上面我们提到开合枢的协调对于门户而言是非常重要的因素。我们先来看三阳这个门。在阳门里，太阳的作用是负责开，“太阳为开”指的就是这层意思。随着太阳主开功能的启动，阳门打开了，阳气得以逐渐地升发释放出来。这个在自然界就表现为春夏，万物逐渐地发陈、蕃秀，而在人体呢？阳气方方面面的作用，就得到充分地发挥。但是，太阳老是这样开，阳气老是处于这个升发释放的状态，就像我们人，老是工作不睡觉成不成呢？这一点我们前面已经作了讨论，知道它绝对不行。所以，开到一定的时候，就有一个关闭的机制，将阳门逐渐关闭，使上述这个蒸蒸日上，升发释放的过程减弱下来，这个就是阳明的合，“阳明为合”指的就是这层功用。前面我们讲过，一个开，一个合，它靠什么来转动呢？靠枢机来转动。所以，太阳的开，阳明的合，就要靠少阳枢机的作用，“少阳为枢”指的就是这个意思。
（2）三阴之开合枢
三阳的作用清楚以后，我们接下来看三阴。阳气的升发释放到一定的程度后，就要靠阳明的作用，使这个过程逐渐衰减下来。这个时候阳气要回头，要从升发转到收降，从出转到入，从浮转到沉。这个时候收藏的门要打开，不能将阳气拒之门外，而这个过程就要落实到“太阴为开”的功能上。所以，太阴开机启动后，阳气就真正进入到收藏状态。与三阳的道理一样，阳气能不能老是呆在收藏状态呢？就像我们老是睡觉不起床，这成何体统？所以，收藏到一定的程度后，这个状态就要慢慢地减下来。收藏的门户要慢慢的关闭，这个关闭作用就要落实到厥阴的合上。太阴开，厥阴合，少阴的作用是枢转开合，这是三阴的关系。
（3）协同作用
从以上这两个方面，我们应该能够看到，阴与阴，阳与阳，阴与阳之间的配合非常重要。太阳主开，开机启动，阳气释放，当释放到一定程度后，释放要终止，开机要关闭，这个作用要依赖阳明，在这个过程，太阳与阳明的开合要适时。释放衰减以后，要转入收藏，这个时候阴门要打开，否则，光终止释放，不转入收藏，这个升降的衔接就会出问题。所以，在这个关键环节上，阳明与太阴的配合非常重要。一个阴，一个阳，一个开，一个合，只有两者默契，释放才能转入收藏。另外一方面就是，收藏到一定程度后，这个过程也要逐渐终止，开机也要关闭，这个作用当然要依赖厥阴。而太阳与厥阴的开合也要适时，在厥阴终止收藏的这个过程，阳门要逐渐打开，否则光终止收藏，不转入释放，这个升降的衔接也会出现问题。因此，在这个关键环节上，厥阴与太阳的配合十分重要。这里也是一个阴一个阳，一个开一个合，只有两者默契，入降才能转到升出。这样一个过程，阴阳确实在互相帮助。太阳的开需要厥阴来帮助，太阴的开需要阳明来帮助。阴阳之间的配合，在开合枢中体现得很充分。《素问·至真要大论》云：“诸寒之而热者取之阴，热之而寒者取之阳。”这里我们可以借用《素问》的这个说法，将它改一改：诸治阳而不愈者，当求之于阴；诸治阴而不愈者，当求之于阳。比如我们治太阳，这个病看上去明明就是一个太阳病，可是怎么弄它都不好，这个时候我们应该考虑，太阳开的过程还有另外一个合的机制在协助它，是不是这个合出了问题，这时我们应当“求之于阴”考虑治治厥阴。反过来，太阴的病我们看得很明确，但是，按照太阴的治法就是解决不了，这个时候，我们也应当“求之于阳”，考虑从阳明来协助治疗。一个“诸寒之而热者取之阴，热之而寒者取之阳”，一个“诸治阳而不愈者求之阴，治阴而不愈者求之阳”，加上下一章要谈的五行隔治法，这些方法掌握了，对于解决疑难问题是很有帮助的。
我们讨论过了，这些功用失常就会产生病变。所以，六经病变说实在的，就是开合枢的失调，就是开合枢的病变。
（1）太阳开机的病变
太阳主开，负责阳门的开启，太阳的开机为什么会发生异常呢？这个原因可能来自内部，也可能来自外部，或兼而有之。外部的因素往往比较典型，如我们常见的伤寒、中风，就是因为外邪侵袭，障碍、束缚了这个开机，使阳气的开发受限，于是太阳病就发生了。除了外因，内在有哪些因素呢？有阳气虚，本身的力量不足，太阳这个开的作用会成问题，或者由于水饮、湿等因素障碍了阳气的外出，太阳的开机也会出现问题。总而言之，太阳开机的功能是帮助阳气外出，帮助阳气发挥作用。而阳气的作用前面讨论过，有宣发，有卫外，有气化等等，如果太阳开机出现障碍，阳气的作用就会受到影响，太阳病的发生就与这些影响直接相关。如太阳篇见得最多的是表病，表病就是因为阳不卫外，遭受外邪侵袭所致。另外，阳不化气，水液的代谢就会失调，从而导致水液代谢障碍相关的疾病。我们看看整个太阳篇，表证、水气、痰饮、蓄水占了绝大多数，这些都是与阳用障碍有关，都与太阳开机不利有关。因此，从太阳开机不利的角度去理解太阳病，就抓住了它的纲领。
（2）阳明合机病变
太阳的开是要使阳气升发，阳明的合是使阳气收降。阳气收降以后，天气变燥、变凉，所以阳明与秋天相应。现在阳明的合机发生障碍，阳气该收不收，该降不降，就会出现热，就会有不降的情况。所以，阳明病最大的特征就是两个，一个是热，一个是不降。热表现在经证里，不降表现在腑证里。当然热与不降，经证与腑证都可以相互影响。我们看阳明的经证用白虎汤，这就很有意思。白虎是什么？白虎是西方的神，主宰西方变化的东西就叫白虎。西方的变化是什么？主要是阳气的收与降。所以，从阳明病用白虎汤，就说明阳气的收降出了问题。
