患者李××，女，54岁。趾、指、腕、踝、肘、膝关节肿痛5年多。医诊类风湿性关节炎。医予抗风湿药、激素等，开始时稍有好转，但长期应用后，非但无效亦且日渐加重。改请中医治疗。先用中药汤剂祛风散寒、活血通络，后用滋补肝肾，除湿化痰，补气养血，以及尫痹冲剂、蚂蚁丸等均无明显效果，邀余诊治。始以鞠通宣痹汤、大秦艽汤、三痹汤、E中下痛风方等诸方加减不效，继以活络效灵丹、桂枝芍药知母汤等亦无功。因思关节者，筋之会也，骨之属也。痹者，闭也，风寒湿杂至合而为之也。祛风除湿散寒，活血通络、益气养血，滋补肝肾法应该有效，然其却不见功者，何也?《灵枢．本输篇》日：“少阳属肾，肾上连肺，故将两脏。三焦者，中渎之府也，水道出焉，属膀胱，是孤之府也，是六府之所与合者。”前用诸方之治肺、治肾均不效者，未调理少阳三焦也。且夫《素问·六节藏象论》日：“凡十一脏取决于胆也。”胆与三焦皆少阳也，和其少阳，肺、肾之通调水道功能自复也。故治宜调理三焦。处方：柴胡10克，枳壳10克，白芍10克，甘草6克，香橼10克，佛手10克，玫瑰花10克，代代花10克，黄芩3克，合欢花15克。服药4剂，非但指、趾、腕、踝、肘、膝疼痛有减，且头痛、胸痛、背痛减轻六七。继服30剂，诸证俱失而竟愈。
患者张××，男，14岁。高度水肿、大量蛋白尿三年多。医诊肾病综合征。先以激素等西药治疗半年不效。继又以中药利水消肿、清热解毒、活血化瘀、益气利水、补肾利水等均无效。邀余诊治。审其高度水肿，纳呆食减，咽干咽痛，尿少而色黄有泡沫，舌苔黄白而腻，脉虚弦滑数。思之：前医之治，或从肺以补气，或从肾以滋阴，然其却久久不效者何也?未理其三焦也。《灵枢·本输篇》日：“少阳属肾，肾上连肺，故将两脏。三焦者，中渎之府也，水道出焉，属膀胱，是孤之府也，是六府之所与合者。”余所研制的肾康灵非但补气以益肺，亦且补阴以益肾，且有调理三焦，交通心肾之药饵。何不与之。因拟肾康灵1次4粒，1日3次。半月之后，浮肿全消，饮食增进；尿蛋白由++++减至++。继服上药两月，诸证俱失，愈。
相似与临床
综观中国医药学的数千年发展史可以看出：中国医药学之所以长盛不衰地进行着发展，就在于它有着一整套的正确的思维方式作指导。翻开从《内经》、《神农本草经》到《伤寒论》《金匮要略》等经典著作和具有卓越成就医家的创新史，不难看出促使这一发展的主要观点正是中国医药学中的相似论——即所谓的取类比象学说。
一、中国医药学相似论的基本内涵
中国医药学的相似论是中国医药学的基本的思维方法，这一方法是在辩证唯物主义思想指导下形成的一种思维方式。这一思维方式认为通过对大量的主、客体的相互类似现象的分析，可以找出各种各样的规律性，并认为各种各样的规律性中。首先的第一位的应该找出的是阴阳、五行规律，即所谓的哪些是属于阴、哪些是属于阳；哪些是属于五行中的木，哪些是属于五行中的火，哪些是属于五行中的土、金、水等。正如《素问》所说：“阴阳者，天地之道也，万物之纲纪，变化之父母，生杀之本始，神明之府也。”所以治病必求于本。
其次，认为在诸多的相似成分中，以系统的、局部的、运动的、静止的相似性为最多，并认为在这四种相似成分中，以系统的、运动的相似为最重要，且其相似物质问的相似成分越多，其性质就越相近。
再次，认为在众多的相似物质之间，不但存在着相似，而且存在着相似间的相互感应性，并且认为相似的物质问的相似成分越多，其相互感应性就越大。所以我们医学工作者，可以通过症状、体征在系统、局部、运动、静止中相似性的多少和它们之间，以及与自然界变化的相互感应性，去发现系统的、局部的、运动的、静止的规律性，并根据这些规律性去治疗疾病。
二、中国医药学相似论的应用
那么中国医药学是怎么应用相似论去发现问题和解决问题的呢?综合起来，大致有以下两点：
(一)将相似论作为发现不同规律性的方法
1．将相似论作为发现新的病因的方法在清代以前的医家中，众多医家对病因中的燥邪一直缺乏深刻的认识，明末清初著名医家喻昌在相似论观点的启发下，根据病因中的相似之理，明确地提出病机十九条独遗燥气。他说：“燥之与湿有霄壤之殊，燥者天之气也，湿者地之气也。水流湿，火就燥，各从其类，此胜彼负，两不相谋。春月地气动而湿胜，斯草木畅茂，秋月天气肃而燥胜，斯草木黄落，故春分之后之湿，秋分以后之燥，各司其政。今指秋月之燥为湿，是必指夏月之热为寒然后可，奈何《内经》病机一十九条独遗燥气，他凡秋伤于燥，皆谓秋伤于湿?历代诸贤，随文作解，弗察其讹。”
2．将相似论作为发现新的生理功能的方法在明代以前，众多医家对命门的认识大多局限于《难经》“命门者，诸神精之所舍，原气之所系也。”而对命门在生理上的重大作用缺乏深刻的认识，至明代赵养葵根据相似论之理，才对命门有了充分的认识。他说：“命门为十二经之主。肾无此，则无以作强，而技巧不出矣；膀胱无此，则三焦之气不化，而水道不通矣；脾胃无此，则不能蒸腐水谷，而五谷不出矣；肝胆无此，则将军无决断，而谋虑不出矣；心无此，则神明昏，而万事不应矣，正所谓主不明则十二官危也。余有一譬焉，譬之元霄之鳌山走马灯，拜者，舞者，飞者，走者，无一不具，其中间惟一火耳，火旺则动速，火微则动缓，火熄则寂然不动，而拜者，舞者，飞者，走者，躯壳未尝不存也，故日汝身非汝所有，是天地之委形也。余所以淳淳必欲明此论者，欲世之养生治病者，的以命门为君主。”
3．将相似论作为发现治则的方法清代医家徐灵胎通过兵法相似之理对各种治疗原则的确立进行了深刻的剖析，并发现了每种治疗原则的内涵。他说：“圣人之所以全民生也，五谷为养，五果为助，五畜为益，五菜为充，而毒药则以之攻邪。故虽甘草、人参，误用致害，皆毒药之类也。古人好服食者，必有奇疾，犹之好战胜者，必有奇殃。是故兵之设也以除暴，不得已而后兴；药之设也以攻疾，亦不得已而后用。其道同也。故病之为患也，小则耗精，大则伤命，隐然一敌国也。以草木之偏胜，攻脏腑之偏胜，必能知彼知己，多方以制之，而后无丧身殒命之忧。是故传经之邪，而先夺其未至，则所以断敌之要道也；横暴之疾，而急保其未病，则所以守我之严疆也。夹宿食而病者，先除其食，则敌之资粮已焚；合旧疾而发者，必防其病，则敌之内应既绝。辨经络而无泛用之药，此之谓响导之师；因寒热而有反用之方，此之谓行间之术。一病而分治之，则用寡可以胜众，使前后不相救，而势自衰；数病而合治之，则并力捣其中坚，使离散无所统，而众悉溃。病方进，则不治其太甚，固守元气，所以老其师；病方衰，则必穷其所之，更益精锐，所以捣其穴。若夫虚邪之体，攻不可过，本和平之药，而以峻药补之；衰敝之日，不可穷民力也。实邪之伤，攻不可缓，用峻厉之药，而以常药和之；富强之国，可以振威武也。然而选材必当，器械必良，克期不衍，布阵有方，此又不可更仆数也。孙武子十三篇，治病之法尽之矣。”
