1，邪伏少阴：伤寒论略例曾说：中而即病者，名伤寒，不即病者，寒毒藏于肌肤，至春变为温病，至夏变为暑病。柳氏对此有异议，他说：“寒毒藏于肌肤一语，于理欠园。冬寒是时令之邪，与疫疠不同，无所谓毒。于寒下加一毒字，已属骇人。再寒邪之内伏者，必因肾气之虚而入，故其伏也每在少阴。若皮肤有卫气流行之处，岂容外邪久伏。况果在皮肤，则病发亦轻，何至深入脏腑，而有险恶之证耶？”对喻嘉言的观点，他亦加以驳斥，认为“尚论后篇，专论伏气发温之病，分为三例：以冬伤于寒，春必病温为一例，谓寒邪之伏于肌肤者；以冬不藏精，春必病温为一例，谓寒邪之伏于骨髓者，以冬不藏精，冬伤于寒为一例，谓内外均受邪，如伤寒二感之证。”这样做，“在作文则为高手，而说理未必皆能精确。伏气发温之病，惟冬伤于寒故病温，惟冬不藏精故受寒。其所受之寒，无不伏于少阴，断无伏于肌肤之理。其肾气未至大虚者，倘能鼓邪外达，则由少阴而达太阳，病势浅而轻。若肾虚不能托邪，则伏于脏而不得外出，病即深而重。同此邪，同此病，证有轻重，而理原一贯，无三纲之可分也。”总之，柳氏认为内经冬伤于寒，春必病温。冬不藏精，春必病温之说，语势虽若二平，其义原归一贯，喻氏分立三纲，不切于病情。伏气温病，本是冬时寒邪，乘肾气之虚，伏藏于少阴，如果冬不藏精，别无受寒之事，则其病为纯虚，便于温病无涉。这一观点，文充理足，较之邪伏肌肤、骨髓诸说，论理更为周密，故显得比较合理。
2·随经可发：柳氏认为：“邪伏少阴，随气而动，流行于诸经，或乘经气之虚而发，或夹新感之邪气而发。其发也，或由三阳而出，或由肺胃；最重者热不外出，而内陷于手足厥阴；或肾气虚不能托邪，而燔结于少阴。是温邪之动，路途多歧，随处可发，初不能指定于何经，”但“张石顽谓温邪之发，必由少阳。陆九芝谓温热病必发于阳明。陈平伯则以肺胃为温邪必犯之地。吴又可又以募原为温疫伏邪之所。”对纷纭之说，柳氏力排众论，独抒己见，认为“诸家所论，虽亦各有所见，但只举温病之一端，而不可以概温病之全体。至吴鞠通温病条辨，横分三焦。谓凡病温者，必始于上焦，在手太阴。是以时感温风之证，指为伏气发温之病。彼此混而不分，其背谬为尤甚。”由此可见，对论温诸家，他对吴鞠通之说最不满，而对难经温邪行在诸经，不知何经之动之说，则最推崇，他说：“伏温之病，随经可发，经训昭垂，已无疑义。”这一病理观，用以解释复杂的温病病机，显得空灵活泼，它较之温邪初起必先犯肺之说，确实是更合临床实际。
因“伏温之邪，冬时之寒邪也，其伤人也，本因肾气之虚，始得入而据之。其乘春阳之气而外达也，亦以肾气暗动，始能鼓邪化热而出。”故柳氏主张当重从肾论治。又因“伏温外发，必从经气之虚处而出，初无一定路径”，故柳氏复撰《伏温由少阴外达三阳证治》、《伏温热结胃腑证治》、《伏温上灼肺金发喘逆咯血咳脓证治》以及伏温化热内陷厥阴、内陷太阴、郁于少阴，内燔营血、外窜血络、外夹新邪等篇详论之。这样条分缕析，备举无遗，对临床实践，很有参考价值。
三、伏气温病的辨证
1，先辨六经：柳氏主张外感应以六经为辨证之总纲，他对叶吴学派废六经的做法曾有批评。认为：“凡外感病，无论暴感伏气，或由外而入内，则由三阳而传入三阴，或由内而达外，则由三阴而外出三阳。六经各有见证，即各有界限可凭。治病者指其见证，即可知其病之浅深。伺其前见何证，今见何证，即可知病之传变。伤寒如此，温病何独不然。素问热病论，仲景伤寒论均以此立法，圣人复起，莫此易也。近贤叶氏，始有伤寒分六经，温热究三焦之论，谓出河间，”“其实河间并无此说，其书俱在，可复按也。厥后吴鞠通著温病条辨，遂专主三焦，废六经而不论。殊不知人身经络，有内外浅深之别，而不欲使上下之截然不通也。其上焦篇提纲云：凡病温者，始于上焦，在手太阴。试观温邪初发者，其果悉见上焦肺经之证乎？即或见上焦之证，其果中下焦能丝毫无病乎？鞠通苟虚心诊视，应亦自知其说之不可通矣。况伤寒温热，为病不同，而六经之见证则同，用药不同，而六经之立法相同。治温病者，乌可舍六经而不讲哉！”观此，可知诊治温病，先辨六经，为柳氏辨证之第一步。
2，再分兼夹：少阴伏邪，随春夏温热之气蒸动而出为常，若外不夹六淫新邪，内不兼痰淤食积，只要辨清六经形证，参以体质虚实，就可以了。但若由新感动引伏邪，或伏温而兼气郁痰饮淤血诸宿病等，就须再作第二层次的辨证。因“新邪引动伏邪之证，随时皆有，”故“为时邪引动而发者，须辨其所夹何邪，或风温，或暴寒，或暑热。”而且，须审“伏邪与新感，孰轻孰重”，待明察轻重缓急，分清经界之后，方可着手。故柳氏继伏温从六经外发诸篇之后，撰《伏暑外夹风寒暑湿各新邪为病》一篇，详伏邪新感轻重、互相关系及治则。亦有“伏温而兼内伤者，则因内伤而留滞伏温，不得爽达。治之不得其法，每有因此淹缠，致成坏证者。”故柳氏复撰《伏气兼夹气郁痰饮食积淤血以及胎产经带诸宿病》一篇，再详内兼气血痰淤胎产经带与伏邪关系及治则。由此可见，继辨析六经之后，再审夹邪兼邪，此为柳氏诊治温病辨证之第二步。
柳氏对温病的辨证，大旨尊伤寒六经之定例，但不泥于古，内容有新的补充，这可从其附录医悟见之：“表证：发热，恶寒，身痛、四肢拘急，喘。太阳经证：头痛，项脊强，脉浮，脉伏。阳明经证：目痛，鼻干、唇焦、漱水不欲咽，尺寸俱长。少阳经证：耳聋、胸闷胁痛、目眩、口苦、苔滑、脉弦。半表里证：呕吐，寒热往来，头汗、盗汗。太阴经证：腹微满，脉沉实，自利。少阴经证：口燥咽干而渴，咽痛，下利清水，目不明。厥阴经证：少腹满，囊缩、舌卷，厥逆、消渴。太阳府证：口喝、溺赤。阳明府证：潮热、詀语、狂乱、不得眠、自汗，手足汗、便闭。”察其内容，可见柳氏六经即经络之观点，这一观点以及夹证兼证的概念，与俞根初等绍派伤寒医家同。它显示了六经辨证法的继承和发展。
四、伏气温病的治疗
1，泄热透邪：柳氏认为伏气温病是寒邪久伏化热，迨春夏阳气内动，由少阴而外出，“虽外有表证，而里热先盛”，故“初起治法，即以清泄里热，导邪外达为主。”而泄热透邪，“用黄芩汤加豆豉、玄参，为至当不易之法。盖黄芩汤为清泄里热之专剂。加以豆豉为黑豆所造，本入肾经，又蒸罨而成，与伏邪之蒸郁而发相同，且性味平和，无迫汗耗阴之弊，故豆豉为宣发少阴伏邪的对之药。再加元参以补肾阴。一面泄热，一面透邪，凡温邪初起，邪热未离少阴者，其治法不外是矣。”若其邪从三阳外出，或兼新感，有表闭无汗等见证，则桂、葛、柴胡，自当参用，若新感引动伏气，新感“重者即当在初起时，着意先撤新邪，俟新邪既解，再治伏邪，方不碍手。此须权其轻重缓急，以定其治法，不可予设成见。”这种治疗主张，主要是强调扩拓伏邪透出之路的重要性。如伏邪化热内壅，结于胃腑，则可用清泄之剂，攻下泄热，导邪从大便出，不能震于攻下之虚声，遂谓已下不可再下：如伏邪一律外透，邪热熏灼肺胃，可清泄胃热，开透肺金。若伏邪内燔营血，或外窜血络，则采用化斑透疹凉血泄热之法以导邪外出，若伏邪内陷手足厥阴，发生痉厥昏蒙等证，第一仍须先为热邪寻出路，以冀不使伏邪乏透出之路而内闭。总之，因伏邪性属里热，病势以外出为顺，故清透泄热，为柳氏治温第一个大法。
