李东垣谓∶桔梗为药中舟楫，能载诸药上浮于至高之分。当时未曾分明甘、苦，而推其
功用
，则当属于甘者；若苦梗泄肺，是能泄至高之气，不能升气于至高也。近日着本草者，列其
说于苦桔梗条内，谬矣。甜桔梗味甘而静，能升发胃气，故能解百药毒，与葛根相近。后人
又谓桔梗能开肺发表。此则甘、苦皆无此功。且诸书并明言咳嗽以苦梗开之，何也?彼盖见
苦梗中挟辛膻之气也，而孰知其辛不敌苦耶!故徐灵胎谓∶外感作咳，用桔梗、麦冬清肺，
便成劳损。可称伟论!
时医无术，不议病而议药，无问病之轻重，但见药力之稍峻者，遂避之如虎，而不察其
所为
峻者，果何在也?故病之当用攻者，轻则桃仁、桑皮，重则大黄、芒硝，再重则宁用牵牛、
巴豆，而所谓 虫，虻虫、水蛭、蛴螬，则断断乎不敢一试。何者?其认病、认药皆不真，
故但取轻者以模棱了事也。误人性命，岂浅鲜耶!夫牵牛、巴豆等药，直行而破气，能推荡
肠胃有形之渣滓，而不能从容旁渗于经络曲折之区，以疏其瘀塞也。
故血痹之在经络脏腑深曲之处者，非抵当辈断不为功，而误用硝、黄、
牵牛、巴豆，直行破气，是诛伐无过矣。且血痹而破其气，气虚而血不愈痹耶?世之乐彼而
恶此者，亦曰虻虫、水蛭有毒耳?牵牛、巴豆独无毒耶?窃以狂夫一得，为天下正告之曰∶牵
牛、巴豆破气而兼能破血者也，其行直而速，病在肠胃直道之中，而未及四渗，则以此下之
愈矣；若血络屈曲，俱有瘀滞，非虻、蛭之横行而缓者不能达也。虻、蛭止攻血，略无伤于
气，且其体为蠕动之物，是本具天地之生气者，当更能略有益于人气也，有气则灵，故能屈
曲而旁达也。海藏云∶妊娠蓄血，忌抵当、桃仁，只以大黄合四物服之，则母子俱可无损而
病愈。以胎倚血养，故不得以虻、蛭破血太急也。然胎亦借大气举之，若气虚者，又不如抵
当、桃仁加补气药之为稳矣。
李东垣曾说：桔梗是药中的舟楫，能够载着其他药物上浮到人体最高部位。当时没有明确区分甘、苦两种桔梗，而推究其功效，应当归属于甘味一类；如果是苦桔梗泄肺，那就是能泄掉高处的肺气，而不能将气升提至高处以发挥作用。最近编写本草著作的人，把这种说法列在苦桔梗条目下，这是错误的。甜桔梗味甘且性静，能够升发胃气，所以能解各种药物的毒，功效与葛根相近。后人又说桔梗能开宣肺气、发散表邪。这无论是甘桔梗还是苦桔梗都没有这个功效。况且各种医书都明确说明咳嗽要用苦桔梗来开宣，为什么呢？那是因为人们看到苦桔梗中夹杂着辛膻的气味，却不知道它的辛味敌不过苦味！所以徐灵胎说：外感引起的咳嗽，如果用桔梗、麦冬清肺，就会造成劳损（虚劳）。这可以称得上是精辟的论述！
当时的医生缺乏医术，不辨析病证而只关注药物，不问病情轻重，只要见到药力稍猛烈的药物，就把它像躲避老虎一样避开，而不考察那些被认为猛烈的药物，究竟猛烈在哪里？所以疾病应当使用攻下法时，轻症用桃仁、桑白皮，重症用大黄、芒硝，再重的就用牵牛子、巴豆，而对于所谓的水蛭、虻虫、水蛭、蛴螬等虫类药，则绝对不敢尝试一次。为什么呢？因为他们对病证的辨识和对药物的认识都不真切，所以只选取药性轻缓的药物来含糊应付了事。这样误人性命，难道不是很大的伤害吗？牵牛子、巴豆等药物，药性直行而破气，能推动肠胃中有形的糟粕排出，但不能从容地旁渗到经络曲折的区域，以疏通其中的瘀塞。
所以血痹发生在经络脏腑深曲之处时，非用抵当汤这类方剂不能见效，而如果误用硝石、大黄、牵牛子、巴豆，它们药性直行破气，这就等于诛伐了没有过错的地方（指未触及病灶却损伤正气）。而且血痹证如果破其气，气虚了血液就不能更好地解除痹阻吗？世人喜欢前者而厌恶后者，也是说虻虫、水蛭有毒吗？难道牵牛子、巴豆就没有毒性吗？我私下认为，即使是狂人的一个见解，也要向天下人郑重宣告：牵牛子、巴豆既能破气又能破血，它们的药性直行而迅速，如果病在肠胃直道之中，尚未波及四周渗透，那么用这些药攻下就能痊愈；如果血络屈曲，都有瘀滞，非用水蛭、虻虫那样横行而缓慢的药力不能到达。水蛭、虻虫只攻血，几乎不伤气，而且它们的身体是蠕动的生物，本身就具备天地的生气，应当更能略微有益于人的生气，有气则灵动，所以能屈曲而旁达。张元素（海藏）说：妊娠蓄血证，忌用抵当汤、桃仁，只用大黄配合四物汤服用，则母子都可无损而病愈。因为胎儿依靠血液滋养，所以不能用虻虫、水蛭破血太急。然而胎儿也借大气举托，如果气虚，又不如用抵当汤、桃仁加上补气药更为稳妥。
Li Dongyuan stated: "Jiegeng (Platycodonis Radix) acts as a boat or pillar among herbs, capable of carrying other medicinal substances upward to the highest regions of the body." At that time, the distinction between sweet and bitter varieties was not clearly made. When deducing its functions, it should be categorized under the sweet nature; whereas bitter Jiegeng drains Lung Qi, meaning it can drain Qi from the high region but cannot raise Qi to the high region. Recently, authors of materia medica texts have listed this view under the entry for Bitter Jiegeng (Ku Jiegeng), which is erroneous. Sweet Jiegeng (Tian Jiegeng) has a sweet taste and a quiet nature; it can ascend and generate Stomach Qi, thereby detoxifying various medicines, functioning similarly to Gegen (Puerariae Lobatae Radix). Later generations also claimed that Jiegeng can open the Lungs and release the exterior. Neither sweet nor bitter Jiegeng possesses this efficacy. Moreover, various medical texts explicitly state that for coughs, bitter Jiegeng should be used to open them. Why? This is likely because people observe the pungent and fishy odor contained within bitter Jiegeng, failing to realize that its pungency cannot overcome its bitterness! Therefore, Xu Lingtai said: "For coughs caused by external pathogens, using Jiegeng and Maidong (Ophiopogonis Radix) to clear the Lungs will result in consumptive disease (Lao Sun). This can be called an outstanding insight!"
