(HT 洄集)
王安道曰。夫子能令母实。母能令子虚。以常情观之。则曰心火实。致肝木亦实。此子
能令
。法当泻心补脾。则肝肺皆平矣。越人则不然。其子能令母实。子谓火。母谓水。固与常情
无异。其母能令子虚。母谓水。子谓木。则与常情不同矣。故曰水者木之母也子能令母实。
一句言病因也。母能令子虚一句言治法也。盖火为木之子。子助其母。使之过分而为(病矣
水为本之毋若补水之虚)使力可胜火。火势退而木势亦退。此则母能虚子之义所谓不治之治
也(此虚谓抑其过而欲虚之也)水胜火三字。此越人寓意处。虽泻火补水并言。而其要又在于
补水耳。然水不虚而火独暴旺者。固不必补水也若先因水虚而致火旺者。不补水可乎。且夫
肝之实也。其因有二心助肝。肝实之一因也肺不能制肝。肝实之二因也。肺之虚也。其因亦
有二。心克肺。肺虚之一因也。脾受肝克而不能生肺。肺虚之二因也。今补水而泻火。火退
则木气削。又金不受克而制木。东方不实矣。金气得平。又土不受克而生金。西方不虚矣。
若以虚则补母言之。肺虚则当补脾。岂知肝势正盛。克土之深。虽每日补脾。安能敌其正盛
之势哉。纵使土能生金。金受火克。亦所得不偿所失矣。此所以不补土而补水也。或疑木旺
补水。恐水生木而木愈旺。殊不知木已旺矣。何待生乎况水之虚。虽峻补尚不能复其本气。
安有余力生木哉。若能生木。则能胜火矣。泻火补水。使金得平木正所谓能治其虚不补土。
不补金乃泻火补水。使金自平。此法之巧而妙者。苟不能晓此法。而不能治此虚。则不须问
其他。必是无能之人矣。
（引自朱丹溪《格致余论》）
王履（字安道）说：孔子（此处指代中医五行相生理论中的逻辑，或借指前人观点，原文语境实为讨论五行生克）能使母脏充实，母脏能使子脏虚弱。从一般常理来看，会说心火亢盛导致肝木也亢盛，这是“子能令母实”的道理。按照这种治法，应当泻心火、补脾土，这样肝和肺就能平衡了。
但扁鹊（越人）的观点则不同。他认为“子能令母实”，其中“子”指火，“母”指水，这确实与一般常理无异（按五行相克，水克火，若火旺则反侮水，或此处指水火既济关系中的异常）。但他所说的“母能令子虚”，其中“母”指水，“子”指木，这就与一般常理不同了。所以说“水者，木之母也”。
“子能令母实”这一句讲的是病因；“母能令子虚”这一句讲的是治法。因为火是木之子，子气助长母气，使其过度而致病。如果水是木之母，若能补足水的不足，使水的力量能够制约火，那么火势减退，木势也随之减退。这就是“母能令子虚”的含义，也就是所谓“不治之治”（即通过调理根本来治疗疾病）。
“水胜火”这三个字，是扁鹊寓意的关键所在。虽然文中同时提到了泻火和补水，但其要点在于补水罢了。然而，如果水并不虚弱，只有火单独暴旺，那确实不必补水；如果是先因水虚而导致火旺，难道可以不补水吗？
况且，肝脏实证的原因有两个：一是心火助长肝木，这是肝实的第一个原因；二是肺金不能制约肝木，这是肝实的第二个原因。
肺脏虚证的原因也有两个：一是心火克制肺金，这是肺虚的第一个原因；二是脾土受肝木克制而不能生养肺金，这是肺虚的第二个原因。
现在通过补水并泻火，火势减退则肝木之气被削弱，同时肺金不再受肝木克制而能制约肝木，东方（肝木）就不实了。肺金之气得以平和，进而脾土不再受肝木克制而能生养肺金，西方（肺金）就不虚了。
如果按照“虚则补其母”的理论来说，肺虚就应当补脾土。哪里知道此时肝木之势正旺盛，对脾土的克制非常深重，即使每天补脾土，怎么能抵挡得住它正旺盛的势头呢？纵使脾土能生肺金，但肺金受到心火的克制，也是得不偿失。这就是为什么不补脾土而选择补水的原因。
有人怀疑：木已经旺盛，再补水，恐怕水生木会使木更加旺盛。殊不知木已经旺盛了，哪里还需要再生长呢？况且水的虚弱，即使是峻补也难以恢复其本源之气，哪有余力去生木呢？如果能生木，那就一定能胜火了。
泻火补水，使肺金得以平和，这正是所谓的“能治其虚而不补土，不补金，乃是泻火补水，使金自平”。这是方法巧妙精妙的地方。如果不能通晓这种方法，就不能治疗这种虚证，那就不用问其他问题了，必定是无能之人。
(Quoted from Zhu Danxi's *Gezhi Yulun*)
Wang Lu (styled Andao) stated: The Master [referring to the theoretical framework or predecessors] can make the Mother organ solid, and the Mother organ can make the Child organ deficient. From a general perspective, one might say that excess Heart Fire causes Liver Wood to also become excessive; this is the principle of "the Child making the Mother solid." According to this logic, the treatment should involve draining Heart Fire and tonifying Spleen Earth, thereby balancing both the Liver and the Lungs.
