经云∶“邪气盛则实，正气夺则虚”。又云∶“有余者泻之，不足者补之。”窃谓虚实两字，是搅病机之
领；补泻两字，是提治法之纲。盖以人之有病，不出一虚一实，医之治病；不过一补一泻。如虚实稍有疑心，
则补泻无从下手。其参症切脉以审虚实，固临症第一要着也，乃有症似实而脉则虚，脉似实而症则虚者。如舍
脉从症，既难信以为真，而舍从脉，又惟恐其是假，则且奈之何哉。不知凡物之理，实则其形坚敛、其色苍老；
虚则其体浮胖、其色娇嫩。而病之现于舌也，其形与色亦然。（故凡病属实者，其舌必坚敛而兼苍老；病属虚者，
其舌必浮胖而兼娇嫩。如此分别，则为虚为实、是假是真，虽未参症切脉，而一目先了然矣。）
虚实既分，补泻固有定见。然虚实各有阴阳，而阴阳迭为虚实，则于虚实分阴阳，临症者又不可混也。
而分之不得其法，则有以阴盛为阳盛、阳虚为阴虚，而不能无误者。且有症本阳虚，而经训曰阴虚，令人错解，
贻害不浅者。如云∶“阴虚出盗汗”。阴言手太阴也，虚言肺气虚也。又云∶“阴虚发夜热”。阴言足太阴也，
虚言脾气虚也。同曰阴虚，而其中有手
足太阴之分。名曰阴虚，而其实是脾肺气虚之症。无如历代医师，从未注明其义，误以脾肺气虚认为肾水不足，
而用滋阴降火之剂，朝夕重阴下逼，逼至土困金败，便溏声嘶，置之死地而不悟者，只此两个阴字，拘义牵文，
以讹传讹。自古迄今，普天之大，不知日杀凡几，良可痛也。况如此类者，经中未易枚举，总缘阴阳混杂，虚
实模糊，但凭脉症，分晰难清耳。（讵知阴虚阳盛者，其舌必干；阳虚阴盛者，其舌必滑；阴虚阳盛而火旺者，
其舌必干而燥；阳虚阴盛而火衰者，其舌必滑而湿。）如此分别，则为阴为阳，谁实谁虚，显然可见，更何似阴
似阳之疑，以致重阴重阳之误，贻人夭殃耶？
《内经》说：“邪气亢盛就表现为实证，正气耗损就表现为虚证。”又说：“有余的要用泻法，不足的要用补法。”我认为“虚实”这两个字，是把握疾病机理的关键；“补泻”这两个字，是统领治疗方法的纲领。大概因为人患病，不出虚和实两种情况，医生治病，不过是用补法和泻法两种手段。如果对虚实稍有疑惑，那么补泻就无从下手。通过参合症状、切按脉象来审察虚实，固然是临证的第一要务，但有时会出现症状看似实证而脉象却显虚象，或者脉象看似实证而症状却显虚象的情况。如果舍弃脉象而从症状判断，既难以确信为真；如果舍弃症状而从脉象判断，又唯恐那是假象，那该怎么办呢？不知道凡物的道理，实证时形体坚实收敛、色泽苍老；虚证时形体浮大肥胖、色泽娇嫩。而疾病反映在舌头上，其形态与色泽也是如此。（所以凡是病属实的，舌头必然坚实收敛且兼有苍老之象；病属虚的，舌头必然浮大肥胖且兼有娇嫩之象。这样加以区分，那么是虚是实、是真是假，即使不参合症状、切按脉象，也能一目了然。）
虚实既然已经分辨清楚，补泻自然就有确定的见解。然而虚实各自又有阴阳之分，而阴阳交替变化导致虚实，所以在虚实中再分阴阳，临证者不可混淆。如果分辨不得当，就会把阴盛当作阳盛、阳虚当作阴虚，从而产生错误。而且有的病症本是阳虚，但经典训示说是阴虚，令人误解，造成危害不小。比如经云：“阴虚出现盗汗。”这里的“阴”指的是手太阴肺经，“虚”指的是肺气虚。又说：“阴虚发生夜间发热。”这里的“阴”指的是足太阴脾经，“虚”指的是脾气虚。同样称为阴虚，其中却有手太阴和足太阴的区别。名义上叫阴虚，实际上是脾肺气虚的症状。无奈历代医师，从未注明其含义，误将脾肺气虚认为是肾水不足，而使用滋阴降火的方剂，早晚重阴逼迫，导致土困金败（脾胃受损、肺气衰竭），出现大便溏薄、声音嘶哑，把人置于死地而不知醒悟的，只是这“两个阴字”，拘泥于文义，以讹传讹。从古至今，普天之下，不知因此害死了多少人，实在令人痛心。况且像这样的情况，经典中不容易一一列举，总归是因为阴阳混杂，虚实模糊，仅凭脉症，分析难以清晰罢了。（哪里知道阴虚阳盛的，舌头必然干燥；阳虚阴盛的，舌头必然滑润；阴虚阳盛且火旺的，舌头必然干燥而焦燥；阳虚阴盛且火衰的，舌头必然滑润而湿润。）这样加以区分，那么是阴是阳，谁实谁虚，显然可见，还有什么似阴似阳的疑惑，从而导致重阴重阳的错误，给人带来夭折灾殃呢？
The *Neijing* (Inner Canon) states: "When pathogenic factors are exuberant, it is excess (Shi); when healthy qi is depleted, it is deficiency (Xu)." It also states: "For what is in excess, use draining (Xie); for what is deficient, use tonifying (Bu)." I consider that the terms "excess" and "deficiency" are the key to grasping the mechanism of disease; "tonifying" and "draining" are the guiding principles for treatment methods. Generally, human illness does not go beyond the two categories of deficiency and excess, and a physician's treatment does not go beyond the two methods of tonification and drainage. If there is any doubt regarding deficiency or excess, then tonification and drainage cannot be applied. Examining symptoms and palpating the pulse to ascertain deficiency and excess is indeed the primary concern in clinical practice. However, there are cases where symptoms appear like excess but the pulse indicates deficiency, or the pulse appears like excess but the symptoms indicate deficiency. If one discards the pulse and follows the symptoms, it is difficult to trust them as true; if one discards the symptoms and follows the pulse, one fears they may be false. What then should be done? One must understand that the principle of all things is: in excess conditions, the form is firm and contracted, and the color is dark and aged; in deficiency conditions, the form is floating and puffy, and the color is delicate and tender. The manifestation of disease on the tongue follows this same rule regarding form and color. (Therefore, for diseases belonging to excess, the tongue must be firm and contracted with a dark, aged appearance; for diseases belonging to deficiency, the tongue must be puffy and floating with a delicate, tender appearance. By distinguishing in this manner, whether it is deficiency or excess, true or false, can be clearly understood at a glance, even without examining symptoms or palpating the pulse.)
