人身本无病也，凡有所病，皆自取之。或耗其精，或劳其神，或夺其气，种种皆致病之由。惟五脏充足，
六腑调和，经脉强盛，虽有所伤，亦不为病∶若脏腑经脉原有不足，又不知持重调摄，而放纵无常，焉得无病！
如脏气不足，病在脏；腑气不足，病在腑；经脉不足，病在经脉。阴血虚而不为阳气之守，则阳病；阳气虚而
不为阴血之使，则阴病。且正气内虚，而淫邪猖獗，则六淫为病。是病皆从内生，岂由外至？其有外至者，惟
暴寒暴热，骤风骤雨，伤人皮腠，乍而为病，则脏腑经脉，运转如常，发之散之，一剂可痊。若先脏腑经脉不
足，而复外邪乘之，则治之又有法，必先调其脏腑，和其经脉，正气足而邪气自退，即所以散之发之也。所谓
治病必求于本；求其本，必知其原；知其原，治之不远矣。
凡人有病，需治在医，医者，人之司命也。既司人命，必知人身有形之经，又当知人身无形之气；辨有形
之有余不足，察无形之离合逆从。有形者，脏腑经络之定位；无形者，阴阳运气之转输。脏腑经脉有病，而阴
阳运气，转旋输布不失其常，虽病可愈；若有形既病，而无形亦逆，便不治矣。盖医不能生人也，不杀人，
便为良医矣。所痛惜者，有形无形，全不之知，离合逆从，并未曾晓，见病即治，知其外，不知其内，究其末，
不究其原，妄曰医者意也，以妄为意，以妄为医，是居盲 而云察秋毫也，岂其然哉！
人体本来是没有疾病的，凡是出现疾病，都是自身原因造成的。或者是耗损了精气，或者是劳累了心神，或者是夺走了正气，种种情况都是导致疾病的原因。只有五脏精气充足，六腑功能调和，经脉强盛有力，即使受到外邪伤害，也不会发病；如果脏腑经脉原本就存在不足，又不知道谨慎调养摄护，而是放纵欲望、行为无常，怎么能不生病呢！
如果脏气不足，疾病就会发生在脏；腑气不足，疾病就会发生在腑；经脉不足，疾病就会发生在经脉。阴血虚弱而不能固守阳气，就会导致阳病；阳气虚弱而不能引导阴血，就会导致阴病。况且如果人体正气内部虚弱，而淫邪（六淫致病因素）猖獗肆虐，就会导致六淫为病。这些疾病都是从体内产生的，难道是由外部侵入的吗？那些确实由外部侵入的，仅仅是暴寒、暴热、骤风、骤雨等，损伤了人的皮肤腠理，突然引发的疾病，此时脏腑经脉运转依然如常，通过发散解表的方法治疗，一剂药就可以痊愈。如果是先有脏腑经脉的不足，再加上外邪乘虚而入，那么治疗方法又有不同，必须先调理脏腑，调和经脉，待正气充足后邪气自然退去，这也就是所谓的发散解表之法。这就是所说的“治病必求于本”；要探求根本，必须知道源头；知道了源头，治疗就不远了。
大凡人有疾病，需要医生来治疗，医生是掌管人生命的人。既然掌管人的性命，就必须知道人体有形的经络，还应当知道人体无形的气机；辨别有形物质的有余或不足，观察无形气机的离合与顺逆。所谓有形，是指脏腑经络的定位；所谓无形，是指阴阳运气（气化运动）的转输变化。如果脏腑经脉有了疾病，但阴阳运气的气化转旋输布仍然不失常态，虽然生病也可以痊愈；如果有形之体已经病了，而无形之气机也逆乱失常，那就难以治愈了。大概医生并不能让人起死回生，只要不害死人，就可以称为良医了。令人痛惜的是，有些人对有形和无形全都不了解，对气机的离合顺逆从未知晓，见到病症就盲目治疗，只知道表面现象，不知道内在机理，只追究细枝末节，不探究根本源头，狂妄地说“医者意也”（医生的诊断靠意念），把妄断当作意会，把妄断当作医术，这就像蒙着眼睛却声称能看清秋天鸟兽新长的细毛一样，怎么可能是这样呢！
The human body is originally free of disease. Any illness that arises is self-inflicted. It may result from the depletion of Jing (Essence), the exhaustion of Shen (Spirit), or the loss of Zheng Qi (Upright Qi); all such factors are causes of disease. Only when the Zang organs are abundant, the Fu organs are harmonious, and the meridians are strong, will injury not lead to illness: if the Zang and Fu organs and meridians are inherently deficient, and one fails to exercise caution in regulation and preservation, but instead indulges without restraint, how can illness be avoided!
If Zang Qi is deficient, the disease resides in the Zang; if Fu Qi is deficient, the disease resides in the Fu; if meridian Qi is deficient, the disease resides in the meridians. If Yin Blood is deficient and cannot guard Yang Qi, then Yang pathology occurs; if Yang Qi is deficient and cannot guide Yin Blood, then Yin pathology occurs. Furthermore, if internal Zheng Qi is deficient while pathogenic factors run rampant, the Six Excesses (Liu Yin) cause disease. Thus, these illnesses originate internally; do they come from the exterior? Those that truly come from the exterior are merely sudden cold, sudden heat, abrupt wind, or heavy rain, which injure the skin and interstices (Cou Li). Such illnesses arise suddenly, yet the Zang and Fu organs and meridians function normally. Through dispersing and releasing methods, a single dose can bring recovery. However, if there is prior deficiency in the Zang and Fu organs and meridians, compounded by external pathogens taking advantage of this weakness, the treatment method differs: one must first regulate the Zang and Fu organs and harmonize the meridians. When Zheng Qi is sufficient, pathogenic Qi recedes naturally; this constitutes the method of dispersing and releasing. This is what is meant by "in treating disease, one must seek the root"; seeking the root requires knowing the origin; knowing the origin makes treatment straightforward.
When a person falls ill, medical intervention is required. The physician is the guardian of human life. Since one guards human life, one must understand both the tangible meridians of the body and the intangible Qi; one must distinguish between excess and deficiency in the tangible, and observe the separation, union, reversal, and compliance of the intangible. The tangible refers to the fixed locations of the Zang-Fu organs and collaterals; the intangible refers to the transformation and distribution of Yin-Yang and Qi dynamics. If the Zang-Fu organs and meridals are diseased, but the transformation and distribution of Yin-Yang and Qi remain normal, recovery is possible despite illness; but if the tangible form is diseased and the intangible Qi is also reversed, the condition becomes incurable. Essentially, physicians cannot resurrect the dead; if they do not kill, they are considered good physicians. What is lamentable is that some know nothing of the tangible and intangible, nor do they comprehend the separation, union, reversal, and compliance of Qi. They treat symptoms upon sight, knowing the exterior but not the interior, investigating the branches but not the root. They arrogantly claim "medicine relies on intuition" (Yi Zhe Yi Ye), mistaking presumption for insight and presumption for medical practice. This is like claiming to see the finest down feathers of autumn while blindfolded—can this really be so!