4．将相似论作为发现不同病机的方法曾治一人，男，45岁。食管灼痛，吞咽时更甚5年多。医诊食管炎。先用西药治疗两年多不效，后又以中药，或活血，或泻火，或疏肝，或健脾等法治之约三年亦无效。邀余治之，前后予药40余剂无明显改善。一日突然来家造访，见其面色咣白无华，顿悟，云：白色属肺，必肺阴不足所致耳。乃拟养阴润肺之剂。处方：百合40克，乌药10克，麦冬10克，4剂后，竞痛减五六，继服20剂，愈。
5．将相似论作为组成新的方剂的认识方法曾治一人，女，50岁。严重失眠两年多，始予镇静催眠之西药尚能入睡片刻，但近半年来，虽遍用西药与中药安神养血、平肝泻火、疏肝解郁之剂不效。邀余诊治。询其病史，云：由于工作长期繁忙，加之又长期精神不够愉快，致使逐渐烦躁失眠。再询其证，云：除严重失眠外，并见胸满气短，时时叹气，头晕乏力，烦躁不安。综合其证，思之：病发于郁，郁者，当调气疏肝。乃予疏肝调气之剂十余剂，寸效不见。再思历代医家曾有思郁宜补之论，乃改用归脾汤7剂治之，不但不效，反见加剧。不得已，乃告患者另请高医治之。数月之后，患者又邀余治。云：诸医之药均无微效，请再处方以试之。正在此时，一医来访，并云：近治一高血压病患者，遍用养阴平肝，清肝泻火之剂不效，不得已，在上方中加入了黄芪一味，不曾想到患者诸证却明显改善，血压亦随之下降，为此曾遇数医的非议，请师一解。答日：黄芪乃补气升阳之品，高血压病大多为肝阳上亢所致，因此高血压病大多不可用黄芪。此证原用平肝泻火之所以不效者，恐为过用寒凉之品郁其阳气所致，所以此时稍予黄芪之甘温，以助郁阳之升发，则清阳可升，浊阴可降，而病解。该医走后，我对以上失眠患者的治法，亦顿然而悟，此患失眠之所以久治不效者，乃前用诸方中舒者不补，补者不舒耳。再察其脉弦而大，乃处补中益气与六味地黄合方。服药2剂，竞睡眠达8小时，又服20剂，愈。
6．将相似论作为发现药物新的功用的方法清代以前对茯苓之赤、白与皮的功用不同，虽然稍有论述，但很不深刻。至黄宫绣著《本草求真》一书，应用相似之理才阐述明白。他说：“茯苓，色白入肺，味甘入脾，味淡渗湿。故书皆载上渗脾肺之湿，下伐肝肾之邪，其气先升后降。凡人病因水湿而见气逆烦满，心下结痛，呃逆呕吐，口苦舌干，水肿淋结，忧恚惊恐，及小便或涩或多者，服此皆能有效。故人四君，则佐参术以渗脾家之湿，入六味，则使泽泻以行肾邪之余，最为利水除湿要药，书日健脾，即水去而脾自健之谓也；又日定魄，即水去而魄自安之意也，且水既去，则小便自开，安有癃闭之虑乎?水去则内湿已消，安有小便多见之谓乎?故水去则胸膈自宽，而结痛烦满不作，水去则津液自生，而口苦舌干悉去。惟水衰精滑，小便不禁，非由水湿致者切忌，恐其走表泄气故耳。茯苓有赤、白之分，赤人小肠，白入膀胱，白微有补，赤则止泻湿热，一气一血，自不容混如此。至皮岢治水肿腹胀，以皮行皮之义。”
(二)将相似论作为进行辨证论治的方法
1．伤寒、温病、温疫
(1)高热不退以时气相似之理推知其为寒包火证，予解表清里始安。
曾治患者李×，男，45岁。一个月前突然恶寒发热、头痛身痛。先予西药治疗一周不效，乃改请中医治疗。医云：近世有人死抱住《伤寒论》一书不放，实际临床上没有一例伤寒，所以只能用银翘散加减治疗。并拟银翘散加减方十余剂治之，药后发热不但不减，反而更甚。患者又易医治之。云：患者体温39．5℃，如此高热怎可用银翘散，只可予白虎汤。服药4剂，诸证仍不见减。邀余诊视。察其证见恶寒发热，头痛身痛，无汗烦躁，脉浮紧而数。乃云：此乃伤寒表寒闭郁至甚之大青龙汤证也。处方：麻黄18克，桂枝9克，杏仁9克，甘草6克，生姜9克，大枣12个，生石膏15克。
1剂后，全身汗出，体温降至37．5℃。乃以半量再服1剂，愈。
某医云：前医曾说当今只有温病而无伤寒，而老师却用伤寒之方取效甚速，其故为何?答日：此病发于小寒大寒之间，乃时令之寒所加所致，根据相似之理辨知其为伤寒无疑，表寒者当予辛温解表，故以大青龙汤一剂得愈。
(2)肺炎咳喘以时令相似之理辨知其为凉燥犯肺，予杏苏散加减而愈。
曾治患者张×，男，8岁。咳嗽阵阵而作，喘而气短，平卧时加甚一个多月。某院诊为肺炎。始予抗生素治疗无功，继又配合中药麻杏石甘汤仍无效。查其体温37．8clC，鼻翼微见煽动，口鼻微干，舌苔薄白，脉浮紧。又思本病正发于秋季，相据相似相应之理，诊为凉燥犯肺，内伏微饮。治拟杏苏饮加减。处方：杏仁6克，紫苏9克，半夏9克，陈皮6克，茯苓6克，枳壳6克，前胡6克，葛根lO克，甘草3克，桔梗6克。服药l剂，发热即消，喘咳大减。继服2剂，愈。
2．内科
(1)口眼喁斜以春夏相似相应之理辨知出其为阴血不足，风邪外客，予养血祛风始安。
曾治患者陈×，女，成。口眼喁斜一个多月。前医以针灸、理疗与中药牵正散、乌药顺气汤加减治之不效。细审其脉浮，口微干，左眼不能闭合，口涎时时从口角流出。根据春夏相似相应之理，审其病发于夏初春末，知其为血虚风热外客，予养血祛风法，一剂减，6剂愈。
(2)贫血尿血以昼夜相似相应之理辨知其病在血分。