Once deficiency and excess are distinguished, the decision to tonify or drain naturally becomes clear. However, both deficiency and excess have their own yin and yang aspects, and yin and yang interplay to create variations in deficiency and excess. Therefore, when distinguishing yin and yang within the context of deficiency and excess, clinicians must not confuse them. If the distinction is not made correctly, one might mistake yin-excess for yang-excess, or yang-deficiency for yin-deficiency, leading to errors. Furthermore, some conditions are fundamentally yang-deficiency, yet classical texts describe them as yin-deficiency, causing misunderstanding and significant harm. For instance, the text says: "Yin-deficiency leads to night sweats." Here, "yin" refers to the Hand-Taiyin Lung Meridian, and "deficiency" refers to Lung Qi deficiency. It also says: "Yin-deficiency causes night fever." Here, "yin" refers to the Foot-Taiyin Spleen Meridian, and "deficiency" refers to Spleen Qi deficiency. Although both are termed "yin-deficiency," there is a distinction between the Hand-Taiyin and Foot-Taiyin meridians. Named "yin-deficiency," these are actually symptoms of Spleen and Lung Qi deficiency. Regrettably, physicians through the ages have never clarified this meaning, mistakenly identifying Spleen and Lung Qi deficiency as Kidney Water insufficiency. Consequently, they use formulas for nourishing yin and descending fire. Day after day, heavy yin forces downward, leading to Earth confinement and Metal failure (Spleen/Stomach impairment and Lung Qi exhaustion), resulting in loose stools and hoarseness, placing patients in a fatal state without realization. This error stems solely from the two characters "yin," adhering rigidly to textual meanings and spreading misinformation. From ancient times to the present, across the vast world, countless lives have been lost due to this, which is truly heartbreaking. Moreover, such cases are numerous in the classics and difficult to enumerate entirely. The root cause lies in the mixing of yin and yang, and the blurring of deficiency and excess, making it difficult to clarify analysis based solely on pulses and symptoms. (Who would know that in yin-deficiency with yang-excess, the tongue must be dry; in yang-deficiency with yin-excess, the tongue must be slippery; in yin-deficiency with yang-excess and vigorous fire, the tongue must be dry and parched; in yang-deficiency with yin-excess and declining fire, the tongue must be slippery and wet.) By distinguishing in this way, whether it is yin or yang, who is excess and who is deficiency, becomes clearly visible. How could there be doubts resembling yin or yang, leading to errors of excessive yin or excessive yang, thereby bringing premature death upon people?