Having your opponent opposed to the world while harmonizing yourself in it, this is called "the way of Tang (Earth)", which is the correct principle of every technique in Taekwondo. You can find everything of TAEKWONDO in this, so it is also the correct way of thinking in Taekwondo. While the way of Haneul (Heaven) is a principle focused on the fundamentally non-distinctive essence of Nature, the way of Tang (Earth) is focused on man's fundamentally distinctive essence, yet they share the same implication, i.e. one thing.
Following the way of Tang can be considered in three dimensions, called respectively Sool (¼ú[âú] technique), Yae (¿¹[çÝ] art) and Do (µµ[Ô³] principle). However, one should understand that each of these is ultimately the same as the others, being only different aspects of one thing. They are simply distinctions of what ultimately is non-distinctive.
Then, what is it to follow Sool, Yae, and Do? Following Sool means subduing one's opponent with perfect Taekwondo technique. Thus we say one faces the opponent with Musool. Following Yae means expressing one's perfect self in the development of technique for the sake of technique itself detached from one's opponent. Thus we say one faces one's opponent with Muyae. Following Do means unifying both Musool and Muyae to transcend the artificial distinction that discerns one's opponent from oneself. Thus we say one faces the entirety with Mudo.
Although your opponent's will always moves him it is your will that determines him. Man or woman's motion can possess power only after it has first attained its own will. While power is a sharp and hard thing, able to shatter a rock, the will is something soft and subtle that can alter and modify itself to the shape of the world. The soft can surpass the hard.
That your will controls everything, and that everything is an expression of your mind so that Yae and Sool are united in one, this is art. That is, art is the unity of Yae, which is the right expression of your will, and of Sool, which is the technique of controlling the world.
These various changes and harmonies are possible only because encompassing them all is that which never changes from beginning to end despite the changes occurring in everything. This non-change is the root of all and underlies every change, and its name is Do. Thus, Do is what makes everything such as it is; it is the one undistinguishable principle that supports all distinguishable ones. This exists neither in nor out of everything, yet does everything depend upon it. It reveals itself to anyone, whoever they may be, whenever one opens one's eyes and eliminates unnecessary distinctions.