2、养阴补托：寒邪深入，伏藏于少阴，其肾气先虚可知。“经言藏于精者，春不病温。则凡病温者，其阴气先虚可知。使或虚而未至于甚，则养阴透邪，治之如法，犹可挽回。若病温者而至虚甚，则邪热内讧，阴精先涸，一发燎原，不可治矣。”故清透泄热之法，仅可用于阴虚未甚者。若肾虚较甚，伏温化热郁于少阴，不达于阳，用药就必须重视扶正养阴，以便使正气有托邪外出之力，“至扶正之法，在温病以养阴为主，以温热必伤阴液也。”亦有肾阳虚馁邪机冰伏，半化半伏，欲达不达者，此则当用温托，倘“但助其阴，而不鼓动其阴中之阳，恐邪机仍深伏而不出。拟于大剂养阴托邪之中，佐以鼓荡阳气之意，俾邪机得外达三阳，方可着手图治。”(《柳宝怡医案》)鼓动阴中之阳的温托药法，柳氏主张师喻氏意而变通之，“如用麻黄汁制豆豉，附子汁制生地”及略佐桂枝之类，这是出于补托目的的变法。但伏邪郁久化热，究以伤阴为常，而“阴液一伤，变证蜂起，故治伏温病，当步步顾其阴液。”即阴虚未甚之时，立法消透，亦当予护阴津，养阴护津之品，柳氏认为除西洋参十分合用外，“余如生地滋肾阴，白芍滋肝阴，石斛养胃阴，沙参养肺阴，麦冬养心阴”之类，“无论发表攻里剂中，均可加入。”要之，因伏温必伤肾阴，正虚邪易内陷，故养阴补托，为柳氏治温第二个大法。
温病当以养阴为第一，还是当以撤热为第一，中医界争论不休，柳氏认为“蒋氏之论，以攻邪为主，盖以邪退而正自复，去邪所以救阴也。吴鞠通温病条辨则以养阴为主。阴气既充，则在表者，液足自能致汗，在里者，增水乃可行舟。阴旺则热自解，养阴即所以泄热也。愚谓此二法，亦当随人而施。如偏于阴虚者，则养阴以泄热，吴氏之论为宜。偏于邪重者，则泄热以存阴，蒋氏之法为合。二者虽似相反，而实，则相成也。”这一观点，允推平正。邪气与阴虚为伏气温病之两面，祛邪与养阴，当以何者为主，宜辨证而定，但一般总以兼顾为较全面，细察柳氏药法，正是如此。
短评：1·有关伏气温病的内容，历代医藉中并不鲜见，但零星如落地散珠，乏一线以贯之，而《温热逢源》对此，则论述较为系统全面，柳氏见解深刻，分析较有条理，这是外感热病学中的一份宝贵遗产，值得认真发掘。
2·柳氏之世，叶吴学说大行，医咸宗之，唯柳氏别具识见，独树一帜，大倡伏气之说，与戴北山之论温相合流，形成为温热学派中一个重要分支，另辟了一境，这对中医研究外感热病，贡献不小。
3·《温热逢源》卷帙不繁，但柳氏议论，多能独抒己见，极少人云亦云，上述如谓吴又可误认伏邪为疫邪等，这虽是一家之言，竟不同于老生之谈，故很有参考价值。
4，柳宝怡的伏气温病观，吴鞠通的必先犯肺说，都是病理上之逻辑法。但柳氏之说空灵活泼，吴氏之说执一不化，就指导临床的实用价值来说，实有上下床之判。
对伤寒学说的独特见解
祝味菊(1885—1951)，浙江绍兴人，出身于医学世家，早年悬壶成都，为四川名医。后因避乱到上海，以擅用温补，独树一帜，有祝附子之号。曾任过中国医学院实习导师，新中国医学院研究院院长等职，生前很受陆渊雷、章次公等时贤之推崇，在近代中医界，具有一定之影响。祝氏学贯中西，毕身致力于中医革命，并不汲汲于著书，据查证，业经手订之著作，约有《伤寒质难》，《伤寒新义》、《伤寒方解》、《诊断提纲》，《脉学举隅》等数种，曾集为《祝氏医学丛书》。从《伤寒质难》来看，祝氏之医学造诣高超，学术风格独特，故其著作，无疑具有相当的学术价值。现仅就《伤寒质难》一书，介绍一下其对伤寒学说的独特见解。
一、对伤寒病因的认识
外感病的病因，温病学派认为多是温邪所引起，故对一般具有发热的急性传染病，几乎多称为温病，且有取代广义伤寒的趋势。伤寒学派则认为是寒邪所引起，故将一切外感热病，统隶于伤寒之内。祝氏则参西说中，认为：
1·病因无温邪可言：祝氏认为：六淫是风、寒、暑、湿、燥、火，原无温邪之说。温热太过，蒸湿成暑，暑能为病，可以理解。但温暖气候，于人体最适。气温之热度，即在夏天，亦低于人体，是不是以形成为一种致病原因的。他说：“寒温之辨，聚讼数百年，其主要之区别，在证候不在原因。然辨之者，必曰其因有别。”所以同一疾病，往往甲曰是伤寒引起，乙曰是温邪引起，甚至弄得诊断上都无法统一。他明确指出；“寒温皆非致病之原”，“所谓伤寒，所谓温热，都是一种想象之邪”，“邪病之用温药而愈者，遂名之曰温邪，邪病之用凉药而愈者，遂名之曰温邪。”“邪机之推测，乃从药效反溯而得之。”因此，祝氏认为：就病因言，并没有什么温邪，所谓温热病，是机体反应亢进之表现，“非另有温热之邪也”
1，邪伏少阴：《伤寒论略例》曾说：“感受寒邪随即发病的，称为伤寒；没有立即发病的，寒毒潜伏在肌肤之间，到了春天就变成温病，到了夏天就变成暑病。”柳氏对此持有异议，他说：“‘寒毒潜伏在肌肤’这一句话，在道理上不够圆满。冬天的寒冷是时令之邪，与疫疠不同，不存在所谓的‘毒’字。在‘寒’字下面加一个‘毒’字，已经令人惊骇。再者，寒邪之所以能内伏，必定是因为肾气虚弱才侵入的，所以它的潜伏往往在少阴经。如果是在皮肤中有卫气流行的地方，哪里容得下外邪长久潜伏呢？况且如果真的在皮肤，那么发病也应该轻微，怎么会深入脏腑，而有险恶的证候呢？”对于喻嘉言的观点，他也加以驳斥，认为“《尚论后篇》专门论述伏气引发的温病，分为三种情况：把‘冬天伤于寒，春天必定得温病’作为一例，说是寒邪潜伏在肌肤；把‘冬天不藏精，春天必定得温病’作为一例，说是寒邪潜伏在骨髓；把‘冬天不藏精，冬天又伤于寒’作为一例，说是内外都受邪气侵袭，如同伤寒双重感邪的证候。”这样做，“在写文章算是高手，但在说理未必都能精确。伏气引发温病的病，只是因为冬天伤于寒所以才得温病，只是因为冬天不藏精所以才受寒。他们所受的寒邪，无不潜伏在少阴，断然没有潜伏在肌肤的道理。那些肾气没有极度虚弱的，如果能鼓动邪气向外透达，就由少阴而达太阳，病势浅而轻。如果肾虚不能托举邪气，则邪气潜伏在脏腑而不能外出，病即深而重。同样是邪气，同样的病，证候有轻重之分，但医理原本是一贯的，没有三纲可以区分。”总之，柳氏认为《内经》中“冬天伤于寒，春天必定得温病”、“冬天不藏精，春天必定得温病”的说法，语势虽然像是两件事，其义理原本归于一贯。喻氏分立三纲，不符合病情实际。伏气温病，本是冬天的寒邪，趁着肾气虚弱，潜伏藏在少阴。如果冬天不藏精，并没有另外受寒的事情，那么这种病就是纯虚证，与温病无关。这一观点，文辞充实，道理充足，比之邪伏肌肤、骨髓等说法，论理更为周密，所以显得比较合理。
