人身养生之气有二∶一曰呼吸天气。盖人在天地气交之中，如鱼之在水也。鱼在水中而
不见水，人在气中亦不见气。试观平人扼吭则绝，无天气也。试观暴绝人气回则苏，通天气也。
无形而至刚，故古之圣人有服气却谷之法。天气至清，全凭呼吸为吐纳。其呼吸之枢，则以
肺为主，《内经》所谓天气通于肺也。天气有春温、夏热、秋燥、冬寒，及四季湿土不同，
得其平则能养人，失其平则病，《内经》所谓天食人以五气是也。一曰饮食地气，即胃所受
水谷也。试观平人绝谷则饥，试观 瘠人美食则肥，则地气之养人可知矣。地气养人有形而
至柔，故形体丰肥者其气反弱。地气至浊，全凭喉舌为出入，其饮食之权则以脾为主，《内
经》所谓地气通于嗌也。地气有三∶食谷者，智人为万物之灵也；食肉者，勇鹰虎之属也；
食草者，力牛马之属也。又有五味∶属木者酸，属火者苦，属金者辛，属水者咸，属土者甘
，《内经》所谓地食人以五味是也。凡婴儿在胎中，亦有天气、地气为养，盖其呼吸、饮食
皆资于母也。地气有形，故医书多言之，若天气无形，医家多不知为何物，故诸书皆置而不
言，无怪医术之多陋也。
宗气者，乃呼吸天气所生，其所居在胸膈之间。《内经》曰∶宗气出于上焦。又曰∶呼
则气出，吸则气入。其大气之抟而不行者，积于胸中，名曰气海是也。凡人身之力，惟胸膈
间最大，此即宗气也。凡头背手足之力，皆取络于胸膈，此气又名膻中，又名心包络，即心
主也，常代心君用事，称为相火。盖心为君火，端拱无为者，性之体也；膻中宗气为相火，
代心
心君用事，与营血俱行脉中耳。其领营血行于脉中也，即从左乳旁下虚里穴起，以次行于各
经。一呼一息，一息行六寸，已详于经络次序。
The qi that nourishes the human body consists of two types: one is the respiration of Heavenly Qi (Tianqi, atmospheric air). Humans exist within the intersection of Heaven and Earth's Qi, much like fish in water. Fish are in water but do not see it; humans are in Qi but do not perceive it. Observe that if a healthy person has their throat choked, they will die because the connection to Heavenly Qi is cut off. Observe that if someone who has suddenly collapsed regains their breath, they revive because the connection to Heavenly Qi is restored. Heavenly Qi is formless yet supremely vigorous; therefore, ancient sages had methods of "ingesting Qi" (Fuqi) and abstaining from grain (Quegu). Heavenly Qi is extremely pure and light, relying entirely on respiration for excretion and ingestion. The pivot of respiration is governed by the Lung Fei (Lungs), as stated in the *Neijing* (Classic of Internal Medicine): "Heavenly Qi connects with the Lungs." Heavenly Qi varies according to seasons—spring warmth, summer heat, autumn dryness, winter cold—and the damp earth of the four seasons. When balanced, it nourishes humans; when imbalanced, it causes disease. This is what the *Neijing* refers to as "Heaven feeds humans with Five Qi." The second type is Dietary Earthly Qi (Diqi), which refers to the food and drink received by the Stomach Wei (Stomach). Observe that a healthy person feels hungry when fasting; observe that a thin person becomes fat after eating well. Thus, we can understand how Earthly Qi nourishes humans. Earthly Qi nourishes humans through tangible yet soft substances; therefore, those with plump and robust bodies often have relatively weak internal Qi. Earthly Qi is turbid and relies entirely on the throat and tongue for intake and output. The authority over dietary processing lies with the Spleen Pi (Spleen), as stated in the *Neijing*: "Earthly Qi connects with the Yi (throat/pharynx)." Earthly Qi has three sources: those who eat grains develop wisdom and become the spirits of all things; those who eat meat possess bravery akin to eagles, hawks, tigers, and wolves; those who eat grass possess strength akin to cattle and horses. There are also Five Flavors: sour belongs to Wood Mu, bitter belongs to Fire Huo, pungent belongs to Metal Jin, salty belongs to Water Shui, and sweet belongs to Earth Tu. This is what the *Neijing* refers to as "Earth feeds humans with Five Flavors." Even infants in the womb are nourished by both Heavenly and Earthly Qi, as their respiration and diet depend on the mother. Since Earthly Qi is tangible, medical texts discuss it frequently. However, since Heavenly Qi is formless, many physicians do not know what it is, so various texts omit it. No wonder medical skills are often shallow.
Zong Qi (Pectoral Qi or Gathering Qi) is generated by the respiration of Heavenly Qi and resides between the chest and diaphragm. The *Neijing* states: "Zong Qi originates from the Upper Jiao (Upper Burner)." It also states: "Exhalation sends Qi out; inhalation brings Qi in." The part of this Great Qi that condenses and does not flow accumulates in the chest, known as the Sea of Qi (Qi Hai). Generally, the greatest force in the human body is located in the chest and diaphragm; this is Zong Qi. The strength of the head, back, hands, and feet all connect to the chest and diaphragm. This Qi is also called Dan Zhong (Chest Center), or Pericardium Luo (Pericardium Collateral), which is the Heart Master Xin Zhu. It often acts on behalf of the Heart Monarch Xin Jun and is referred to as Ministerial Fire Xiang Huo. Because the Heart is Sovereign Fire Jun Huo, remaining dignified, non-actionable, and wu-wei (non-doing), this represents the substance of nature. The Zong Qi at Dan Zhong, acting as Ministerial Fire, performs duties on behalf of the Heart Monarch, traveling together with Ying Blood (Nutritive Blood) within the vessels. Its leadership of Ying Blood within the vessels begins at the Xu Li point (located below the left nipple) and proceeds sequentially through the various meridians. With each breath (one inhale and one exhale constitutes one Xi), Qi and Blood travel six cun, as detailed in the sequence of meridians.