We've already looked at the subject of the Central Ground as one of the Four Tangibles ( http://www.coldmountaininternalarts.com/single-post/2016/12/14/The-Four-Tangibles-Tai-Chi-Self-Defence ). One aspect of the Central Ground is the Axis which forms the longitudinal core of our bodies. This is a deep subject. It relates to posture, movement, grounding, and also to the mysterious tradition of Internal Alchemy.
Neidan, or Internal Alchemy, consists of practices intended to refine and purify the body and soul. Its objectives include spiritual enlightenment and the prolongation of life. It is distinguished from Weidan or External Alchemy which attempts to achieve these ends through the ingestion of esoteric substances such as mercuric oxide and various types of mushrooms and toadstools (which usually achieves the opposite effect!).
A relatively innocuous version of Neidan, in the form of medical qigong, is now one of the five components of the relatively new discipline called Traditional Chinese medicine. Traditional Neidan has become rather rare.
In physical terms Central Equilibrium is fundamental to rooting power.
In this picture I am applying quite a bit of force to one of my students who is in her 70's and maybe weighs 135 pounds wet! She is standing in a high wujibu (preparatory stance) and is grounding my push with ease. This lady is a Tai Chi beginner. She is resting into her structure so that the central axis of her body is gently held over her feet. The weight distribution between her feet has been forced to her right, but she holds to the central axis and is undisturbed.
Grounding of this sort is the first lesson I teach; the mechanics are outlined in the blog entry referenced above. When one can do this, one is physically embodying the Tai Chi principle. Yang rests in; Yin supports. Resting in to one's structure permits one to support considerable external force. One does not resist. One does not tense up. There is also a psychic component to this.
This prerequisite skill is essential for progress in Tai Chi.
Here I am performing a Tai Chi sword routine. It is a worthwhile clip to consider. In it I can be seen holding to the centre as I retreat while striking to front and rear, stand on one leg and then thrust to my right rear, turn with side-thrust and follow-step, stand on one leg again, jump 180 degrees, pose twice in one-legged stances, jump and then turn.... And in all of this it is as though the central axis is unmoved. In a sense, I throughout am turning around my centre.
In this exercise the sword I am using is a real wu-jian with a folded-steel blade; it is not a light-weight practice sword. Managing the power of this sword forces me to be careful about weight-distribution and central axis. The implement may be only two pounds or so, but that is enough to pull me off-balance or out-of-centre if I get sloppy!
In comparison with empty-hand routines, weapons work 'forces the issue' a bit. Extension of weight beyond the body requires resting-in and supporting skills to be tested. It is a little less forgiving.
Getting back to Internal Alchemy, it is significant that sword practice and dancing are part of the Tantric and Chinese hermetic traditions. The Bodhisattva Manjusri (Jap. Monju), the personification of the Buddhist principle of emptiness, is recognizable by his sword, as is the Daoist Immortal Lu Tung-ping, and as is the Lord of the North Star, Zheng-wu. In fact the one-legged sword stance where the sword is held over the head is named after him: 'Largest Pole-star of the Literary God'. In all cases the sword represents self-discipline and the cutting-off of vanity and illusion.
In the case of the Lord of the Dipper, Zheng Wu, the north star represents the Dao - the eternal principle. The central axis of the earth which points to the north star is the macrocosmic aspect of our own bodily central axis. The voyage of the soul upward into the spititual realm corresponds to the movement of the Qi up our own inner axis to the crown and beyond - the activation of the shen, our spiritual capacity.
It is this journey which is encoded into the Tai Chi sword forms.