（3）少阳枢病
少阳主枢，负责调节开合，如果开合没有问题，你很难发现枢机的毛病。我们看一看三阳篇，太阳篇占 179条，阳明的篇幅也不少，而少阳则仅仅十来条。是不是少阳不重要呢？绝对不是！少阳主枢，关乎太阳、阳明的开合，怎么会不重要呢？这个篇幅上的差距，很重要的一个原因是，少阳枢机的病变很多都体现在太阳和阳明篇里面。比如小柴胡汤大家都公认它是少阳病的主方，可是小柴胡汤在少阳病篇的运用只有一次，而其他大量的运用是在太阳和阳明病篇。枢机主管开合，因而枢机的病变往往也要从开合上看。这是枢机病变的一个特色。前面讲伤寒和杂病概念的时候，我们曾经说过，世间上的疾病，如果从发热与非发热这个角度去划分，则可以分为两类，一类是伤寒，一类就是杂病。那么，现在我们从开合的角度讲，世间的疾病也不外乎两个，一个是开的问题，一个是合的问题。为什么这么说呢？因为人体的生理主要就靠这个阴阳的升降出入。升降出入正常，一切都正常；而一旦升降出入异常，一切相关的疾病就会发生。那么，升降出入靠什么把持呢？就靠这个开合。所以，从这个层面去思维，我们把天下的疾病分开合两类，应该是如理如法的。依着上面的这个思路再深入一步，我们又发现，开合的作用是由枢机的转动来维系的。因此，调节枢机便能调节开合，调节开合便能调节升降出入。所以，枢机对于整个机体来说，真可谓触一发而动万机。历史上有许多医家善用柴胡剂，一个是小柴胡调阳枢，一个是四逆散调阴枢。利用柴胡剂加减化裁，通治临床各科的疾病。比如北京中医学院已故元老陈慎吾先生，现尚健在的四川乐山名医江尔逊都是善用柴胡剂者。历史上往往将这些善用柴胡剂的医家称为柴胡派，善用一个方，就能成就一个派，这真是不简单的事。这个现象很值得思考。为什么柴胡剂的化裁能够治疗这么多的疾病？根本的一个原因就在于它对枢机的特别作用。所以，我们不要看到少阳篇只有十条条文，就以为它不重要，应该考虑到枢机的特殊性。枢机影响到开的一面它的病变就表现在太阳里，枢机影响到合的一面，它的病变就表现在阳明里。所以，临床上见到许多太阳、阳明的病变，你从本经去治，效果不理想，这个时候如果调一调枢，往往就迎刃而解。
（4）太阴开机病变
接下来是太阴，太阴也主开，这个开是使阴门开启（收藏之门），阳气内入转入收藏。如果太阴开机产生障碍，就会影响到阳气的内入。阳气内入有两个作用：一方面是为了阳气本身休养生息；另一方面是内入的阳气可以温养脏腑。所以，阳气内入障碍以后就有两方面的不妥，一是阳气得不到休养，二是脏腑得不到温养。脏失温养就会产生太阴病。因此，整个太阴病的主导，就像太阴病提纲条文所说的：“太阴之为病，腹满而吐，食不下，自利益甚，时腹自痛，若下之，必胸下结硬。”都是由于脏失温养的缘故，都是由于脏寒的缘故。就如 227条所云：“自利不渴者，属太阴，以其藏有寒故也，当温之，宜服四逆辈。”这些都说明了，脏腑失去温养是太阴病的主导。如果太阴开机失调，阳气得不到很好的休养，人体的能量得不到贮养、蓄积，阳气就会真正衰少，这个时候情况就会严重，就会转入少阴病。我们从太阴病治疗主要用温养的方法，如四逆辈等，也可以说明这一点。太阴属脾土，土是主养藏的。藏什么呢？就是藏阳气。土能生养万物，它靠什么来生养，靠的就是所藏的这个阳气。所以，土之所以能生养这些形形色色的万物，与它的这个“开”，与它的这个“藏”是分不开的。如果开机有障碍，接下来的藏，接下来的生养就会有问题。
（5）少阴枢病
少阴也主枢，它的作用也是或影响开，或影响合。少阴枢机的重要性比少阳枢又进了一步，它主导水与火的枢转。少阴是水火之脏，这个枢就对水火的调节起作用。水火并非不相容，它们需要相互接触、相互依转、相互调和。如果枢机出了问题，就会影响到水火的调和，或者就会出现水太过，水太过必寒；或者会出现火太过，火太过必热。所以，少阴篇的核心，就是一个寒化与热化的问题。少阴这一经真正关系到阳的体，我们说三阴为体，三阳为用，体阴用阳。三阳的病变主要是阳用发生障碍，用有障碍了，这个问题还不太大，用现代医学的术语这还是功能性病变的阶段。所以，三阳的病很少死人。而病变到了三阴，这就危及到“体”了，按西医的说法就是器质性的损害。体与用，一个讲器质，一个讲功用。少阳的枢只是对用的枢转，而少阴的枢则是对体的枢转。体能不能得到真正的蓄养，这就要看少阴枢的功能。所以，少阴的枢转是很重要很重要的，为什么少阴病死证这么多？就是因为少阴不好，阳之体就没有办法保养。
（6）厥阴合机病变
前面讲过厥阴是主合的，当阳气蓄养到一定的时候，这个合机就要启动，从而结束这个蓄养状态，开始一个新的状态。所以，厥阴又是罢极之本，罢极就是使这个藏的状态结束，进入生的状态，进而生长收藏。前面的太阴、少阴都在收藏，到了厥阴就要结束这个过程，使阳气转入到升发的状态，出的状态。如果这个过程障碍了，那会出现什么结果？阳气当出不出，就会产生热。但，这个热与阳明的热不同，阳明的热是阳气在外，当降不降产生热；厥阴的热是阳气在里，当出不出而热。所以，阳明热与厥阴热的区别，一个是外热，一个是内热；一个是气热，一个是血热。那么，什么原因最容易引起这个厥阴合机的障碍呢？也就是说上述这个收藏状态结束转为升发状态的过程，或者说阳出的过程最容易受什么因素影响？是什么因素能跟这个过程相对？当然是寒，寒主收引，因此，最容易引起这个障碍。大家看到，厥阴篇的大量篇幅都在讨论寒热错杂，用药方面，既有大苦大寒的川连、黄柏，又有大辛大热的川椒、细辛、附子、桂枝、干姜。看上去很矛盾，但，实际上厥阴的本身就是这个情况，就是寒热错杂。过去都认为厥阴篇是《伤寒论》最头痛的一篇，可是，你从合机的角度去分析，就会发现厥阴篇并不困难。以上我们从开合枢来谈了三阴三阳，谈了六经病，这虽然是一个比较粗略的勾画，但是，六经病的脉络已然非常明晰地摆在我们面前，因此，大家应该认识到，从这个角度，从这个层面去学习《伤寒论》，是一个比较方便的法门。