However, Bian Que (Yueren) held a different view. He posited "the Child makes the Mother solid," where "Child" refers to Fire and "Mother" refers to Water. This aligns with common understanding in certain contexts (e.g., pathological interaction). But his statement "the Mother makes the Child deficient," where "Mother" refers to Water and "Child" refers to Wood, differs from common intuition. Thus, it is said: "Water is the Mother of Wood."
The phrase "the Child makes the Mother solid" explains the etiology of the disease. The phrase "the Mother makes the Child deficient" explains the therapeutic method. Since Fire is the Child of Wood, the Child's qi assists its Mother, causing her to become excessive and diseased. If Water, the Mother of Wood, is supplemented to restore its deficiency, its strength will be sufficient to overcome Fire. As the Fire pathogen recedes, the Wood pathogen also subsides. This embodies the meaning of "the Mother makes the Child deficient," which is referred to as "treating without directly treating" (i.e., addressing the root cause).
The three characters "Water overcomes Fire" represent the core implication of Bian Que's theory. Although both draining Fire and tonifying Water are mentioned, the key lies in tonifying Water. However, if Water is not deficient and only Fire is violently excessive, then indeed, tonifying Water is unnecessary. But if Fire becomes excessive due to prior Water deficiency, can one omit tonifying Water?
Furthermore, there are two reasons for Liver Excess: First, Heart Fire aids Liver Wood, which is one cause of Liver Excess. Second, Lung Metal fails to control Liver Wood, which is the second cause.
There are also two reasons for Lung Deficiency: First, Heart Fire controls Lung Metal, which is one cause of Lung Deficiency. Second, Spleen Earth is controlled by Liver Wood and thus cannot generate Lung Metal, which is the second cause.
By tonifying Water and draining Fire, the Fire recedes, thereby weakening the Qi of Wood. Simultaneously, Metal is no longer controlled by Wood and can restrain Wood, so the East (Liver Wood) will not be excessive. The Qi of Metal becomes balanced, and consequently, Earth is no longer controlled by Wood and can generate Metal, so the West (Lung Metal) will not be deficient.
If one were to apply the principle "tonify the Mother when the Child is deficient," one would tonify Spleen Earth for Lung Deficiency. However, at this time, the momentum of Liver Wood is strong, deeply controlling Earth. Even if Spleen Earth were tonified daily, how could it withstand such strong momentum? Even if Earth could generate Metal, Metal would still be controlled by Fire, resulting in gains not compensating for losses. This is why one does not tonify Earth but instead chooses to tonify Water.
Some may doubt: If Wood is already excessive, tonifying Water might cause Water to generate more Wood, making Wood even more excessive. Little do they know that Wood is already excessive; what need is there for further generation? Moreover, Water is deficient; even vigorous tonification may struggle to restore its original Qi, let alone have surplus strength to generate Wood. If it could generate Wood, it would certainly be able to overcome Fire.
Draining Fire and tonifying Water allows Metal to become balanced. This is precisely the method of "being able to treat the deficiency without tonifying Earth, without tonifying Metal, but rather by draining Fire and tonifying Water to allow Metal to balance itself." This is the cleverness and subtlety of this method. One who cannot comprehend this method cannot treat this type of deficiency; such a person should not be asked about other matters, as they must be incompetent.