天地之道，生一气而判清浊，而清者轻而上升为天，浊者重而下降为地。天为阳，地为阴，
乃为二仪。
阴阳之气，各分三品，多寡不同，故有三阴三阳之六气。然天非纯阳，而亦有三阴，地非纯
阴，而亦有三阳，故天地各有三阴三阳，总之以十二矣。
然天之阴阳者，寒暑燥湿风火也，地之阴阳者，木火土金水火也。金火不同其运，是故五行
彰矣。然天地气运，升降不以，阴阳相感，化生万物矣。其在天则气结成象，以为日月星辰也，
在地则气化为形，以生人为万物也。
然人为万物之灵也，非天垂象，而莫能测矣。其我机理，归自然也，其非圣意，而宣悟玄玄
之理。故有祖圣伏牺占天望气，及视龙马灵龟，察其形象，而密解玄机，无不符其天理。乃以始
为文本画卦，造六甲历纪命
曰《太始天元册文》，垂示之于后人也。以诮神农，昭明其道，乃始令人食谷，以尝百药，而
制《本草》矣。然后黄帝命其岐伯及鬼臾区，以发明太古灵文，宣陈造化之理，论其疾苦，以着
《内经》焉。
凡此三皇三经，命曰三坟，通为教之本始，为万法宗源，诚为天之候也。若论愈病疾，济苦
保命防危，非斯圣典，则安得致之矣。然经之所论，玄机奥妙，旨趣幽深，习者卒无所悟，而悟
得其意者鲜矣。完素愚诚，辄考圣经，撮其枢要，积而岁久，集就斯文，以分三卷，叙为九篇，
勒成一部，乃号《内经运气要旨论》尔。乃以设图彰奥，绮贯纪倜，袭句注辞，而敷其言意。或
可类推者，以例傍通，例成而陈精粹之文。诂训难明者，兼义释字音，以附之于后。虽言词鄙陋，
所乘从俗，而庶览者曷为悟古圣之妙道矣。
河间刘守真谨序
The way of Heaven and Earth is that from the Qi of primordial unity, clarity and turbidity are distinguished. The clear Qi, being light, ascends to form Heaven; the turbid Qi, being heavy, descends to form Earth. Heaven belongs to Yang, and Earth belongs to Yin; thus, the Two Modes (Liangyi, referring to the two poles of Yin and Yang) are established.
The Qi of Yin and Yang is further divided into three categories each, with varying degrees of abundance, giving rise to the concept of the Six Qi (Liùqì), comprising Three Yin and Three Yang. However, Heaven is not purely Yang, but also contains Three Yin; Earth is not purely Yin, but also contains Three Yang. Therefore, both Heaven and Earth possess Three Yin and Three Yang, totaling twelve in all.
Regarding the Yin and Yang of Heaven, they manifest as Cold, Heat, Dryness, Dampness, Wind, and Fire (the Six Climatic Factors). Regarding the Yin and Yang of Earth, they correspond to Wood, Fire, Earth, Metal, and Water (the Five Phases/Elements). Since Metal and Fire have different operational characteristics, the attributes of the Five Phases become evident. Nevertheless, through the continuous ascent and descent of the Qi of Heaven and Earth, and the mutual interaction of Yin and Yang, all things are transformed and generated. In Heaven, Qi condenses into forms, becoming the Sun, Moon, Stars, and Constellations; on Earth, Qi transforms into physical shapes, thereby generating humans and all living beings.
Humans, as the most spiritual of all beings, cannot fathom these mysteries without the signs manifested by Heaven. The mechanisms of the human body return to the Way of Nature, not merely by the will of sages, but to elucidate profound and mysterious principles. Thus, the ancestral sage Fuxi observed celestial phenomena and atmospheric qi, and examined the images of the Dragon-Horse and the Spirit Turtle. By inspecting their forms, he deeply understood the hidden mysteries, finding no contradiction with Heavenly Principles. He then began to create characters and draw trigrams, inventing the calendar system based on the Sexagenary Cycle (Liujia), naming it *Tai Shi Tian Yuan Ce Wen* (Record of the Primordial Beginning of Heavenly Origin), to be passed down to posterity. Subsequently, Shennong illuminated this Way, initiating the consumption of grains for sustenance and the tasting of hundreds of herbs, thereby compiling the *Ben Cao* (Materia Medica). Later, the Yellow Emperor commissioned Qibo and Gui Yuzhou to expound upon the ancient sacred texts, articulate the principles of creation, discuss the afflictions of diseases, and thus compose the *Nei Jing* (Inner Canon).
These three Emperors (Fuxi, Shennong, Yellow Emperor) and their three canonical works (*Tai Shi Tian Yuan Ce Wen*, *Ben Cao*, *Nei Jing*) are collectively referred to as the "San Fen" (Three Tombs/Archives). They serve as the fundamental origin of teaching and the source of all methods, truly representing the manifestations of Heaven. If one wishes to cure diseases, alleviate suffering, preserve life, and prevent danger, without relying on these sacred classics, how could such results be achieved? However, the discussions within these classics involve profound mysteries and deep intentions. Most learners fail to comprehend them, and few truly grasp their essence. I, Liu Wansu, though humble and sincere, have examined the sacred scriptures, extracted their pivotal essentials, and after many years of accumulation, compiled this work. It is divided into three volumes and nine chapters, forming a single book, titled *Suwen Yaozhi Lun* (Discourse on the Key Principles of the Suwen). I have employed diagrams to reveal profound meanings, organized the narrative structure, annotated sentences and words, and elaborated on their implications. For matters that can be inferred by analogy, examples are provided to facilitate understanding, presenting refined texts once the examples are established. Where exegesis is difficult to clarify, I have included semantic explanations and phonetic annotations at the end. Although my language may be crude and my approach conventional, I hope that readers may thereby comprehend the subtle Dao of the ancient sages.
Liu Shouzhen of Hejian respectfully prefaces.