To inspect the pulse, one must distinguish between the Renying (Human Welcome) and Qikou (Qi Mouth) pulses to determine whether the cause is internal or external; this is the essential path for learning diagnosis. Thus, the *Mai Zan* (Pulse Eulogy) states: "One fen before the Guan (Cun position) is the master of life." Since there are three categories of causes (Internal Causes, External Causes, and Non-internal/Non-external Causes), they cannot be treated uniformly, but upon detailed examination, the principles are naturally complete.

For instance, extreme physical exhaustion, depletion of mental energy, irregular eating and drinking, shouting or running that disperses Qi, sexual excess or imbalance in work and rest, as well as metal wounds and fractures, bites from tigers, wolves, wild dogs, or poisonous insects, Gui Zhu Ke Wu (diseases caused by evil spirits or strange influences), fear of crushing or drowning, etc., do not belong to the External Six Evils (Wind, Cold, Summer-heat, Dampness, Dryness, Fire), nor to the Internal Seven Emotions (Joy, Anger, Worry, Pensive, Sorrow, Fear, Fright). They are neither purely external nor purely internal, and thus must belong to the Non-internal/Non-external Causes.

Although Han dynasty theories state: "A tight and full Renying pulse indicates injury by Cold; a tight and full Qikou pulse indicates injury by food." This fails to recognize that when food enters the stomach, it can aggravate existing latent pathogens. The reason such conditions manifest at the Qikou pulse is precisely due to the eruption of stagnant emotions, which become apparent with the aid of food; originally, retained food does not directly correspond to the Qikou pulse. Moreover, regarding the pulse of retained food, it may be floating, large, and slightly choppy, or rapid and slippery and solid. (Choppy in Yin positions, slippery in Yang positions.) If retained food is not digested, the pulse is deep and tight; if retained food forms a mass (Jia), the pulse is heavy and deep. These named syndromes are all said to injure the Stomach; what relation does the Stomach have with the Qikou pulse?

As for extreme physical exhaustion, the pulse is wiry, rapid, and solid. Pain in the sinews involves movement, indicating injury to the Liver; fixed thinking leads to a slippery pulse, and depletion of Shen (Spirit) leads to a scattered pulse, both indicating injury to the Heart; chanting consumes Qi, resulting in a soggy and weak pulse; shouting disperses Qi, resulting in a scattered and urgent pulse, both indicating injury to the Lung; sexual excess leading to loss of essence results in floating and scattered pulses at both Chi (Cubit) positions; nocturnal emission in men and miscarriage in women result in wiry, large, and leather-like pulses, all indicating injury to the Kidney. What relation do these explicit texts have with the Qikou pulse?

Furthermore, in cases of Zang Cold causing Ascaris Jue (Ascariasis with cold extremities), the pulse is naturally slightly floating, or tight and slippery; in cases of Stomach deficiency preventing eating, the pulse must be slow, or also slightly soggy; in cases of Five Drinks stagnating, the pulse is floating, fine, and slippery; in cases of long-term accumulation, the pulse is deep, fine, and soft; in cases of form deficiency with spontaneous sweating, the pulse is always slightly soggy; in cases of sudden chaos and disorder (Huo Luan), the pulse is naturally deep and hidden; in cases of falling or collapsing, the pulse is fine and slippery; in cases of fracture injuries with blood stasis inside, or Hernia masses and abdominal lumps causing pain in the five viscera, the pulse is always wiry and tight; in cases of Cold invasion with knotting, the pulse is slow and choppy; in cases of Five Accumulations and Six Gatherings, where food, drink, phlegm, and Qi remain stagnant and do not disperse, causing blockage in the meridians, the pulse is always hurried and knotted; in cases of Three Consumptions with heat in the middle, the Chi pulse is flooding and large; in cases of Mania and Madness with chaotic spirit, the Guan pulse is flooding and rapid; in cases of Qi excess, the pulse is deep; in cases of Blood excess, the pulse is slippery; when Qi and Blood struggle, the pulse is also deep and solid. In pregnant women, the pulse is harmonious and slippery; in cases of Dun Shi Shi Zhu (hidden corpses or lingering pestilence), the pulse is deep and does not reach the Cun (Inch) position, or the three positions are urgent; when possessed by evil spirits, the pulse at both hands fluctuates between large and small, short and long. When Yang evils appear, the pulse is floating and flooding; when Yin evils appear, the pulse is deep and tight. In cases of Gui Zhu Ke Wu, the three positions are all slippery, flooding and large yet faint, deep and glossy; any case where the pulse does not match the symptoms is attributed to the Five Corpses, Ghost Evils, Dun Shi, or Gui Zhu.

If such pulse and symptom patterns are diagnosed, even if they correspond to the Renying and Qikou pulses, one must still analyze them to trace the Three Causes, combining the four phrases (Single Internal, Single External, Non-internal/Non-external, Both Internal and External) to categorize them as Single Internal, Single External, Non-internal/Non-external, or Both Internal and External. The principles of the pulse are subtle, and skills are difficult to master; only through learning does one realize their deficiencies, and only through teaching does one encounter difficulties. This is what is meant. However, phenomena appearing in signs and numbers cannot be mastered without study, nor can they fail to be achieved after study. Students should pay close attention to this.

Moreover, if one suddenly sees strange images, becoming confused and dizzy, the pulse often loses its order; in cases of sudden emptiness and stroke, where the five viscera are closed and cut off, the pulse ceases to flow; similarly, in cases of falling or drowning, the pulse is unobservable; and in cases of metal wounds and fractures where Qi and Blood suddenly leak away, the pulse has no standard. Students should observe the external symptoms and should not be rigidly bound by the pulse.