2·随经可发：柳氏认为：“邪气潜伏在少阴，随着气机而动，流行于各条经脉，或者乘着经气虚弱而发作，或者夹带新感的邪气而发作。它的发作，有的从三阳经而出，有的从肺胃而出；最严重的是热邪不能向外透达，而内陷入手足厥阴经；或者是肾气虚弱不能托举邪气，而在少阴经燔结。这样看来，温邪的变动，路途多歧，随处可以发作，起初不能指定在某一条经脉。”但是“张石顽说温邪的发作，必定由少阳经开始。陆九芝说温热病必定发于阳明经。陈平伯则认为肺胃是温邪必定侵犯的地方。吴又可又说募原是温疫伏邪潜伏的地方。”面对这些纷纭的说法，柳氏力排众论，独自发表自己的见解，认为“各家所论述的，虽然也各有见地，但只举出了温病的一个方面，而不能概括温病的整体。至于吴鞠通《温病条辨》，横着划分三焦。说凡是得温病的人，一定始于上焦，在手太阴肺经。于是把时行感受温风的证候，指为伏气引发的温病。彼此混淆而不分，其谬误尤其严重。”由此可见，对于讨论温病的各家学说，他对吴鞠通的说法最不满意，而对《难经》中关于温邪运行在各条经脉，不知道是哪条经脉发动的说法，则最为推崇。他说：“伏温的病，随着经脉可以发作，经典训示昭然若揭，已无疑义。”这一病理观，用来解释复杂的温病病机，显得空灵活泼，它比之温邪初起必定侵犯肺脏的说法，确实更符合临床实际。
因为“伏温的邪气，是冬天的寒邪，它伤害人体，本是因为肾气虚弱，才得以进入并占据。它乘着春天的阳气而向外透达，也是因为肾气暗中触动，才能鼓动邪气化热而出。”所以柳氏主张应当重视从肾脏论治。又因为“伏温向外发散，必定从经气虚弱的地方而出，起初没有固定的路径”，所以柳氏又撰写了《伏温由少阴外达三阳证治》、《伏温热结胃腑证治》、《伏温上灼肺金发喘逆咯血咳脓证治》以及伏温化热内陷厥阴、内陷太阴、郁于少阴，内燔营血、外窜血络、外夹新邪等篇章详细论述。这样条理分明，列举无遗，对临床实践，很有参考价值。
三、伏气温病的辨证
1，先辨六经：柳氏主张外感病应当以六经作为辨证的总纲，他对叶天士、吴鞠通学派废弃六经的做法曾有批评。认为：“凡是外感病，无论是暴感还是伏气，或者是由外而入内，则由三阳传入三阴；或者是由内而达外，则由三阴外出至三阳。六经各有见证，也就各有界限可凭依。治病的人指出它的见证，就可以知道病的深浅。观察它先前是什么证，现在是什么证，就可以知道病的传变。伤寒是这样，温病为什么唯独不是这样？《素问·热论》、张仲景《伤寒论》都用此立法，即使圣人复生，也没有比这更容易的了。近代的贤者叶天士，才开始有‘伤寒分六经，温热究三焦’的论点，说是出自刘河间。”“其实刘河间并没有这个说法，他的书都在，可以复核。此后吴鞠通著《温病条辨》，于是专主三焦，废弃六经不论。殊不知人身经络，有内外浅深的区别，而不希望使上下截然不通。他的上焦篇提纲说：‘凡是得温病的人，始于上焦，在手太阴。’试看温邪初发的时候，果真全都见到上焦肺经的证候吗？即使见到上焦的证候，果真中焦下焦能丝毫无病吗？吴鞠通如果虚心诊视，应该也知道他的说法不可通融。况且伤寒和温热，致病不同，但六经的见证则相同；用药不同，但六经的立法相同。治疗温病的人，怎么能舍弃六经不讲呢！”看这一点，可知诊治温病，先辨六经，是柳氏辨证的第一步。
2，再分兼夹：少阴伏邪，随着春夏温热之气蒸动而出是常态，如果外不夹带六淫新邪，内不兼夹痰瘀食积，只要辨清六经形证，参合体质虚实，就可以了。但如果由新感动引伏邪，或伏温兼有气郁痰饮瘀血等宿疾等，就必须再做第二层次的辨证。因为“新邪引动伏邪的证候，随时都有发生”，所以“被时邪引动而发的，必须辨别它所夹带的什么邪气，或是风温，或是暴寒，或是暑热。”而且，必须审察“伏邪与新感，哪个轻哪个重”，待明察轻重缓急，分清经界之后，方可着手治疗。所以柳氏在继伏温从六经外发诸篇之后，撰写了《伏暑外夹风寒暑湿各新邪为病》一篇，详细论述伏邪新感轻重、互相关系及治则。也有“伏温兼有内伤的，则因内伤而留滞伏温，不得爽达。治疗不得法，常常因此缠绵，导致成为坏证。”所以柳氏又撰写了《伏气兼夹气郁痰饮食积瘀血以及胎产经带诸宿病》一篇，再详细论述内兼气血痰瘀胎产经带与伏邪的关系及治则。由此可见，继辨析六经之后，再审察夹邪兼邪，这是柳氏诊治温病辨证的第二步。
柳氏对温病的辨证，大旨尊崇伤寒六经的定例，但不拘泥于古法，内容有新的补充，这可以从他的附录《医悟》中看到：“表证：发热，恶寒，身痛、四肢拘急，喘。太阳经证：头痛，项脊强，脉浮，脉伏。阳明经证：目痛，鼻干、唇焦、漱水不欲咽，尺寸俱长。少阳经证：耳聋、胸闷胁痛、目眩、口苦、苔滑、脉弦。半表里证：呕吐，寒热往来，头汗、盗汗。太阴经证：腹微满，脉沉实，自利。少阴经证：口燥咽干而渴，咽痛，下利清水，目不明。厥阴经证：少腹满，囊缩、舌卷，厥逆、消渴。太阳府证：口喝、溺赤。阳明府证：潮热、谵语、狂乱、不得眠、自汗，手足汗、便闭。”观察其内容，可见柳氏认为六经即经络的观点，这一观点以及夹证兼证的概念，与俞根初等绍派伤寒医家相同。它显示了六经辨证法的继承和发展。
四、伏气温病的治疗
1，泄热透邪：柳氏认为伏气温病是寒邪久伏化热，等到春夏阳气内动，由少阴而外出，“虽然外表有表证，但里热先盛”，所以“初起的治法，即以清泄里热，导邪外达为主。”而泄热透邪，“用黄芩汤加豆豉、玄参，是最恰当不变的方法。因为黄芩汤是清泄里热的专用方剂。加上豆豉是用黑豆制造的，本来入肾经，又是蒸罨而成的，与伏邪蒸郁而发相同，且性味平和，没有迫汗耗阴的弊端，所以豆豉是宣发少阴伏邪的对证药物。再加元参以补肾阴。一面泄热，一面透邪，凡是温邪初起，邪热未离开少阴的，其治法不外乎如此。”如果邪气从三阳外出，或兼有新感，有表闭无汗等见证，则桂枝、葛根、柴胡，自然应当参用。如果新感引动伏气，新感“重的应当在初起时，着重先撤除新邪，等新邪既解，再治伏邪，才不会碍手。这需要权衡轻重缓急，以确定治法，不可以预先设定成见。”这种治疗主张，主要是强调开拓伏邪透出之路的重要性。如伏邪化热内壅，结于胃腑，则可用清泄之剂，攻下泄热，导邪从大便出，不要因为害怕攻下的虚名，就说已经下过不可再下；如伏邪一律外透，邪热熏灼肺胃，可清泄胃热，开透肺金。若伏邪内燔营血，或外窜血络，则采用化斑透疹凉血泄热之法以导邪外出，若伏邪内陷手足厥阴，发生痉厥昏蒙等证，第一仍须先为热邪寻找出路，以期不让伏邪缺乏透出之路而内闭。总之，因为伏邪性质属于里热，病势以外出为顺，所以清透泄热，是柳氏治疗温病的第一大法。