Contemporary physicians lack skill; they discuss herbs rather than analyze diseases. Regardless of the severity of the condition, whenever they encounter a herb with slightly potent force, they avoid it like a tiger, without investigating where the alleged potency lies. Thus, when a disease requires purgation, mild cases are treated with Taoren (Prunus Persica Seed) and Sangbaipi (Mori Cortex); severe cases with Dahuang (Rhei Radix et Rhizoma) and Mangxiao (Natrii Sulfas); even more severe cases with Qianniuzi (Semen Phytolaccae) and Badou (Crotonis Fructus). However, regarding insect-based drugs such as Shuizhi (Hirudo), Mengchong (Tabanus), and Qicao (Otiorhynchus larva), they absolutely dare not try them once. Why? Because their understanding of both the disease and the herbs is imprecise, so they merely select mild agents to muddle through. Does this not cause significant harm to people's lives! Drugs like Qianniuzi and Badou act directly to break Qi; they can push out有形 (solid) waste in the intestines and stomach but cannot leisurely secrete laterally into the tortuous areas of meridians to relieve stasis.
Therefore, for Blood Bi (Blood Stasis Obstruction) located in the deep and tortuous parts of meridians and organs, only formulas like Didang Tang (Resist the Stasis Decoction) will achieve success. Misusing Xiaoshi (Natrii Nitras), Dahuang, Qianniuzi, and Badou, which act directly to break Qi, amounts to punishing the innocent (damaging healthy Qi while missing the pathogen). Furthermore, if Blood Bi is present and Qi is broken, will Qi deficiency not prevent the blood from resolving the obstruction? The reason people prefer one approach and detest another is often simply that Mengchong and Shuizhi are considered toxic. Are Qianniuzi and Badou truly non-toxic? I privately assert, offering even a trivial insight as a solemn declaration to the world: Qianniuzi and Badou break both Qi and Blood; their action is direct and rapid. If the pathology is within the straight pathways of the intestines and stomach and has not yet spread to lateral infiltration, purging with these agents will cure the disease. However, if blood vessels are tortuous and all have stasis, only the horizontal and slow action of Mengchong and Shuizhi can reach the affected areas. Mengchong and Shuizhi attack Blood exclusively, causing minimal damage to Qi. Moreover, being creatures that move by wriggling, they inherently possess the vital energy of Heaven and Earth, and thus can slightly benefit human vital Qi. Having Qi implies agility, allowing them to navigate tortuous paths and reach lateral areas. Zhang Yuansu (Haizang) stated: "In pregnancy complicated by Blood Accumulation, Didang Tang and Taoren are contraindicated; instead, using Dahuang combined with Siwu Tang ensures neither mother nor fetus is harmed, and the disease resolves." Since the fetus relies on Blood for nourishment, one must not use Mengchong and Shuizhi to break Blood too aggressively. However, the fetus is also supported by Great Qi; if there is Qi deficiency, it is safer to use Didang Tang and Taoren supplemented with Qi-tonifying herbs.