患者李××，女性，54岁。脚趾、手指、手腕、脚踝、肘部、膝关节肿痛五年多。医生诊断为类风湿性关节炎。医生给予抗风湿药、激素等治疗，起初稍有好转，但长期应用后，不仅无效反而日渐加重。改请中医治疗。先用中药汤剂祛风散寒、活血通络，后用滋补肝肾、除湿化痰、补气养血的方法，以及尫痹冲剂、蚂蚁丸等药物均无明显效果，邀请余诊治。开始使用鞠通宣痹汤、大秦艽汤、三痹汤、E中下痛风方等诸方加减治疗未见效，继以活络效灵丹、桂枝芍药知母汤等也无功。因为思考关节是筋的会合处，骨的所属部分。痹症，就是闭塞的意思，风寒湿邪杂至合而致病。祛风除湿散寒、活血通络、益气养血、滋补肝肾的方法应该有效，然而其却不见功者，为什么呢？《灵枢·本输篇》说：“少阳属肾，肾上连肺，故将两脏。三焦者，中渎之府也，水道出焉，属膀胱，是孤之府也，是六府之所与合者。”前用诸方治肺、治肾均不效者，是因为没有调理少阳三焦。而且《素问·六节藏象论》说：“凡十一脏取决于胆也。”胆与三焦皆属于少阳，调和其少阳，肺、肾的通调水道功能自然恢复。所以治疗宜调理三焦。处方：柴胡10克，枳壳10克，白芍10克，甘草6克，香橼10克，佛手10克，玫瑰花10克，代代花10克，黄芩3克，合欢花15克。服药4剂，不仅指、趾、腕、踝、肘、膝疼痛减轻，且头痛、胸痛、背痛减轻六七成。继服30剂，诸证俱失而竟愈。
患者张××，男性，14岁。高度水肿、大量蛋白尿三年多。医生诊断为肾病综合征。先以激素等西药治疗半年不效。继又以中药利水消肿、清热解毒、活血化瘀、益气利水、补肾利水等均无效。邀请余诊治。审其高度水肿，纳呆食减，咽干咽痛，尿少而色黄有泡沫，舌苔黄白而腻，脉虚弦滑数。思之：前医的治疗，或从肺以补气，或从肾以滋阴，然而其却久久不效者为什么呢？没有调理其三焦。《灵枢·本输篇》说：“少阳属肾，肾上连肺，故将两脏。三焦者，中渎之府也，水道出焉，属膀胱，是孤之府也，是六府之所与合者。”余所研制的肾康灵不仅补气以益肺，亦且补阴以益肾，且有调理三焦、交通心肾的药物。何不与之。因此拟定肾康灵1次4粒，1日3次。半月之后，浮肿全消，饮食增进；尿蛋白由++++减至++。继服上药两月，诸证俱失，痊愈。
相似与临床
综观中国医药学的数千年发展史可以看出：中国医药学之所以长盛不衰地进行着发展，就在于它有着一整套的正确的思维方式作指导。翻开从《内经》、《神农本草经》到《伤寒论》《金匮要略》等经典著作和具有卓越成就医家的创新史，不难看出促使这一发展的主要观点正是中国医药学中的相似论——即所谓的取类比象学说。
一、中国医药学相似论的基本内涵
中国医药学的相似论是中国医药学的基本的思维方法，这一方法是在辩证唯物主义思想指导下形成的一种思维方式。这一思维方式认为通过对大量的主、客体的相互类似现象的分析，可以找出各种各样的规律性，并认为各种各样的规律性中。首先的第一位的应该找出的是阴阳、五行规律，即所谓的哪些是属于阴、哪些是属于阳；哪些是属于五行中的木，哪些是属于五行中的火，哪些是属于五行中的土、金、水等。正如《素问》所说：“阴阳者，天地之道也，万物之纲纪，变化之父母，生杀之本始，神明之府也。”所以治病必求于本。
其次，认为在诸多的相似成分中，以系统的、局部的、运动的、静止的相似性为最多，并认为在这四种相似成分中，以系统的、运动的相似为最重要，且其相似物质间的相似成分越多，其性质就越相近。
再次，认为在众多的相似物质之间，不但存在着相似，而且存在着相似间的相互感应性，并且认为相似的物质间的相似成分越多，其相互感应性就越大。所以我们医学工作者，可以通过症状、体征在系统、局部、运动、静止中相似性的多少和它们之间，以及与自然界变化的相互感应性，去发现系统的、局部的、运动的、静止的规律性，并根据这些规律性去治疗疾病。
二、中国医药学相似论的应用
那么中国医药学是怎么应用相似论去发现问题和解决问题的呢？综合起来，大致有以下两点：
(一)将相似论作为发现不同规律性的方法
1．将相似论作为发现新的病因的方法在清代以前的医家中，众多医家对病因中的燥邪一直缺乏深刻的认识，明末清初著名医家喻昌在相似论观点的启发下，根据病因中的相似之理，明确地提出病机十九条独遗燥气。他说：“燥之与湿有霄壤之殊，燥者天之气也，湿者地之气也。水流湿，火就燥，各从其类，此胜彼负，两不相谋。春月地气动而湿胜，斯草木畅茂，秋月天气肃而燥胜，斯草木黄落，故春分之后之湿，秋分以后之燥，各司其政。今指秋月之燥为湿，是必指夏月之热为寒然后可，奈何《内经》病机一十九条独遗燥气，他凡秋伤于燥，皆谓秋伤于湿？历代诸贤，随文作解，弗察其讹。”
2．将相似论作为发现新的生理功能的方法在明代以前，众多医家对命门的认识大多局限于《难经》“命门者，诸神精之所舍，原气之所系也。”而对命门在生理上的重大作用缺乏深刻的认识，至明代赵养葵根据相似论之理，才对命门有了充分的认识。他说：“命门为十二经之主。肾无此，则无以作强，而技巧不出矣；膀胱无此，则三焦之气不化，而水道不通矣；脾胃无此，则不能蒸腐水谷，而五谷不出矣；肝胆无此，则将军无决断，而谋虑不出矣；心无此，则神明昏，而万事不应矣，正所谓主不明则十二官危也。余有一譬焉，譬之元霄之鳌山走马灯，拜者，舞者，飞者，走者，无一不具，其中间惟一火耳，火旺则动速，火微则动缓，火熄则寂然不动，而拜者，舞者，飞者，走者，躯壳未尝不存也，故曰汝身非汝所有，是天地之委形也。余所以淳淳必欲明此论者，欲世之养生治病者，的以命门为君主。”
3．将相似论作为发现治则的方法清代医家徐灵胎通过兵法相似之理对各种治疗原则的确立进行了深刻的剖析，并发现了每种治疗原则的内涵。他说：“圣人之所以全民生也，五谷为养，五果为助，五畜为益，五菜为充，而毒药则以之攻邪。故虽甘草、人参，误用致害，皆毒药之类也。古人好服食者，必有奇疾，犹之好战胜者，必有奇殃。是故兵之设也以除暴，不得已而后兴；药之设也以攻疾，亦不得已而后用。其道同也。故病之为患也，小则耗精，大则伤命，隐然一敌国也。以草木之偏胜，攻脏腑之偏胜，必能知彼知己，多方以制之，而后无丧身殒命之忧。是故传经之邪，而先夺其未至，则所以断敌之要道也；横暴之疾，而急保其未病，则所以守我之严疆也。夹宿食而病者，先除其食，则敌之资粮已焚；合旧疾而发者，必防其病，则敌之内应既绝。辨经络而无泛用之药，此之谓响导之师；因寒热而有反用之方，此之谓行间之术。一病而分治之，则用寡可以胜众，使前后不相救，而势自衰；数病而合治之，则并力捣其中坚，使离散无所统，而众悉溃。病方进，则不治其太甚，固守元气，所以老其师；病方衰，则必穷其所之，更益精锐，所以捣其穴。若夫虚邪之体，攻不可过，本和平之药，而以峻药补之；衰敝之日，不可穷民力也。实邪之伤，攻不可缓，用峻厉之药，而以常药和之；富强之国，可以振威武也。然而选材必当，器械必良，克期不衍，布阵有方，此又不可更仆数也。孙武子十三篇，治病之法尽之矣。”