2、养阴补托：寒邪深入，伏藏于少阴，其肾气先虚可知。“经文说‘藏于精者，春不病温’。那么凡是得温病的人，其阴气先虚可知。如果虚而没有到极甚的程度，那么养阴透邪，治疗得当，还可以挽回。如果得温病的人到了极度虚弱，那么邪热内讧，阴精先涸，一发燎原，不可治了。”所以清透泄热之法，仅可用于阴虚未甚的情况。如果肾虚较甚，伏温化热郁于少阴，不达于阳，用药就必须重视扶正养阴，以便使正气有托举邪气外出的力量，“至于扶正的方法，在温病中以养阴为主，因为温热必定损伤阴液。”也有肾阳虚馁，邪机冰伏，半化半伏，欲达不达的情况，这时应当用温托法，倘若“只助其阴，而不鼓动其阴中之阳，恐怕邪机仍然深伏而不出。拟在大剂养阴托邪之中，佐以鼓荡阳气之意，使得邪机能够外达三阳，方可着手图治。”（《柳宝怡医案》）鼓动阴中之阳的温托药法，柳氏主张师法喻嘉言的意思而变通使用，“如用麻黄汁制豆豉，附子汁制生地”及略佐桂枝之类，这是出于补托目的的变法。但伏邪郁久化热，终究以伤阴为常，而“阴液一伤，变证蜂起，所以治疗伏温病，应当步步顾护其阴液。”即在阴虚未甚之时，立法消透，也应当给予护阴津、养阴护津的药物，柳氏认为除西洋参十分合用外，“其余如生地滋肾阴，白芍滋肝阴，石斛养胃阴，沙参养肺阴，麦冬养心阴”之类，“无论发表攻里剂中，均可加入。”总之，因为伏温必定损伤肾阴，正虚邪易内陷，所以养阴补托，是柳氏治疗温病的第二个大法。
温病应当以养阴为第一，还是当以撤热为第一，中医界争论不休，柳氏认为“蒋氏的论点，以攻邪为主，大概认为邪退而正自复，去邪所以救阴。吴鞠通《温病条辨》则以养阴为主。阴气既充，则在表的，液足自能致汗，在里的，增水乃可行舟。阴旺则热自解，养阴即所以泄热也。我认为这两种方法，也应当随人而施。如偏于阴虚的，则养阴以泄热，吴氏的论点为宜。偏于邪重的，则泄热以存阴，蒋氏的法子为合。二者虽然看似相反，实则相辅相成。”这一观点，值得推崇为平正。邪气与阴虚为伏气温病的两面，祛邪与养阴，应当以何者为主，宜辨证而定，但一般总以兼顾为较全面，细察柳氏的药法，正是如此。
短评：1·有关伏气温病的内容，历代医籍中并不鲜见，但零星如落地散珠，缺乏一线以贯穿，而《温热逢源》对此，则论述较为系统全面，柳氏见解深刻，分析较有条理，这是外感热病学中的一份宝贵遗产，值得认真发掘。
2·柳氏所处的时代，叶天士、吴鞠通的学说大行其道，医生们都宗奉它们，只有柳氏别具识见，独树一帜，大力倡导伏气之说，与戴北山的论温相合流，形成温热学派中的一个重要分支，另辟了一境，这对中医研究外感热病，贡献不小。
3·《温热逢源》篇幅不大，但柳氏议论，多能独抒己见，极少人云亦云，上述如谓吴又可误认伏邪为疫邪等，这虽是一家之言，竟不同于老生常谈，故很有参考价值。
4，柳宝怡的伏气温病观，吴鞠通的必先犯肺说，都是病理上的逻辑推演。但柳氏之说空灵活泼，吴氏之说执一不化，就指导临床的实用价值来说，实在有天壤之别。
对伤寒学说的独特见解
祝味菊(1885—1951)，浙江绍兴人，出身于医学世家，早年悬壶成都，为四川名医。后因避乱到上海，以擅用温补，独树一帜，有“祝附子”之称。曾任过中国医学院实习导师，新中国医学院研究院院长等职，生前很受陆渊雷、章次公等当时贤者的推崇，在近代中医界，具有一定影响。祝氏学贯中西，毕生致力于中医革命，并不汲汲于著书，据查证，业经手订之著作，约有《伤寒质难》，《伤寒新义》、《伤寒方解》、《诊断提纲》，《脉学举隅》等数种，曾集为《祝氏医学丛书》。从《伤寒质难》来看，祝氏之医学造诣高超，学术风格独特，故其著作，无疑具有相当的学术价值。现仅就《伤寒质难》一书，介绍一下其对伤寒学说的独特见解。
一、对伤寒病因的认识
外感病的病因，温病学派认为多是温邪所引起，故对一般具有发热的急性传染病，几乎多称为温病，且有取代广义伤寒的趋势。伤寒学派则认为是寒邪所引起，故将一切外感热病，统隶于伤寒之内。祝氏则参西说中，认为：
1·病因无温邪可言：祝氏认为：六淫是风、寒、暑、湿、燥、火，原无温邪之说。温热太过，蒸湿成暑，暑能为病，可以理解。但温暖气候，于人体最适。气温之热度，即使在夏天，亦低于人体体温，是不是以形成为一种致病原因的。他说：“寒温之辨，聚讼数百年，其主要之区别，在证候不在原因。然而辨析的人，必定说它们的成因有别。”所以同一疾病，往往甲说是伤寒引起，乙说是温邪引起，甚至弄得诊断上都无法统一。他明确指出：“寒温皆非致病之原”，“所谓伤寒，所谓温热，都是一种想象之邪”，“邪病之用温药而愈者，遂名之曰温邪，邪病之用凉药而愈者，遂名之曰温邪。”“邪机的推测，乃从药效反溯而得之。”因此，祝氏认为：就病因言，并没有什么温邪，所谓温热病，是机体反应亢进之表现，“非另有温热之邪也”
1. Pathogen Lurking in Shaoyin: The *Lueli of Shanghan Lun* (Brief Examples of the Treatise on Cold Damage) once stated: "Those who contract cold pathogens and fall ill immediately are named as having Shanghan (Cold Damage); those who do not fall ill immediately harbor the 'cold toxin' in their skin and muscles. By spring, this transforms into Wenbing (Warm Disease), and by summer, it becomes Shubing (Summerheat Disease)." Mr. Liu held objections to this, stating: "The phrase 'cold toxin lurking in skin and muscles' is logically flawed. Winter cold is a seasonal pathogen, different from epidemic pestilence, and there is no such thing as a 'toxin'. Adding the character 'toxin' under 'cold' is already