4.伤寒传足不传手
我们在前面提到，开、合、枢的协调对于门户而言是非常重要的因素。我们先来看三阳这个门。在阳门中，太阳的作用是负责“开”，所谓“太阳为开”指的就是这层意思。随着太阳主开功能的启动，阳门打开，阳气得以逐渐升发释放出来。这在自然界表现为春夏季节，万物逐渐萌发、繁茂秀丽；而在人体，阳气各方面的作用就得到充分发挥。但是，如果太阳一直这样开，阳气一直处于这种升发释放的状态，就像人一直工作不睡觉行不行呢？这一点我们前面已经讨论过，知道绝对不行。所以，开到一定程度时，就会有一个关闭的机制，将阳门逐渐关闭，使上述蒸蒸日上、升发释放的过程减弱下来，这就是阳明的“合”，所谓“阳明为合”指的就是这层功用。前面我们讲过，一个开，一个合，它们靠什么来转动呢？靠枢机来转动。所以，太阳的开、阳明的合，就要靠少阳枢机的作用，“少阳为枢”指的就是这个意思。
（2）三阴之开合枢
三阳的作用清楚以后，我们接下来看三阴。阳气的升发释放到一定程度后，就要靠阳明的作用，使这个过程逐渐衰减下来。这个时候阳气要回头，要从升发转到收降，从出转到入，从浮转到沉。这个时候收藏的门要打开，不能将阳气拒之门外，而这个过程就要落实到“太阴为开”的功能上。所以，太阴开机启动后，阳气就真正进入到收藏状态。与三阳的道理一样，阳气能不能老是呆在收藏状态呢？就像我们老是睡觉不起床，这成何体统？所以，收藏到一定程度后，这个状态就要慢慢地减下来。收藏的门户要慢慢关闭，这个关闭作用就要落实到厥阴的“合”上。太阴开，厥阴合，少阴的作用是枢转开合，这是三阴的关系。
（3）协同作用
从以上这两个方面，我们应该能够看到，阴与阴、阳与阳、阴与阳之间的配合非常重要。太阳主开，开机启动，阳气释放，当释放到一定程度后，释放要终止，开机要关闭，这个作用要依赖阳明，在这个过程中，太阳与阳明的开合要适时。释放衰减以后，要转入收藏，这个时候阴门要打开，否则，光终止释放，不转入收藏，这个升降的衔接就会出问题。所以，在这个关键环节上，阳明与太阴的配合非常重要。一个阴，一个阳，一个开，一个合，只有两者默契，释放才能转入收藏。另外一方面就是，收藏到一定程度后，这个过程也要逐渐终止，开机也要关闭，这个作用当然要依赖厥阴。而太阳与厥阴的开合也要适时，在厥阴终止收藏的这个过程中，阳门要逐渐打开，否则光终止收藏，不转入释放，这个升降的衔接也会出现问题。因此，在这个关键环节上，厥阴与太阳的配合十分重要。这里也是一个阴一个阳，一个开一个合，只有两者默契，入降才能转到升出。这样一个过程，阴阳确实在互相帮助。太阳的开需要厥阴来帮助，太阴的开需要阳明来帮助。阴阳之间的配合，在开合枢中体现得很充分。《素问·至真要大论》云：“诸寒之而热者取之阴，热之而寒者取之阳。”这里我们可以借用《素问》的这个说法，将它改一改：诸治阳而不愈者，当求之于阴；诸治阴而不愈者，当求之于阳。比如我们治太阳病，这个病看上去明明就是一个太阳病（Taiyang disease），可是怎么弄它都不好，这个时候我们应该考虑，太阳开的过程还有另外一个合的机制在协助它，是不是这个合出了问题，这时我们应当“求之于阴”考虑治治厥阴。反过来，太阴的病我们看得很明确，但是，按照太阴的治法就是解决不了，这个时候，我们也应当“求之于阳”，考虑从阳明来协助治疗。一个“诸寒之而热者取之阴，热之而寒者取之阳”，一个“诸治阳而不愈者求之阴，治阴而不愈者求之阳”，加上下一章要谈的五行隔治法，这些方法掌握了，对于解决疑难问题是很有帮助的。
3. 开合枢病变
开合枢的正常功用
我们讨论过了，这些功用失常就会产生病变。所以，六经病变说实在的，就是开合枢的失调，就是开合枢的病变。
（1）太阳开机的病变
太阳主开，负责阳门的开启，太阳的开机为什么会发生异常呢？这个原因可能来自内部，也可能来自外部，或兼而有之。外部的因素往往比较典型，如我们常见的伤寒（Cold Damage）、中风（Wind Strike），就是因为外邪侵袭，障碍、束缚了这个开机，使阳气的开发受限，于是太阳病就发生了。除了外因，内在有哪些因素呢？有阳气虚，本身的力量不足，太阳这个开的作用会成问题，或者由于水饮、湿等因素障碍了阳气的外出，太阳的开机也会出现问题。总而言之，太阳开机的功能是帮助阳气外出，帮助阳气发挥作用。而阳气的作用前面讨论过，有宣发，有卫外，有气化等等，如果太阳开机出现障碍，阳气的作用就会受到影响，太阳病的发生就与这些影响直接相关。如太阳篇见得最多的是表病（Exterior syndrome），表病就是因为阳不卫外，遭受外邪侵袭所致。另外，阳不化气，水液的代谢就会失调，从而导致水液代谢障碍相关的疾病。我们看看整个太阳篇，表证、水气、痰饮、蓄水占了绝大多数，这些都是与阳用障碍有关，都与太阳开机不利有关。因此，从太阳开机不利的角度去理解太阳病，就抓住了它的纲领。
