素问·离合真邪 The Divergence and Convergence of True and Pathogenic Qi
黄帝问曰：余闻九针九篇，夫子乃因而九之，九九八十一篇，余尽通其意矣。经言气之盛衰，左右倾移，以上调下，以左调右，有馀不足，补写于荣输，余知之矣。此皆荣卫之倾移，虚实之所生，非邪气从外入于经也。余愿闻邪气之在经也，其病人何如，取之奈何。歧伯对曰：夫圣人之起度数，必应于天地，故天有宿度，地有经水，人有经脉。天地温和，则经水安静；天寒地冻，则经水凝泣；天暑地热，则经水沸溢；卒风暴起，则经水波涌而陇起。夫邪之入于脉也，寒则血凝泣，暑则气淖泽，虚邪因而入客，亦如经水之得风也，经之动脉，其至也亦时陇起，其行于脉中循循然，其至寸口中手也，时大时小，大则邪至，小则平，其行无常处，在阴与阳，不可为度，从而察之，三部九候，卒然逢之，早遏其路。吸则内针，无令气忤，静以久留，无令邪布，吸则转针，以得气为故，候呼引针，呼尽乃去，大气皆出，故命曰写。帝曰：不足者补之，柰何。歧伯曰：必先扪而循之，切而散之，推而按之，弹而怒之，抓而下之，通而取之，外引其门，以闭其神，呼尽内针，静以久留，以气至为故，如待所贵，不知日暮，其气以至，适而自护，候吸引针，气不得出，各在其处，推阖其门，令神气存，大气留止，故命曰补。
帝曰：候气奈何。歧伯曰；夫邪去络入于经也，舍于血脉之中，其寒温未相得，如涌波之起也，时来时去，故不常在。故曰：方其来也，必按而止之，止而取之，无逢其冲而写之。真气者，经气也，经气太虚，故曰：其来不可逢，此之谓也。故曰：候邪不审，大气已过，写之则真气脱，脱则不复，邪气复至，而病益蓄，故曰：其往不可追，此之谓也。不可挂以发者，待邪之至时而发针写矣，若先若后者，血气已尽，其病不可下，故曰：知其可取如发机，不知其取如扣椎，故曰：知机道者不可挂以发，不知机者扣之不发，此之谓也。帝曰：补写奈何。歧伯曰：此攻邪也，疾出以去盛血，而复其真气，此邪新客，溶溶未有定处也，推之则前，引之则止，逆而刺之，温血也。刺出其血，其病立已。
帝曰：善。然真邪以合，波陇不起，候之柰何。歧伯曰：审扪循三部九候之盛虚而调之，察其左右上下相失及相减者，审其病藏以期之。不知三部者，阴阳不别，天地不分。地以候地，天以候天，人以候人，调之中府，以定三部，故曰：刺不知三部九候病脉之处，虽有大过且至，工不能禁也。诛罚无过，命曰：大惑，反乱大经，真不可复，用实为虚，以邪为真，用针无义，反为气贼，夺人正气，以从为逆，荣卫散乱，真气已失，邪独内著，绝人长命，予人天殃，不知三部九候，故不能久长。因不知合之四时五行，因加相胜，释邪攻正，绝人长命。邪之新客来也，未有定处，推之则前，引之则止，逢而写之，其病立已.
Huangdi asked: I have heard of the Nine Needles in nine chapters, and you, Master, multiplied this ninefold, into nine times nine — eighty-one chapters — and I have now thoroughly grasped their meaning. The classics speak of the waxing and waning of qi, its shifting to the left and right, of regulating below by means of above, regulating the right by means of the left, and of supplementing and draining the nutritive qi at the transport points according to excess and insufficiency — these I understand. But all of this concerns the shifting of nutritive and defensive qi, and how deficiency and excess arise from within — not pathogenic qi entering the channels from outside. I wish to hear about pathogenic qi being present in the channels: how does it afflict a person, and how is it treated? Qibo replied: When the sages established their measures and numbers, these necessarily corresponded to heaven and earth. Thus heaven has its lodge-degrees of the stars, earth has its rivers, and man has his channels and vessels. When heaven and earth are warm and mild, the rivers are calm and still; when heaven is cold and earth is frozen, the rivers congeal and stagnate; when heaven is hot and earth is scorching, the rivers boil and overflow; when a sudden violent wind arises, the rivers surge in waves and swell into mounds. So too, when pathogenic qi enters the vessels: in cold, the blood congeals and stagnates; in heat, the qi becomes fluid and moist; depleting pathogenic qi thereby enters and lodges in the channels, just as the rivers are affected by wind. The pulsing vessels of the channels, when pathogenic qi arrives, likewise at times swell into mounds; normally, qi travels through the vessels smoothly and continuously, but when it reaches the cunkou pulse under the examining hand, it is at times large and at times small — when large, pathogenic qi has arrived; when small, the pulse is calm. Its movement has no constant location; whether in yin or yang channels, it cannot be measured by fixed rule. One must trace and examine it through the three sections and nine indicators, and when one suddenly encounters it, one must block its path early. Insert the needle upon inhalation, so as not to let it clash with the flow of qi; hold it still and retain it for a long while, so as not to let the pathogenic qi spread; upon the next inhalation, rotate the needle, aiming to obtain the arrival of qi; wait for the exhalation and then withdraw the needle, removing it only once the exhalation is complete, so that the great pathogenic qi is entirely expelled — this is called draining. Huangdi said: How does one supplement what is insufficient? Qibo said: One must first press and trace along the vessel with the palm, pinch and disperse any obstruction, push and press upon it, flick it to make it swell up, scratch the skin and press the needle down, and open a path to insert it. Draw open its gateway from outside so as to close in its spirit within; insert the needle only upon completion of the exhalation, hold it still and retain it for a long while, aiming to obtain the arrival of qi — waiting as one would await something precious, unmindful of the lateness of the day, until the qi arrives. Then attend to it and guard it carefully; wait for the inhalation and then withdraw the needle, so that the qi cannot escape but remains each in its place; press the gateway closed, so that the spirit-qi is preserved and the great qi is retained and held in place — this is called supplementing.
