阴阳之理。变化无穷。不可尽述。姑举其要者言之。夫言阴阳者。或指天地。或指气血。或指乾坤。此对待
之体。其实阳统乎阴。天包乎地。血随乎气。故圣人作易。于干则曰大哉干元。乃统天。于坤则曰至哉坤元。乃
顺承天。古人善体易义。治血必先理气。血脱益气。故有补血不用四物汤之论。如血虚发热。立补血汤一方。以
黄一两为君。当归四钱为臣。气药多而血药少。使阳生阴长。又如失血暴甚欲绝者。以独参汤一两顿煎服。
纯用气药。斯时也。有形之血。不能速生。几微之气。所当急固。使无形生出有形。盖阴阳之妙。原根于无也。
故曰无名天地之始。生死消长。阴阳之常度。岂人所能损益哉。圣人裁成天地之化。辅相天地之宜。每寓扶阳抑
阴之微权。方复而先忧七日之来。未济而预有衣HT 之备。防未然而治未病也。然生而老。老而病。病而死。人
所不能免。但其间有寿夭长短之差。此岐黄之道所由始。神农尝药。按阴阳而分寒热温凉辛甘酸苦咸之辨。凡
辛甘者属阳。温热者属阳。寒凉者属阴。酸苦者属阴。阳主生。阴主杀。司命者欲人远杀而就生。甘温者用之。
辛热者用之。使共跻乎春风生长之域。一应苦寒者俱不用。不特苦寒不用。至于凉者亦少用。盖凉者秋气也。
万物逢秋风不长矣。或时当夏令。暑邪侵入。或过食炙 辛热而成疾者。暂以苦寒一用。中病
即止。终非济生之品。世之惯用寒凉者。闻余言而怪矣。幸思而试之。其利溥哉。若夫尊生之士。不须服食。
不须导引。不须吐纳。能大明生死。几于道矣。生之门。死之户。不生则不死。上根顿悟无生。其次莫若寡欲。
未必长生。亦可却病。反而求之。人之死。由于生。人之病。由于欲。上工治未病。下工治已病。已病
矣。绎其致病之根。由于不谨。急远房帏。绝嗜欲。庶几得之。世人服食以图长生惑矣。甚者日服补药。以资纵
欲。则惑之甚也。
天上地下。阴阳之定位。然地之气每交于上。天之气每交于下。故地天为泰。天地为否。圣人参赞天地。
有转否为泰之道。如阳气下陷者。用味薄气轻之品。若柴胡升麻之类。举而扬之。使地道左旋。而升于九天之
上。阴气不降者。用感秋气肃杀为主。若瞿麦扁蓄之类。抑而降之。使天道右迁而入于九地之
下。此东垣补中益气汤。万世无穷之利。不必降也。升清浊自降矣。
春秋昼夜。阴阳之门户。一岁春夏为阳。秋冬为阴。一月朔
后为阳。望后为阴。一日昼为阳。夜为阴。又按十二时而分五藏之阴阳。医者全凭此。以明得病之根原。而施
治疗之方术。
春夏秋冬。非今行夏之时。当根据周正建子。冬至一阳生。夏至一阴生。此二至最为紧要。至者极也。阴极生
阳。绝处逢生。自无而有。阳极生阴。从有而无。阳变阴化之不同也。若春分秋分。不过从其中平分之耳。然
其尤重者。独在冬至。故易曰。先王以至日闭关。闭关二字。须看得广。观月令云。是月斋戒掩
身。以待阴阳之所定。则不止关市之门矣。
或问冬至一阳生。当渐向暖和。何为腊月大寒。冰雪反盛。夏至一阴生。当渐向清凉。何为三伏溽暑。酷
热反炽。亦有说乎。曰此将来者进。成功者退。隐微之际。未易以明也。盖阳复于下。逼阴于上。井水气蒸。
而坚冰至也。阴盛于下。逼阳于上。井水寒。而雷电合也。今人病面红口渴烦燥喘咳者。谁不曰火
盛之极。抑孰知其为肾中阴寒所逼乎。以寒凉之药进而毙者。吾不知其几矣。冤哉冤哉。
朔望分阴阳者。初一日为死魄。阴极阳生。初三日而 。十三日而几望。十五则盈矣。渐至二十已后。
月廓空虚。海水东流。人身气血亦随之。女人之经水。期月而满。满则溢。阴极而
少阳生。始能受孕。故望以前属阳。
阳病则昼重而夜轻。阳气与病气交旺也。阴病则昼轻而夜重。阴气与病气交旺也。若夫阳虚病则昼轻。
阴虚病则夜轻。阴阳各归其分也。治之者既定其时。以证其病。若未发之时。当迎而夺之。如孙子之用兵。在
山谷则塞渊泉。在水陆则把渡口。若正发之时。当避其锐锋。若势已杀。当击其惰归。恐旷日迟久。
反生他患也。至于或昼或夜。时作时止。不时而动。是纯虚之证。又不拘于昼夜之定候。当广服补药。以养其
正。如在平川广漠。当清野千里。又以十二时。分发五脏六腑。自子至午。行阳
之分。自午至亥。行阴之分。仲景云。少阴之病欲解时。从子至寅。乘此阳道方亨之时而投之。药易以入。故
仲景伤寒论中。逐时分治。不可不考。
年月日时。皆当各分阴阳。此其大略也。独甲子运气。内经虽备言之。往往不验。当时大挠作甲子。即以
本年本月本日本时为始。统纪其数如此。未必能直推至上古甲子年甲子月日时为历元也。内经特明气运有如许
之异。民病亦有如许之别如此。读内经者。不可执泥。譬如大明统历。选择已定。可信乎。不可信乎。
阳一而实。阴二而虚。盖阴之二。从阳一所分。故日秉全体。月有盈亏。人之初生。纯阳无阴。赖其母
厥阴乳哺。而阴始生。是以男子至二八。而精始通。六十四而精已绝。女子至二七。而经始行。四十九而经已
绝。人身之阴。止供三十年之受用。可见阳常有余。阴常不足。况嗜欲者多。节欲者少。故自幼至老。补阴
之功。一日不可缺。此阴字指阴精而言。不是泛言阴血。今之以四物汤补阴者误也。王节斋云。水虚成病者。
十之八九。火虚成病者。十之一二。微得其意矣。褚侍中云。男子阴已耗。而思色以降其精。则精不出而内败。
小便道涩如淋。阳巳痿而复竭之。则大小便牵痛。愈痛则愈便。愈便则愈痛。玩褚王二公之言。阴中有水有火。
水虚者固多。火衰者亦不少。未有精泄已虚。而元阳能独全者。况阴阳互为其根。议补阴者。须以阳为
主。盖无阳则阴无以生也。
男子抱阳而负阴。女子抱阴而负阳。人身劈中分阴阳左右。男子右属火而为气。左属水而为血。女子右属
水。而左属火。凡人半肢风者。男子多患左。女子多患右。岂非水不能营耶。
此皆泛言阴阳之理。有根阴根阳之妙。不穷其根。阴阳或
几乎息矣。谈阴阳者。俱曰气血。是矣。讵知火为阳气之根。水为阴血之根。盍观之天地间。日为火之精。故
气随之。月为水之精。故潮随之。然此阴阳水火。又同出一根。朝朝禀行。夜夜复命。周流而不息。相偶而不离
。惟其同出一根。而不相离也。故阴阳又各互为其根。阳根于阴。阴根于阳。无阳则阴无以生。无
阴则阳无以化。从阳而引阴。从阴而引阳。各求其属而穷其根也。世人但知气血为阴阳。而不知水火为阴阳之
根。能知水火为阴阳。而误认心肾为水火之真。此道之所以不明不行也。试观之天上。金木水火土五星见在。
而日月二曜。所以照临于天地间者。非真阴真阳乎。人身心肝脾肺肾五行俱存。而所以营运于五脏六腑之间者。
何物乎。有无形之相火行阳二十五度。无形之肾水行阴二十五度。而其根则原于先天太极之真。此所
以为真也。一属有形。俱为后天。而非真矣非根矣。谓之根。如木之根而枝叶所由以生者也。