（2）阳明合机病变
太阳的开是要使阳气升发，阳明的合是使阳气收降。阳气收降以后，天气变燥、变凉，所以阳明与秋天相应。现在阳明的合机发生障碍，阳气该收不收，该降不降，就会出现热，就会有不降的情况。所以，阳明病最大的特征就是两个，一个是热，一个是不降。热表现在经证里，不降表现在腑证里。当然热与不降，经证与腑证都可以相互影响。我们看阳明的经证用白虎汤（Baihu Decoction），这就很有意思。白虎是什么？白虎是西方的神，主宰西方变化的东西就叫白虎。西方的变化是什么？主要是阳气的收与降。所以，从阳明病用白虎汤，就说明阳气的收降出了问题。
（3）少阳枢病
少阳主枢，负责调节开合，如果开合没有问题，你很难发现枢机的毛病。我们看一看三阳篇，太阳篇占 179条，阳明的篇幅也不少，而少阳则仅仅十来条。是不是少阳不重要呢？绝对不是！少阳主枢，关乎太阳、阳明的开合，怎么会不重要呢？这个篇幅上的差距，很重要的一个原因是，少阳枢机的病变很多都体现在太阳和阳明篇里面。比如小柴胡汤（Xiaochaihu Decoction）大家都公认它是少阳病的主方，可是小柴胡汤在少阳病篇的运用只有一次，而其他大量的运用是在太阳和阳明病篇。枢机主管开合，因而枢机的病变往往也要从开合上看。这是枢机病变的一个特色。前面讲伤寒和杂病概念的时候，我们曾经说过，世间上的疾病，如果从发热与非发热这个角度去划分，则可以分为两类，一类是伤寒，一类就是杂病。那么，现在我们从开合的角度讲，世间的疾病也不外乎两个，一个是开的问题，一个是合的问题。为什么这么说呢？因为人体的生理主要就靠这个阴阳的升降出入。升降出入正常，一切都正常；而一旦升降出入异常，一切相关的疾病就会发生。那么，升降出入靠什么把持呢？就靠这个开合。所以，从这个层面去思维，我们把天下的疾病分开合两类，应该是如理如法的。依着上面的这个思路再深入一步，我们又发现，开合的作用是由枢机的转动来维系的。因此，调节枢机便能调节开合，调节开合便能调节升降出入。所以，枢机对于整个机体来说，真可谓触一发而动万机。历史上有许多医家善用柴胡剂，一个是小柴胡调阳枢，一个是四逆散（Sini San）调阴枢。利用柴胡剂加减化裁，通治临床各科的疾病。比如北京中医学院已故元老陈慎吾先生，现尚健在的四川乐山名医江尔逊都是善用柴胡剂者。历史上往往将这些善用柴胡剂的医家称为柴胡派，善用一个方，就能成就一个派，这真是不简单的事。这个现象很值得思考。为什么柴胡剂的化裁能够治疗这么多的疾病？根本的一个原因就在于它对枢机的特别作用。所以，我们不要看到少阳篇只有十条条文，就以为它不重要，应该考虑到枢机的特殊性。枢机影响到开的一面它的病变就表现在太阳里，枢机影响到合的一面，它的病变就表现在阳明里。所以，临床上见到许多太阳、阳明的病变，你从本经去治，效果不理想，这个时候如果调一调枢，往往就迎刃而解。
（4）太阴开机病变
接下来是太阴，太阴也主开，这个开是使阴门开启（收藏之门），阳气内入转入收藏。如果太阴开机产生障碍，就会影响到阳气的内入。阳气内入有两个作用：一方面是为了阳气本身休养生息；另一方面是内入的阳气可以温养脏腑。所以，阳气内入障碍以后就有两方面的不妥，一是阳气得不到休养，二是脏腑得不到温养。脏失温养就会产生太阴病。因此，整个太阴病的主导，就像太阴病提纲条文所说的：“太阴之为病，腹满而吐，食不下，自利益甚，时腹自痛，若下之，必胸下结硬。”都是由于脏失温养的缘故，都是由于脏寒的缘故。就如 227条所云：“自利不渴者，属太阴，以其藏有寒故也，当温之，宜服四逆辈。”这些都说明了，脏腑失去温养是太阴病的主导。如果太阴开机失调，阳气得不到很好的休养，人体的能量得不到贮养、蓄积，阳气就会真正衰少，这个时候情况就会严重，就会转入少阴病。我们从太阴病治疗主要用温养的方法，如四逆辈等，也可以说明这一点。太阴属脾土，土是主养藏的。藏什么呢？就是藏阳气。土能生养万物，它靠什么来生养，靠的就是所藏的这个阳气。所以，土之所以能生养这些形形色色的万物，与它的这个“开”，与它的这个“藏”是分不开的。如果开机有障碍，接下来的藏，接下来的生养就会有问题。
（5）少阴枢病
少阴也主枢，它的作用也是或影响开，或影响合。少阴枢机的重要性比少阳枢又进了一步，它主导水与火的枢转。少阴是水火之脏，这个枢就对水火的调节起作用。水火并非不相容，它们需要相互接触、相互依转、相互调和。如果枢机出了问题，就会影响到水火的调和，或者就会出现水太过，水太过必寒；或者会出现火太过，火太过必热。所以，少阴篇的核心，就是一个寒化与热化的问题。少阴这一经真正关系到阳的体，我们说三阴为体，三阳为用，体阴用阳。三阳的病变主要是阳用发生障碍，用有障碍了，这个问题还不太大，用现代医学的术语这还是功能性病变的阶段。所以，三阳的病很少死人。而病变到了三阴，这就危及到“体”了，按西医的说法就是器质性的损害。体与用，一个讲器质，一个讲功用。少阳的枢只是对用的枢转，而少阴的枢则是对体的枢转。体能不能得到真正的蓄养，这就要看少阴枢的功能。所以，少阴的枢转是很重要很重要的，为什么少阴病死证这么多？就是因为少阴不好，阳之体就没有办法保养。
