There a five essential characters in Tai ji chuan, where the intention of the mind should develop and remain focused in.
Hsin- Heart and Mind
Heart and Mind should be conjoined together, in intent and expression. The mind should remain calm. In calmness one can anticipate, follow, and direct. What ever part of the body is touched the mind is followed. One begins to see that the one no longer follows the opponent but controls the opponent.
One must be agile. One must know empty and weighted. In distiguishing the two one can be able to follow, advance and retreat with ease. The qi is like a wheel, the body must coordinate so. One side empties, the other weighs. One side then weighs, while the other empties. One must follow one’s opponent and not oneself, for when one follows himself, he will get clumsy, and loose coordination in selfconciousness. When one follows, the mind will follow, the body will adjust, and the mind will order, what is empty and what is weighed. Instead of telling itself this is empty and this is weighed.
When the qi is dispersed, it is easily scattered. The qi should gather and be stored. The qi should flow through out the body, residing in the dantien. Inhalation closes, and Exhalation opens. Likewise, respectively they also lift and sink. In this way the qi can be mobilized to uproot or to ground.
Qin- Internal force
Qin of the body must be focused and act as one force. The Qin draws up from the feet, up to the waist, into the torso, and then expressed out the arms and finger tips. One must raise shen when an opponents Qin is about to manifest, before it starts to express, in this way one can borrow force to strike the opponent
Upon having all four the shen can become concentrated. It is continuous and concentrated. Opening and closing happens naturally, empty and weighted become more observed, and distinguished. One doesn’t seperate, and look outside of oneself, one can see part of the greater continuity and borrow force from the opponent seeing him as an extension of the self.