药之相须、相使、相恶、相反，出北齐徐之才药对，非上古之论也。聿考《伤寒》、《金匮》、《千金》
诸方，相畏、相反者多并用。有云相畏者，如将之畏帅，勇往直前，不敢退却；相反者，彼此相忌，能各
立其功，圆机之士，又何必胶执于时袭之固陋乎！
《至真要论》曰∶近者奇之，远者偶之；汗者不以奇，下者不以偶。夫近奇、远偶者，谓奇上而偶
下，犹天地之定位也；下宜奇而汗宜偶者，以降者谓天，升者谓地，地气升而后能为云、为雨也。夫天地
阴阳之道，天气下降，气流于地，地气上升，气腾于天，不则天地四塞，而汗从何来？有不明天地气交之
道者，泥于近奇、远偶之句，反改为汗不以偶、下不以奇，此不通之甚也。《大要》曰∶君一臣二，奇之
制也；君二臣四，偶之制也；君二臣三，奇之制也；君二臣六，偶之制也。近而奇偶，制小其服，远而奇
偶，制大其服。大则数少，小则数多。多则九之，少则二之。盖数少而分两重者为大方，数多而分两少者为
小方。是以上古之方，少者一二三味，其分两各三两四两，多者不过八九味，分两亦各有两数，（古之二
两，今之一两也。）皆有君臣佐使之分焉。有独赞东垣能用大方，如韩信将兵，多多益善。噫！此但知有东垣，而
不知有《内经》者也。夫东垣之大方，不过以数方合用，是为复方。如清暑益气汤，以补中益气汤内，加
二妙、生脉二方，焉能如先圣之大方乎？（上古大方，间或用之。）试观鳖甲煎丸，用至二十四味，其间参伍错综，
如孔明阵图，人莫能识。
药物之间的相须、相使、相恶、相反关系，出自北齐徐之才的《药对》，并非上古时期的理论。我考察《伤寒论》、《金匮要略》、《千金方》等书中的方剂，发现相畏、相反的药物经常同时使用。所谓“相畏”，就像将领畏惧主帅一样，勇往直前，不敢退缩；所谓“相反”，是指彼此相互禁忌，但又能各自发挥功效。具有灵活变通智慧的人，又何必拘泥于当时沿袭的浅陋见解呢！
《素问·至真要大论》说：“病位近的用奇方，病位远的用偶方；发汗不用奇方，攻下不用偶方。”所谓“近用奇、远用偶”，是指奇数药在上（主升），偶数药在下（主降），这如同天地各有定位一样；而“下法宜用奇方，发汗宜用偶方”，是因为以下行为天（主降），以上行为地（主升），地气上升后才能化为云、雨。天地阴阳的道理是：天气下降，气流注于地；地气上升，气腾扬于天。如果不这样，天地之气就会闭塞不通，汗液从何而来？那些不明白天地气交道理的人，拘泥于“近者奇之，远者偶之”的字句，反而改为“汗不以偶，下不以奇”，这是非常不通达的。《大要》说：“君药一味，臣药二味，是奇方的制度；君药二味，臣药四味，是偶方的制度；君药二味，臣药三味，是奇方的制度；君药二味，臣药六味，是偶方的制度。”病位近而用奇方或偶方，则制剂量小；病位远而用奇方或偶方，则制剂量大。大方则药味少而分量重，小方则药味多而分量轻。药味多则达到九味，药味少则仅二味。大概药味少而剂量重的是大方，药味多而剂量轻的是小方。所以上古的方剂，少的只有两三味药，每味药的剂量各为三两或四两；多的不过八九味药，剂量也各有几两。（古代的二两，相当于现在的一两。）这些方剂都有君、臣、佐、使的分工。有人单独称赞李东垣善于使用大方，像韩信带兵一样，越多越好。唉！这只是知道有李东垣，却不知道有《黄帝内经》啊。李东垣的大方，不过是把几个方子合在一起使用，这叫复方。比如清暑益气汤，是在补中益气汤中加入二妙散和生脉散两个方子，怎么能比得上先圣的大方呢？（上古的大方，偶尔也会使用。）试看鳖甲煎丸，用到二十四味药，其中参伍错综，排列组合，就像诸葛亮的八阵图一样，人们无法识破其奥秘。
The relationships of mutual synergy (Xiangxu), mutual assistance (Xiangshi), mutual aversion (Xiang'e), and mutual incompatibility (Xiangfan) among herbs originate from Xu Zhicai's *Yao Dui* (Drug Pairs) of the Northern Qi dynasty, rather than being theories from ancient times. Upon examining prescriptions in *Shanghan Lun* (Treatise on Cold Pathogenic Diseases), *Jingui Yaolue* (Essential Prescriptions of the Golden Cabinet), and *Qianjin Fang* (Prescriptions Worth a Thousand Gold), it is found that herbs with mutual aversion or incompatibility are often used together. "Mutual aversion" is likened to a general fearing his commander, marching bravely forward without retreating; "mutual incompatibility" implies mutual taboo, yet each can still achieve its efficacy. Those with flexible wisdom need not rigidly adhere to the narrow-minded conventions of their time!