（6）厥阴合机病变
前面讲过厥阴是主合的，当阳气蓄养到一定的时候，这个合机就要启动，从而结束这个蓄养状态，开始一个新的状态。所以，厥阴又是罢极之本，罢极就是使这个藏的状态结束，进入生的状态，进而生长收藏。前面的太阴、少阴都在收藏，到了厥阴就要结束这个过程，使阳气转入到升发的状态，出的状态。如果这个过程障碍了，那会出现什么结果？阳气当出不出，就会产生热。但，这个热与阳明的热不同，阳明的热是阳气在外，当降不降产生热；厥阴的热是阳气在里，当出不出而热。所以，阳明热与厥阴热的区别，一个是外热，一个是内热；一个是气热，一个是血热。那么，什么原因最容易引起这个厥阴合机的障碍呢？也就是说上述这个收藏状态结束转为升发状态的过程，或者说阳出的过程最容易受什么因素影响？是什么因素能跟这个过程相对？当然是寒，寒主收引，因此，最容易引起这个障碍。大家看到，厥阴篇的大量篇幅都在讨论寒热错杂，用药方面，既有大苦大寒的川连、黄柏，又有大辛大热的川椒、细辛、附子、桂枝、干姜。看上去很矛盾，但，实际上厥阴的本身就是这个情况，就是寒热错杂。过去都认为厥阴篇是《伤寒论》最头痛的一篇，可是，你从合机的角度去分析，就会发现厥阴篇并不困难。以上我们从开合枢来谈了三阴三阳，谈了六经病，这虽然是一个比较粗略的勾画，但是，六经病的脉络已然非常明晰地摆在我们面前，因此，大家应该认识到，从这个角度，从这个层面去学习《伤寒论》，是一个比较方便的法门。
4. 伤寒传足不传手
As mentioned earlier, the coordination of Opening (Kai), Closing (He), and Pivot (Shu) is a very important factor for the "gates." Let us first look at the gate of the Three Yang channels. Within the Yang gates, the function of Taiyang (Greater Yang) is responsible for "Opening," which is what is meant by "Taiyang governs Opening." With the initiation of Taiyang's governing-opening function, the Yang gate opens, allowing Yang Qi to gradually rise and be released. In nature, this manifests as spring and summer, when all things gradually sprout and flourish; in the human body, the various functions of Yang Qi are fully exerted. However, if Taiyang continues to open indefinitely, keeping Yang Qi in a state of constant rising and release, would it be acceptable for a person to work constantly without sleeping? As discussed previously, we know this is absolutely not feasible. Therefore, once opening reaches a certain degree, a closing mechanism is triggered to gradually close the Yang gate, thereby weakening the aforementioned process of vigorous rising and release. This is the "Closing" of Yangming (Yang Brightness), meaning "Yangming governs Closing." We have previously discussed that between an Opening and a Closing, what drives their rotation? It is driven by the Pivot mechanism. Thus, the Opening of Taiyang and the Closing of Yangming rely on the pivot action of Shaoyang (Lesser Yang), which is what is meant by "Shaoyang governs the Pivot."