既有真阴真阳。何谓假阴假阳。曰此似是而非。多以误人。不可不知。如人大热发燥口渴舌燥。非阳证
乎。余视其面色赤。此戴阳也。切其脉。尺弱而无力。寸关豁大而无伦。此系阴盛于下。逼阳于上。假阳之证。
余以假寒之药。从其性而折之。顷刻平矣。如人恶寒身不离复衣。手足厥冷。非阴证乎。余视其面色滞。切其
脉涩。按之细数而有力。此系假寒之证。寒在皮肤。热在骨髓。余以辛凉之剂。温而行之。一汗而愈。凡此皆因
真气之不固。故假者得以乱其真。假阳者。不足而示之有余也。假阴者。有余而示之不足也。既已识其假矣。
而无术以投其所欲。彼亦捍格而不入。经曰。伏其所主。而先其所因。其始则异其终则同。可使去邪。而归于正矣。
有偏阴偏阳者。此气禀也。太阳之人。虽冬月身不须绵。口
常饮水。色欲无度。大便数日一行。芩连栀柏大黄芒硝。恬不知
怪。太阴之人。虽暑月不离复衣。食饮稍凉。便觉腹痛泄泻。参术姜桂。时不绝口。一有欲事。呻吟不已。此
两等人者。各禀阴阳之一偏者也。与之谈医。各执其性之一偏而目为全体。常试而漫为之。虽与之言。必不见
信。是则偏之为害。而误人多矣。今之为医者。鉴其偏之弊。而制为不寒不热之方。举世宗之。以
为医中王道。岂知人之受病。以偏得之。感于寒则偏于寒。感于热则偏于热。以不寒不热之剂投之。何以补其
偏而救其弊哉。故以寒治热。以热治寒。此方士之绳墨也。然而苦寒频进。而积热弥炽。辛热比年。而沉寒益
滋者何耶。此不知阴阳之属也。经曰。诸寒之而热者取之阴。诸热之而寒者取之阳。所谓求其属也。斯理也。
惟王太仆能穷之。注云。寒之不寒。是无水也。热之不热。是无火也。无水者。壮水之主。以镇阳光。无火者。
益火之原。以消阴翳。启玄达至理于绳墨之外。而开万世医学之源也。
阴阳者虚名也。水火者物理也。寒热者。天下之淫气也。水火者。人之真元也。淫气凑疾。可以寒热药施
之。真元致病。即以水火之真调之。然不求其属。投之不入。先天水火。原属同宫。火以水为主。水以火为
原。故取之阴者。火中求水。其精不竭。取之阳者。水中寻火。其明不熄。斯大寒大热之病。得其平
矣。偏寒偏热之士。不可与言也。至于高世立言之士。犹误认水火为心肾。无怪乎后人之懵懵也。
阴阳的道理，变化无穷无尽，无法全部陈述。姑且列举其中重要的方面来说明。所谓阴阳，有时指天地，有时指气血，有时指乾坤。这是相对立的实体，但实际上阳统摄阴，天包裹地，血跟随气。所以圣人创作《易经》，对于乾卦说：“伟大啊，乾元！它统领着天。”对于坤卦说：“至美啊，坤元！它顺承着天。”古人善于体悟《易经》的含义，治疗血病必须先调理气机，血脱失时应当益气，因此有“补血不用四物汤”的论述。比如血虚发热，创立了补血汤一方，以黄耆一两为君药，当归四钱为臣药，气药多而血药少，使阳气生发则阴血随之增长。又如失血严重几乎断绝者，用独参汤一两顿服煎剂，纯用补气药。在这个时候，有形的血液不能快速生成，细微的气机应当紧急固护，使无形之气生出有形之血。大概阴阳的奥妙，原本根源于无。所以说“无名是天地万物的开始”。生死消长，是阴阳的正常规律，难道是人所能增减的吗？圣人裁成天地的化育，辅助顺应天地的适宜，每每寓含扶持阳气、抑制阴气的微妙权变。在复卦（一阳来复）之前先忧虑七日来复的到来，在未济卦（事未成）之前就预先做好穿衣渡河的准备，这是防止未然之患，治疗未病之症。然而人从生到老，从老到病，从病到死，是人所不能避免的。只是其中有寿命长短的差异，这就是岐伯、黄帝医学之道由此产生的原因。神农尝百草，按照阴阳属性区分寒、热、温、凉、辛、甘、酸、苦、咸的性质。凡是辛味、甘味的属于阳，温热性质的属于阳；寒凉性质的属于阴，酸味、苦味的属于阴。阳主生长，阴主肃杀。掌管生命的人希望人们远离肃杀而趋向生长，所以使用甘温的药物，使用辛热的药物，使人们共同进入如春风般生长的境界。所有苦寒的药物都不使用。不仅苦寒的不使用，至于凉性的也很少使用。因为凉性对应秋气，万物遇到秋风就不再生长了。或者时令正当夏季，暑邪侵入，或者过食炙烤辛辣热性食物而成疾者，暂时使用一次苦寒药物，中病即止，终究不是救生的良品。世间惯用寒凉药物的人，听到我的话会感到奇怪。希望他们思考并尝试我的观点，其利益将是广泛的。至于尊重生命的人士，不需要服食丹药，不需要导引术，不需要吐纳法，能通晓生死道理，就接近于道了。生之门，死之户，不生则不死。上等根器的人顿悟无生之理，其次不如寡欲。未必能长生，也可以祛病。反过来推求，人的死，由于贪生；人的病，由于欲望。上等的医生治疗未病，下等的医生治疗已病。既然已经病了，推究致病的根源，是由于不谨慎，应迅速远离房事，断绝嗜好欲望，差不多就能痊愈了。世人服用丹药以求长生，是被迷惑了。更甚者每天服用补药，以此资助放纵欲望，则是更加迷惑了。
天上地下，阴阳的位置是固定的。然而地气常常上交于天，天气常常下交于地，所以地天相交为泰卦，天地不交为否卦。圣人参与赞助天地的化育，有将否转化为泰的方法。如阳气下陷者，使用气味淡薄轻清的药材，如柴胡、升麻之类，提升并举扬它们，使地道左旋，升腾于九天之上。阴气不降者，以感受秋气肃杀为主，如瞿麦、扁蓄之类，抑制并使之下行，使天道右迁而入于九地之下。这是李东垣补中益气汤，造福万世无穷的益处，不必强行降浊，清气上升则浊气自然下降。
春秋昼夜，是阴阳的门户。一年之中春夏为阳，秋冬为阴；一月之中初一之后为阳，十五之后为阴；一日之中白天为阳，夜晚为阴。又按十二时辰分配五脏的阴阳。医生完全凭借这些，来明白生病的根本原因，从而施治。
春夏秋冬，不应只遵循夏历的时节，应当根据周历建子月计算。冬至时一阳初生，夏至时一阴初生。这两个节气最为紧要。“至”就是极的意思。阴极则生阳，绝境中逢生，从无到有；阳极则生阴，从有到无。这是阳变阴化的不同之处。至于春分秋分，不过是从中平分之罢了。然而其中尤其重要的是冬至。所以《易经》说：“先王在冬至日关闭关口。”“闭关”二字，必须看得广泛。观察《月令》说：“这个月斋戒掩身，以等待阴阳的定数。”那么就不止是关闭市场的大门了。
有人问：冬至一阳初生，应当逐渐变暖，为什么腊月大寒，冰雪反而兴盛？夏至一阴初生，应当逐渐清凉，为什么三伏天湿热，酷热反而炽盛？也有说法吗？回答说：这是因为将要前进的（新生之气）进，已经成功的（旧有之气）退。在隐微之际，不容易看清。大概阳气回复于下，逼迫阴气于上，井水气蒸腾，而坚冰到来。阴气盛于下，逼迫阳气于上，井水冷冽，而雷电相合。现在人患病面红、口渴、烦躁、喘咳的，谁不说这是火盛到了极点？又有谁知道这是肾中阴寒逼迫阳气上浮呢？用寒凉药物进治而致死的人，我不知道有多少了。冤枉啊，冤枉啊！