startling. Furthermore, for cold pathogens to lurk internally, it must be due to a deficiency of Kidney Qi that allows invasion; thus, their lurking usually occurs in the Shaoyin channel. If衛氣 (Wei Qi / Defensive Qi) circulates in the areas of the skin, how could external pathogens linger there for long? Moreover, if they were truly in the skin, the onset of illness would be mild. How could it penetrate deeply into the Zang-Fu organs, resulting in perilous syndromes?" He also refuted Yu Jiayan's viewpoint, arguing that "In the *Shanglun Hou Pian* (Post-Commentary on Comparative Discussion), which specifically discusses Wen diseases caused by latent Qi, three cases are distinguished: 'Winter injury by cold, spring must get Wen disease' is one case, claiming cold pathogens lurk in the skin and muscles; 'Winter fails to store essence, spring must get Wen disease' is another case, claiming cold pathogens lurk in the bone marrow; 'Winter fails to store essence, winter injured by cold' is a third case, claiming both internal and external factors are involved, similar to double infection in Shanghan. Doing so 'makes one a master writer, but the reasoning may not be precise. In diseases of Wen caused by latent Qi, one gets Wen disease only because of winter cold injury, and one contracts cold only because of failing to store essence in winter. The cold they contract invariably lurks in Shaoyin; there is absolutely no logic for it to lurk in the skin and muscles. For those whose Kidney Qi is not extremely deficient, if they can urge the pathogen outward, it moves from Shaoyin to Taiyang, resulting in a shallow and mild condition. If Kidney deficiency prevents pushing out the pathogen, it lingers in the Zang organs without exiting, resulting in a deep and severe condition. With the same pathogen and the same disease, although syndromes vary in severity, the underlying principle is consistent, with no basis for dividing it into three categories.' In short, Mr. Liu believed that the statements in the *Neijing* (Inner Canon) regarding 'Winter injury by cold, spring must get Wen disease' and 'Winter fails to store essence, spring must get Wen disease,' while seemingly distinct in phrasing, share a unified meaning. Yu's division into three categories does not fit the actual clinical picture. Latent Wen disease originates from winter cold pathogens taking advantage of Kidney Qi deficiency to hide in Shaoyin. If one fails to store essence in winter but does not contract cold, the disease is purely deficiency-related and unrelated to Wen disease. This viewpoint is well-supported by text and reason, more rigorous than theories of pathogens lurking in skin/muscles or bone marrow, and thus appears more reasonable.
