命门者，人身之真阳，肾中之元阳是已，非另是一物也。后世立论，有谓在两肾中间者，有误引“七节之旁，中有
小心”为命门者；至谓其形如胡桃，尤为荒诞！夫越人倡右肾命门之说，而后人非之，抑思不有越人，又何从有命门之
说乎，其意以阳气为重，人身左血右气，故归之右也。人之每藏每府，各具阴阳，肾为一身之根柢，元阳为人身所尤重，
故特揭之也。自古命门治法，亦惟温补肾阳而已，别无他法也。故虞天民两肾总号命门之说，最为近理。景岳亦有分而
言之，则左水右火，合而言之，为水火之府，阴阳之宅，及命门总主乎两肾，两肾皆属于命门之论。至以子肠当之，又
于理未安也。孙东宿以生气立论，其意颇合，竟指为先天之太极，亦非也。近时灵胎徐氏，谓肾之有两，则皆名为肾，
不得名为命门，盖肾为牝藏，其数偶，命门之义，惟冲脉之根柢，其位适当两肾之中，真可称为命之门，不得以右肾当
之也。夫以牝藏释两肾，其说最的；以冲脉当命门，倡论似甚新奇，细按亦非确当，不过执两肾中间之语，而另开一说
耳。窃以为两肾为立命之门，命门穴在中间，似因肾而得名，越人以肾为命门，又因穴而名之也。总之、《三十六难》曰∶
“命门者，诸神精之所舍，原气之所系也。男子以藏精，女子以系胞。”此真上补《素》、《灵》之未及，惟“非皆
肾”、“知肾有一”二语，不免词病，以致后人辨论纷纷也。
命门，就是人身体的真阳，也就是肾中的元阳，并不是另外独立存在的一个物体。后世的医家提出各种理论，有的说命门位于两肾的中间，有的错误地引用《难经》中“第七节脊椎旁边，中间有心”这句话来指代命门；甚至有人说它的形状像胡桃，这更是荒谬！
当初越人（扁鹊）提出了右肾为命门的说法，后来的人对此进行非议，但大家是否想过，如果没有越人，又从哪里产生关于命门的学说呢？他的本意是重视阳气，认为人体左边主血、右边主气，所以将命门归属于右侧。人的每一个脏器和腑器，都各自具备阴阳属性。肾作为一身之根本，元阳又是人身所特别重视的，所以特意将其单独揭示出来。
自古以来，治疗命门的方法，也只是温补肾阳而已，没有其他方法。因此，虞天民提出的“两肾总称为命门”的说法，最为接近事理。张景岳也有分别论述和综合论述的观点：分别来说，左肾属水，右肾属火；综合来说，命门是水火的府库，阴阳的宅舍，并且命门总领两肾，两肾都属于命门。至于用子肠（直肠下端或子宫相关部位）来对应命门，这在道理上也不妥当。孙东宿以“生气”立论，其意思颇为契合，但他竟将命门指认为先天的太极，这也是不对的。
近代徐灵胎（徐大椿）认为，既然肾脏有两个，那么都叫作肾，不能叫作命门。因为肾属于阴脏（牝藏），其数量为偶数；而命门的含义，应该是冲脉的根本所在，其位置正好在两肾中间，真正可以称为“生命之门”，不能把右肾当作命门。他用阴脏来解释两肾，这个说法最确切；用冲脉来对应命门，虽然倡导的理论看似新奇，但仔细推敲也并不确切，不过只是执着于“两肾中间”这句话，另辟一说罢了。
我个人认为，两肾是确立生命的门户，命门穴位于两肾中间，似乎是因肾脏而得名；而越人将肾称为命门，则是因穴位而命名。总之，《三十六难》中说：“命门，是诸神精所居之处，原气所系之地。男子用以贮藏精气，女子用以维系胞宫。”这真正弥补了《素问》、《灵枢》未曾涉及的内容，只是其中“并非都是肾”、“知道肾只有一个”这两句话，不免有文字瑕疵，导致后人争论纷纷。
Mingmen (Gate of Life) refers to the True Yang (True Fire) of the human body, which is the Original Yang (Yuan Yang) within the Kidneys; it is not a separate, independent entity. Later theorists proposed various arguments: some claimed it is located between the two kidneys, while others erroneously cited the phrase "beside the seventh vertebra, there is a small heart" from the *Nan Jing* to designate Mingmen. It is even more absurd for some to claim its shape resembles a walnut!
When Yue Ren (Bian Que) advocated the theory that the right kidney is Mingmen, later scholars criticized this view. However, one should consider: without Yue Ren, where would the concept of Mingmen have originated? His intent was to emphasize Yang Qi. Since the left side of the body governs Blood and the right side governs Qi, he assigned Mingmen to the right. Every Zang (Solid Organ) and Fu (Hollow Organ) possesses both Yin and Yang. The Kidney serves as the root of the entire body, and Original Yang is particularly crucial to life; thus, it was specifically highlighted.
Since ancient times, the treatment method for Mingmen has been solely to warm and tonify Kidney Yang, with no other methods. Therefore, Yu Tianmin's theory that "the two kidneys are collectively called Mingmen" is the most reasonable. Zhang Jingyue also discussed this by distinguishing and integrating aspects: separately, the left represents Water and the right represents Fire; integratively, Mingmen is the residence of Water and Fire, and the dwelling of Yin and Yang, governing both kidneys, such that both kidneys belong to Mingmen. To equate Mingmen with the "Zi Chang" (rectum or uterus-related area) is logically unsound. Sun Dongsu based his argument on "Vital Qi," which aligns well with the concept, yet identifying it as the Pre-heaven Taiji (Supreme Ultimate) is incorrect.
In recent times, Xu Lingtai (Xu Dacun) argued that since there are two kidneys, both should be named Kidneys and not Mingmen. Because the Kidney is a Yin Zang (Pǐn Zàng), an even-numbered organ, whereas the meaning of Mingmen implies the root of the Chong Mai (Penetrating Vessel). Its position is exactly between the two kidneys, truly deserving the name "Gate of Life," and thus the right kidney cannot be designated as Mingmen. Explaining the two kidneys as Yin Zangs is the most accurate statement; however, using the Chong Mai to represent Mingmen, while seemingly novel, is not strictly correct upon close examination. It merely takes the phrase "between the two kidneys" to propose an alternative theory.
I personally believe that the two kidneys constitute the Gate of establishing Life. The Mingmen acupoint is located in the middle, likely named after the kidneys. Conversely, Yue Ren naming the Kidney as Mingmen was likely named after the acupoint. In summary, the *Thirty-Sixth Difficulty* states: "Mingmen is the abode of all spirits and essences, and the connection point of Yuan Qi (Original Qi). In men, it stores Essence; in women, it connects to the Bao Gong (Uterus)." This truly supplements what the *Su Wen* and *Ling Shu* omitted. However, the phrases "not all are Kidneys" and "knowing there is only one Kidney" contain textual flaws, leading to endless debates among later generations.