朔望区分阴阳。初一为死魄，阴极阳生。初三新月出现。十三接近满月。十五则圆满了。渐渐到二十以后，月廓空虚，海水向东流，人身气血也随之变化。女人的月经，每月期满。满了就会溢出。阴极而少阳生，才能受孕。所以望日之前属阳。
阳病则白天重晚上轻，因为阳气与病气交相旺盛。阴病则白天轻晚上重，因为阴气与病气交相旺盛。如果是阳虚病则白天轻，阴虚病则晚上轻，阴阳各归其位。治疗的人确定了时间，以验证病情。如果在未发作之时，应当迎头痛击夺取病势，像孙子用兵一样，在山谷则堵塞深渊泉水，在水陆交界处则把守渡口。如果正在发作之时，应当避开其锐利锋芒。如果势头已衰，应当攻击其懈怠而归。恐怕拖延时日，反而产生其他祸患。至于或昼或夜，时作时止，不时而动，这是纯虚的证候，又不拘泥于昼夜的固定时刻。应当广泛服用补药，以养护正气。像在平原广阔之地，应当实行清野千里策略。又以十二时辰分发五脏六腑。自子时至午时，运行于阳之分；自午时至亥时，运行于阴之分。张仲景说：“少阴病欲解时，从子时至寅时。”乘此阳气方通亨之时投药，药容易进入。所以张仲景《伤寒论》中，逐时分治，不可不考察。
年月日时，都应当分别阴阳。这是大概情况。唯独甲子运气学说，《内经》虽然详尽论述，往往不灵验。当时大挠制作甲子，即以本年本月本日此时为始，统纪其数如此，未必能直接推至上古甲子年甲子月甲子日甲子时为历法元年。《内经》特别阐明气运有这样多的差异，百姓生病也有这样多的区别。读《内经》的人，不可固执拘泥。譬如大明王朝的统历，选择既定，可信吗？不可信吗？
阳一是实，阴二是虚。大概阴的二，是从阳的一所分出来的。所以太阳秉受全体，月亮有盈亏。人刚出生时，纯阳无阴，依赖母亲厥阴经的乳汁哺育，阴才开始生长。所以男子到十六岁，精气才通畅，六十四岁精气才枯竭。女子到十四岁，月经才开始通行，四十九岁月经才枯竭。人身之阴，仅供三十年受用。可见阳常有余，阴常不足。何况嗜欲的人多，节制欲望的人少。所以从小到老，补阴的功夫，一天也不可缺少。这里的“阴”字指阴精而言，不是泛言阴血。现在用四物汤补阴是错误的。王节斋说：水虚成病的，十之八九；火虚成病的，十之一二。略微得其意了。褚侍中说：男子阴精已耗损，还想通过色欲来泄精，则精液不出而内部败坏，小便道涩滞如淋证。阳痿后又竭尽它，则大小便牵拉疼痛。越痛就越想排便，越排便就越痛。玩味褚、王二位先生的话，阴中有水有火。水虚固然多，火衰的也不少。没有精液泄后已虚，而元阳能独自保全的。况且阴阳互为其根。议补阴者，必须以阳为主。因为没有阳则阴无法生成。
男子抱阳而负阴，女子抱阴而负阳。人身中间分为阴阳左右。男子右边属火而为气，左边属水而为血。女子右边属水，左边属火。半身不遂的风病，男子多患左侧，女子多患右侧。这难道不是水不能滋养的缘故吗？
这些都是泛言阴阳的道理，有根阴根阳的奥妙。不穷究其根本，阴阳或许几乎息灭了。谈论阴阳的人，都说气血，是对的。岂知火是阳气的根本，水是阴血的根本。何不观察天地间，太阳是火的精华，所以气随它运行；月亮是水的精华，所以潮汐随它涨落。然而这阴阳水火，又同出一根，朝朝禀行，夜夜复命，周流不息，相偶不离。正因为同出一根而不分离，所以阴阳又各互为其根。阳根于阴，阴根于阳。无阳则阴无以生，无阴则阳无以化。从阳而引阴，从阴而引阳，各自寻求所属而穷究其根本。世人只知道气血是阴阳，而不知道水火是阴阳的根本。能知道水火是阴阳，却误认心肾为水火的真体。这就是医道之所以不明朗不流行的原因。试看天上，金木水火土五星存在，而日月二曜，所以照临于天地间的，不就是真阴真阳吗？人身心肝脾肺肾五行俱存，而所以营运于五脏六腑之间的，是什么东西呢？有无形之相火行阳二十五度，无形之肾水行阴二十五度，而其根本则原于先天太极之真。这才是所谓的真。一属有形，都是后天，就不是真也不是根了。称为根，就像树的根而枝叶由此生长一样。
既有真阴真阳，什么是假阴假阳？回答说：这是似是而非，大多误导人，不可不知。比如人大热发燥、口渴舌燥，不是阳证吗？我看他面色赤，这是戴阳证。切他的脉，尺部弱而无力，寸关部豁大而无伦次。这是系阴盛于下，逼迫阳气于上，假阳的证候。我用假寒性质的药物，顺从其本性而折伏它，顷刻间就平复了。比如人恶寒身体离不开厚衣，手足厥冷，不是阴证吗？我看他面色滞暗，切他的脉涩，按之细数而有力。这是假寒的证候。寒在皮肤，热在骨髓。我用辛凉的药剂，温而行之，一出汗就好了。凡此都是因为真气不固，所以假象得以扰乱真象。假阳者，是不足而表现出有余。假阴者，是有余而表现出不足。既然已经识别出假象了，而没有法术去投其所好（顺其假象），病人也会抗拒而不接受。《内经》说：“伏其所主，而先其所因。其始则异，其终则同。”可以使邪气去除，而归于正道。
有偏阴偏阳者，这是气质禀赋。太阳之人，虽然冬天也不需要棉衣，口常饮水，色欲无度，大便数日一行，用黄芩、黄连、栀子、黄柏、大黄、芒硝等药，安然不觉奇怪。太阴之人，虽然夏天离不开厚衣，饮食稍凉，就觉得腹痛泄泻，人参、白术、干姜、肉桂，口中不绝。一有房事，呻吟不止。这两等人，各自禀受阴阳的一偏。与他们谈医，各执其性之一偏而目为全体，经常尝试而随意为之，即使跟他们说话，一定不被相信。这就是偏颇的危害，而误导人多矣。现在的医生，鉴于偏颇的弊端，而制定不寒不热的方子，举世尊崇，以为医中的王道。哪里知道人得病，是以偏得之。感于寒则偏于寒，感于热则偏于热。用不寒不热的药剂投治，怎么能补其偏而救其弊呢？所以以寒治热，以热治寒，这是方士的法度准则。然而苦寒药频频进用，而积热更加炽盛；辛热药连年使用，而沉寒更加滋生的原因是什么呢？这是不知道阴阳的归属。《内经》说：“诸寒之而热者取之阴，诸热之而寒者取之阳。”所谓求其归属。这个道理，只有王太仆（王冰）能穷尽它。注释说：“寒之不寒，是无水也。热之不热，是无火也。”无水者，壮水之主，以镇阳光；无火者，益火之源，以消阴翳。启玄子（王冰号）通达至理于法度之外，而开启万世医学之源。
阴阳是虚名，水火是物理。寒热，是天下泛滥之气。水火，是人的真元。淫气凑集致病，可以用寒热药施治。真元致病，就用真水火来调治。然而不求其归属，投药不入。先天水火，原本同宫。火以水为主，水以火为原。所以取之阴者，火中求水，其精不竭；取之阳者，水中寻火，其明不熄。这样大寒大热的病，得到平衡了。偏寒偏热之士，不可与他们言说。至于高世立言之士，还误认水火为心肾，难怪后人懵懂无知。
