圣谓人身生生之本，根于金水二脏，一水既亏，则五火随炽，上炎烁金，伤其化源，则
生生之机已息，而痨瘵之证成焉。何也？夫真水既亏，则阳自偏胜，以阳从阳，物从其类，
气得火而行健，故阳急阴缓，气疾血徐，不相偕随，所以错经妄行，越出上窍，而为咳唾等
候。然血失既多，则阴虚阳胜，阳既偏胜，则自侵阴分亢害，所谓阴虚生内热，故其潮汗遗
滑证，皆胎于此矣。诸证既见，则日消其阴，火专其令，上而烁金为咳，下涸水为遗，金既
绝其生化之源，则水为涸流之纪矣。于是精神日浅，肌肉日消，毛皮日槁，因而致此极也。
当此之际，犹鱼游辙水，即沛挽天潢，亦何济哉？必神于治者，乃可冀其万一耳。虽然，病
固水亏，不察其所亏之由以治，安得投其隙乎？如始于风寒，时未即发，致火郁久咳，伤其
肺金，是谓母令子虚，法当君以清金，佐以滋水，使以降火，所谓补母益子，伐邪制亢之意
也。又如久病久疟，真气已亏，复以劳欲损其心肾，是谓以虚益虚，法当君以益气，佐以滋
水，使以养血，所谓无伐天和之意也。又如过力伤筋，动而生阳，肝不纳血，血骤妄行，致
阴虚之极者，法当君以养血，佐以降火调气，使以消瘀，所谓攻守兼备之法也。至于膏粱逸
士，酗酒恣欲，致脾肾两亏，水涸火炎，金衰木旺，母子俱病，法当君以补水养血，佐以清
金益士，使以降火平肝，所谓治病必求其本也。若夫前论，所谓五脏相传之证，固为亢害承
制，所必然者，而其所载之候，未必一一全具，但医当素蕴胸中，惟以面色主之，以亢，他
证
倘不察其微，而概以制亢，恣意伐邪，猛浪投剂，虚虚之祸，咎将安归。
龚居中认为，人体生命活动的根本，源于肺（金）和肾（水）两脏。一旦肾水亏损，五脏之火便会随之炽盛，向上灼烧肺金，损伤其化生之源，那么生命的生机就会停止，痨瘵（肺结核等慢性消耗性疾病）的病症也就形成了。为什么呢？因为真阴之水已经亏损，阳气自然偏胜。以阳助阳，物以类聚，气得到火的作用而运行刚健，所以阳气急迫而阴血舒缓，气行疾速而血行缓慢，二者不能协调跟随，因此导致月经错乱妄行，血液从上部七窍溢出，出现咳嗽、吐痰等症状。然而，血液流失过多，则导致阴虚阳亢；阳气既然偏胜，就会侵犯阴分造成亢害，这就是所说的“阴虚生内热”，所以潮热、盗汗、遗精滑泄等症状，都孕育于此了。各种症状既已显现，则阴液日渐消损，火热之邪独掌权令。向上灼烧肺金导致咳嗽，向下耗竭肾水导致遗精。肺金既然断绝了生化之源，那么肾水就成了干涸河流的结局。于是精神日益衰败，肌肉日渐消瘦，毛发皮肤日渐枯槁，最终导致这种极端的状况。到了这个时候，就像鱼在车辙的浅水中游动，即使引来天河的水，又有什么用呢？只有精通医术的人，才可能希望有万分之一的治愈机会。虽然如此，疾病固然因为水亏，如果不考察其亏损的原因来治疗，怎么能抓住病机呢？比如始于风寒，当时没有立即发作，导致火邪郁结引起久咳，损伤了肺金，这叫做“母令子虚”（肺为肾之母，或此处指金生水，肺伤及肾），治法应当以清润肺金为主药，辅以滋补肾水，使火势下降，这就是所谓的补母益子，抑制邪气亢盛的意思。又如久病或长期疟疾，真气已经亏损，再加上劳累和房事损伤心肾，这叫做“以虚益虚”，治法应当以益气为主药，辅以滋补肾水，使以养血，这就是所谓的不破坏人体自然和谐之意。又如过度用力损伤筋脉，动而生阳，肝不能收纳血液，血液突然妄行，导致阴虚到极点的情况，治法应当以养血为主药，辅以降火调气，使以消除瘀血，这就是所谓的攻守兼备的方法。至于那些生活优裕、安逸的士人，酗酒纵欲，导致脾肾两亏，水涸火炎，金衰木旺，母子同病，治法应当以补水养血为主药，辅以清润肺金、健脾益土，使以降火平肝，这就是所谓的治病必求其本。至于前面论述的所谓五脏相传的病症，固然是亢害承制（五行相克失衡后的自我调节机制）必然的结果，但其中记载的症状，未必会一一全部具备。医生应当在心中早有定见，主要通过面色来判断病情。如果不同时观察细微征兆，就一概采用抑制亢盛、肆意攻伐邪气的方法，猛浪地投药，造成“虚虚”（使虚者更虚）的祸患，责任将归于谁呢？
Gong Juzhong posits that the root of human vitality lies in the Lung (Metal) and Kidney (Water) organs. Once Kidney Water is deficient, the Fire of the Five Zang organs flares up accordingly, scorching Lung Metal upwards and damaging its source of transformation. Consequently, the mechanism of life ceases, and the syndrome of Lao Zhai (consumption disease, such as tuberculosis) manifests. Why is this? Since True Yin Water is depleted, Yang naturally becomes excessive. Yang assists Yang, and things follow their kind; Qi, empowered by Fire, moves vigorously. Thus, Yang becomes urgent while Yin/Yin Blood becomes slack; Qi moves rapidly while Blood flows slowly, failing to coordinate with each other. This leads to irregular and erratic menstruation, bleeding from the upper orifices, and symptoms such as coughing and expectoration. However, excessive blood loss results in Yin deficiency and Yang hyperactivity. Once Yang is excessively dominant, it invades the Yin aspect causing hyperactive harm, which is referred to as "Yin deficiency generating internal heat." Therefore, syndromes such as tidal fever, night sweats, seminal emission, and slipping are all conceived here. Once these syndromes appear, Yin is consumed daily, and Fire exclusively dominates. Upwards, it scorches Metal causing cough; downwards, it dries Water causing emission. Since Metal