4．将相似论作为发现不同病机的方法曾治一人，男，45岁。食管灼痛，吞咽时更甚5年多。医生诊断为食管炎。先用西药治疗两年多不效，后又以中药，或活血，或泻火，或疏肝，或健脾等法治之约三年亦无效。邀请余治之，前后予药40余剂无明显改善。一日突然来家造访，见其面色㿠白无华，顿悟，云：白色属肺，必肺阴不足所致耳。乃拟养阴润肺之剂。处方：百合40克，乌药10克，麦冬10克，4剂后，竞痛减五六，继服20剂，痊愈。
5．将相似论作为组成新的方剂的认识方法曾治一人，女，50岁。严重失眠两年多，始予镇静催眠之西药尚能入睡片刻，但近半年来，虽遍用西药与中药安神养血、平肝泻火、疏肝解郁之剂不效。邀请余诊治。询其病史，云：由于工作长期繁忙，加之又长期精神不够愉快，致使逐渐烦躁失眠。再询其证，云：除严重失眠外，并见胸满气短，时时叹气，头晕乏力，烦躁不安。综合其证，思之：病发于郁，郁者，当调气疏肝。乃予疏肝调气之剂十余剂，寸效不见。再思历代医家曾有思郁宜补之论，乃改用归脾汤7剂治之，不但不效，反见加剧。不得已，乃告患者另请高医治之。数月之后，患者又邀余治。云：诸医之药均无微效，请再处方以试之。正在此时，一医来访，并云：近治一高血压病患者，遍用养阴平肝，清肝泻火之剂不效，不得已，在上方中加入了黄芪一味，不曾想到患者诸证却明显改善，血压亦随之下降，为此曾遇数医的非议，请师一解。答曰：黄芪乃补气升阳之品，高血压病大多为肝阳上亢所致，因此高血压病大多不可用黄芪。此证原用平肝泻火之所以不效者，恐为过用寒凉之品郁其阳气所致，所以此时稍予黄芪之甘温，以助郁阳之升发，则清阳可升，浊阴可降，而病解。该医走后，我对以上失眠患者的治法，亦顿然而悟，此患失眠之所以久治不效者，乃前用诸方中舒者不补，补者不舒耳。再察其脉弦而大，乃处补中益气与六味地黄合方。服药2剂，竟睡眠达8小时，又服20剂，痊愈。
6．将相似论作为发现药物新的功用的方法清代以前对茯苓之赤、白与皮的功用不同，虽然稍有论述，但很不深刻。至黄宫绣著《本草求真》一书，应用相似之理才阐述明白。他说：“茯苓，色白入肺，味甘入脾，味淡渗湿。故书皆载上渗脾肺之湿，下伐肝肾之邪，其气先升后降。凡人病因水湿而见气逆烦满，心下结痛，呃逆呕吐，口苦舌干，水肿淋结，忧恚惊恐，及小便或涩或多者，服此皆能有效。故人四君，则佐参术以渗脾家之湿，入六味，则使泽泻以行肾邪之余，最为利水除湿要药，书曰健脾，即水去而脾自健之谓也；又曰定魄，即水去而魄自安之意也，且水既去，则小便自开，安有癃闭之虑乎？水去则内湿已消，安有小便多见之谓乎？故水去则胸膈自宽，而结痛烦满不作，水去则津液自生，而口苦舌干悉去。惟水衰精滑，小便不禁，非由水湿致者切忌，恐其走表泄气故耳。茯苓有赤、白之分，赤人小肠，白入膀胱，白微有补，赤则止泻湿热，一气一血，自不容混如此。至皮可治水肿腹胀，以皮行皮之义。”
(二)将相似论作为进行辨证论治的方法
1．伤寒、温病、温疫
(1)高热不退以时气相似之理推知其为寒包火证，予解表清里始安。
曾治患者李×，男，45岁。一个月前突然恶寒发热、头痛身痛。先予西药治疗一周不效，乃改请中医治疗。医生云：近世有人死抱住《伤寒论》一书不放，实际临床上没有一例伤寒，所以只能用银翘散加减治疗。并拟银翘散加减方十余剂治之，药后发热不但不减，反而更甚。患者又易医治之。云：患者体温39.5℃，如此高热怎可用银翘散，只可予白虎汤。服药4剂，诸证仍不见减。邀请余诊视。察其证见恶寒发热，头痛身痛，无汗烦躁，脉浮紧而数。乃云：此乃伤寒表寒闭郁至甚之大青龙汤证也。处方：麻黄18克，桂枝9克，杏仁9克，甘草6克，生姜9克，大枣12个，生石膏15克。
1剂后，全身汗出，体温降至37.5℃。乃以半量再服1剂，痊愈。
某医云：前医曾说当今只有温病而无伤寒，而老师却用伤寒之方取效甚速，其故为何？答曰：此病发于小寒大寒之间，乃时令之寒所加所致，根据相似之理辨知其为伤寒无疑，表寒者当予辛温解表，故以大青龙汤一剂得愈。
(2)肺炎咳喘以时令相似之理辨知其为凉燥犯肺，予杏苏散加减而愈。
曾治患者张×，男，8岁。咳嗽阵阵而作，喘而气短，平卧时加甚一个多月。某院诊断为肺炎。始予抗生素治疗无功，继又配合中药麻杏石甘汤仍无效。查其体温37.8℃，鼻翼微见煽动，口鼻微干，舌苔薄白，脉浮紧。又思本病正发于秋季，相据相似相应之理，诊为凉燥犯肺，内伏微饮。治拟杏苏饮加减。处方：杏仁6克，紫苏9克，半夏9克，陈皮6克，茯苓6克，枳壳6克，前胡6克，葛根10克，甘草3克，桔梗6克。服药1剂，发热即消，喘咳大减。继服2剂，痊愈。
2．内科
(1)口眼喁斜以春夏相似相应之理辨知其出其为阴血不足，风邪外客，予养血祛风始安。
曾治患者陈×，女，[年龄缺失]。口眼喁斜一个多月。前医以针灸、理疗与中药牵正散、乌药顺气汤加减治之不效。细审其脉浮，口微干，左眼不能闭合，口涎时时从口角流出。根据春夏相似相应之理，审其病发于夏初春末，知其为血虚风热外客，予养血祛风法，一剂减，6剂痊愈。
Patient Li XX, female, 54 years old. Swelling and pain in the toes, fingers, wrists, ankles, elbows, and knee joints for over five years. The physician diagnosed rheumatoid arthritis. The physician prescribed anti-rheumatic drugs, hormones, etc. Initially, there was slight improvement, but after long-term application, it not only became ineffective but also worsened day by day. Treatment was changed to Traditional Chinese Medicine (TCM). First, TCM