The principle of Yin and Yang (Yin-Yang) is infinite in its changes and cannot be fully described. I shall briefly mention the most important points. When speaking of Yin and Yang, one may refer to Heaven and Earth (Tian-Di), Qi and Blood (Qi-Xue), or Qian and Kun. These are opposing entities; however, in reality, Yang governs Yin, Heaven envelops Earth, and Blood follows Qi. Thus, when the Sages created the *I Ching* (Book of Changes), regarding Qian (Heaven), they said: "Great indeed is the Primordial Power of Qian! It leads Heaven." Regarding Kun (Earth), they said: "Most excellent indeed is the Primordial Power of Kun! It follows and receives from Heaven." The ancients were adept at comprehending the meaning of the *I Ching*. In treating blood disorders, one must first regulate Qi. In cases of blood loss with deficiency, one should tonify Qi. Hence, there is the theory that "tonifying blood does not necessarily require Si Wu Tang (Four Substances Decoction)." For instance, in cases of fever due to Blood deficiency, a formula called Bu Xue Tang (Blood Tonifying Decoction) was established, using Huang Qi (Astragali Radix) as the sovereign herb at 1 liang, and Dang Gui (Angelicae Sinensis Radix) as the minister herb at 4 qian. There are more Qi-regulating herbs than Blood-nourishing herbs, so that when Yang generates, Yin grows. Similarly, in cases of severe hemorrhage where life is nearly lost, Du Shen Tang (Single Ginseng Decoction) is decocted at 1 liang and taken in one dose, using purely Qi-tonifying herbs. At this time, tangible Blood cannot be quickly generated, but subtle Qi must be urgently secured, allowing the intangible to generate the tangible. The wonder of Yin and Yang originates from the non-existent. Hence it is said, "The nameless is the beginning of Heaven and Earth." Birth, death, decline, and growth are the normal laws of Yin and Yang; can humans add to or subtract from them? The Sages shaped the transformations of Heaven and Earth and assisted their appropriateness, often embedding the subtle balance of supporting Yang and suppressing Yin. Before the return of Yang (Fu Hexagram), one worries about the coming seven days; before completion (Wei Ji Hexagram), one prepares for crossing the river. This is preventing illness before it arises and treating disease before it occurs. However, from birth to old age, from old age to sickness, and from sickness to death, these are unavoidable for humans. There are only differences in longevity. This is how the Way of Qi Bo and Huang Di began. Shennong tasted herbs, distinguishing cold, hot, warm, cool, pungent, sweet, sour, bitter, and salty based on Yin and Yang attributes. Pungent