万事皆有本，而治病之法，尤惟求本为首务。所谓本者，唯一而无两也。盖或因外感者
，本于表也。或因内伤者，本于里也。或病热者，本于火也。或病冷者，本于寒也。邪有余
者，本于实也。正不足者，本于虚也。但察其因何而起，起病之因，便是病本，万病之本，
只此表里寒热虚实六者而已。知此六者，则表有表证，里有里证，寒热虚实，无不皆然。六
者相为对待，则冰炭不同，辨之亦异。凡初病不即治，及有误治不愈者，必致病变日多，无
不皆从病本生出，最不可逐件猜摸，短觑目前。经曰∶众脉不见，众凶弗闻，外内相得，无
以形先。是诚求本之至要也。苟不知此，必庸流耳。故明者独知所因，而直取其本，则所生
诸病，无不随本皆退矣。
至若六者之中，多有兼见而病者，则其中亦自有源有流，无弗可察。然惟于虚实二字总
贯乎前之四者，尤为紧要当辨也。盖虚者本乎元气，实者由乎邪气。元气若虚，则虽有邪气
不可攻，而邪不能解，则又有不得不攻者，此处最难下手。但当察其能胜攻与不能胜攻，或
宜以攻为补，或宜以补为攻，而得其补泻于微甚可否之间，斯尽善矣。且常见有偶感微疾者
，病原不甚，斯时也，但知拔本，则一药可愈，而庸者值之，非痰曰痰，非火曰火，四路兜
拿，茫无真见，而反遗其本。多致轻者日重，重者日危，而殃人祸人，总在不知本末耳
。甚矣！医之贵神，神奚远哉！予故曰∶医有慧眼，眼在局外；医有慧心，心在兆前。使果能
洞能烛，知几知微，此而曰医，医云乎哉？他无所谓大医王矣。
万事万物都有根本，而治疗疾病的方法，尤其以探求病本为首要任务。所谓“本”，就是唯一而没有两样的东西。大概因为外感邪气引起的，病本在表；因为内伤饮食情志引起的，病本在里；患热病的，病本在于火（热邪）；患冷病的，病本在于寒（寒邪）。邪气有余的，病本在于实；正气不足的，病本在于虚。只要考察清楚病因是什么，起病的起因，就是病本。万病的根本，只不外乎表、里、寒、热、虚、实这六者罢了。懂得这六者，那么表有表证，里有里证，寒热虚实的情况，没有不清晰的。这六者是相互对立的，就像冰和炭性质不同，辨别起来也有差异。凡是初得病不及时治疗，以及被误治而未痊愈的，必然导致病变日益增多，无不都是从病本衍生出来的，最不可逐件猜测，目光短浅只看眼前。《内经》说：“众脉不见，众凶弗闻，外内相得，无以形先。”这确实是探求病本的关键要点。如果不知道这些，必定是平庸的医生罢了。所以高明的人独自知道病因，直接针对病本治疗，那么由此产生的各种病症，没有不随着病本的解决而消退的。
至于这六者之中，有很多是兼夹出现而致病的，那么其中自然也有源头和支流，没有不可以察明的。然而只有“虚”和“实”这两个字总括了前面的四种情况（表里寒热），尤为紧要应当仔细辨别。因为虚证的根本在于元气不足，实证源于邪气盛。如果元气虚弱，那么即使有邪气也不可轻易攻伐，否则邪气不能解除，反而可能导致不得不攻伐的局面，这里是最难下手的。但应当考察患者能否承受攻伐，或者适宜以攻代补，或者适宜以补代攻，从而在补泻之间把握分寸，做到恰到好处，这才是尽善尽美的。而且常见有偶然感受轻微疾病的，病原并不深重，这个时候，只要懂得拔除病根，一剂药就可以治愈，但庸医遇到这种情况，不是说是痰就是说是火，四面兜捕，茫然没有真知灼见，反而遗忘了真正的病本。多导致轻的病逐渐加重，重的病日益危险，祸害他人，全是因为不知道病本和末节的关系啊。真是厉害啊！医学贵在神妙，神妙哪里远呢？我所以说：医生要有慧眼，眼睛要看局外；医生要有慧心，心思要在征兆之前。如果真的能够洞察烛照，知晓几微之变，这才能称为医生，难道仅仅是医生吗？那就不存在所谓的“大医王”了（意指达到最高境界）。
All things have a root, and in the treatment of disease, seeking the root is the primary task. The so-called "root" refers to that which is unique and singular. Generally, if caused by external pathogens, the root lies in the Exterior (Biao). If caused by internal injury, the root lies in the Interior (Li). If suffering from heat disease, the root lies in Fire (Heat pathogen). If suffering from cold disease, the root lies in Cold (Cold pathogen). If there is an excess of pathogenic factors, the root lies in Excess (Shi). If there is a deficiency of healthy Qi, the root lies in Deficiency (Xu). One must only investigate the cause of onset; the cause of the disease's onset is the disease root. The roots of all diseases are merely these six: Exterior, Interior, Cold, Heat, Excess, and Deficiency. Understanding these six allows one to clearly distinguish Exterior syndromes, Interior syndromes, and the states of Cold, Heat, Excess, and Deficiency. These six exist in opposition to each other, like ice and charcoal, and their differentiation varies. For illnesses not treated promptly at the onset, or those not cured due to misdiagnosis and mistreatment, pathological changes inevitably multiply day by day, all stemming from the disease root. It is most inadvisable to guess item by item or to have short-sighted vision focused only on the present. The Classic says: "When numerous pulses are not seen, and numerous ominous signs are not heard, when the exterior and interior correspond, do not let form precede." This is indeed the utmost importance in seeking the root. If one does not know this, one is merely a mediocre practitioner. Therefore, the wise alone know the cause and directly target the root; consequently, all resulting diseases will recede along with the resolution of the root.
Among these six, many cases present with combined manifestations, yet within them, there are sources and branches, all of which can be observed. However, the characters "Deficiency" and "Excess" summarize the preceding four categories, making them particularly crucial to differentiate. Deficiency originates from the insufficiency of Primordial Qi (Yuan Qi), while Excess arises from pathogenic Qi. If Primordial Qi is deficient, even if pathogenic Qi exists, it cannot be attacked vigorously; otherwise, the pathogen cannot be resolved, potentially leading to a situation where attack becomes unavoidable, which is the most difficult area to handle. One must assess whether the patient can withstand attack, or whether it is appropriate to use attack as tonification, or tonification as attack, thereby mastering the balance between tonifying and purging with precision. This achieves perfection. Moreover, it is common to see occasional mild ailments where the pathogenesis is not severe. At such times, knowing how to remove the root allows for cure with a single prescription. Yet, mediocre practitioners, upon encountering this, label everything as Phlegm or Fire, attacking from all directions without true insight, thereby neglecting the actual root. This often results in mild conditions worsening daily and severe conditions becoming critical, harming people entirely due to ignorance of the root and branch relationship. Indeed! Medicine values spiritual acuity; where is this acuity far? I thus say: A physician has a wise eye, looking beyond the immediate situation; a physician has a wise heart, perceiving before signs manifest. If one can truly penetrate and illuminate, understanding the subtle beginnings, then one can be called a physician—is that all? There would be no need for the concept of a "Great Medical King" (a supreme healer).