门人朱济公问曰∶有云两肾皆属水，命门居两肾之中，在脊之十四椎内，为三焦生气之原，有如坎中
之满，此说甚为有理。曰∶此不经之语耳！夫医道始于黄岐，脏腑血气之生始出入，非生知之圣，孰能究
其精微？奈何后学不体认圣经，反好为异说。夫人之始结胚胎，犹太极耳！三月而成形，先生两肾，犹太
极而生两仪。天一之水生木，木生火；地二之火生土，土生金。是先天止有水火，后天始备五行。五行
之中有二火，合而为三阴三阳，以配六脏六腑。故《灵
枢·本输篇》曰∶少阳属肾，肾上连肺，故将两脏。盖少阳乃三焦之生气，发于右肾，上合包络，为相火之
原，左肾属水，上连于肺，故为两脏也。（肾上连肺，详《水热穴沦》。）又《本脏篇》曰∶肾合三焦膀胱。盖右肾之气上
合于心主包络，而为一脏。又《素问·咳论》曰∶肾咳不已，则膀胱受之；久咳不已，则三焦受之。是
《内经》止曰肾，而原无命门之名。盖以一肾合三焦，一肾合膀胱，是为两脏而配合两腑者也。夫人秉
阴阳水火而生，若以两肾象坎中之满，又将何脏以象离中之虚乎？潜心圣经，自不为前人所惑。
济公复问曰∶《难经》谓右肾主男子藏精，女子系胞。师言为相火生气之原，是左肾主水，右肾主
火，精水止生于左，而胞当偏于右矣。曰∶非此之谓也，夫天地阴阳之道，在无形之气，曰阴、曰阳；有
形之征，曰水、曰火；在人之元神，曰气、曰精。天一生水，地二生火，阴中有阳，阳中有阴，两肾之
气，交相贯通，左右之皆有精有气。水即是精，火即是气。阴阳水火，互相资生，否则孤阳不生，独阴不
长矣。夫藏精系胞之说，亦不过分别男女而言。然在女子未尝不藏精，在男子亦可以结胎者也。胞之所
系，盖言天主生物，地主成物，故系于右，乃气之所感，非胞之联系于右肾也。如云日月星辰系焉，亦大气
之所载，日月营运，星移斗转，又何尝有所系带乎？
弟子朱济公问道：“有人说两肾都归属于水，命门位于两肾之间，在脊柱第十四椎的内部，是三焦产生生气的根源，就像《易经》坎卦中阳爻的充实一样，这种说法非常有道理。”我说：“这是没有根据的荒谬言论！医学之道始于黄帝和岐伯，脏腑气血的生成与运行规律，如果不是天生智慧的圣人，谁能探究其中的精微之处？为何后辈学者不体悟经典著作，反而喜欢标新立异。人最初形成胚胎时，就像太极一样！三个月时形体初成，先生出两肾，就像太极生出两仪（阴阳）。天一之水生成木，木再生火；地二之火生成土，土再生金。因此先天只有水和火，后天才具备五行。五行之中包含两种火，合并成为三阴三阳，以配属六脏六腑。所以《灵枢·本输篇》说：少阳经隶属于肾，肾向上连接肺，所以能统辖这两脏。盖少阳是三焦产生生气的源头，发源于右肾，向上合于包络，是相火的根源；左肾归属于水，向上连接于肺，所以称为两脏。（‘肾上连肺’详见《素问·水热穴论》。）又《灵枢·本脏篇》说：肾与三焦、膀胱相合。盖右肾之气向上合于心主包络，从而构成一脏。又《素问·咳论》说：肾咳不止，则病传至膀胱；久咳不止，则病传至三焦。由此可见，《内经》只提到肾，原本并没有‘命门’这个名称。大概是因为一个肾配合三焦，一个肾配合膀胱，这就是两脏配合两腑的道理。人禀受阴阳水火之气而生，如果把两肾比作坎卦中的阳爻（实），那么又将哪个脏器来比拟离卦中的阴爻（虚）呢？潜心研读经典，自然不会被前人迷惑。
朱济公又问道：“《难经》说右肾主管男子藏精，女子系胞。老师您说是相火生气的根源，这意味着左肾主水，右肾主火，精气只生于左肾，而胞宫应当偏在于右侧了。”我说：“不是这个意思。天地阴阳的道理，在于无形的气，称为阴、称为阳；有形的征象，称为水、称为火；在人体的元神方面，称为气、称为精。天一生水，地二生火，阴中有阳，阳中有阴，两肾之气，相互贯通，左右两边都有精和气。水就是精，火就是气。阴阳和水火互相资助生长，否则孤阳不能生，独阴不能长。所谓‘藏精系胞’的说法，也不过是分别针对男女而言罢了。然而在女子身上也未尝不藏精，在男子身上也可以结胎。胞宫之所以说系于右，大概是说天主宰万物的生成，地主宰万物的成形，所以说系于右边，这是气的作用感应，并非胞宫在解剖上联系于右肾。如果说日月星辰系于那里，那也是大气的承载，日月运行，星移斗转，又何曾有所系带束缚呢？”
The disciple Zhu Jigong asked, "It is said that both kidneys belong to Water. The Mingmen (Gate of Life) resides between the two kidneys, inside the fourteenth thoracic vertebra of the spine, and serves as the source of Qi generation for the Sanjiao (Triple Burner), resembling the fullness within the Kan trigram (☵). This explanation seems very reasonable." I replied, "This is baseless nonsense! The Way of Medicine began with Huangdi (Yellow Emperor) and Qibo. The origins and movements of Zang-Fu organs, Blood, and Qi are not known by innate wisdom; who but a sage could fathom their subtleties? Why do later scholars fail to comprehend the sacred classics and instead prefer heterodox theories? When a human embryo first forms, it is like the Taiji (Supreme Ultimate)! At three months, the form takes shape, and the two kidneys are born first, just as Taiji generates the Liangyi (Two Modes/Yin and Yang). Tian Yi produces Water, which generates Wood; Wood generates Fire. Di Er produces Fire, which generates Earth; Earth generates Metal. Thus, in the Pre-Heaven state, there were only Water and Fire; it was in the Post-Heaven state that the Five Phases were complete. Among the Five Phases, there are two Fires, which combine to form the Three Yin and Three Yang, corresponding to the Six Zang and Six Fu organs. Therefore, *Ling Shu: Ben Shu* states: 'Shaoyang belongs to the Kidney, and the Kidney connects upward to the Lung, thus governing these two Zang organs.' Shaoyang is the source of Qi generation for the Sanjiao, originating from the Right Kidney, connecting upward to the Bao Luo (Pericardium), serving as the origin of Ministerial Fire. The Left Kidney belongs to Water and connects upward to the Lung, hence referred to as the two Zang organs. ('Kidney connects upward to Lung' is detailed in *Su Wen: Shui Re Xue Lun*.) Furthermore, *Ben Zang* states: 'The Kidney harmonizes with the Sanjiao and Bladder.' The Qi of the Right Kidney connects upward to the Xin Zhu (Heart Master/Pericardium), forming one Zang organ. Additionally, *Su Wen: Ke Lun* states: 'If Kidney cough persists, it affects the Bladder; if chronic cough persists, it affects the Sanjiao.' Thus, *Nei Jing* mentions only the Kidney, with no original mention of 'Mingmen'. It is likely that one Kidney corresponds to the Sanjiao, and the other to the Bladder, constituting two Zang organs coordinating with two Fu organs. Humans are born endowing Yin, Yang, Water, and Fire. If both kidneys are likened to the solid line in the Kan trigram (representing Water/Fire duality with Yang within Yin), which Zang organ would correspond to the broken line in the Li trigram (Fire)? By immersing oneself in the sacred classics, one will naturally not be confused by predecessors.
Zhu Jigong asked again, "*Nan Jing* states that the Right Kidney governs storing Essence in men and anchoring the Bao Gong (Uterus) in women. You stated it is the source of Ministerial Fire and Qi generation, implying the Left Kidney governs Water and the Right Kidney governs Fire. Thus, Essence/Water is generated only in the Left Kidney, and the Bao Gong should be situated on the right." I said, "That is not what is meant. The Way of Heaven and Earth Yin and Yang lies in formless Qi, called Yin and Yang; in有形 (form) manifestations, called Water and Fire; in the human Shen Yuan (Primordial Spirit), called Qi and Jing. Tian One produces Water, Di Two produces Fire. Yin contains Yang, and Yang contains Yin. The Qi of the two kidneys penetrates each other mutually; both left and right possess Jing and Qi. Water is Jing, and Fire is Qi. Yin and Yang, Water and Fire, mutually nourish and generate each other; otherwise, solitary Yang cannot generate, and isolated Yin cannot grow. The saying about 'storing Essence and anchoring the Uterus' merely distinguishes between males and females. However, females also store Essence, and males can also form embryos. The statement that the Uterus is 'anchored' on the right implies that Heaven governs the generation of life, and Earth governs the completion of form; thus, it is anchored on the right due to the influence of Qi, not because the Uterus is anatomically connected to the Right Kidney. Just as the sun, moon, and stars are said to be 'anchored' there, they are carried by the great Qi. The movement of the sun and moon, and the shifting of stars, never involves any physical tethering."