Mind intent (yi) and Fa Jing
Tai Chi Chuan can also develop the facility of issuing power outside the body to affect other people or bounce people off with a strike. This power is the result of a combination of yielding jing and fa jing (discharging) power. Therefore, it can be said that if one does not have this yielding jing and fa jing skill, one does not really practice Tai Chi Chuan correctly.
Intent is what's necessary. It is the commander of all movement. It is said in the six harmony theory that when the intent is there, the chi is there and the power is there. A movement without intent is nothing. An intent without movement is nothing too. An intent combined with movement that is not applied to an opponent is nothing. When intent combined with movement is applied on an opponent, then something is achieved.
The question is how do we strenghen our Intent so that we can achieve Fa Jing or Linkonjing
It is said that the strengh of YI comes out from a normal person every once and a while especially those cases when a person's life is at stake or saving another.