The gate of life and the cinnabar field

In the Lingshu, 命門 is not on the back. The Gen Jie chapter (根結), which describes where each channel takes root and where it ties off, says: “太陽根於至陰，結於命門。命門者，目也”. The Taiyang takes root at Zhiyin, BL67, the last point of the foot, and ties off at the gate of life, which is the eyes, where the channel begins, at BL1.

The Nanjing changes the meaning. In Difficulty 36 it gives the name to the right kidney and defines it as the root of life: “命門者，諸神精之所捨，原氣之所繫也。故男子以藏精，女子以系胞”. It is the dwelling of the spirits and essences, the place to which the Original Qi is tied; in it, men store essence, and women anchor the uterus. In Difficulty 66 it describes that Qi in words that anticipate the dantian: “臍下腎間動氣者，人之生命也，十二經之根本也，故名曰原”. The Qi that pulses below the navel, between the kidneys, is a person's life and the root of the twelve channels.

The name ended up on two points. GV4, Mingmen, is on the spine, below the second lumbar vertebra, between the two Kidney Shu points, and the Zhenjiu Jiayi Jing already records it under that name: “命門，一名屬累，在十四椎節下間”. But the same book gives 命門 as an alias of another point, on the abdomen: “石門，三焦募也，一名利機，一名精露，一名丹田，一名命門”. CV5, Shimen, is at once called gate of life and cinnabar field, and is, in the texts that have been compared, the earliest mention of 丹田 as the name of a point.

The doctrine then kept moving. Ming-dynasty physicians placed the gate of life between the two kidneys and spoke of its fire as the root of the Yang of the whole body. The entry for GV4 tells the story of that evolution.

丹田 is not a term of the Neijing. It comes from the Taoist tradition of cultivation, in which cinnabar, 丹, is the substance of immortality, and the field is the place in the body where it is cultivated. Medicine adopted it as an alias of several points on the lower abdomen, and for centuries there was debate over which was the true one. Three candidates compete for it: CV5, Shimen, the one in the Jiayi Jing; CV4, Guanyuan, three cun below the navel; and CV6, Qihai, the sea of Qi.

A Song-dynasty text shows the confusion. Zhuang Chuo, in his treatise on Gaohuang moxibustion, recommends that after the treatment one moxa one of four points below the navel: “可灸臍下氣海、丹田、關元、中極四穴中一穴”. Qihai, Guanyuan, and CV3, Zhongji, appear under their own names, and the dantian as a point distinct from all of them, which can only be Shimen.

CV6 also has a root of its own in the canon. The Jiu Zhen Shi Er Yuan chapter of the Lingshu, after the Yuan points of the five organs, adds two more: “膏之原，出於鳩尾……肓之原，出於脖胦”. The origin of the gao is at CV15, Jiuwei, and that of the huang is at Boyang, the ancient name of Qihai. The gao and the huang are the two regions that give BL43, Gaohuang, its name, the point of the incurable illness of the Duke of Jin.

CV4, Guanyuan, the barrier of origin, is the point the Jiayi Jing places “在臍下三寸”. And at the center, CV8, the navel, which tradition called Shenque, the tower of the spirit, was always a place forbidden to the needle: “臍中，禁不可刺，刺之令人惡瘍，遺矢者死不治”. It receives only moxa, on salt or ginger.

Internal alchemy (內丹) speaks of three cinnabar fields: in the lower abdomen, in the chest, and in the head. That image entered the Suwen (Basic Questions) by a side door. Two chapters already missing from Wang Bing's edition, the Ci Fa Lun (刺法論) and the Ben Bing Lun (本病論), circulated later as recovered chapters (遺篇), and critics consider them late additions. In the second we read that, when the spirit loses its post, “神遊上丹田”, it wanders in the upper cinnabar field, and the same sentence names the palace of the niwan (泥丸宮).

The first of them goes so far as to say that needling is not only for curing: “刺法有全神養真之旨，亦法有修真之道，非治疾也”. The art of the needle aims to keep the spirit whole and to nourish what is true; it is also a path of cultivation, not only of treatment. In the body, the niwan is GV20, Baihui, which the Song-dynasty Benshi Fang calls 泥丸宮.

The Taoist practice of the small celestial circulation (小周天) sends qi up the back and down the front, along the two vessels of the midline. The anatomy it uses is that of the Nanjing (Classic of Difficulties), which in Difficulty 28 describes both: “督脈者，起於下極之俞，並於脊裡，上至風府，入屬於腦”, the Du Mai begins at the base, rises inside the spine to Fengfu, and enters the brain; “任脈者，起於中極之下，以上毛際，循腹裡，上關元，至喉咽”, the Ren Mai rises through the abdomen, passes Guanyuan, and reaches the throat. The circuit begins at the perineum, at CV1, Huiyin, and GV1, Changqiang. The name and the method are Taoist and later; the two pathways come from the canon.