太极之道，动而生阳，静而生阴，是气血人身之两仪也。血为荣，气为卫，荣行脉中，卫行脉外，是气血阴
阳之体用也。以体言，飞 蓊郁者云也，故气象云。沂浴泽沛者水也，故血象水。以用言，轻清上覆，无形而致
形者为天，故气拟天。重浊下载，无物而育物者为地，故血拟地。天降地升，云腾水流，万物适其性而发荣。阳
平阴秘，气行血随，百骸得其调而大治。反此则脏腑违和，能上空窍作病，是故血虽静，欲使其行，不行则凝，
凝则经络不通。气虽动，欲使其聚，不聚则散，散则经络不收。不通不收，邪则乘间而入，为阴病从本生也。经
曰∶足阳明胃之脉常多血多气，又曰常生气生血。手太阳小肠之脉斜络于目 ，足太阳膀胱之脉起于目内 ，二
经多血少气，生多无益，少则固能为祸。且肠胃如市，无物不藏，遇风则暴露；肠胃如炉，无物不化，遇寒则阻
抑。一阻一暴，邪则乘时而出，为阳病从末生也。再饮食不节，无时劳怒，凝则愈凝，散者愈散，本末俱生，遂
混而成结，结则无所去还，故为疣、为疮、为丝泪、为翳障，毕具于两目之中，而变化莫测焉。于以知血气之体
犹太极，气血之用犹阴阳。以其盛也，斫之丧之，而乃与荆蔓争腐。以其衰也，培之渥之，而乃与松柏并寿矣。
是为说。
The Dao of Taiji (Supreme Ultimate) generates Yang through movement and Yin through stillness; these are the two poles of Qi (Vital Energy) and Blood in the human body. Blood belongs to Ying (Nutritive Qi), and Qi belongs to Wei (Defensive Qi). Ying circulates within the vessels, while Wei circulates outside the vessels; this constitutes the substance (Ti) and function (Yong) of Qi and Blood, corresponding to Yin and Yang. From the perspective of substance: what flies and flourishes is cloud, so Qi is likened to cloud; what moistens and nourishes is water, so Blood is likened to water. From the perspective of function: what is light, clear, and ascending, formless yet giving rise to form, is Heaven, so Qi is compared to Heaven; what is heavy, turbid, and descending, formless yet nurturing all things, is Earth, so Blood is compared to Earth. As Heaven descends and Earth ascends, clouds surge and waters flow, allowing all things to flourish according to their nature. When Yang is balanced and Yin is secure, Qi moves and Blood follows, harmonizing the entire skeletal system and achieving great health. If the reverse occurs, the Zang-Fu organs become disharmonious, and pathogens can ascend to affect the orifices, causing disease. Therefore, although Blood is inherently static, it must be made to move; if it does not move, it stagnates, and stagnation leads to blockage of the meridians. Although Qi is inherently dynamic, it must be made to gather; if it does not gather, it scatters, and scattering leads to the inability of the meridians to retain themselves. When meridians are neither unblocked nor retained, pathogens take advantage of the opportunity to enter, causing Yin diseases to arise from the root. The Classics state: "The Foot-Yangming Stomach Meridian usually has abundant Blood and Qi," and also that it "constantly generates Qi and Blood." The Hand-Taiyang Small Intestine Meridian crosses and connects to the eye, and the Foot-Taiyang Bladder Meridian originates at the inner canthus of the eye; these two meridians have abundant Blood but deficient Qi. Abundant Blood offers no benefit, while deficient Qi becomes a source of disaster. Moreover, the intestines and stomach are like a marketplace, storing everything; when exposed to Wind, they become vulnerable. They are like a furnace, digesting everything; when exposed to Cold, their function is obstructed. Obstruction and exposure allow pathogens to act in time, causing Yang diseases to arise from the branches. Furthermore, irregular diet and untimely labor or anger cause stagnation to deepen and scattering to worsen. When both root and branch are diseased, they mix to form knots. These knots have nowhere to disperse or return, thus forming warts, sores, thread-like tears, and visual obstructions (cataracts/opacities), manifesting fully in both eyes with unpredictable changes. Thus, we know that the substance of Blood and Qi is like Taiji, and their function is like Yin and Yang. For those with abundant Qi and Blood, if depleted and damaged, they will rot like brambles and vines. For those with deficient Qi and Blood, if nurtured and enriched, they will live as long as pine and cypress. This is the discourse.