“A legend states that one day Zhang heard birds on Wudang mountain making an unusual noise and saw them all staring down at the ground where a snake was lifting its head and watching upward. A moment later, a magpie spread its wings and descended to attack the snake. The snake moved slightly to escape the attack, but maintained its circular shape. The contest continued, up and back, down and forth, several times until Zhang stepped out of the door. Immediately the magpie flew away and the snake disappeared. Zhang then realised the truth of softness over firmness and created Tai Chi Chuan. ”
From “The Tao of Tai Chi Chuan” by Jou Tsung Hwa