近时医者偏执己见或好用热药或好用凉药然素问有异法方宜论抑何尝偏执邪古之良医必
量人
之虚实察病之阴阳而后投以汤剂或补或泻各随其症若的是阳虚失血治以干姜附子诸虚百损补
以人参黄 痰热壅嗽清以芩连大便结热利以硝黄其法岂尽废乎许叔微有云形有寒邪虽婴孩亦
可服金液脏有热毒虽老羸亦可服大黄至哉通变之说也
病有正治有反治然正治之法人皆知之反治者从顺病气之法也假如治热症不可纯用寒凉佐
以辛
温之药为之向导治寒症不可纯用温热佐以辛凉之药为之向导否则病拒药而 格不入其病反纵
反纵则痛发尤甚丹溪治疝用山栀除湿热佐以乌头散寒郁古方以蜜煎附子葱白散加大黄之属即
经所谓用寒远寒用热远热之意云
昔闻老医云治北方之疾宜以攻伐外邪为先治南方之疾宜以保养内气为本盖北方风气浑浓
禀
赋雄壮兼之饮食倍常居室俭素殊少戕贼元气之患一有疾病辄以苦寒疏利之其病如脱而快意通
神
矣若夫东南之人体质柔脆腠理不密而饮食色欲之过侈与西北之人迥异概以苦寒之剂攻之不几
于操刃而杀人乎余因其言而推展之曰北人禀气固浓安能人人皆实南人禀气虽薄安能人人皆虚
学人当以权变处治因其虚实而药之斯无一偏之弊矣
嘉禾周伯器(鼎)云惟贵势人之病难治者有三群医争欲售所能攻补杂施一难也遇下不以礼
自重
者不苟往所往者非所重二难也唯唯取悦孰得尽禁其欲三难也余亦有三难以补周之未备朝病暮
药速欲求效四难也猎涉方书有病自治五难也不信服药惟仗鬼神六难也
近时的医生偏执于自己的见解，有的喜欢用热性药，有的喜欢用凉性药。然而《素问》中有《异法方宜论》，哪里曾有过偏执呢？古代的良医必定衡量病人的虚实，察辨疾病的阴阳，然后才施用汤剂，或补或泻，都根据病症而定。如果是阳虚导致的失血，就用干姜、附子等治疗；各种虚损，用人参、黄芪来补益；痰热壅盛引起的咳嗽，用黄芩、黄连来清热；大便结滞有热，用芒硝、大黄来通便泄热。这些方法难道全都废弃了吗？许叔微曾说：“形体有寒邪，即使是婴儿也可以服用金液丹（一种温阳救逆的成药）；脏腑有热毒，即使是年老体弱的人也可以服用大黄。”这真是关于通权达变说法的精妙之处啊！
疾病有正治和反治两种方法。然而正治的方法大家都知道了，反治是顺从病气表象的治疗方法。例如治疗热症，不可以单纯使用寒凉药，要佐以辛温的药作为向导；治疗寒症，不可以单纯使用温热药，要佐以辛凉的药作为向导。否则，病邪会抗拒药物，导致格拒而不入，病情反而加重。病情加重则疼痛发作得更加厉害。朱丹溪治疗疝气，用山栀清除湿热，佐以乌头散寒郁。古方中用蜜煎附子、葱白散加大黄之类的方剂，就是《内经》所说的“用寒远寒，用热远热”的意思。
过去听老医生说，治疗北方的疾病应当以攻伐外邪为先；治疗南方的疾病应当以保养内气为本。大概北方风气浓厚，人的禀赋雄壮，加上饮食加倍于常人，居室俭朴，很少有害伤元气的祸患。一旦有了疾病，就用苦寒疏利的药物，病就像脱去束缚一样爽快，通达神明。至于东南地区的人，体质柔脆，腠理不致密，而且饮食色欲过度奢侈，与西北之人截然不同。一概用苦寒的药剂去攻伐，这不近乎拿着刀杀人吗？我根据他的话而推演发挥说：北方人禀受的气机坚固浓厚，难道每个人都是实证吗？南方人禀受的气机虽然薄弱，难道每个人都是虚证吗？学医的人应当根据权变来处理治疗，依据病人的虚实来用药，这样就没有偏颇的弊病了。
嘉禾周伯器（名鼎）说：只有权贵之人的病难治的有三种情况：群医争着展示才能，攻补杂施，这是第一难；遇到地位低下的人不以礼相待，自己不自重，所交往的人不是他所看重的，这是第二难；唯唯诺诺取悦于人，怎么能完全禁止他的欲望呢？这是第三难。我也有三种困难来补充周先生没有完备的地方：早晨生病晚上吃药，急于求效，这是第四难；猎涉方书，有病自行治疗，这是第五难；不相信服药，只依靠鬼神，这是第六难。
Contemporary physicians are often biased by their own preconceptions; some prefer to use hot-natured medicines, while others prefer cold-natured medicines. However, the *Suwen* (Plain Questions) contains the chapter "Yi Fa Fang Yi Lun" (Discussion on Different Methods and Appropriate Locations), which indicates that there was never such bias in ancient times. Ancient excellent physicians would always assess the patient's deficiency or excess (*Xu Shi*) and observe the Yin or Yang nature of the disease before administering decoctions. Whether tonifying or purging, treatment was tailored to the specific syndrome. For instance, if bleeding resulted from Yang deficiency, *Gan Jiang* (Dried Ginger) and *Fu Zi* (Prepared Aconite Root) were used; for various deficiencies and damages, *Ren Shen* (Ginseng Root) and *Huang Qi* (Astragalus Root) were employed to tonify; for coughs caused by phlegm-heat obstruction, *Huang Qin* (Scutellaria Root) and *Lian Zi* (Lotus Plumule) were used to clear heat; for constipation with heat accumulation, *Xiao Shi* (Mirabilite) and *Da Huang* (Rhubarb Root and Rhizome) were used to purge heat and promote bowel movement. Were these methods entirely abandoned? Xu Shuwei once stated: "Even infants with cold pathogens in the body can take *Jin Ye Dan* (Golden Liquid Pill); even the elderly and frail with heat toxins in the viscera can take *Da Huang*." This truly exemplifies the profound principle of adapting treatment to changing circumstances.
