舌者，心之窍。心，火也。舌红，火之正色也；上舍微胎，火之蕴蓄也∶此为平人之舌色。若病则君
火内虚，胃无谷神，舌色变而胎垢生，今人妄谓胸中有食，则舌上有胎，非理也。若谓胎因食生，则平人一
日数餐，何无胎？若谓平人食而即消，病则停滞胎生，何初病一二日，舌上无苔，至三四日谷食不入，舌反
有苔？则有食有苔之说，可知其讹谬矣。方书辨三十六舌，张大繁言，毫无征验。世医不知此属伪言，临病施
治，执以为信，非所以救之，适所以害之矣。夫平人之舌本无苔，微有苔者，不过隐隐微微，淡白、淡黄
之间耳！惟三焦火热之气，为寒所侵，则舌上白苔而滑，身发热而谷不入，中、上二焦，虚热相蒸，则舌上
粘苔而垢。苔色淡黄，或微黄者，中土虚也；苔色灰褐，或酱板色者，中土
寒也。舌上紫色者，虚寒也；深紫色者，大虚大寒也；紫色光亮者，久病火衰，土无生原也，淡白光亮者，
久病阴虚，荣血内脱也。苔色黑色者，君火虚衰，水色上乘也。须知舌者，火也，火得其色，乃为平人之舌。
平人五火齐明，如天日光明，阴翳消除，何苔之有？惟伤寒大病，君火不明，至三焦相火乘于君火之位，则
舌色反常。夫相火之乘于君火也，非相火之有余，乃君火之不足。医者不知救助君火之不明，反 没相火
之上乘，进以寒凉，则君火愈亏，相火并竭，神志散乱，未有不毙。平人胃气有余，三焦和畅，君火光明，凡五
味入口，无论酸、咸、甘、苦，皆过而无苔；病则胃气空虚，三焦失职，君火衰微，若五味入口，遇酸、咸、
甘、苦，则舌上凝滞而苔生矣。人不之信，但观小儿服药，舌上药色凝而不退，大人食酸，舌苔即黑，此其
征矣。夫黑者，水色也。伤寒苔黑，世有火极似水之说，品方用药，仍议清凉。夫火极似水，所谓物极必反也。
既极而反，理应从治，不应对治，对治固宜清凉，从治则宜温热矣。奈何认舌，皆以虚为实，以寒为热，不能
探本澄源，尽是以讹传讹。虽谓舌色反常，亦有实热之证，然舌色反常而实热者，十有二三，此三阳病也；舌
色反常而虚寒者，十有七八，此三阴病也。舌色反常上有红点，大如芥子，此虚热舌也；舌色如常，上有红点，
大如芥子，此实热舌
也。舌上苔黑而热极者，其苔高浮于上，不伤舌之本体，或黑或灰，此犀角、芩、连、石膏之证，乃百中之一
耳！至大、小承气之证，舌上亦有燥黑者，然必出言壮厉，神气虽昏，而原本之神凝聚于内，承气下之而愈，
亦百中之一耳！其有散黑而润，四边灰紫者，虚寒舌也。又有凝黑而枯，上如鳞甲者，大虚大寒舌也，并宜参、
术、桂、附，大忌寒凉。若胃气已绝，满舌如茧，板硬而黄，或板硬而黑，如是之舌，百无一生。余之辨舌，
不合方书，观者未必能信，如能不弃余言，则杀人亦差少耳！
舌，是心的外窍。心，属火。舌色红，是火的正常本色；舌尖略有薄苔，是火气蕴蓄的表现：这是健康人的舌色。如果生病，则君火（心火）内部虚弱，胃中缺乏谷气的滋养，舌色就会改变并生出苔垢，现在的人胡乱认为胸中有积食，所以舌上有苔，这不符合道理。如果说苔是因为食物产生的，那么健康人一天吃好几顿饭，为什么没有苔？如果说健康人吃了就消化了，生病则停滞才生苔，为什么刚病一二天时，舌上没有苔，到了三四天不吃东西时，舌上反而有苔？那么“有食才有苔”的说法，就可以知道它是错误谬误的了。医书中辨别三十六种舌象，夸大其辞，毫无验证依据。世间的医生不知道这些属于伪言，面对疾病进行治疗时，固执地相信它，这不是救治病人，反而是害了病人啊。
健康人的舌本无苔，即使微有苔，也不过是隐隐约约、淡淡白色或淡黄色之间罢了！只有当三焦火热之气被寒邪侵袭时，舌上才会出现白苔且滑润，身体发热但不思饮食；中焦、上焦二焦虚热相互蒸腾，则舌上出现粘腻的苔垢。苔色淡黄，或微黄的，是中焦脾胃虚弱；苔色灰褐，或像酱板颜色的，是中焦脾胃寒凉。舌上呈紫色的，是虚寒；深紫色的，是大虚大寒；紫色光亮者，是久病火衰，土（脾）失去生化之源；淡白光亮者，是久病阴虚，营血在内脱失。苔色黑色者，是君火虚衰，水色（肾水之黑）上乘所致。必须知道舌属火，火得其本色，才是健康人的舌。健康人五脏之火齐明，如同天空太阳光明，阴翳消除，哪里有苔？只有患伤寒大病时，君火不明亮，导致三焦相火侵犯君火的位置，舌色才反常。
