In our Western culture, society seems to have put an inordinately high premium on "doing." In Tai Chi one learns that if listening precedes doing, it is generally more effective. But listening can be quite a challenge as it can only be achieved through the state of "not doing." In this state we listen with the whole body, which I would call mindful intent or focus. Essentially the entire body becomes a relay for information gleaned through touch via our synapses. I tell my students that by doing this we are developing the world's smartest bodies, as they now can hear with every nerve and fiber.
By paying attention to our bodies in each movement we find that creating a movement from emptiness with a structure that generates power while being aware of any flaw in balance can actually be quite challenging. At first the mind wanders and just as if you were balancing multiple spinning plates, as soon as that happens they start to drop. In time we learn to focus more deeply and can add another plate and eventually more. The mindful intent we develop through this practice is what I believe to be the greatest power of Tai Chi.
Focus is what eventually enables our bodies to listen to the point where spontaneous action is simply a result of this attention and effectiveness the result of spontaneous action. The stillness that pervades our movement enables a growing awareness of everything that happens around us. We learn to respond to the vibration that any intent or movement generates. Eventually we go beyond the awareness of our own bodies, extending that focus to the movements of others and deeper connection to all that is. In the self defense applications we become aware of the flaws in their movement as a result of having fixed them in our own. By learning to listen with our bodies we can begin to hear the voices of the other bodies.
When our movements react spontaneously to the movements of another we discover the supreme importance of superior timing. This, as far as I'm concerned, is the holy grail of Tai Chi Ch'uan. Timing enables us to accomplish the most dynamic results with the least amount of effort.
Just the other day, I watched my cat stalk a baby rabbit in our back yard. I was surprised that the rabbit just froze, allowing the cat to go from 30 feet away to within 4 feet of it. As the cat dropped into a crouch to spring, the rabbit bolted. The cat was unable to even to start to react, it just sat there. The rabbit was perfectly focused and saw in the way that the cat approached it could instantly give chase, but only in the moment the cat went into its' crouch, would it be unable to. The rabbits' focus was highly tuned and its timing was impeccable. The cat did not stand a chance. Consider how superior focus and timing might improve everyone's life, it certainly has made a vast difference in mine.
They say in the Tai Chi Classics that the Tai Chi practitioner approaches his goals like a stone sinking to the bottom of a pond. It is focus that enables that.