(2) The Opening, Closing, and Pivot of the Three Yin Channels
Once the functions of the Three Yang channels are clear, we next examine the Three Yin channels. After the rising and release of Yang Qi reaches a certain extent, the function of Yangming is required to gradually attenuate this process. At this time, Yang Qi must turn back, shifting from rising to descending, from exiting to entering, and from floating to sinking. At this juncture, the gate of storage must open so as not to reject Yang Qi outside; this process is implemented through the function of "Taiyin (Great Yin) governs Opening." Thus, after the Taiyain opening mechanism starts, Yang Qi truly enters a state of storage. Just as with the Three Yang channels, can Yang Qi remain in a storage state indefinitely? Would it be proper for us to sleep constantly without getting up? Therefore, once storage reaches a certain degree, this state must gradually subside. The gate of storage must slowly close; this closing action is implemented through the "Closing" of Jueyin (Terminal Yin). Taiyin governs Opening, Jueyin governs Closing, and Shaoyin (Lesser Yin) serves as the pivot for Opening and Closing; this constitutes the relationship among the Three Yin channels.
(3) Synergistic Effects
From these two aspects above, we should be able to see that the cooperation among Yin and Yin, Yang and Yang, and Yin and Yang is extremely important. Taiyang governs Opening; once the opening mechanism starts, Yang Qi is released. When release reaches a certain degree, release must terminate, and the opening mechanism must close; this action relies on Yangming. During this process, the Opening and Closing of Taiyang and Yangming must be timely. After release attenuates, the process must transition into storage; at this time, the Yin gate must open. Otherwise, if one only terminates release without transitioning into storage, the connection of ascending and descending will encounter problems. Therefore, at this critical juncture, the cooperation between Yangming and Taiyin is very important. One is Yin, one is Yang; one is Opening, one is Closing. Only through tacit understanding between the two can release transition into storage. On the other hand, once storage reaches a certain degree, this process must also gradually terminate, and the opening mechanism must close; this action naturally relies on Jueyin. Furthermore, the Opening and Closing of Taiyang and Jueyin must be timely. During the process where Jueyin terminates storage, the Yang gate must gradually open. Otherwise, if one only terminates storage without transitioning into release, the connection of ascending and descending will also encounter problems. Therefore, at this critical juncture, the cooperation between Jueyin and Taiyang is extremely important. Here again, one is Yin, one is Yang; one is Opening, one is Closing. Only through tacit understanding between the two can descending and entering transition into rising and exiting. Through such a process, Yin and Yang indeed help each other. The Opening of Taiyang requires assistance from Jueyin, and the Opening of Ta iyin requires assistance from Yangming. The cooperation between Yin and Yang is fully reflected in the Opening, Closing, and Pivot mechanisms. *Suwen: Zhizhen Yao Dalun* states: "For those who are cold but become hot, treat the Yin; for those who are hot but become cold, treat the Yang." Here, we can borrow this statement from *Suwen* and modify it: For those treated for Yang conditions who do not recover, seek treatment in Yin; for those treated for Yin conditions who do not recover, seek treatment in Yang. For example, when treating Taiyang disease, although it appears clearly as a Taiyang disease, if it does not improve regardless of the treatment, we should consider whether there is another closing mechanism assisting the Taiyang opening process, and whether this closing mechanism has malfunctioned. In this case, we should "seek treatment in Yin" and consider treating Jueyin. Conversely, if a Ta iyin disease is clearly diagnosed, but standard Ta iyin treatments fail to resolve it, we should also "seek treatment in Yang" and consider assisting therapy via Yangming. Combining "For those who are cold but become hot, treat the Yin; for those who are hot but become cold, treat the Yang" with "For those treated for Yang who do not recover, seek treatment in Yin; for those treated for Yin who do not recover, seek treatment in Yang," along with the Five Elements Intermittent Treatment method discussed in the next chapter, mastering these methods is very helpful for solving difficult and complicated cases.
3. Pathological Changes of Opening, Closing, and Pivot
Normal Functions of Opening, Closing, and Pivot
We have discussed that dysfunction of these functions leads to pathological changes. Therefore, strictly speaking, the pathological changes of the Six Channels are nothing more than the disharmony or pathology of the Opening, Closing, and Pivot mechanisms.
(1) Pathology of Taiyang Opening Mechanism
Taiyang governs Opening and is responsible for opening the Yang gate. Why might the Taiyang opening mechanism become abnormal? The cause may originate internally, externally, or both. External factors are often typical; for instance, common Cold Damage (Shanghan) and Wind Strike (Zhongfeng) occur because external pathogens invade, obstructing and binding this opening mechanism, thereby restricting the development of Yang Qi, leading to the occurrence of Taiyang disease. Besides external causes, what are the internal factors? If Yang Qi is deficient and its inherent strength is insufficient, the Taiyang opening function will be problematic. Alternatively, if factors such as fluid retention or dampness obstruct the outward movement of Yang Qi, the Taiyang opening mechanism will also encounter issues. In summary, the function of the Taiyang opening mechanism is to assist Yang Qi in moving outward and exerting its effects. As discussed previously, the functions of Yang Qi include dispersing, defending the exterior, and transforming Qi. If the Taiyang opening mechanism is obstructed, the functions of Yang Qi will be affected, and the occurrence of Taiyang disease is directly related to these impacts. For example, the most common manifestations in the Taiyang chapter are Exterior Syndromes (Biao Bing), which result from Yang failing to defend the exterior and suffering invasion by external pathogens. Additionally, if Yang fails to transform Qi, water metabolism will be disordered, leading to diseases related to water metabolism disorders. Looking at the entire Taiyang chapter, Exterior Patterns, Water Qi, Phlegm-Fluids, and Fluid Retention account for the vast majority. All these are related to obstacles in Yang function and difficulties in the Taiyang opening mechanism. Therefore, understanding Taiyang disease from the perspective of impaired Taiyang opening captures its essence.
