诊面之法。有形焉。有容焉。分而言之。则理明。合而诊之。则病着。夫形也者。言乎其体也。容也者。言乎其态
也。以形为体。以态为用。而五脏之分。五志之辨。可由是而察焉。何者。怒则厉然而目张。喜则油然而颐解。
思则妪然而睑定。悲则瞿然而泣出。恐则薄然而气下。怒者肝之容。喜者心之容。思者脾之容。悲者肺之
容。恐者肾之容。此面容五脏之分也。怒则气逆。喜则气缓。思则气结。悲则气消。恐则气下。此五脏之分。五
志之病也。由是而观。有太过。有不及。太过者。病在外。不及者。病在内。太过则薄所胜。而乘所不胜。其不及
则所胜妄行。而所生受病。所不胜薄之也。然此就太过不及而言。又当随时以处中焉。中庸云。喜怒哀乐
之未发。谓之中。发而皆中节。谓之和。盖中者无所偏倚。和者无所乖戾。当喜怒而喜怒。当哀乐而哀乐。无
病之容也。其或发而不中。则有偏倚。发而失节。即有乖戾。故经曰。多阳者多喜。多阴者多怒。肝气虚则恐。
实则怒。心气虚则悲。实则笑不休。怒伤肝。悲胜怒。喜伤心。恐胜喜。思伤脾。怒胜思。忧伤肺。喜胜忧。恐伤肾。
思胜恐。盖以五志之变。合五行而推也。善诊者。观察病患之态。推而极之。补其偏。救其弊。则失中者中。而
违和者和矣。
The method of examining the face involves two aspects: *xing* (form/structure) and *rong* (expression/demeanor). When analyzed separately, the principles become clear; when examined comprehensively, the diseases manifest. *Xing* refers to the physical structure of the face, while *rong* refers to its expressive demeanor. Taking form as the substance and demeanor as the function, one can observe the distinctions among the Five Zang Organs (Liver, Heart, Spleen, Lung, Kidney) and differentiate the Five Emotions (Anger, Joy, Pensiveness, Grief, Fear). Why is this so? Anger presents with a stern countenance and dilated eyes; joy presents with a relaxed countenance and unclenched jaw; pensiveness presents with a constrained countenance and still eyelids; grief presents with a startled countenance and flowing tears; fear presents with a timid countenance and sinking Qi (vital energy). Anger is the expression of the Liver; joy is the expression of the Heart; pensiveness is the expression of the Spleen; grief is the expression of the Lung; fear is the expression of the Kidney. This constitutes the correspondence between facial expressions and the Five Zang Organs. Anger causes Qi to rebel upward; joy causes Qi to relax; pensiveness causes Qi to knot; grief consumes Qi; fear causes Qi to sink. These are the pathological manifestations of the Five Zang Organs and the Five Emotions. From this perspective, there are conditions of excess and deficiency. Excess indicates disease in the exterior; deficiency indicates disease in the interior. In cases of excess, the organ overacts upon what it normally controls (Sheng cycle) and attacks what controls it (Ke cycle); in cases of deficiency, what it normally controls acts recklessly, what it generates suffers disease, and what controls it bullies it. However, this discussion pertains only to excess and deficiency; one must also apply the principle of the Mean according to circumstances. The *Zhongyong* (Doctrine of the Mean) states: "When the emotions of anger, joy, sorrow, and happiness have not yet arisen, it is called 'Zhong' (the Mean); when they arise and all accord with due measure, it is called 'He' (Harmony)." Zhong means having no bias; He means having no discord. Feeling anger or joy when appropriate, and sorrow or happiness when appropriate, represents the demeanor of health. If emotions arise without adhering to the Mean, there is bias; if they arise without proper measure, there is discord. Therefore, the classics state: Those with abundant Yang tend toward joy; those with abundant Yin tend toward anger. Liver Qi deficiency leads to fear; Liver Qi excess leads to anger. Heart Qi deficiency leads to grief; Heart Qi excess leads to incessant laughter. Anger injures the Liver; Grief overcomes Anger. Joy injures the Heart; Fear overcomes Joy. Pensiveness injures the Spleen; Anger overcomes Pensiveness. Sorrow injures the Lung; Joy overcomes Sorrow. Fear injures the Kidney; Pensiveness overcomes Fear. This deduction is based on the variations of the Five Emotions combined with the theory of the Five Elements (Wu Xing). A skilled examiner observes the patient's demeanor, deduces its extreme changes, supplements deficiencies, corrects abnormalities, thereby restoring balance to those who have lost the Mean and harmony to those who have deviated from it.