From the moment of conception, there is an Original Qi contained within that nurtures the body. There is no excess or deficiency; it is balanced and does not flow. It is ultimately good and complete, and is known as the True Yang. This is the same as the so-called centralized qi. This qi normally benefits the four corners of the body, and penetrate to nourish the bones. There is no place in the body it does not reach, there is no point in time which it is absent. The internal and external are united in a single qi. It flows ceaselessly without a break. The opening and closing, movement of stillness of martial forms have this qi as their root. The mystery of the various extensions and contractions springs forth from this qi. To open is to extend and to move. To close is to contract and to be still. Opening is yang and closing is yin. To issue, extend, or move is yang. To withdraw, contract, or become still is yin. Opening and closing is like the one qi moving through the cycles of yin and yang. Tai Ji is the one qi. The one qi is Tai Ji. When referring to the body, it is called Tai Ji. When referring to the use, it is called the one qi. When yang is called for, it is yang. When yin is called for, it is yin. When it should be above, it is above. When it should be below, it is below. From yang comes yin and from yin comes yang. The one qi is lively and active. It is established everywhere.
Opening and closing are natural; they alternate as appropriate to the situation. This is the same as Tai Ji Quan. The ancient were not able to demonstrate this to others or write it in books. This is the way it is. If the student is able to alternate opening and closing as well as stillness and movement, and comes to a deep understanding of their source, the commen root of every posture will be clear and one will obtain their mysterious uses(1. The central feature of the postures is the combination of an empty circle which has form and a formless circle which is full. These two circles represent the principle of the “empty” and “substantial.” Within the postures there is an apparent emptiness, but the posture is not really empty; it appears to be substantial, but there is in reality emptiness(2. This qi flows to all places without obstruction. It is rounded and lively without angles. It is without excesses or deficiencies. When manifest, the Six Harmonies are complete(3. When returning, it is hidden as a treasure within. Its changes are without limit. Its uses are inexhaustible. Herein lies the real teachings. It is the sum of Tai Ji Quan.
1) There is a famous saying that “The Tai Ji never departs from Yin and Yang; Tai Ji Quan never departs from opening and closing.”
2) In Tai Ji Quan, each part of the body has a balance of the “substantial” and the “insubstantial”. In general, the leg that supports most of the weight and the parts of the body that are applying relatively more force are substantial. The leg that bears less weight and the more passive parts of the body are insubstantial. Every move in Tai Ji Quan seeks to maintain the balance between the two states at all times and in equal proportions.
3) As described above, the Six Harmonies are divided into the Three Internal Harmonies (heart harmonizing with intent, intent harmonizing with qi, qi harmonizing with force) and the Three External Harmonies (shoulders coordinate with hips, elbows coordinate with knees, and hands coordinate with feet).