2. Eruption Along Channels: Mr. Liu believed: "Pathogens lurking in Shaoyin move with Qi, circulating through various channels. They erupt either by exploiting deficiencies in channel Qi or by carrying new contracted pathogens. Their eruption may occur via the Three Yang channels or through the Lung and Stomach; the most severe cases involve heat failing to exit externally and sinking inward into the Hand and Foot Jueyin channels; or, due to Kidney Qi deficiency failing to support the pathogen, it blazes and knots in Shaoyin. Thus, the movement of Wen pathogens is diverse, capable of erupting anywhere, and initially cannot be pinpointed to a specific channel." However, "Zhang Shiweng stated that Wen pathogen eruption must begin in Shaoyang. Lu Jiuzhi claimed that Warm-Heat diseases must erupt in Yangming. Chen Pingbo considered Lung and Stomach as the inevitable sites of Wen pathogen invasion. Wu Keyou argued that the Mu Yuan (Sea of Origin) is where epidemic latent pathogens reside." Facing these conflicting theories, Mr. Liu rejected the consensus and expressed his own view, stating: "Although each school has its insights, they only address one aspect of Wen disease and cannot cover the whole. Wu Jutong's *Wenbing Tiaobian* (Systematic Differentiation of Warm Diseases) horizontally divides the Sanjiao (Triple Burner). He claims that all Wen diseases start in the Upper Jiao, involving the Hand Taiyin channel. Consequently, he classifies seasonal warm wind infections as diseases of latent Wen Qi. Confusing the two is particularly erroneous." Thus, among scholars discussing Wen diseases, he was most dissatisfied with Wu Jutong's theory and most revered the *Nanjing* (Classic of Difficult Issues) statement that Wen pathogens travel through various channels without specifying which channel initiates the movement. He said: "Diseases of latent Wen can erupt along any channel; this is clearly taught in the classics, leaving no doubt." This pathological perspective, used to explain complex Wen disease mechanisms, appears flexible and dynamic. Compared to the theory that Wen pathogens must initially invade the Lung, it is indeed more consistent with clinical reality.
Because "the pathogen of latent Wen is the cold pathogen of winter. It harms humans originally due to Kidney Qi deficiency, allowing entry and occupation. When it moves outward driven by Spring Yang Qi, it is also due to the subtle stirring of Kidney Qi that urges the pathogen to transform into heat and exit." Therefore, Mr. Liu advocated treating primarily from the Kidney perspective. Furthermore, because "latent Wen erupts outward necessarily from areas of channel Qi deficiency, without a fixed path," Mr. Liu wrote detailed treatises such as *Zhengzhi of Latent Wen Reaching the Three Yang from Shaoyin*, *Zhengzhi of Latent Wen Heat Knotting in the Stomach Fu*, *Zhengzhi of Latent Wen Scorching Lung Metal Causing Asthma, Hemoptysis, and Purulent Cough*, as well as chapters on latent Wen transforming into heat and sinking into Jueyin, sinking into Taiyin, stagnating in Shaoyin, blazing Ying-Blood internally, wandering blood collaterals externally, and mixing with new pathogens. Such detailed analysis, covering all aspects, offers great reference value for clinical practice.
III. Syndrome Differentiation of Latent Wen Disease
1. First, Differentiate the Six Channels: Mr. Liu advocated using the Six Channels as the general outline for differentiating exogenous diseases. He criticized the Ye-Wu school for abandoning the Six Channels. He believed: "For all exogenous diseases, whether acute contraction or latent Qi, whether entering from outside to inside (moving from Three Yang to Three Yin) or emerging from inside to outside (moving from Three Yin to Three Yang), each of the Six Channels has its own manifestations and boundaries. A healer identifying these manifestations can know the depth of the disease. Observing previous and current symptoms reveals disease transmission. Shanghan follows this; why should Wenbing be different? The *Suwen: Relian Lun* (Plain Questions: Discourse on Hot Diseases) and Zhang Zhongjing's *Shanghan Lun* both establish laws based on this. Even if sages rose again, nothing would be easier. Recent sage Ye Tianyi introduced the theory 'Shanghan differentiated by Six Channels, Warmth investigated by Sanjiao,' attributing it to Liu Hejian." "Actually, Liu Hejian never said this; his books exist and can be verified. Later, Wu Jutong wrote *Wenbing Tiaobian*, focusing exclusively on Sanjiao and ignoring Six Channels. Little did he know that human meridians have distinctions of interior/exterior and shallow/deep, preventing a rigid separation between upper and lower. His Upper Jiao chapter outline states: 'All Wen diseases start in the Upper Jiao, involving Hand Taiyin.' Observe when Wen pathogens first erupt: do patients always present solely with Upper Jiao Lung channel symptoms? Even if Upper Jiao symptoms appear, can Middle and Lower Jiao remain completely unaffected? If Wu Jutong examined patients with an open mind, he would realize his theory is untenable. Moreover, although Shanghan and Warmth differ in pathology, their Six Channel manifestations are identical; although medications differ, the legislative principles of the Six Channels are the same. How can practitioners of Wen disease abandon the study of Six Channels!" From this, it is clear that differentiating Six Channels first is Step One of Mr. Liu's differentiation method for treating Wen disease.
