老子曰∶吾所以有大患者，为吾有身。使吾无身，吾有何患？余则曰∶吾所以有大乐者
，为吾有形。使吾无形，吾有何乐？是可见人之所有者唯吾，吾之所赖者唯形耳！无形则无吾
矣，谓非人身之首务哉。第形之为义，其义甚微，如言动视听，非此形乎？俊丑美恶，非此
形乎？勇怯愚智，非此形乎？死生安否，非此形乎？人事之交，以形交也。功业之建，以形建
也。此形之为义，从可知也。奈人昧养形之道，不以情志伤其府舍之形，则以劳役伤其筋骨
之形。内形伤则神气为之消靡，外形伤则肢体为之偏废。甚至肌肉尽削，其形可知，其形既
败，其命可知。然则善养生者，可不先养此形，以为神明之宅，善治病者，可不先治此形，
以为兴复之基乎。
虽治形之法，非止一端，而形以阴言，实惟精血二字足以尽之。所以欲祛外邪，非从精
血不能利而达；欲固中气，非从精血不能蓄而强。水中有真气，火中有真液，不从精血，何
以使之降升？脾为五脏之根本，肾为五脏之化源，不从精血，何以使之灌溉？然则精血即形也
。形即精血也，天一生水，水即形之祖也。故凡欲治病者，必以形体为主；欲治形者，必以
精血为先，此实医家之大门路也。使能知此，则变化可以无方，神明自有莫测。
然用此之法，无逾药饵，而药饵之最切于此者，不过数味之间，其他如性有偏用者，惟
堪佐使而已。亦犹饮食于人，凡可口者，孰无资益，求其纯正无损而最宜于胃气者，则惟谷
食，类可见矣。或问余以所宜者，果属何物？余则难以显言之。盖善吾言者，必如醴如饴，
而不善吾言者，必反借此为射的，以资口吻之基矣。余故不能显言之，姑发明此义，以俟有
心者之自悟。
老子说：“我之所以有大患，是因为我有身体。假使我没有身体，我还有什么祸患呢？”我却说：“我之所以有大乐，是因为我有形体。假使我没有形体，我还有什么快乐呢？”由此可见，人所拥有的唯有自身，自身所依赖的唯有形体罢了！没有形体就没有自我了，这难道不是人身的首要任务吗？只是“形”的含义，其道理非常精微，比如言谈、行动、看、听，不都是依靠这个形体吗？俊美或丑陋、美好或恶劣，不都是这个形体吗？勇敢或怯懦、愚笨或智慧，不都是这个形体吗？死亡或生存、安宁或危险，不都是这个形体吗？人际关系的交往，是通过形体来交际的；功业的建立，是通过形体来成就的。这个形体的意义，由此就可以知道了。无奈人们不明白保养形体的道理，不是让情志损伤脏腑的形体，就是让劳役损伤筋骨的形体。内形的损伤会导致神气消减耗散，外形的损伤会导致肢体偏瘫废用。甚至肌肉全部消瘦，形体可见衰败，形体既然败坏，生命也就可想而知了。既然如此，善于养生的人，能不先保养这个形体，作为神明居住的宅邸吗？善于治病的人，能不先治疗这个形体，作为复兴的基础吗？
虽然保养形体的方法不止一种，但就形体属阴而言，实际上只有“精”和“血”两个字足以概括它。所以想要祛除外邪，不从精血入手就不能通利而达到病所；想要固护中气，不从精血入手就不能蓄积而强盛。水中有真气，火中有真液，如果不从精血着手，凭什么使它们降下和上升？脾是五脏的根本，肾是五脏化生的源头，如果不从精血着手，凭什么使它们灌溉滋养全身？然而精血就是形体，形体就是精血。天一生水，水就是形体的祖先。所以凡是想要治病的人，必须以形体为主；想要治疗形体的人，必须以精血为先，这确实是医家的根本大法。如果能懂得这一点，那么变化就可以无穷无尽，神妙自然就有不可测度的境界。
然而使用这种方法，没有超过药物饵剂的，而在药物饵剂中最切合这一点的，不过是几味药之间，其他的如药性有偏颇专用的，只堪作佐药和使药罢了。这也就像饮食对人一样，凡是可口的食物，谁没有益处，寻求其中纯正无损害且最适合胃气的，那就只有谷食，由此类推就可以明白了。有人问我适宜的药物究竟是什么？我很难明确说出来。因为善于理解我的话的人，一定会觉得像甜酒和糖浆一样甘美；而不善于理解我的人，一定会反过来借此作为攻击我的靶子，以此作为夸耀口才的基础。所以我不能明确说出来，姑且阐明这个道理，以等待有心人自己领悟。
Laozi said: "The reason I have great afflictions is that I have a body. If I did not have a body, what afflictions would I have?" I, however, say: "The reason I have great joy is that I have a physical form. If I did not have a physical form, what joy would I have?" This shows that what a person possesses is only the self, and what the self relies upon is only the physical form! Without a physical form, there is no self; is this not the primary task of human life? The meaning of "form" is subtle. For instance, speaking, moving, seeing, and hearing—are these not dependent on this form? Handsomeness or ugliness, beauty or baseness—are these not this form? Courage or timidity, foolishness or wisdom—are these not this form? Life or death, peace or peril—are these not this form? Human interactions are conducted through forms; achievements are established through forms. The significance of this form can be understood from this. Alas, people fail to understand the way of nourishing the form. They either allow emotional states