This saying is a clue to the real relationship between Mind (attention) and body. There are two aspects of Mind when you are practicing. One is knowing the movements and mechanics behind the movements. The other aspect of Mind is the ebb and flow of attention, its expansion and relaxing. This aspect is like the ocean currents. The “knowing” aspect is like a scuba diver who wants to get from here to there and get things done. He still has to yield to the ocean currents, which are much stronger than him.
The flowing aspect of Mind is not fixed at one spot, such as in the head. It does not give orders to the body. It flows, and the body responds because that is its nature. I also want to make clear that I am NOT talking about imagining the movement in your head first and then doing it. Attention simply flows here or there, it sinks or expands. It is Yin. It is the job of the other aspect of Mind, Yang, to exert influence on the body so that the movements are specific. But Yang Mind does not interfere or overcome Yin Mind.
Another saying is that “The one begets the two, the two begets the three and the three begets the ten thousand things”. At a beginners stage of training, the two aspects of Mind and the body are fused. Everything is tight. There is no relationship among these parts of us. In order to have a relationship, each member of the relationship must be free and independent yet coordinated with the others. If any one member is frozen, there is no relationship. If each is completely independent, with no connection, there is still no relationship. When all three are fused and locked, there is certainly no relationship.
Yet that fused, locked state is the condition of modern people. In order to develop relationship you can practice the form in this way: First allow your attention to move towards where your body will go, and then move the body there. The attention will be like a bungee cord, pulling the body, or like a boat, pulling a water skier. The attention will create a pathway that the body will follow.
You will gradually become aware of the Yin and Yang aspects of attention and their relationship with the body. In fact, everyday the Yin aspect of attention tries to “break its chains” and flow but we are so unused to that that we tighten up right away to stop it. If you know this, and look for it in your everyday life, you can attempt to extend the time that Yin attention is free by not reacting against it. Then you will have a chance for a real relationship between the parts of attention (“Mind”) and the body. (Don’t do this while driving).
When you first begin your Tai-chi practice you bring to it the state of Mind you have. But that frozen state makes it hard to learn Tai-chi. So you either do Tai-chi stiffly, or you struggle to do it in a flowing way. The only way you can really do Tai-chi well is through a transformation of Mind itself, allowing for the relationship described above. That new state of Mind then stays with you all day. You bring it into your everyday interactions and you find that, not only does this new Mind help you in your Tai-chi practice, but in your everyday life as well. And that is one of the great benefits of Tai-chi.