2. Second, Differentiate Concurrent Factors: The emergence of Shaoyin latent pathogens driven by Spring-Summer warmth is the norm. If there is no external contraction of the Six Excesses (new pathogens) and no internal accumulation of Phlegm, Stasis, or Food Retention, simply differentiating the Six Channel syndromes and assessing constitutional deficiency/excess is sufficient. However, if new pathogens trigger latent pathogens, or if latent Wen is complicated by chronic conditions like Qi Stagnation, Phlegm-Fluid, or Blood Stasis, a second level of differentiation is required. Because "syndromes of new pathogens triggering latent pathogens occur at any time," one "must differentiate what pathogen is carried, whether Wind-Warmth, sudden Cold, or Summerheat." Furthermore, one must assess "which is heavier, the latent pathogen or the new contraction." Only after clarifying severity and urgency, and distinguishing channel boundaries, can treatment begin. Thus, following his chapters on latent Wen erupting from Six Channels, Mr. Liu wrote *Disease Caused by Latent Summerheat Mixed with Wind-Cold, Summerheat-Dampness and Other New Pathogens*, detailing the weight, relationship, and treatment principles of latent vs. new pathogens. Regarding "latent Wen complicated by internal injury," he noted that internal injury causes latent Wen to stagnate, preventing smooth release. Improper treatment often leads to lingering complications and deteriorated syndromes. Therefore, he wrote *Latent Qi Complicated by Qi Stagnation, Phlegm, Food Retention, Blood Stasis, and Chronic Conditions Related to Pregnancy, Childbirth, and Menstruation*, further detailing the relationships and treatment principles between internal factors (Qi, Blood, Phlegm, Stasis, reproductive history) and latent pathogens. Thus, after analyzing Six Channels, examining mixed and concurrent pathogens constitutes Step Two of Mr. Liu's diagnostic approach.
Mr. Liu's differentiation of Wen disease largely respected the established rules of Shanghan's Six Channels but did not blindly follow antiquity, adding new content. This can be seen in his appendix *Yiwu*: "Exterior Syndromes: Fever, aversion to cold, body pain, limb rigidity, asthma. Taiyang Channel Syndrome: Headache, neck/back stiffness, floating pulse, hidden pulse. Yangming Channel Syndrome: Eye pain, nasal dryness, lip scorching, rinsing mouth without swallowing, long pulses at Cun and Chi positions. Shaoyang Channel Syndrome: Deafness, chest/flank fullness, dizziness, bitter taste, slippery coating, wiry pulse. Half-Exterior/Half-Interior Syndrome: Vomiting, alternating chills and fever, head sweating, night sweats. Taiyin Channel Syndrome: Slight abdominal fullness, deep-solid pulse, spontaneous diarrhea. Shaoyin Channel Syndrome: Dry mouth/throat with thirst, sore throat, watery diarrhea, blurred vision. Jueyin Channel Syndrome: Lower abdominal fullness, retraction of testicles, curled tongue, cold extremities, excessive thirst. Taiyang Fu Syndrome: Hoarseness, dark urine. Yangming Fu Syndrome: Tidal fever, delirium, mania, insomnia, spontaneous sweating, hand/foot sweating, constipation." Analyzing this content reveals Mr. Liu's view that Six Channels equate to Meridians. This concept, along with mixed/concurrent syndromes, aligns with Shao-pai Shanghan physicians like Yu Genchu. It demonstrates the inheritance and development of Six Channel differentiation.
IV. Treatment of Latent Wen Disease
1. Draining Heat and Expelling Pathogens: Mr. Liu believed that latent Wen disease involves cold pathogens lingering and transforming into heat. When Spring-Summer Yang Qi stirs internally, moving outward from Shaoyin, "although exterior symptoms exist, interior heat is already abundant." Therefore, "the initial treatment method focuses on clearing/draining interior heat and guiding pathogens outward." For draining heat and expelling pathogens, "using Huangqin Tang (Scute Decoction) added with Douchi (Fermented Soybean) and Xuanshen (Scrophularia) is the most appropriate and unchangeable method. Huangqin Tang is the specialized formula for clearing interior heat. Douchi, made from black beans, enters the Kidney channel, and its steaming process mirrors the steaming/accumulation of latent pathogens. Its mild nature avoids the harm of forcing sweat and consuming Yin. Thus, Douchi is the correct herb for ventilating Shaoyin latent pathogens. Adding Xuanshen nourishes Kidney Yin. One side drains heat, the other expels pathogens. For early-stage Wen pathogens where heat has not left Shaoyin, this is the primary method." If pathogens exit via Three Yang or mix with new contractions presenting with exterior closure and no sweat, Guizhi (Cinnamon Twig), Gegen (Kudzu Root), and Chaihu (Bupleurum) should be used. If new contractions trigger latent Qi, "for severe new contractions, focus on resolving them first at the onset. Once resolved, treat the latent pathogen to avoid interference. This requires weighing severity to determine treatment, avoiding preconceived notions." This therapeutic stance emphasizes the importance of opening pathways for latent pathogens to exit. If latent heat obstructs internally and knots in the Stomach Fu, purgatives can drain heat and guide pathogens out via stool; one should not fear purgation so much as to forbid repeated use. If latent pathogens generally erupt, scorching Lung and Stomach, clear Stomach heat and ventilate Lung metal. If latent pathogens blaze Ying-Blood internally or wander blood collaterals externally, use methods to resolve macules, vent rashes, cool blood, and drain heat. If latent pathogens sink into Hand/Foot Jueyin causing spasms, convulsions, or coma, the priority is still finding an exit for heat to prevent internal closure. In summary, since latent pathogens are interior heat and the disease trend favors outward movement, clearing, venting, and draining heat is Mr. Liu's first major principle for treating Wen disease.
2. Nourishing Yin and Supporting/Urging: Deep penetration of cold pathogens hiding in Shaoyin indicates prior Kidney Qi deficiency. "The Classic states: 'Those who store essence will not get Wen disease in spring.' Thus, for all Wen disease patients, Yin Qi is deficient beforehand. If deficiency is not extreme, nourishing Yin and venting pathogens, treated correctly, can still reverse the condition. If Wen disease patients reach extreme deficiency, internal rebellion of pathogenic heat and exhaustion of Yin essence lead to uncontrollable flare-ups, making it incurable." Therefore, clearing and venting heat is only applicable when Yin deficiency is not severe. If Kidney deficiency is significant, with latent Wen transforming into heat and stagnating in Shaoyin without reaching Yang, medication must emphasize supporting Zheng Qi and nourishing Yin to provide strength for pushing pathogens out. "Regarding supporting Zheng Qi, in Wen disease, nourishing Yin is primary because Warm-Heat inevitably damages Yin fluids." In cases of Kidney Yang deficiency with frozen pathogenic mechanisms, half-transformed/half-lurking, desiring to exit but unable to, one should use Warming Support methods. If "one only assists Yin without stirring Yang within Yin, the pathogenic mechanism may remain deeply hidden. In large doses of Yin-nourishing pathogen-supporting formulas, add intent to stir Yang Qi, allowing the pathogenic mechanism to reach the Three Yang before proceeding with treatment." (*Liuyi Yian*). For warming support to stir Yang within Yin, Mr. Liu advocated adapting Yu Jiayan's ideas, "such as processing Douchi with Mahuang juice, Shengdi with Fuzi juice," and slightly adding Guizhi. These are variations for the purpose of support. However, since latent pathogens stagnate and transform into heat, damaging Yin is the norm. "Once Yin fluids are damaged, complications arise rapidly; thus, treating latent Wen requires guarding Yin fluids at every step." Even when using dispersing/venting methods for mild Yin deficiency, one must include Yin-nourishing agents. Besides Xiyangshen (American Ginseng), Mr. Liu considered "Shengdi nourishing Kidney Yin, Baishao nourishing Liver Yin, Shihu nourishing Stomach Yin, Shashen nourishing Lung Yin, Maidong nourishing Heart Yin" suitable for addition to both exterior-releasing and interior-purgative formulas. In essence, since latent Wen inevitably damages Kidney Yin, leading to Zheng deficiency and easy pathogen sinking, nourishing Yin and supporting is Mr. Liu's second major principle.