decoctions were used to dispel wind, scatter cold, invigorate blood, and unblock collaterals; later, methods to tonify the liver and kidney, dampness-resolving and phlegm-transforming, qi-tonifying and blood-nourishing, as well as Wangbi Granules (Wangbi Chongji) and Ant Pills (Mayi Wan), showed no obvious effect. I was invited to treat the patient. Initially, modifications of Ju Tong Xuanbi Decoction (Jutong Xuanbi Tang), Da Qin Jiao Decoction (Daqin Jiao Tang), Sanbi Decoction (Sanbi Tang), and E Zhongxia Gout Formula (E Zhongxia Tongfeng Fang) were ineffective. Subsequently, Huoluo Xiaoling Dan (Huoluo Xiaoling Dan) and Guizhi Shaoyao Zhimu Tang (Guizhi Shaoyao Zhimu Tang) also yielded no results. Reflecting on the fact that joints are the gathering points of tendons and belong to bones, and "Bi" syndrome refers to obstruction caused by the confluence of wind, cold, and dampness pathogens, one might expect methods such as dispelling wind, resolving dampness, scattering cold, invigorating blood, unblocking collaterals, benefiting qi, nourishing blood, and tonifying the liver and kidney to be effective. However, why did they fail? *Lingshu: Benshu Chapter* states: "Shaoyang belongs to the Kidney, and the Kidney connects upward to the Lung, thus governing both organs. The Sanjiao is the mansion of middle waterways, from which water passages emerge; it belongs to the Bladder. It is the solitary mansion and is associated with the six fu organs." The previous treatments targeting the Lung and Kidney failed because the Shaoyang Sanjiao was not regulated. Furthermore, *Suwen: Liujie Zangxiang Lun* states: "All eleven organs depend on the Gallbladder." Both the Gallbladder and the Sanjiao belong to Shaoyang. Harmonizing the Shaoyang will naturally restore the Lung and Kidney's functions of regulating water passages. Therefore, treatment should focus on regulating the Sanjiao. Prescription: Chaihu (Bupleuri Radix) 10g, Zhike (Aurantii Fructus Immaturus) 10g, Baishao (Paeoniae Radix Alba) 10g, Gancao (Glycyrrhizae Radix et Rhizoma) 6g, Xiangyuan (Citri Reticulatae Pericarpium Viride) 10g, Foshou (Citri Sarcodactylis Fructus) 10g, Meiguihua (Rosae Rugosae Flos) 10g, Daidaihua (Citri Aurantii Flos) 10g, Huangqin (Scutellariae Radix) 3g, Hehuanhua (Albiziae Cortex Flos) 15g. After taking 4 doses, not only was the pain in the fingers, toes, wrists, ankles, elbows, and knees reduced, but headaches, chest pain, and back pain were also alleviated by 60-70%. After continuing for 30 doses, all symptoms disappeared, and the patient recovered.