Huangdi said: How does one watch for the arrival of qi? Qibo said: When pathogenic qi leaves the network vessels and enters the channels, it lodges within the blood vessels; before its coldness or warmth has settled with the body, it is like a surging wave rising up — coming at times, going at times, and thus not constantly present. Hence it is said: just as it arrives, one must press and stop it, stop it and then draw it out, but must not meet it head-on and drain it prematurely. True qi is the channel qi; if the channel qi is already quite deficient, one must not attack it as pathogenic qi arrives — this is the meaning of 'one must not meet it upon its arrival.' Hence it is said: if one watches for pathogenic qi without due care, and the great pathogenic qi has already passed, then to drain at that point would cause the true qi to be lost; once lost, it cannot be restored, and the pathogenic qi will return again, so that the disease accumulates further — hence it is said: 'one cannot pursue it after it has departed' — this is the meaning of that. As for the timing being so precise that it cannot be off even by the breadth of a hair: one must wait for the moment the pathogenic qi arrives and then release the needle to drain it; if one acts too early or too late, the blood and qi will already be exhausted, and the disease cannot then be brought down. Hence it is said: knowing when it can be drawn out is like releasing a trigger; not knowing how to draw it out is like knocking on a wooden post that will not sound. Hence it is said: one who knows the way of the critical moment will not be off even by the breadth of a hair; one who does not know the critical moment will knock and get no response — this is the meaning of that. Huangdi said: How is supplementing and draining done in this case? Qibo said: This is a matter of attacking pathogenic qi — one must swiftly let it out so as to remove the pooled blood and restore the true qi. When the pathogenic qi is newly lodged, it drifts about without a fixed location: pushed, it moves forward; pulled, it stops. Needle against its direction of movement — this warms the blood. Needle to let out its blood, and the disease will be resolved at once.
Huangdi said: Good. But when true qi and pathogenic qi have already merged, and no wave or mound rises — how does one examine for it then? Qibo said: Carefully press and trace along the three sections and nine indicators for abundance and deficiency, and regulate accordingly; observe where left and right, above and below, fail to correspond or are diminished relative to each other; carefully determine the diseased viscus and gauge the critical time accordingly. One who does not understand the three sections cannot distinguish yin from yang, nor differentiate heaven from earth. Among the nine indicators, the earth positions examine the earth, the heaven positions examine the heaven, and the man positions examine the man; one regulates them at the central organs, so as to fix the three sections. Hence it is said: if one needles without knowing the locations of the diseased pulses of the three sections and nine indicators, then even though a great excess arrives, the practitioner cannot prevent it. To punish where there is no fault is called great confusion — on the contrary it throws the great channels into disorder, so that the true qi cannot be restored; such a practitioner treats excess as deficiency and takes pathogenic qi for true qi; his use of the needle is without proper principle, and instead becomes a brigand against qi, robbing the person of their upright qi; he treats compliance as rebellion, so that nutritive and defensive qi scatter into disorder and true qi is already lost, while pathogenic qi alone remains lodged within — this cuts short the person's long life and brings upon him calamity from heaven. Not knowing the three sections and nine indicators, such a practitioner cannot help patients endure long. Because he does not know how to correlate treatment with the four seasons and the five phases, and misapplies the mutual-overcoming relations among the phases, he releases the pathogenic and attacks the upright, thereby cutting short the person's long life. When pathogenic qi is newly arrived as a guest in the body, it has as yet no fixed location: pushed, it moves forward; pulled, it stops. Meet it directly and drain it, and the disease will be resolved at once.