Diseases are treated by either direct regulation (*Zheng Zhi*) or contrary regulation (*Fan Zhi*). While everyone knows the method of direct regulation, contrary regulation involves following the apparent manifestation of the pathogenic qi. For example, when treating heat syndromes, one should not use only cold-natured medicines but must assist them with acrid-warm medicines as guides; when treating cold syndromes, one should not use only warm-natured medicines but must assist them with acrid-cool medicines as guides. Otherwise, the disease will reject the medicine, leading to rejection and non-entry of the drug, causing the condition to worsen. If the condition worsens, pain will become even more severe. Zhu Danxi treated hernia by using *Zhi Zi* (Gardenia Fruit) to remove damp-heat, assisted by *Wu Tou* (Aconite Root) to disperse cold stagnation. Ancient formulas using honey-fried *Fu Zi* combined with *Cong Bai San* (Green Onion White Powder) plus *Da Huang*, etc., reflect the meaning of the *Neijing* (Inner Canon): "When using cold, avoid cold [pathogens/seasons]; when using heat, avoid heat."
I once heard an old physician say that treating diseases in the North should prioritize attacking external pathogens, whereas treating diseases in the South should focus on preserving internal Qi. Generally, the wind and qi in the North are dense, people have robust constitutions, consume twice as much food as usual, live simply, and rarely suffer damage to their Yuan Qi. When illness occurs, bitter-cold and draining medicines are used, making the patient feel as if a burden has been lifted, bringing relief and clarity. In contrast, people in the Southeast have fragile constitutions, loose interstices (*Cou Li*), and indulge excessively in diet and sexual desires, which is vastly different from those in the Northwest. To indiscriminately attack them with bitter-cold agents would be akin to killing someone with a blade. Expanding upon his words, I argue: Northerners have solid and dense Qi, yet does this mean everyone presents with excess patterns? Southerners have thin Qi, yet does this mean everyone presents with deficiency patterns? Practitioners must apply flexible judgment, treating according to the patient's deficiency or excess, thereby avoiding the弊端 of bias.
Zhou Boqi (Ding) from Jiahe stated that there are three difficulties in treating patients of high status: First, many physicians compete to display their skills, mixing attacking and tonifying methods indiscriminately. Second, they encounter individuals who do not treat themselves with dignity or respect others, associating only with those they deem unworthy. Third, they yield to flattery and cannot completely forbid the patient's desires. I also have three difficulties to supplement Zhou's incomplete points: Fourth, prescribing medication on the same day as onset, seeking immediate effects. Fifth, browsing medical texts and self-treating illnesses. Sixth, distrusting herbal medicine and relying solely on ghosts and gods.