When you first start to study tai chi the body informs the mind – this is done by what you feel and see when scanning the body for tension, checking your weight differentiation and foot placements, monitoring your alignment, and coordinating the body mechanics from the vertical and horizontal axis. After a period of time – usually about the time it takes to learn the form, the mind begins to inform the body. This is accomplished by the use of several methods – continuity of motion; guiding the changing of shapes (known as postures and transitional movements of the form); the wave of energy that is engaged as it flows upward from the feet into the awakening of the posture, and then recedes back downward towards the earth, as you let go of that posture and begin the next; and the spirit of your action – which is the dynamic application of force within the posture.