and sweet flavors belong to Yang; warm and hot natures belong to Yang. Cold and cool natures belong to Yin; sour and bitter flavors belong to Yin. Yang governs generation, and Yin governs destruction. Those who manage life wish for people to avoid destruction and approach generation, so they use sweet-warm herbs and pungent-hot herbs, enabling people to enter a realm of spring-like growth. All bitter-cold herbs are unused. Not only are bitter-cold herbs unused, but cool herbs are also rarely used. Coolness corresponds to autumn energy, and all things cease to grow upon encountering autumn wind. If the season is summer and summer-heat pathogen invades, or if illness results from overeating roasted, pungent, and hot foods, bitter-cold herbs may be used temporarily, stopping once the disease is addressed. They are ultimately not products for saving lives. Those accustomed to using cold-cool herbs will find my words strange. I hope they reflect and try them; the benefits will be extensive. As for those who revere life, there is no need for elixirs, no need for Daoyin (guiding and pulling exercises), no need for Tuna (breathing regulation). Understanding life and death thoroughly brings one close to the Dao. Life is the gate, death is the door. Without life, there is no death. Those with superior roots attain sudden enlightenment of non-life; next best is reducing desires. One may not achieve immortality, but one can eliminate disease. Reflecting on this, human death stems from excessive striving for life; human illness stems from desires. Superior physicians treat disease before it arises; inferior physicians treat disease after it has arisen. Once diseased, trace the root of the illness to imprudence. Urgently avoid sexual indulgence and cut off cravings, and recovery is likely. People taking elixirs seeking immortality are deluded. Worse still, those taking tonic herbs daily to fuel licentiousness are even more deluded.
Above heaven and below earth, the positions of Yin and Yang are fixed. Yet Earth's Qi often rises to meet Heaven, and Heaven's Qi often descends to meet Earth. Thus, Earth over Heaven forms Tai (Peace), while Heaven over Earth forms Pi (Standstill). The Sages participated in assisting Heaven and Earth, possessing the way to transform Pi into Tai. For sinking Yang Qi, use herbs with thin flavor and light aroma, such as Chai Hu (Bupleuri Radix) and Sheng Ma (Cimicifugae Rhizoma), to lift and raise them, causing Earth's path to rotate left and ascend to the highest heavens. For descending Yin Qi, rely primarily on the肃杀 (austere and killing) energy of autumn, such as Qu Mai (Dianthi Herba) and Bian Xu (Polygoni Avicularis Herba), to suppress and descend them, causing Heaven's path to move right and enter the deepest earth. This is the endless benefit of Li Dongyuan's Bu Zhong Yi Qi Tang (Tonify the Middle and Augment the Qi Decoction). There is no need to forcibly descend turbidity; when clear Qi ascends, turbid Qi naturally descends.