Patient Zhang XX, male, 14 years old. Severe edema and massive proteinuria for over three years. The physician diagnosed nephrotic syndrome. Western medicine treatment with hormones, etc., for half a year was ineffective. Subsequent TCM treatments including diuresis and edema reduction, clearing heat and detoxifying, invigorating blood and resolving stasis, benefiting qi and promoting urination, and tonifying the kidney and promoting urination were all ineffective. I was invited to treat the patient. Upon examination, severe edema, poor appetite, decreased food intake, dry and painful throat, scanty yellow foamy urine, yellow-white greasy tongue coating, and deficient, wiry, slippery, and rapid pulse were observed. Reflecting on this: Previous physicians either benefited the Lung by tonifying qi or nourished the Kidney by tonifying yin, yet why did they fail for so long? Because the Sanjiao was not regulated. *Lingshu: Benshu Chapter* states: "Shaoyang belongs to the Kidney, and the Kidney connects upward to the Lung, thus governing both organs. The Sanjiao is the mansion of middle waterways, from which water passages emerge; it belongs to the Bladder. It is the solitary mansion and is associated with the six fu organs." My developed Shenkangling (Shenkangling) not only benefits qi to aid the Lung but also nourishes yin to benefit the Kidney, and contains herbs that regulate the Sanjiao and communicate between the Heart and Kidney. Why not use it? Therefore, Shenkangling was prescribed, 4 capsules per dose, 3 times daily. After half a month, edema completely subsided, and appetite improved; urinary protein decreased from ++++ to ++. After two months of continued medication, all symptoms disappeared, and the patient recovered.
Similarity and Clinical Practice
Observing the millennia-long development history of Chinese medicine, it can be seen that the reason for its enduring vitality lies in its guiding set of correct thinking modes. Turning to the innovation histories of classic works from *Neijing*, *Shennong Bencao Jing* to *Shanghan Lun* and *Jingui Yaolue*, and of physicians with outstanding achievements, it is not difficult to see that the main viewpoint driving this development is the theory of similarity in Chinese medicine—the so-called "taking analogy and comparing images" doctrine.
I. Basic Connotation of the Theory of Similarity in Chinese Medicine
The theory of similarity is the basic thinking method of Chinese medicine, formed under the guidance of dialectical materialist thought. This thinking mode believes that by analyzing numerous similar phenomena between subjects and objects, various regularities can be found. Among these regularities, the primary ones to identify are the laws of Yin-Yang and Five Elements, i.e., determining what belongs to Yin, what to Yang; what belongs to Wood, Fire, Earth, Metal, Water in the Five Elements. As *Suwen* states: "Yin and Yang are the Way of Heaven and Earth, the general principles of all things, the parents of change, the origin of life and death, and the residence of spiritual clarity." Therefore, treating disease must seek the root.
Secondly, among many similar components, systemic, local, dynamic, and static similarities are the most common. Among these four types, systemic and dynamic similarities are considered the most important, and the more similar components exist between similar substances, the closer their nature becomes.
Thirdly, among numerous similar substances, not only do similarities exist, but there is also mutual resonance between them. It is believed that the more similar components exist between similar substances, the greater their mutual resonance. Thus, medical workers can discover systemic, local, dynamic, and static regularities through the degree of similarity in symptoms and signs within systems, localities, motion, and stillness, as well as their mutual resonance with natural changes, and treat diseases based on these regularities.
II. Application of the Theory of Similarity in Chinese Medicine
How does Chinese medicine apply the theory of similarity to discover and solve problems? Generally, there are two aspects:
(A) Using the theory of similarity as a method to discover different regularities
1. Using the theory of similarity to discover new etiological factors. Before the Qing Dynasty, many physicians lacked a profound understanding of Dryness pathogen in etiology. Inspired by the theory of similarity, the famous physician Yu Chang in the late Ming and early Qing dynasties clearly pointed out that the Nineteen Pathogenesis Mechanisms omitted Dryness. He said: "Dryness and Dampness differ vastly. Dryness is the Qi of Heaven, Dampness is the Qi of Earth. Water flows to dampness, fire goes to dryness, each following its kind. When one wins, the other loses, without conspiring. In spring, earth Qi moves and Dampness prevails, causing grass and trees to flourish. In autumn, heaven Qi becomes solemn and Dryness prevails, causing grass and trees to yellow and fall. Thus, Dampness after Spring Equinox and Dryness after Autumn Equinox each govern their respective terms. To point to autumn Dryness as Dampness would require pointing to summer Heat as Cold. How can *Neijing*'s Nineteen Pathogenesis Mechanisms omit Dryness, while stating that autumn injuries due to Dryness are actually injuries due to Dampness? Past sages interpreted texts literally without noticing the error."
2. Using the theory of similarity to discover new physiological functions. Before the Ming Dynasty, most physicians' understanding of the Gate of Life (Mingmen) was limited to *Nanjing*: "The Gate of Life is where spirits and essences reside and where original Qi is rooted." They lacked a profound understanding of its major physiological role. It was not until Zhao Yangkui in the Ming Dynasty, based on the theory of similarity, that he had a full understanding of Mingmen. He said: "Mingmen is the master of the twelve meridians. Without it, the Kidneys cannot perform strength, and skills do not emerge; without it, the Bladder cannot transform Sanjiao Qi, and water passages do not flow; without it, the Spleen and Stomach cannot steam and rot water and grain, and the five grains do not emerge; without it, the Liver and Gallbladder lack decision-making, and strategies do not emerge; without it, the Heart loses spiritual clarity, and matters do not respond. This is precisely 'when the ruler is unclear, the twelve officials are in danger.' I have an analogy: like the lantern parade at the Lantern Festival, bowing, dancing, flying, walking figures are all present, but in the center is only one fire. When the fire is strong, movement is fast; when weak, slow; when extinguished, silent. Yet the bodies remain. Thus, your body does not belong to you; it is a form entrusted by Heaven and Earth. I earnestly wish to clarify this theory so that those who cultivate health and treat diseases may truly regard Mingmen as the monarch."