相火侵犯君火，并非相火有余，而是君火不足。医生不知道救助君火的昏暗，反而压制相火的上乘之势，进用寒凉药物，则君火更加亏损，相火也一并枯竭，神志散乱，没有不死亡的。健康人胃气有余，三焦和畅，君火光明，凡五味入口，无论酸、咸、甘、苦，都经过而舌上无苔；生病则胃气空虚，三焦失职，君火衰微，若五味入口，遇到酸、咸、甘、苦，就在舌上凝滞而生苔。人们不相信这一点，只看小儿服药后，舌上药色凝结不退，大人吃酸物，舌苔即变黑，这就是征象。黑色，是水色。伤寒苔黑，世间有“火极似水”的说法，品评方药用药，仍议论清凉。所谓“火极似水”，就是物极必反的道理。既然极而反，理应从治（顺从病性治疗），不应对治（对抗病性治疗），对治固然适宜清凉，从治则适宜温热了。奈何辨认舌象，都把虚证当作实证，把寒证当作热证，不能探求本源澄清源头，全都是以讹传讹。虽然也说舌色反常，也有实热的证候，然而舌色反常而属实热的，十人中有一二人，这是三阳病；舌色反常而属虚寒的，十人中有七八人，这是三阴病。
舌色反常上面有红点，大如芥子，这是虚热舌；舌色如常，上面有红点，大如芥子，这是实热舌。舌上苔黑且热极的，其苔高浮于上，不伤及舌的本体，或黑或灰，这是犀角、黄芩、黄连、石膏的适应证，是百中仅有一例的情况！至于大承气汤、小承气汤的适应证，舌上也有干燥发黑的，但必定言语壮厉，神气虽然昏沉，但原本的神气凝聚于内，用承气汤攻下而痊愈，也是百中仅有一例的情况！那些散黑而湿润，四边灰紫的，是虚寒舌。又有凝黑而枯干，上面如鳞甲般的，是大虚大寒舌，都适宜人参、白术、肉桂、附子，大忌寒凉。如果胃气已绝，满舌如茧，板硬而黄，或板硬而黑，这样的舌，百无一活。我的辨舌方法，不合于医书，观看的人未必能相信，如果能不弃弃我的言论，那么杀人的情况也能减少一些啊！
The tongue is the orifice of the Heart (Xin). The Heart belongs to Fire. A red tongue color is the normal hue of Fire; a slight coating on the upper part indicates the accumulation of Fire: this is the tongue color of a healthy person. If one falls ill, the Ministerial Fire (Jun Huo, referring to Heart Fire) becomes deficient internally, and the Stomach lacks the nourishment of grain qi, causing the tongue color to change and a coating to form. People nowadays mistakenly claim that food stagnation in the chest leads to a tongue coating, which is illogical. If coatings were generated by food, why do healthy people who eat several times a day have no coatings? If it is argued that healthy people digest food immediately while sick people retain it leading to coatings, why is there no coating on the first or second days of illness, but a coating appears on the third or fourth days when food intake has ceased? Thus, the theory that "food presence causes coatings" can be known as erroneous. Medical texts distinguishing thirty-six types of tongues exaggerate and complicate matters without any empirical verification. Physicians of the world, unaware that these are false statements, rely on them rigidly when treating diseases; this does not save patients but rather harms them.
