|Taekwondo Bible, Vol.2||
What is Yu? Generally Yu means "softness". The soft thing is the light grass or feather that moves touched by tender wind. The essence of its property is that it follows any change, however little, without resistence. Even a slight wind can blow a feather or move grass that dances just as much as wind flows. Thus it never resists. This is what Yu(i.e. softness) implies.
Then what is Yu in Taekwondo? The intentional meaning of concept of Yu is "to get what you want to get following your opponent wants to do or the state of affair changes". Its essential point can be summed up as, "following your opponent". And it is the extentional meaning of the concept of Yu.
A grass of a feather can be so soft as it swims even with the current of the slight wind. It means, its obedience produces its softness. On the contrary, if you cling to only what you want to do with resistance to the trend you cannot control you will only fall in danges. Therefore, Chuang-tzu says; "Don't you know about the praying mantis that waved its arms angrily in front of an approaching carrage, unaware that they were incapable of stopping it? Such was the high opinion it had of its talents. Be careful, be on your guard! If you offend him by parading your store of talents, you will be in danger!"1)
This is what the essence of Yu tells us. This following in Yu is the essential principle in efficient management of power and connection of changes.
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