3. Using the theory of similarity to discover treatment principles. Qing dynasty physician Xu Lingtai profoundly analyzed the establishment of various treatment principles through the logic of military strategy similarity, discovering the connotation of each principle. He said: "The sage ensures people's lives by using five grains for nourishment, five fruits for assistance, five meats for benefit, and five vegetables for supplementation, while toxic substances are used to attack evil. Thus, even Licorice and Ginseng, if misused, cause harm and are classified as toxic. Ancients who loved consuming tonics inevitably acquired strange diseases, just as those who loved winning battles inevitably suffered strange disasters. Therefore, armies are established to eliminate violence, raised only when necessary; medicines are established to attack diseases, used only when necessary. Their ways are the same. Disease as a affliction consumes essence slightly or injures life greatly, resembling an enemy state. Using the partial advantages of herbs to attack the partial excesses of zang-fu organs requires knowing oneself and the enemy, employing multiple strategies to control it, avoiding the worry of losing one's life. Thus, for transmitted pathogenic factors, seizing those not yet arrived cuts off the enemy's key routes; for violent diseases, urgently protecting the uninfected defends our strict borders. For patients with retained food, removing the food first burns the enemy's supplies; for diseases combined with old ailments, preventing the disease cuts off the enemy's internal response. Differentiating meridians without indiscriminate medication is called guiding troops; using contrary formulas due to cold and heat is called maneuvering tactics. Treating one disease by dividing it allows few to defeat many, making front and rear unable to rescue each other, causing momentum to decline; treating multiple diseases together attacks their core, leaving them disorganized and defeated. If the disease is advancing, do not treat it too severely; conserve vital Qi to exhaust the enemy's army. If the disease is declining, pursue it relentlessly, adding elite forces to strike the den. For deficiency evils, attacks should not exceed limits; use mild medicines supplemented with harsh ones; on days of decline, do not exhaust people's strength. For excess evils, attacks should not be delayed; use harsh medicines harmonized with common ones; a wealthy nation can display majesty and might. However, selecting materials appropriately, ensuring good instruments, meeting deadlines without delay, and deploying formations correctly—these cannot be counted one by one. Sun Tzu's Thirteen Chapters encompass all methods of treating disease."
4. Using the theory of similarity to discover different pathogenesis mechanisms. I once treated a man, 45 years old. Burning pain in the esophagus, worsening during swallowing, for over 5 years. Diagnosed as esophagitis. Western medicine treatment for over two years was ineffective. Subsequent TCM treatments involving invigorating blood, purging fire, soothing the Liver, or strengthening the Spleen for about three years were also ineffective. I was invited to treat him. Over 40 doses of medicine provided no obvious improvement. One day, he visited unexpectedly. Seeing his pale and lusterless complexion, I suddenly realized: White corresponds to the Lung; it must be caused by Lung Yin deficiency. I then formulated a formula to nourish Yin and moisten the Lung. Prescription: Baihe (Lilii Bulbus) 40g, Wuyao (Linderae Radix) 10g, Maidong (Ophiopogonis Radix) 10g. After 4 doses, pain decreased by 50-60%. After continuing for 20 doses, he recovered.
5. Using the theory of similarity as a cognitive method for composing new formulas. I once treated a woman, 50 years old. Severe insomnia for over two years. Initially, sedative-hypnotic Western medicines allowed brief sleep, but for the past half year, despite using various Western and TCM medicines for calming the mind, nourishing blood, pacifying the Liver, purging fire, soothing the Liver, and relieving depression, there was no effect. I was invited to treat her. Asking about her history, she said: Due to long-term busy work and prolonged mental dissatisfaction, she gradually became irritable and insomniac. Asking about her symptoms, she said: Besides severe insomnia, she experienced chest fullness, shortness of breath, frequent sighing, dizziness, fatigue, and restlessness. Synthesizing her symptoms, I reflected: The disease originated from stagnation; stagnation requires regulating Qi and soothing the Liver. I prescribed Qi-regulating and Liver-soothing agents for over ten doses, with no effect. Recalling that past physicians argued that mental stagnation should be tonified, I switched to Guipi Tang (Guipi Decoction) for 7 doses. Not only was it ineffective, but symptoms worsened. Reluctantly, I advised the patient to seek another doctor. Months later, the patient invited me again, saying: All doctors' medicines had no effect; please prescribe again to try. At that moment, a physician visited and said: Recently, I treated a hypertension patient. Various Yin-nourishing, Liver-pacifying, Liver-clearing, and Fire-purging agents were ineffective. Reluctantly, I added Astragalus (Huangqi) to the above formula. Unexpectedly, the patient's symptoms improved significantly, and blood pressure dropped accordingly. I faced criticism from several physicians; please explain. I answered: Astragalus is a Qi-tonifying and Yang-raising substance. Most hypertension cases are caused by Liver Yang rising; therefore, Astragalus is generally contraindicated in hypertension. The reason the previous Liver-pacifying and Fire-purging approach failed here is likely due to excessive use of cold-cooling substances suppressing Yang Qi. Thus, adding a small amount of Astragalus' sweet-warm nature helps promote the rise of suppressed Yang, allowing Clear Yang to ascend and Turbid Yin to descend, resolving the disease. After that physician left, I suddenly understood the treatment method for the above insomnia patient. The reason previous treatments failed was that those that dispersed did not tonify, and those that tonified did not disperse. Observing her pulse was wiry and large, I prescribed a combination of Buzhong Yiqi Tang (Buzhong Yiqi Decoction) and Liuwei Dihuang Wan (Six-Ingredient Pill with Rehmannia). After 2 doses, sleep reached 8 hours. After another 20 doses, she recovered.