The tongues of healthy people naturally have no coating; if slightly present, it is merely faint, appearing between pale white and pale yellow! Only when the heat-fire qi of the Sanjiao (Triple Burner) is invaded by cold will a white, slippery coating appear on the tongue, accompanied by fever and loss of appetite. When deficiency-heat in the Middle and Upper Jiao steams each other, a sticky and dirty coating forms. A pale yellow or slightly yellow coating indicates Spleen/Stomach (Middle Earth) deficiency; a gray-brown or sauce-board colored coating indicates Middle Earth cold. A purple tongue indicates deficiency-cold; a deep purple tongue indicates severe deficiency-cold. A bright purple tongue indicates long-standing disease with fire decline and the Earth (Spleen) losing its source of generation; a pale white and bright tongue indicates long-standing Yin deficiency with internal depletion of Ying Blood. A black coating indicates the decline of Jun Fire, allowing the Water color (Kidney Water) to ascend. It must be understood that the tongue belongs to Fire; when Fire displays its true color, it is the tongue of a healthy person. In a healthy person, the five fires shine brightly, like the sun illuminating the sky, eliminating shadows; how could there be a coating? Only in severe Shanghan (Cold Damage) diseases, when Jun Fire is dim, does the Sanjiao Xiang Fire (Ministerial Fire) invade the position of Jun Fire, causing abnormal tongue colors.
The invasion of Jun Fire by Xiang Fire is not due to an excess of Xiang Fire, but a deficiency of Jun Fire. Physicians, failing to understand the need to support the dim Jun Fire, instead suppress the ascending Xiang Fire with cooling medicines. This further depletes Jun Fire, exhausts Xiang Fire, scatters the spirit and consciousness, inevitably leading to death. In healthy people, Stomach Qi is abundant, the Sanjiao is harmonious, and Jun Fire shines brightly. Whatever flavors enter the mouth—sour, salty, sweet, or bitter—they pass through without leaving a coating. When ill, Stomach Qi is empty, the Sanjiao fails in its duties, and Jun Fire declines. If flavors enter the mouth, encountering sour, salty, sweet, or bitter elements, they stagnate on the tongue and generate a coating. People do not believe this; they only observe that after children take medicine, the medicinal color condenses on the tongue and does not fade, or when adults eat sour food, the tongue coating turns black. These are the signs. Black is the color of Water. In Shanghan, a black coating is often explained by the theory of "extreme heat resembling water," yet prescriptions still advocate cooling. The phrase "extreme heat resembles water" refers to the principle that things reverse when they reach an extreme. Having reversed, treatment should follow the nature of the disease (Cong Zhi), not oppose it (Dui Zhi). Opposing treatment suits cooling, but following treatment suits warming. Alas, in identifying tongues, deficiency is mistaken for excess, and cold for heat; failing to trace the root and clarify the source, errors are passed down as truths. Although abnormal tongue colors can also indicate excess-heat syndromes, only one or two out of ten cases are excess-heat, corresponding to Yangming/ShaoYang/Taiyang diseases; seven or eight out of ten are deficiency-cold, corresponding to Taiyin/Yangming/Jueyin diseases.
If an abnormal tongue has red spots as large as mustard seeds, it is a deficiency-heat tongue. If the tongue color is normal but has red spots as large as mustard seeds, it is an excess-heat tongue. If the tongue has a black coating due to extreme heat, the coating floats high on the surface without damaging the tongue body itself, appearing black or gray; this is the indication for Rhinoceros Horn (Xi Jiao), Scutellaria (Huang Qin), Coptis (Huang Lian), and Gypsum (Shi Gao). This occurs in only one out of a hundred cases! Regarding indications for Da Cheng Qi Tang (Major Order the Qi Decoction) and Xiao Cheng Qi Tang (Minor Order the Qi Decoction), the tongue may also be dry and black, but the patient must speak forcefully; although the spirit seems confused, the original spirit remains condensed within. Treatment with Cheng Qi Decoctions leads to recovery, also occurring in only one out of a hundred cases! If the blackness is scattered and moist, with gray-purple edges, it is a deficiency-cold tongue. If the blackness is condensed and withered, resembling scales on top, it is a severe deficiency-cold tongue; both are suitable for Ginseng (Ren Shen), Atractylodes (Bai Zhu), Cinnamon Twig (Gui Zhi), and Prepared Aconite Root (Fu Zi), and strictly prohibit cooling medicines. If Stomach Qi is exhausted, the entire tongue resembles a cocoon, hard and yellow, or hard and black; such a tongue has less than one chance in a hundred of survival. My method of tongue diagnosis differs from medical texts, and readers may not believe it. However, if you do not discard my words, the number of deaths caused by misdiagnosis will be reduced.