Spring and Autumn, day and night, are the portals of Yin and Yang. In a year, Spring and Summer are Yang, Autumn and Winter are Yin. In a month, the period after the new moon is Yang, after the full moon is Yin. In a day, daytime is Yang, nighttime is Yin. Furthermore, divide the twelve double-hours among the Five Zang Organs' Yin and Yang. Physicians rely entirely on this to understand the origin of disease and apply treatment methods.
Spring, Summer, Autumn, and Winter should not merely follow the Xia calendar but should be calculated according to the Zhou calendar starting with Zi month. At Winter Solstice, one Yang is born; at Summer Solstice, one Yin is born. These two solstices are most critical. "Solstice" means extremity. When Yin reaches extremity, Yang is born; from despair comes life, from non-existence to existence. When Yang reaches extremity, Yin is born; from existence to non-existence. This is the difference between Yang transformation and Yin change. Equinoxes merely divide the middle equally. However, Winter Solstice is particularly important. Thus, the *I Ching* says: "The former kings closed the passes on the solstice day." The term "closing the passes" must be viewed broadly. Observing the *Monthly Ordinances*: "In this month, fast and restrain oneself, waiting for the determination of Yin and Yang." This implies more than just closing market gates.
One might ask: At Winter Solstice, when one Yang is born, warmth should gradually increase. Why is the twelfth lunar month extremely cold, with ice and snow intensifying? At Summer Solstice, when one Yin is born, coolness should gradually increase. Why are the Three Fu periods humid and hot, with intense heat prevailing? Is there an explanation? I reply: This is because what is advancing enters, and what has succeeded retreats. In the hidden and subtle moments, it is not easy to clarify. Generally, Yang recovers below, forcing Yin above; well water steams, yet solid ice arrives. Yin dominates below, forcing Yang above; well water becomes cold, yet thunder and lightning combine. Today, patients presenting with red face, thirst, irritability, wheezing, and coughing are universally said to have extreme Fire excess. Who knows that this is actually forced upward by Kidney Yin-Cold? How many have died due to the administration of cold-cooling medicines? Oh, what injustice!
