先生张元素，〔字〕洁古，易水人也。八岁试童经，二十七经义登科，犯章庙讳
出落，于是怠仕进，遂潜心于医学，二十余年虽记诵广博书，（然）治人之术，不出
人右。其夜梦人柯斧长凿，〔凿心〕开窍，纳书数卷于其中，见其题曰《内经主治
备要》，骇然惊悟，觉心痛，只为凶事也，不敢语人。自是心目洞彻，便为传道轩岐，
指挥秦越也。河间刘守真医名贯世，视之蔑如也。异日守真病伤寒八日误下证，头
疼脉紧，呕恶不食，门人侍病，未知所为，请洁古诊之，至则守真面壁罔顾也。洁
古曰∶〔何〕视我直如此卑也？诊其脉，（谓）之曰∶脉病乃尔，初〔服〕
某药犯某味药乎？曰∶然。洁古曰∶差之甚也。守真遽然起曰∶何谓也？曰∶某药味
寒，下降，走太阴，阳亡，汗不彻故也。今脉〔如此〕，当以某药〔服〕之。守真首〔恳〕
大服其能，一服而愈，自是名满天下。洁古治病，不用古方，但
云∶古方新病，〔甚〕不相宜，反以害人。每自从病处方，刻期见效，药〔下〕
如攫，当时目之曰神医。暇日辑（集）《素问》五运六气，《内经》治要，《本草》药性，
名曰《医学启源》，以教门生，及有《医方》三十卷传于世。〔壬辰遗失，□□□存者惟《医学
启源》〕。真定李明之，门下高弟也，请余为序，故书之。兰泉老人张吉甫〔序〕。
先生张元素，字洁古，是易水人。八岁时参加童经考试，二十七岁因精通经义考中进士，后因触犯章庙的名讳被除名落第，于是对仕途进取感到倦怠，转而潜心研究医学。二十多年来，虽然他的记诵广博，但治疗人的医术，并不比别人高明多少。
有一天夜里，他梦见有人拿着大斧和长凿，凿开他的心窍，将几卷书放入其中，看到书名题作《内经主治备要》，他惊恐地惊醒，醒来后感到心痛，认为这是凶兆，不敢告诉别人。从此以后，他的心目变得通透明彻，便立志传承轩辕、岐伯的医学，指挥如秦越人（扁鹊）般的医术。河间的刘守真医名冠绝世间，张元素起初轻视他。后来有一天，刘守真患伤寒八天，被误用下法，出现头痛、脉紧、呕吐恶心、不能进食的症状，门人侍奉生病的老师，不知该怎么办，请张元素来诊治。张元素到了之后，刘守真背对着墙不理睬他。张元素说：“为什么把我看得如此卑微？”诊察了他的脉搏，对他说：“脉象病情竟然到了这种地步，起初是不是服用了某种药，与某种药性相冲突？”刘守真说：“是的。”张元素说：“错得很严重啊。”刘守真突然起身问道：“这是什么意思？”张元素说：“那味药性质寒凉，主下降，走太阴经，导致阳气亡失，汗出不透彻的缘故。现在的脉象如此，应当服用某药。”刘守真非常佩服他的才能，吃了一服药就痊愈了，从此张元素的名声传遍天下。
张元素治病，不使用古方，只是说：“古方的新病，非常不相适宜，反而害人。”他总是根据病情自行处方，限定日期见效，药一下去就像抓取东西一样迅速奏效，当时的人称他为神医。闲暇时，他编纂《素问》五运六气，《内经》治要，《本草》药性，命名为《医学启源》，用来教导门生，另外还有《医方》三十卷流传于世。（壬辰年遗失，现存者只有《医学启源》）。真定李明之，是张元素门下的高徒，请求我为此书作序，所以写下这些文字。兰泉老人张吉甫作序。
Mr. Zhang Yuansu, courtesy name Jiegu, was a native of Yishui. At the age of eight, he took the examination for children's classics; at twenty-seven, he passed the imperial examination due to his mastery of classical interpretations. However, he was dismissed from office because his name offended the taboo of Emperor Zhang's ancestral temple. Consequently, he lost interest in official career advancement and devoted himself to medicine. For over twenty years, although his memorization was extensive, his medical skills in treating people were no better than those of others.
One night, he dreamed that someone used a large axe and a long chisel to open a cavity in his heart, placing several volumes of books inside. He saw the title inscribed as *Jingnei Zhuzhi Beiyao* (Essentials of Indications from the Inner Canon). Startled awake by fear, he felt heart pain upon waking and considered it an ominous sign, so he dared not tell anyone. From then on, his mind and vision became clear and penetrating, and he resolved to transmit the medical teachings of Xuanyuan and Qibo, wielding medical prowess comparable to that of Qin Yue (Bian Que). Liu Shouzhen of Hejian had a medical reputation that spanned the world, but Zhang initially regarded him with disdain.
Later, Liu Shouzhen contracted cold damage (*Shanghan*) for eight days and was mistakenly treated with purgatives. He suffered from headache, tight pulse, vomiting, nausea, and inability to eat. His disciples, attending to their sick teacher, did not know what to do and requested Zhang Jiegu to examine him. Upon arrival, Liu turned his back to the wall and ignored him. Zhang said, "Why do you regard me with such contempt?" After examining the pulse, he said, "The pulse and condition are indeed severe. Did you initially take a certain medicine that conflicted with another?" Liu replied, "Yes." Zhang said, "The error is very serious." Liu suddenly rose and asked, "What do you mean?" Zhang explained, "That medicine is cold in nature and descending, affecting the Taiyin channel, leading to the loss of Yang qi and incomplete sweating. Given the current pulse, you should take [a specific] medicine." Liu was deeply convinced by Zhang's ability. After one dose, he recovered, and Zhang's fame spread throughout the world.
When treating diseases, Zhang did not use ancient prescriptions, stating instead, "Ancient prescriptions for new diseases are highly inappropriate and can harm people." He always formulated prescriptions according to the specific illness, ensuring efficacy within a set timeframe. The medicine acted swiftly, like grasping something, and people of the time called him a Divine Physician. In his leisure time, he compiled materials on the Five Movements and Six Qi from the *Suwen*, essential treatments from the *Inner Canon*, and drug properties from the *Bencao*, naming the work *Yixue Qiyuan* (Origin of Medicine) to teach his disciples. Additionally, thirty volumes of *Medical Prescriptions* (*Yifang*) were transmitted to the world. [Lost during the Renchen year, only *Yixue Qiyuan* remains]. Li Mingzhi of Zhengding, a senior disciple of Zhang, requested me to write a preface, so I have written these words. Preface by Zhang Jifu, the Old Man of Lanquan.