The *Zhi Yao Lun* chapter of *Suwen* states: "For conditions near the surface, use odd-numbered formulas; for conditions far within, use even-numbered formulas. For diaphoresis (sweating method), do not use odd numbers; for purgation, do not use even numbers." The phrase "near uses odd, far uses even" refers to odd numbers governing the upper (ascending) and even numbers governing the lower (descending), analogous to the fixed positions of Heaven and Earth. However, "purgation should use odd numbers, and diaphoresis should use even numbers" because descending actions correspond to Heaven (in this context referring to the downward movement of Qi) and ascending actions to Earth; only when Earth's Qi ascends can it transform into clouds and rain. The principle of Heaven and Earth's Yin and Yang is that Heavenly Qi descends, flowing into the Earth, while Earthly Qi ascends, rising to Heaven. If this does not occur, the Qi of Heaven and Earth becomes blocked, and from where would sweat come? Those who fail to understand the Dao of Qi interaction between Heaven and Earth, by clinging literally to the phrases "near uses odd, far uses even," mistakenly reverse them to "diaphoresis does not use even, purgation does not use odd," which is extremely illogical. The *Da Yao* states: "One sovereign herb and two minister herbs constitute an odd formula; two sovereign and four minister herbs constitute an even formula; two sovereign and three minister herbs constitute an odd formula; two sovereign and six minister herbs constitute an even formula." When the condition is near, whether using odd or even formulas, the dosage is small; when the condition is far, whether using odd or even formulas, the dosage is large. Large formulas have fewer ingredients but heavier dosages; small formulas have more ingredients but lighter dosages. The number of ingredients may reach nine, or be as few as two. Generally, formulas with fewer ingredients and heavier dosages are considered large formulas, while those with more ingredients and lighter dosages are small formulas. Thus, ancient formulas contained one to three ingredients, each weighing three or four liang, and rarely exceeded eight or nine ingredients, with dosages varying accordingly. (Two liang in ancient times equate to one liang today.) All these formulas had distinct roles of sovereign (Jun), minister (Chen), assistant (Zuo), and courier (Shi). Some praise Li Dongyuan solely for his ability to use large formulas, comparing him to Han Xin leading troops, where more is better. Alas! This shows knowledge only of Li Dongyuan, but ignorance of the *Neijing*. Li Dongyuan's "large formulas" are merely combinations of several existing formulas, known as compound formulas. For instance, *Qingshu Yiqi Tang* (Clear Heat and Boost Qi Decoction) combines *Buzhong Yiqi Tang* (Tonify the Middle and Boost Qi Decoction) with *Er Miao San* (Two Marvels Powder) and *Shengmai San* (Generate the Pulse Powder). How can this compare to the large formulas of the ancient sages? (Large formulas were occasionally used in ancient times.) Consider *Biejia Jian Wan* (Softshell Turtle Pill), which contains twenty-four ingredients, intricately arranged like Zhuge Liang's Eight Formation Diagram, incomprehensible to ordinary people.