The new and full moons distinguish Yin and Yang. The first day is the dark moon, where Yin is extreme and Yang is born. On the third day, the crescent appears. On the thirteenth, it approaches fullness. On the fifteenth, it is complete. Gradually, after the twentieth, the moon's outline empties, seawater flows eastward, and human Qi and Blood follow suit. Women's menstruation fills monthly. When full, it overflows. When Yin is extreme, Shaoyang (Lesser Yang) is born, enabling conception. Therefore, the period before the full moon belongs to Yang.
Yang diseases are heavier during the day and lighter at night because Yang Qi and Pathogenic Qi flourish together. Yin diseases are lighter during the day and heavier at night because Yin Qi and Pathogenic Qi flourish together. If it is Yang deficiency disease, it is lighter during the day; if Yin deficiency disease, it is lighter at night, as Yin and Yang return to their respective domains. The healer determines the time to verify the disease. Before onset, attack and seize the momentum, like Sun Tzu using troops: in valleys, block springs; at water crossings, guard the ferry. During active onset, avoid the sharp edge. When the momentum fades, attack the retreating laxity. Delaying too long may cause other complications. If symptoms occur randomly day or night, intermittently, this is pure deficiency, not bound by day/night patterns. Broadly administer tonic herbs to nourish Zheng Qi (Upright Qi). Like clearing fields in open plains. Distribute the Twelve Double-Hours among the Five Zang and Six Fu Organs. From Zi to Wu hours, Yang circulates; from Wu to Hai hours, Yin circulates. Zhang Zhongjing stated: "Shao Yin disease resolves from Zi to Yin hours." Administer medicine during this time when Yang Qi is flourishing, making absorption easier. Thus, in Zhang Zhongjing's *Treatise on Cold Damage*, hour-by-hour treatment must be studied carefully.
Years, months, days, and hours should all be divided into Yin and Yang. This is the general overview. Specifically, the Jiazi Yunqi (Six Qi and Five Movements) theory, though detailed in the *Nei Jing* (Inner Canon), often fails. When Da Nao invented Jiazi, he started counting from the current year, month, day, and hour. He did not necessarily push back to the primordial Jiazi year/month/day/hour as the calendar origin. The *Nei Jing* specifically clarifies that Qi movements have such variations and illnesses have such differences. Readers of the *Nei Jing* should not be dogmatic. Just as the Great Ming Calendar is fixed, is it credible or not?
Yang is one and solid; Yin is two and empty. Yin's two derives from Yang's one. Thus, the Sun holds the whole form, while the Moon has waxing and waning. At birth, humans are purely Yang without Yin. Relying on the mother's Ju Yin (Jueyin) breast milk, Yin begins to grow. Men reach seminal emission at sixteen (2x8) and seminal exhaustion at sixty-four (8x8). Women begin menstruation at fourteen (2x7) and menstruation ends at forty-nine (7x7). Human Yin suffices for only thirty years of usage. Thus, Yang is often in excess, and Yin is often deficient. Moreover, those indulging in desires are many, while those restraining desires are few. Therefore, from youth to old age, the work of tonifying Yin cannot be absent for a day. Here, "Yin" refers to Jing (Essence), not generally Blood. Using Si Wu Tang (Four Substances Decoction) to tonify Yin today is mistaken. Wang Jiezhai said: Eight or nine out of ten illnesses stem from Water deficiency; one or two from Fire deficiency. He grasped the essence somewhat. Chu Shizhong said: When men's Yin Essence is depleted, yet they seek sexual release, the essence does not exit but rots internally, causing urinary difficulty resembling strangury. If impotence is followed by further depletion, urination and defecation become painful. The more pain, the more urge to defecate; the more defecation, the more pain. Reflecting on Chu and Wang's words, within Yin there is Water and Fire. Water deficiency is common, but Fire decline is also frequent. After essence depletion and deficiency, Yuan Yang (Primordial Yang) cannot remain intact alone. Since Yin and Yang are roots of each other, when discussing tonifying Yin, one must prioritize Yang. Without Yang, Yin cannot generate.
Men embrace Yang and bear Yin; women embrace Yin and bear Yang. The human body divides Yin and Yang into left and right. In men, the right belongs to Fire and is Qi; the left belongs to Water and is Blood. In women, the right belongs to Water, and the left belongs to Fire. Hemiplegia affects the left side more often in men and the right side more often in women. Is this not because Water fails to nourish?
