Yang Style Tai Chi Quan was founded as Rou Quan (soft boxing) as opposed to the hard style of the Shaolin style. Tai Chi Quan does not show their fa jin and was practiced slowly because this is the first step: To slow down movement to discover yourself and your bodies.
The second step is build on top of correct posture and movement dynamics （AKA Fa Jin). Yang Style tai chi quan fa jin is not ONE Jin, its eight Jin all at the same time. In the beginning most cannot understand it so you still need to each of the eight Jin and learn to merge them into ONE. Yes you saw what i wrote, its eight jin merge into one.
The third stage is when you merge all the jin into one and your form become formless. As in the classic, in this stage you are one with the water/air and your spirit will be bright.
The fourth stage is when you are unbounded by the elements and you are forever listening and applying, and you do not resist or use brute force.