(2) Pathology of Yangming Closing Mechanism
The Opening of Taiyang aims to raise Yang Qi, while the Closing of Yangming aims to descend Yang Qi. After Yang Qi descends, the weather becomes dry and cool; thus, Yangming corresponds to autumn. Now, if the Yangming closing mechanism encounters obstruction, Yang Qi fails to descend when it should, resulting in Heat and failure to descend. Therefore, the two greatest characteristics of Yangming disease are Heat and failure to descend. Heat manifests in Channel Syndromes (Jing Zheng), while failure to descend manifests in Organ Syndromes (Fu Zheng). Of course, Heat and failure to descend, as well as Channel and Organ syndromes, can influence each other. Consider the use of Baihu Decoction (White Tiger Decoction) for Yangming Channel Syndromes, which is quite interesting. What is Baihu (White Tiger)? Baihu is the deity of the West, governing the changes of the West. What are the changes of the West? Primarily, they are the gathering and descending of Yang Qi. Thus, the use of Baihu Decoction for Yangming disease indicates that there is a problem with the gathering and descending of Yang Qi.
(3) Pathology of Shaoyang Pivot
Shaoyang governs the Pivot, responsible for regulating Opening and Closing. If Opening and Closing are normal, it is difficult to detect abnormalities in the Pivot mechanism. Looking at the chapters on the Three Yang channels, the Taiyang chapter contains 179 clauses, and the Yangming chapter is also substantial, whereas the Shaoyang chapter contains merely about ten clauses. Does this mean Shaoyang is unimportant? Absolutely not! Shaoyang governs the Pivot, concerning the Opening and Closing of Taiyang and Yangming; how could it be unimportant? A major reason for this disparity in length is that many pathological changes of the Shaoyang Pivot are manifested within the Taiyang and Yangming chapters. For instance, Xiaochaihu Decoction (Minor Bupleurum Decoction) is universally recognized as the principal formula for Shaoyang disease. However, its application in the Shaoyang disease chapter occurs only once, while its extensive applications appear in the Taiyang and Yangming disease chapters. Since the Pivot governs Opening and Closing, pathological changes of the Pivot are often viewed through the lens of Opening and Closing. This is a distinctive feature of Pivot pathology. Previously, when discussing the concepts of Cold Damage and Miscellaneous Diseases, we stated that diseases in the world can be divided into two categories based on fever versus non-fever: one is Cold Damage, and the other is Miscellaneous Disease. Now, viewing from the perspective of Opening and Closing, worldly diseases essentially fall into two categories: problems of Opening and problems of Closing. Why say this? Because human physiology primarily relies on the ascending, descending, exiting, and entering of Yin and Yang. When ascending, descending, exiting, and entering are normal, everything is normal; once they become abnormal, all related diseases occur. What controls ascending, descending, exiting, and entering? It is controlled by Opening and Closing. Therefore, thinking from this level, dividing the world's diseases into Opening and Closing categories is logical and appropriate. Taking this line of thought a step further, we discover that the function of Opening and Closing is maintained by the rotation of the Pivot. Therefore, regulating the Pivot regulates Opening and Closing, and regulating Opening and Closing regulates ascending, descending, exiting, and entering. Thus, the Pivot can be said to affect the entire organism, where touching one hair moves ten thousand mechanisms. Historically, many physicians were adept at using Chaihu (Bupleurum) formulas; one used Xiaochaihu to regulate the Yang Pivot, and another used Sini San (Frigid Extremities Powder) to regulate the Yin Pivot. By modifying and adapting Chaihu formulas, they treated diseases across all clinical specialties. For example, the late Mr. Chen Shenwu, a veteran of the Beijing College of Traditional Chinese Medicine, and the still-living renowned physician Mr. Jiang Erxun from Leshan, Sichuan, were both adept users of Chaihu formulas. Historically, physicians skilled in using Chaihu formulas were often called the "Chaihu School." Being able to establish a school by mastering a single formula is truly remarkable. This phenomenon is worth pondering. The fundamental reason why modified Chaihu formulas can treat so many diseases lies in their special effect on the Pivot mechanism. Therefore, we should not assume the Shaoyang chapter is unimportant simply because it contains only ten clauses; we must consider the uniqueness of the Pivot mechanism. When the Pivot affects the aspect of Opening, its pathology manifests in Taiyang; when it affects the aspect of Closing, its pathology manifests in Yangming. Thus, clinically, when encountering many Taiyang or Yangming pathologies, if treating the respective primary channel yields unsatisfactory results, adjusting the Pivot often resolves the issue effortlessly.