These are general statements on Yin and Yang principles, containing the subtlety of rooting Yin in Yang and Yang in Yin. Without exploring the root, Yin and Yang might almost cease to function. Those discussing Yin and Yang say Qi and Blood, which is correct. But do they know that Fire is the root of Yang Qi, and Water is the root of Yin Blood? Observe Heaven and Earth: The Sun is the essence of Fire, so Qi follows it. The Moon is the essence of Water, so tides follow it. However, this Yin-Yang and Water-Fire share the same root, circulating daily and returning nightly, flowing endlessly, paired inseparably. Because they share one root and do not separate, Yin and Yang are mutually rooted. Yang roots in Yin, Yin roots in Yang. Without Yang, Yin cannot generate; without Yin, Yang cannot transform. Draw Yin from Yang, draw Yang from Yin, seeking their belonging and exhausting their roots. People only know Qi and Blood as Yin and Yang, not knowing Water and Fire are the roots of Yin and Yang. Even knowing Water and Fire are Yin and Yang, mistaking Heart and Kidney for the true Water and Fire is why the Dao remains obscure. Look at the sky: The five planets exist, but the Sun and Moon illuminate the world—are they not True Yin and True Yang? In the human body, the Five Elements of Heart, Liver, Spleen, Lung, and Kidney exist, but what operates among the Five Zang and Six Fu Organs? There is Formless Ministerial Fire circulating Yang twenty-five times, and Formless Kidney Water circulating Yin twenty-five times. Their root originates from the True Essence of the Primordial Taiji. This is what makes it True. Anything tangible is Post-heaven, not True, not Root. A root is like a tree's root from which branches and leaves grow.
If there are True Yin and True Yang, what are False Yin and False Yang? I say: These are似是而非 (seemingly correct but actually wrong) and often mislead people; one must know them. For example, a person has high fever, dryness, thirst, and dry tongue—is this not a Yang syndrome? I observe his red face; this is Dai Yang (Floating Yang). Palpating his pulse, the Chi position is weak and powerless, while Cun and Guan positions are hollow and large without order. This indicates Yin excess below forcing Yang above—a False Yang syndrome. I use medicines with false-cold properties, following its nature to subdue it, and it calms instantly. Conversely, a person fears cold, refuses to remove layers, and has cold limbs—is this not a Yin syndrome? I observe his dull complexion and choppy pulse, fine and rapid but forceful upon pressure. This is a False Cold syndrome. Cold is in the skin, Heat is in the marrow. I use pungent-cool agents, warming and promoting circulation, and he sweats and heals. All these cases arise because True Qi is insecure, allowing falsehood to confuse truth. False Yang presents excess where there is deficiency. False Yin presents deficiency where there is excess. Having identified the falsehood, if one lacks the method to cater to its desire (follow the false presentation), the patient will resist. The Classic says: "Subdue the dominant factor and address the cause first. Initially different, finally the same." This allows expelling evil and returning to orthodoxy.
Some have biased Yin or Yang constitutions. Tai Yang persons do not need cotton in winter, drink water constantly, indulge in sex excessively, and pass stool every few days. They use Huang Qin (Scutellariae Radix), Huang Lian (Coptidis Rhizoma), Zhi Zi (Gardeniae Fructus), Huang Bai (Phellodendri Cortex), Da Huang (Rhei Radix et Rhizoma), and Mang Xiao (Natrii Sulfas) calmly, showing no surprise. Tai Yin persons cannot remove layers in summer; slight cooling of food/drink causes abdominal pain and diarrhea. They constantly consume Ren Shen (Ginseng Radix), Bai Zhu (Atractylodis Macrocephalae Rhizoma), Gan Jiang (Zingiberis Rhizoma), and Rou Gui (Cinnamomi Cortex). Any sexual activity causes groaning. These two types embody a bias of Yin or Yang. Discussing medicine with them, they cling to their bias as the whole. Trying random treatments, they will not believe you. This is the harm of bias, misleading many. Modern doctors, seeing this bias, create neutral (neither cold nor hot) formulas, revered as the "King's Way" of medicine. But illness is contracted through bias. Contracting cold leads to cold bias; contracting heat leads to heat bias. How can neutral formulas correct bias and save the situation? Therefore, treating heat with cold, and cold with heat, is the standard rule. Yet, why does frequent bitter-cold intake exacerbate accumulated heat? Why does annual pungent-hot intake deepen deep-seated cold? This is ignorance of Yin-Yang affiliation. The Classic says: "For those whose heat persists despite cold treatment, treat Yin. For those whose cold persists despite heat treatment, treat Yang." This is seeking the affiliation. Only Wang Bing (Wang Taipu) exhausted this principle. His commentary states: "Cold fails to reduce heat—this is Water deficiency. Strengthen the master of Water to suppress Solar brilliance. Heat fails to warm—this is Fire deficiency. Benefit the source of Fire to dissipate Yin shadows." Qixuanzi (Wang Bing's pseudonym) revealed profound truths beyond conventions, opening the source of medicine for millennia.
Yin and Yang are abstract names; Water and Fire are physical realities. Cold and Heat are rampant energies of the world. Water and Fire are human True Yuan (Primordial Energy). Rampant energies causing disease can be treated with cold/heat drugs. True Yuan causing disease must be regulated with True Water/Fire. Without seeking affiliation, drugs will not enter. Primordial Water and Fire originate in the same palace. Fire relies on Water as master; Water relies on Fire as source. Thus, treating Yin involves seeking Water within Fire, ensuring Essence does not deplete. Treating Yang involves seeking Fire within Water, ensuring Brilliance does not extinguish. Thus, extreme cold and heat diseases achieve balance. Biased cold/heat scholars cannot be spoken to. Scholars of high standing still mistake Water/Fire for Heart/Kidney, no wonder later generations are ignorant.