素问·八正神明论 Discourse on the Eight Correct Periods and Spirit Illumination
黄帝问曰：用针之服，必有法则焉，今何法何则。歧伯对曰：法天则地，合以天光。帝曰：愿卒闻之。歧伯曰：凡刺之法，必候日月星辰四时八正之气，气定，乃刺之。是故天温日明，则人血淖液，而卫气浮，故血易写，气易行；天寒日阴，则人血凝泣，而卫气沈。月始生，则血气始精，卫气始行；月郭满，则血气实，肌肉坚；月郭空，则肌肉减，经络虚，卫气去，形独居。是以因天时而调血气也。是以天寒无刺，天温无疑。月生无写，月满无补，月郭空无治，是谓得时而调之。因天之序，盛虚之时，移光定位，正立而待之。故日月生而写，是谓藏虚；月满而补，血气扬溢，络有留血，命曰重实；月郭空而治，是谓乱经。阴阳相错，真邪不别，沈以留止，外虚内乱，淫邪乃起。
帝曰：星辰八正何候。歧伯曰；星辰者，所以制日月之行也。八正者，所以候八风之虚邪，以时至者也。四时者，所以分春秋冬夏之气所在，以时调之也，八正之虚邪，而避之勿犯也。以身之虚，而逢天之虚，两虚相感，其气至骨，入则伤五藏，工候救之，弗能伤也，故曰：天忌不可不知也。
帝曰：善。其法星辰者，余闻之矣，愿闻法往古者。歧伯曰；法往古者，先知针经也。验于来今者，先知日之寒温，月之虚盛，以候气之浮沈，而调之于身，观其立有验也。观其冥冥者，言形气荣卫之不形于外，而工独知之，以日之寒温，月之虚盛，四时气之浮沈，参伍相合而调之，工常先见之，然而不形于外，故曰观于冥冥焉。通于无穷者，可以传于后世也，是故工之所以异也，然而不形见于外，故俱不能见也。视之无形，尝之无味，故谓冥冥，若神仿𨱰。虚邪者，八正之虚邪气也。正邪者，身形若用力，汗出，腠理开，逢虚风，其中人也微，故莫知其情，莫见其形。上工救其萌牙，必先见三部九候之气，尽调不败而救之，故曰上工。下工救其已成，救其已败。救其已成者，言不知三部九候之相失，因病而败之也，知其所在者，知诊三部九候之病脉处而治之。故曰守其门户焉，莫知其情而见邪形也。
帝曰：余闻补写，未得其意。歧伯曰：写必用方，方者，以气方盛也，以月方满也，以日方温也，以身方定也，以息方吸而内针，乃复候其方吸而转针，乃复候其方呼而徐引针，故曰写必用方，其气而行焉。补必用员，员者，行也，行者，移也，刺必中其荣，复以吸排针也。故员与方，非针也。故养神者，必知形之肥瘦，荣卫血气之盛衰。血气者，人之神，不可不谨养。
帝曰：妙乎哉论也。合人形于阴阳四时，虚实之应，冥冥之期，其非夫子孰能通之。然夫子数言形与神，何谓形，何谓神，愿卒闻之。歧伯曰：请言形，形乎形，目冥冥，问其所病，索之于经，慧然在前，按之不得，不知其情，故曰形。帝曰：何谓神。歧伯曰：请言神，神乎神，耳不闻，目明心开，而志先，慧然独悟，口弗能言，俱视独见，适若昏，昭然独明，若风吹云，故曰神。三部九候为之原，九针之论，不必存也。
Huangdi asked: In the practice of using needles, there must be rules and standards. What are these rules and standards? Qibo replied: One models on heaven and takes law from earth, according with the light of heaven — the sun, moon, and stars. Huangdi said: I wish to hear the whole of it. Qibo said: In the method of needling, one must always observe the qi of the sun, moon, stars, the four seasons, and the eight correct periods; only when the qi is settled should one needle. Therefore, when the weather is warm and the sun bright, people's blood becomes fluid and moist, and the defensive qi floats near the surface, so blood is easily drained and qi easily moves; when the weather is cold and the sky overcast, people's blood congeals and stagnates, and the defensive qi sinks. When the moon begins to wax, blood and qi begin to grow refined and the defensive qi begins to circulate; when the moon's disk is full, blood and qi become replete and the flesh becomes firm; when the moon's disk is empty, the flesh diminishes, the channels and network vessels become empty, the defensive qi departs, and the bodily form stands alone and unsupported. Therefore one adjusts blood and qi in accordance with the timing of heaven. For this reason, do not needle when the weather is cold, and do not hesitate to needle when the weather is warm. Do not drain when the moon is waxing; do not supplement when the moon is full; do not treat when the moon's disk is empty — this is called obtaining the proper time and regulating accordingly. Following the sequence of heaven and the times of abundance and depletion, one tracks the movement of light to fix one's position, and stands correctly to await the right moment. Therefore, to drain when the sun and moon are newly waxing is called emptying the viscera; to supplement when the moon is full causes blood and qi to overflow in excess, with stagnant blood lodging in the network vessels — this is called doubled excess; to treat when the moon's disk is empty is called disordering the channels. In such cases yin and yang become interlaced and confused, true qi and pathogenic qi cannot be distinguished, pathogenic qi sinks in and lingers, the exterior becomes deficient and the interior disordered, and excessive pathogenic influences then arise.