(4) Pathology of Ta iyin Opening Mechanism
Next is Ta iyin. Ta iyin also governs Opening; this Opening refers to opening the Yin gate (the gate of storage), allowing Yang Qi to enter inward and transition into storage. If the Ta iyin opening mechanism encounters obstruction, it will affect the inward entry of Yang Qi. The inward entry of Yang Qi has two functions: on one hand, it allows Yang Qi itself to rest and recuperate; on the other hand, the inward-entering Yang Qi can warm and nourish the Zang organs. Therefore, after the inward entry of Yang Qi is obstructed, two disadvantages arise: Yang Qi fails to rest, and the Zang organs fail to receive warming and nourishment. If the Zang organs lose warming and nourishment, Ta iyin disease arises. Therefore, the main theme of Ta iyin disease, as stated in the outline clause of Ta iyin disease, is: "In Ta iyin disease, there is abdominal fullness and vomiting, inability to eat, worsening spontaneous diarrhea, and occasional spontaneous abdominal pain. If purgatives are used, there will certainly be hardness below the chest." All of these are due to the loss of warming and nourishment of the Zang organs, specifically due to Cold in the Zang organs. As Clause 227 states: "Spontaneous diarrhea without thirst belongs to Ta iyin, because the Zang organs have Cold; therefore, warmth should be applied, and formulas similar to Sini Tang are suitable." These illustrate that the loss of warming and nourishment of the Zang organs is the dominant factor in Ta iyin disease. If the Ta iyin opening mechanism is disordered, Yang Qi cannot rest well, and the body's energy cannot be stored and accumulated. Consequently, Yang Qi will truly decline, the situation will become severe, and it will transition into Shaoyin disease. The fact that Ta iyin disease is mainly treated with warming and nourishing methods, such as formulas similar to Sini Tang, also illustrates this point. Ta iyin belongs to Earth (Spleen); Earth is primarily responsible for nurturing and storing. What does it store? It stores Yang Qi. Earth can generate and nourish all things; what does it rely on to do so? It relies on this stored Yang Qi. Therefore, the ability of Earth to generate and nourish diverse things is inseparable from its "Opening" and its "Storage." If the opening mechanism is obstructed, the subsequent storage and generation/nourishment will be problematic.
(5) Pathology of Shaoyin Pivot
Shaoyin also governs the Pivot; its function either influences Opening or influences Closing. The importance of the Shaoyin Pivot goes a step further than the Shaoyang Pivot, as it governs the pivot of Water and Fire. Shaoyin is the Zang organ of Water and Fire; this Pivot acts to regulate Water and Fire. Water and Fire are not incompatible; they need to contact, rely on, and harmonize with each other. If the Pivot mechanism malfunctions, it will affect the harmony of Water and Fire, potentially leading to excess Water, which inevitably causes Cold; or excess Fire, which inevitably causes Heat. Therefore, the core of the Shaoyin chapter revolves around Cold Transformation and Heat Transformation. The Shaoyin channel truly concerns the "Substance" (Ti) of Yang. We say the Three Yin constitute the Substance, and the Three Yang constitute the Function; the Substance is Yin, and the Function is Yang. Pathological changes in the Three Yang are mainly obstacles in Yang Function. If Function is obstructed, the problem is not too severe; in modern medical terms, this is still a stage of functional disorder. Therefore, deaths from Three Yang diseases are rare. Once pathology reaches the Three Yin channels, it endangers the "Substance"; in Western medicine terms, this is organic damage. Substance and Function refer to organic structure and physiological function, respectively. The Shaoyang Pivot only pivots Function, whereas the Shaoyin Pivot pivots Substance. Whether Substance can be truly nourished depends on the function of the Shaoyin Pivot. Therefore, the pivoting of Shaoyin is extremely important. Why are there so many fatal cases in Shaoyin disease? Because if Shaoyin is dysfunctional, the Substance of Yang cannot be maintained.
(6) Pathology of Jueyin Closing Mechanism
Previously, we stated that Jueyin governs Closing. When Yang Qi has been stored to a certain extent, the Closing mechanism must activate, thereby ending this storage state and beginning a new one. Thus, Jueyin is also the root of fatigue (Ba Ji); "Ba Ji" means ending the state of storage and entering the state of growth, thereby initiating the cycle of growth, flourishing, harvesting, and storage. While Ta iyin and Shaoyin are in the phase of storage, upon reaching Jueyin, this process must end, transitioning Yang Qi back to a state of rising and exiting. If this process is obstructed, what result will occur? Yang Qi should exit but fails to do so, generating Heat. However, this Heat differs from the Heat of Yangming. The Heat of Yangming is caused by Yang Qi being outside and failing to descend; the Heat of Jueyin is caused by Yang Qi being inside and failing to exit. Therefore, the distinction between Yangming Heat and Jueyin Heat is that one is External Heat and the other is Internal Heat; one is Qi Heat and the other is Blood Heat. So, what factor most easily causes obstruction of the Jueyin Closing mechanism? That is, what factor most easily influences the process of ending the storage state and transitioning to the rising/exiting state, or the process of Yang exiting? What factor opposes this process? Naturally, Cold. Cold governs contraction and drawing-in; therefore, it most easily causes this obstruction. As you can see, a large portion of the Jueyin chapter discusses mixed Cold and Heat. Regarding medication, it includes bitter-cold herbs like Chuanlian (Coptis Rhizome) and Huangbai (Phellodendron Bark), as well as pungent-hot herbs like Chuanjiao (Zanthoxylum Pericarpium), Xixin (Asarum Root), Fuzi (Aconite Lateralis Radix Praeparata), Guizhi (Cinnamon Twig), and Ganjiang (Zingiberis Rhizoma). This seems contradictory, but actually, the nature of Jueyin itself is mixed Cold and Heat. In the past, many considered the Jueyin chapter the most headache-inducing part of *Shanghan Lun*. However, analyzing it from the perspective of the Closing mechanism reveals that the Jueyin chapter is not difficult. Above, we discussed the Three Yin and Three Yang, and the Six Channel diseases, from the perspective of Opening, Closing, and Pivot. Although this is a rough sketch, the脉络 (thread/structure) of Six Channel diseases is now clearly laid out before us. Therefore, everyone should recognize that learning *Shanghan Lun* from this angle and level is a relatively convenient method.
4. Cold Damage Transmits via Foot Channels, Not Hand Channels