Three Stage of Tai CHi standing
Because Yin and Yang depend on each other (each exists as a precondition for the other), pure Yin does not last, and pure Yang does not endure. Hence, in martial arts, there is no absolute relaxation or tension. Complete relaxation is slackness, and complete tension is stiffness. There is relaxation within tension, and tension within relaxation, the transformations of Yin and Yang are infinitely profound.