together, the situation changed drastically; this indicated that the left eye was overpowered by the right eye. Conversely, closing my left eye and using only my right eye to aim at the bird as if pulling a tight rope, and then opening both eyes to look together, the image remained consistent; this indicated that the right eye was not overpowered by the left eye. Does this not prove that the right eye is strong and the left eye is weak? Therefore, I do not believe the statement in the Classics that the right ear and eye are less acute than the left.
The Fu organs are Yang, and the Zang organs are Yin. In finer detail, the Heart and Lung are located in the upper part and belong to Yang; the Liver and Kidney are located in the lower part and belong to Yin. Furthermore, comparing the Heart and Lung, the Lung belongs to Metal and is Yin, while the Heart belongs to Fire and is Yang. Comparing the Liver and Kidney, the Kidney belongs to Water and is Yin, while the Liver belongs to Wood and is Yang. Comparing the Lung and Liver, the Lung governs descending and is Yin, while the Liver governs ascending and is Yang. Moreover, the Kidney contains both Water and Fire; Kidney Fire is Yang, and Kidney Water is Yin. These distinctions are complex and variable, without fixed names. Medical texts often speak of Yin and Yang without specifically pointing out which category they refer to, which is very vague and should be clarified in detail. (For example, when stating "Yin Deficiency," it is unclear whether it refers to Blood Deficiency, Lung Deficiency, Kidney Water Deficiency, or Kidney Fire Deficiency. Why not specify explicitly as Blood Deficiency, Lung Deficiency, Kidney Water Deficiency, or Kidney Fire Deficiency for clarity? These have been analyzed one by one in this collection.)