to damage the form of their internal organs (Zang-Fu), or they allow labor and exertion to damage the form of their sinews and bones. Damage to the inner form causes Shen (Spirit) and Qi (Vital Energy) to dissipate; damage to the outer form leads to paralysis or dysfunction of the limbs. Eventually, muscles may waste away completely. Once the form is ruined, the fate of life is evident. Therefore, those skilled in health preservation must first nourish this form as the residence of the Shen (Spirit); those skilled in treating disease must first treat this form as the foundation for recovery.
Although methods for nourishing the form are numerous, since the form belongs to Yin, the two characters "Jing" (Essence) and "Xue" (Blood) suffice to encompass it entirely. Thus, to dispel external pathogenic factors (Exogenous Pathogens), one cannot achieve efficacy without addressing Jing and Xue; to consolidate Middle Qi (Spleen and Stomach Qi), one cannot strengthen it without nourishing Jing and Xue. True Qi resides within Water (Kidney/Yin), and True Fluids reside within Fire (Heart/Yang). Without Jing and Xue, how can one facilitate their descent and ascent? The Spleen is the root of the Five Zang Organs, and the Kidneys are the source of transformation for the Five Zang Organs. Without Jing and Xue, how can they irrigate and nourish the body? Therefore, Jing and Xue constitute the form, and the form constitutes Jing and Xue. "Heaven generates One with Water," and Water is the ancestor of the form. Hence, whoever wishes to treat disease must prioritize the physical form; whoever wishes to treat the form must prioritize Jing and Xue. This is indeed the fundamental approach for physicians. Those who comprehend this can adapt to changes without fixed patterns, and their spiritual insight will naturally become unfathomable.
However, among all methods, none surpasses herbal medicine (Medicinal Decoctions). Among herbs, only a few are most directly applicable to this purpose; others, which have specific biased properties, serve merely as Assistant (Zuo) and Guide (Shi) herbs. This is analogous to food: while any palatable food provides benefit, the substance that is pure, unadulterated, and most suitable for Stomach Qi is grain. Someone asked me what specific substances are suitable. I find it difficult to state them explicitly. Those who understand my words well will perceive them as sweet as nectar or syrup; those who do not understand will use them as targets for criticism to bolster their own rhetoric. Therefore, I cannot state them explicitly. I merely elucidate this principle, awaiting those with sincere hearts to realize it themselves.