6. Using the theory of similarity to discover new functions of herbs. Before the Qing Dynasty, although there were some discussions on the different functions of red/white Poria (Fuling) and its peel, they were not profound. It was not until Huang Gongxiu wrote *Bencao Qiuyuan* (Compendium of Materia Medica Seeking Truth) that he clarified this using the logic of similarity. He said: "Poria is white, entering the Lung; sweet in taste, entering the Spleen; bland in flavor, leaching out dampness. Books record that it leaches Dampness from the Spleen and Lung above and eliminates Evil from the Liver and Kidney below. Its Qi rises first and descends later. For anyone whose disease causes Qi rebellion, vexation, fullness, epigastric knotted pain, hiccups, vomiting, bitter taste, dry tongue, edema, strangury, sorrow, anger, fright, and fear, and where urination is either obstructed or excessive, taking this herb is effective. Thus, in Sijunzi Tang (Four Gentlemen Decoction), it assists Ginseng and Atractylodes to leach Spleen Dampness; in Liuwei Dihuang Wan, it aids Alisma to expel Kidney Evil. It is the most important herb for promoting urination and resolving dampness. 'Strengthening the Spleen' means the Spleen strengthens itself after water is removed; 'Calming the Soul' means the Soul calms itself after water is removed. Moreover, once water is removed, urination opens naturally, so why worry about strangury? Once water is removed, internal dampness is eliminated, so why worry about excessive urination? Thus, once water is removed, the chest and diaphragm widen, and knotted pain and vexation cease; once water is removed, fluids generate naturally, and bitter taste and dry tongue disappear. Only in cases of water deficiency, seminal emission, and involuntary urination not caused by water-dampness should it be strictly avoided, lest it leak Qi from the exterior. Poria has red and white varieties. Red enters the Small Intestine, White enters the Bladder. White has slight tonifying properties, Red stops diarrhea and clears damp-heat. Qi and Blood are naturally distinct. As for the peel, it treats edema and abdominal distension, following the principle of 'peel acting on peel.'"
(B) Using the theory of similarity as a method for syndrome differentiation and treatment
1. Shanghan, Wenbing, Wenyi
(1) Persistent high fever inferred as Cold enveloping Fire based on seasonal climate similarity, resolved by releasing the exterior and clearing the interior.
I once treated patient Li X, male, 45 years old. Suddenly experienced aversion to cold, fever, headache, and body pain one month ago. Western medicine treatment for one week was ineffective, so TCM treatment was sought. The physician said: Nowadays, some people cling rigidly to *Shanghan Lun*, claiming there are no cases of Shanghan clinically, so only Yin Qiao San (Yinqiao Powder) modifications can be used. He prescribed Yin Qiao San modifications for over ten doses. After medication, fever did not decrease but increased. The patient changed doctors. The new physician said: Patient's temperature is 39.5°C. How can Yin Qiao San be used for such high fever? Only Baihu Tang (White Tiger Decoction) can be used. After 4 doses, symptoms remained unchanged. I was invited to examine. Observing aversion to cold, fever, headache, body pain, absence of sweat, irritability, and floating-tight-numerous pulse, I said: This is a Da Qing Long Tang (Major Green Dragon Decoction) syndrome of severe closure of exterior Cold in Shanghan. Prescription: Mahuang (Ephedrae Herba) 18g, Guizhi (Cinnamomi Ramulus) 9g, Xingren (Armeniacae Semen Amarum) 9g, Gancao (Glycyrrhizae Radix et Rhizoma) 6g, Shengjiang (Zingiberis Rhizoma Recens) 9g, Dazao (Ziziphi Jujubae Fructus) 12 pieces, Sheng Shigao (Gypsum Fibrosum) 15g.
After 1 dose, whole-body sweating occurred, and temperature dropped to 37.5°C. Half dosage was taken for another dose, and the patient recovered.
A physician asked: The previous physician claimed that nowadays there are only Wenbing (Warm Diseases) and no Shanghan, yet the teacher achieved rapid results with a Shanghan formula. Why? I answered: This disease occurred between minor and major cold periods, caused by seasonal cold addition. Based on similarity logic, it is undoubtedly Shanghan. For exterior Cold, acrid-warm exterior-releasing methods should be used, hence recovery with one dose of Da Qing Long Tang.
(2) Pneumonia cough and asthma identified as Cool-Dryness invading the Lung based on seasonal similarity, cured with Xing Su San (Apricot and Perilla Powder) modifications.
I once treated patient Zhang X, male, 8 years old. Paroxysmal cough, wheezing with shortness of breath, worsening when lying flat for over a month. Diagnosed as pneumonia at a certain hospital. Antibiotic treatment was ineffective, followed by Ma Xing Shi Gan Tang (Ephedra, Apricot Kernel, Gypsum, and Licorice Decoction) with no effect. Temperature was 37.8°C, nasal wings slightly flaring, mouth and nose slightly dry, thin-white tongue coating, floating-tight pulse. Reflecting that this disease occurred in autumn, based on similarity and correspondence principles, diagnosed as Cool-Dryness invading the Lung with latent fluid retention. Treatment planned with Xing Su Yin (Apricot and Perilla Drink) modifications. Prescription: Xingren (Armeniacae Semen Amarum) 6g, Zisu (Perillae Folium) 9g, Banxia (Pinelliae Rhizoma) 9g, Chenpi (Citri Reticulatae Pericarpium) 6g, Fuling (Poria) 6g, Zhike (Aurantii Fructus Immaturus) 6g, Qianhu (Peucedani Radix) 6g, Gegen (Puerariae Lobatae Radix) 10g, Gancao (Glycyrrhizae Radix et Rhizoma) 3g, Jiegeng (Platycodonis Radix) 6g. After 1 dose, fever subsided, and cough/wheezing greatly reduced. After 2 more doses, the patient recovered.
2. Internal Medicine
(1) Facial paralysis inferred as Yin-Blood deficiency with external Wind pathogen based on Spring-Summer similarity and correspondence, resolved by nourishing Blood and dispelling Wind.
I once treated patient Chen X, female, [age missing]. Facial paralysis for over a month. Previous treatments with acupuncture, physical therapy, and TCM medications Qianzheng San (Qianzheng Powder) and Wuyao Shunqi Tang (Wuyao Smooth-Qi Decoction) modifications were ineffective. Carefully examining floating pulse, slightly dry mouth, inability to close the left eye, and drooling from the corner of the mouth. Based on Spring-Summer similarity and correspondence principles, observing the disease onset in late spring/early summer, determined it as Blood deficiency with external Wind-Heat. Prescribed Blood-nourishing and Wind-dispelling method. Symptoms reduced after 1 dose, cured after 6 doses.
(2) Anemia and hematuria identified as Blood-level pathology based on Day-Night similarity and correspondence.