Whether Wen disease treatment prioritizes nourishing Yin or reducing heat has been debated endlessly in TCM circles. Mr. Liu believed: "Jiang's argument prioritizes expelling pathogens, assuming that as pathogens retreat, Zheng recovers; removing pathogens saves Yin. Wu Jutong's *Wenbing Tiaobian* prioritizes nourishing Yin. Once Yin is充盈 (abundant), exterior fluids enable sweating, and interior fluid increase allows navigation ('increasing water to move the boat'). Abundant Yin resolves heat; nourishing Yin is equivalent to draining heat. I believe these two methods should be applied according to the patient. For those biased toward Yin deficiency, nourishing Yin to drain heat suits Wu's theory. For those biased toward heavy pathogens, draining heat to preserve Yin suits Jiang's method. Though seemingly opposite, they complement each other." This view is commendably balanced. Pathogens and Yin deficiency are two sides of latent Wen disease. Whether to prioritize expelling pathogens or nourishing Yin depends on differentiation, but generally, addressing both is more comprehensive. Careful examination of Mr. Liu's prescriptions confirms this.
Short Comments:
1. Content regarding latent Wen disease is not rare in historical medical texts, but scattered like pearls on the ground, lacking a unifying thread. *Wenre Fengyuan* provides a systematic and comprehensive discussion. Mr. Liu's profound insights and logical analysis constitute a valuable legacy in exogenous febrile disease studies, worthy of serious excavation.
2. During Mr. Liu's era, the theories of Ye and Wu dominated, with doctors revering them. Only Mr. Liu possessed unique insight, establishing an independent school, vigorously advocating latent Qi theory, merging with Dai Beishan's warm disease discussions, forming a significant branch of the Warm-Heat School, carving a new path, contributing significantly to TCM research on exogenous febrile diseases.
3. *Wenre Fengyuan* is concise, yet Mr. Liu's arguments often express independent views, rarely echoing others. For instance, his claim that Wu Keyou mistook latent pathogens for epidemic pathogens, though one person's opinion, differs from clichés and holds reference value.
4. Mr. Liuyi's view of latent Wen disease and Wu Jutong's theory that pathogens must first invade the Lung are both logical deductions in pathology. However, Mr. Liu's theory is flexible and dynamic, whereas Wu's is rigid. In terms of practical clinical value, there is a vast difference between them.
Viewing Zhu Weiju through *Shanghan Zhinan*
Unique Insights into Shanghan Theory
Zhu Weiju (1885–1951), from Shaoxing, Zhejiang, came from a medical family. He practiced in Chengdu early on, becoming a famous Sichuan physician. Later fleeing turmoil to Shanghai, he stood out for his skill in using warming and tonifying methods, earning the nickname "Zhu Fuzi" (Zhu Aconite). He served as an internship tutor at China Medical College and Dean of the Research Institute of New China Medical College. Highly esteemed by contemporaries such as Lu Yuanlei and Zhang Cigong during his lifetime, he had considerable influence in modern TCM circles. Mastering both East and West, Zhu dedicated his life to TCM revolution but did not rush to publish. Verified manuscripts include approximately *Shanghan Zhinan* (Difficult Questions on Shanghan), *Shanghan Xinyi* (New Meaning of Shanghan), *Shanghan Fangjie* (Explanation of Shanghan Formulas), *Zhenduan Tigang* (Outline of Diagnosis), and *Maixue Juyu* (Preliminaries of Pulse Studies), collected as *Zhu Shi Yixue Congshu* (Zhu's Medical Series). Based on *Shanghan Zhinan*, Zhu's medical attainment was superb and his academic style unique, giving his works undeniable academic value. Here, we introduce his unique insights into Shanghan theory based solely on this book.
I. Understanding of Shanghan Etiology
The etiology of exogenous diseases: The Warm-Heat School believes they are mostly caused by Warm pathogens, thus nearly all acute infectious diseases with fever are called Warm diseases, showing a trend to replace broad-sense Shanghan. The Shanghan School attributes them to Cold pathogens, classifying all exogenous febrile diseases under Shanghan. Zhu, incorporating Western perspectives, argued:
1. No Concept of 'Warm Pathogen' in Etiology: Zhu believed: The Six Excesses are Wind, Cold, Summerheat, Dampness, Dryness, and Fire; originally, there is no concept of a 'Warm pathogen.' Excessive warmth steams dampness into Summerheat, which can cause disease, which is understandable. But warm climate is most suitable for the human body. Even in summer, ambient temperature is lower than body temperature; how can it form a致病 (pathogenic) cause? He stated: "The debate between Cold and Warm has lasted centuries. The main distinction lies in syndromes, not causes. Yet debaters insist on different causes." Thus, for the same disease, Person A says it is caused by Shanghan, Person B says by Warm pathogen, leading to diagnostic inconsistency. He explicitly pointed out: "Neither Cold nor Warm is the original cause of disease." "What is called Shanghan or Warmth are imagined pathogens." "When a disease cured by warming herbs is named Warm pathogen, and one cured by cooling herbs is named Warm pathogen [Note: Text likely implies 'Cold pathogen' here contextually, or refers to naming conventions], the speculation of pathogenic mechanisms is derived retroactively from drug efficacy." Therefore, Zhu believed: regarding etiology, there is no such thing as a Warm pathogen. What is called Warm-Heat disease is a manifestation of hyperactive bodily response, "not the presence of a separate Warm pathogen."