cuts off its source of generation, Water becomes a dried-up stream. Thus, spirit diminishes daily, muscles waste away, and hair and skin become withered, leading to this extreme state. At this juncture, it is like a fish swimming in a rut's water; even if one were to draw down the Milky Way to replenish it, what good would it do? Only those skilled in treatment may hope for a one-in-ten-thousand chance of recovery. Nevertheless, although the disease is indeed due to Water deficiency, if one does not investigate the cause of the deficiency to treat it, how can one seize the opportunity? For instance, if it begins with Wind-Cold, which does not manifest immediately, causing Fire to be constrained and resulting in chronic cough that damages Lung Metal, this is called "Mother causing Child deficiency" (referring to the Metal-Water relationship). The method should employ clearing and moistening Metal as the sovereign herb, assisting with nourishing Water, to descend Fire. This embodies the meaning of tonifying the Mother and benefiting the Child, suppressing pathogenic excess. Again, in cases of chronic illness or long-standing malaria where True Qi is already deficient, further damage to Heart and Kidney from labor and sexual indulgence constitutes "adding deficiency to deficiency." The method should employ tonifying Qi as the sovereign herb, assisting with nourishing Water, and using blood-nourishing herbs, embodying the principle of not disrupting the natural harmony of Heaven (the body). Again, if excessive force injures the sinews, moving and generating Yang, and the Liver fails to store Blood, causing sudden erratic bleeding leading to extreme Yin deficiency, the method should employ blood-nourishing herbs as the sovereign, assisting with descending Fire and regulating Qi, and using blood-stasis-resolving herbs, representing a method of both attack and defense. As for the pampered and idle scholars who indulge in alcohol and lust, causing dual deficiency of Spleen and Kidney, drying Water and flaming Fire, weakening Metal and flourishing Wood, affecting both Mother and Child, the method should employ tonifying Water and nourishing Blood as the sovereign, assisting with clearing Lung Metal and benefiting Earth, and using herbs to descend Fire and calm the Liver, embodying the principle that treating disease requires seeking its root. Regarding the previously discussed syndromes of transmission among the Five Zang organs, although they are necessarily subject to the law of hyperactivity and constraint (Kang-Hai Cheng-Zhi), the recorded symptoms may not always present completely. Physicians must have these principles firmly in mind and primarily diagnose based on facial complexion. If one fails to observe subtle signs and indiscriminately applies methods to suppress hyperactivity and ruthlessly attack pathogens, prescribing aggressively, thereby causing the disaster of "deficiency inducing deficiency" (making the deficient more deficient), whose fault shall it be?