The following is derived from a translation of the classic writings concerning Tai Chi which are said to date back to the Ming Dynasty (approx.1362).
Tai Chi (the Supreme Ultimate) arises from WU CHI (The formless). It is the origin of movement and quietude they close. There should be no exess, no insufficiency. Yield to your opponents advances and adhere when he retreats. When the other's movement comes quickly, respond quickly; when the other's movement comes slowly, respond slowly. The techniques change but this principle remains constant.

Through the process of long and diligent practice, there comes an understanding of the "internal force". From this understanding, comes a "spiritual illumination". But you will not understand this without much time and effort.

The top of the head is empty, alert and still. The breath sinks to the "dan tien" The body is not inclined, leaning, or stretching. The opponent can not detect as you become "empty" where he attacks, and you become "solid" and follow him when he reteats. The body becomes so sensitive that when the weight of a fly landing on you sets you in motion-shifting from solid to empty.

Stand as a balanced scale, move like a wheel. Keep one leg heavy, one leg light. If the weight is kept on both legs, you will never get good results. To avoid this you must know Yin and Yang. To "adhere" is also to withdraw, and to withdraw is also to "adhere". Yin does not leave Yang and yang does not leave Yin. Yin and Yang necessarily compliment each other and one does not exist without the other. You will understand the "internal force" if you understand this concept.

The mind directs the breath, and orders it to sink so that it may be gathered by the bones. Then, the breath moves the body freely, following the desire of the mind. When you want to use the "chi", sink the breath deeply, but remain relaxed and quiet, and then concentrate in a single direction toward the opponent. when you are standing, the body must be straight, relaxed and balanced so that you may protect yourself from all directions. When you use this energy, it is like finely refined steel-able to defeat all hardness. In appearance be like an eagle swooping down on a rabbit; in spirit, as a cat catching a mouse.

When quiet be like a mountain; when moving, like water running in a great river.

Storing up breath is like drawing a bow; releasing it is like shooting an arrow. Find the straight from the curved. When you move back and forth, the body must ave folds. when you advance and retreat, you must have turns and changes. If you can regulate the inhalation and exhalation, then the body can be light and lively.

The mind give the command; the breath goes forth as the banner, and the waist executes the command.

If the opponent does not move, then you do not move. If the opponent moves even slightly, then you move faster than him.

The energy is rooted in the feet, it passes through the legs, is controlled and directed by the waist, and emerges in the fingers.

All parts of the body must be thought of as connected, like a string of pearls.