Huangdi said: What do the stars and the eight correct periods indicate? Qibo said: The stars are what regulate the movements of the sun and moon. The eight correct periods are what indicate the depleting pathogenic influence of the eight winds, which arrive at their proper times. The four seasons are what divide where the qi of spring, autumn, winter, and summer resides, so that one may regulate accordingly with the season; one must recognize the depleting pathogenic winds of the eight correct periods and avoid exposure to them. When bodily deficiency meets with heaven's deficiency, the two deficiencies resonate with each other, and this pathogenic qi penetrates to the bone; entering, it damages the five viscera. But if the practitioner watches for it and treats it in time, it cannot cause harm. Therefore it is said: the prohibitions of heaven must not go unknown.
Huangdi said: Good. I have now heard about modeling on the stars; I wish to hear about modeling on the ancients. Qibo said: To model on the ancients is first to know the classics of needling. To verify one's practice in the present day is first to know the cold and warmth of the days and the waxing and waning of the moon, so as to observe whether qi floats or sinks, and regulate it in the body, observing that this immediately proves effective. As for observing what is obscure and unseen — this refers to the fact that the bodily form, qi, and nutritive and defensive qi do not show themselves outwardly, yet the skilled practitioner alone knows them: by the cold and warmth of the day, the waning and waxing of the moon, and the floating and sinking of qi through the four seasons, examined together and cross-checked, he regulates accordingly. The skilled practitioner always perceives this beforehand, though it does not show outwardly — hence it is called observing what is obscure and unseen. One who penetrates the inexhaustible may transmit this knowledge to later generations; this is precisely wherein the skilled practitioner differs from others, yet since it does not show outwardly, others altogether cannot perceive it. Looked at, it has no form; tasted, it has no flavor — hence it is called the obscure and unseen, as if divine, as if numinous. As for depleting pathogenic qi — this is the depleting pathogenic qi of the eight correct periods. As for upright, ordinary pathogenic influence — when the body exerts effort, sweat is emitted, and the interstices open, and one then meets an ordinary depleting wind, it strikes the person only lightly, so that none can know its true nature nor see its form. The superior practitioner treats disease at its budding stage — he must first perceive the qi of the three sections and nine indicators, regulating fully before it has deteriorated, and thereby rescues the patient; hence he is called a superior practitioner. The inferior practitioner treats disease only after it has already formed, or after it has already broken down. Treating it after it has already formed means he does not know how the three sections and nine indicators have lost their proper coordination, and so the disease is allowed to progress to breakdown. Knowing where the disease lies means knowing how to diagnose the diseased pulse locations of the three sections and nine indicators and treat accordingly. Hence it is said: guard the gateways of the body — for none can know the pathogen's true nature, yet the skilled practitioner can perceive the pathogen's form.
Huangdi said: I have heard of supplementing and draining, but have not grasped their meaning. Qibo said: Draining must employ the 'square' method — 'square' meaning to act when the qi is just at its height, when the moon is just full, when the day is just warm, when the body is just settled, and when the breath is just inhaling — one inserts the needle then; then again one waits for the next inhalation to rotate the needle; then again one waits for the exhalation to slowly withdraw the needle. Hence it is said: draining must employ the 'square' timing, so that the pathogenic qi is made to move out. Supplementing must employ the 'round' method — 'round' meaning to move, and to move means to shift; the needling must strike the nutritive qi precisely, and the needle is then withdrawn upon inhalation. Thus 'round' and 'square' do not refer to the shape of the needle itself, but to the manner and timing of its use. Therefore, one who nourishes the spirit must know whether the body is fat or thin, and the abundance or decline of the nutritive and defensive qi and of blood and qi. Blood and qi are the person's spirit, and must not fail to be carefully nourished.
Huangdi said: How subtle and marvelous is this discourse! Uniting the human bodily form with yin and yang and the four seasons, the correspondences of deficiency and excess, and the timing of what is obscure and unseen — who but you, Master, could penetrate these things? Yet you have repeatedly spoken of form and spirit — what is meant by form, and what is meant by spirit? I wish to hear the whole of it. Qibo said: Let me speak of form. Form, ah, form — even when the eyes are dim and cannot see it directly, one asks about the patient's disease and seeks it in the channels: it becomes clearly present before one, yet when pressed for, it cannot be grasped, and its true nature remains unknown — hence it is called form. Huangdi said: What is meant by spirit? Qibo said: Let me speak of spirit. Spirit, ah, spirit — the ears do not hear it, but the eyes become clear and the heart opens, and the intention goes before; one comes to a sudden and solitary realization, which the mouth cannot put into words. All look upon it, yet the skilled practitioner alone perceives it; it is as if in dimness, and then suddenly and uniquely bright, like wind blowing away the clouds — hence it is called spirit. The three sections and nine indicators are its foundation; as for the discourses on the nine needles, they need not necessarily be retained.