I used the pen name Wu Wu in my book That Is That and the words equate to Negating Negation.
What strikes many people, even if not in the logical mind but somewhere deeper, when reading the Tao Te Ching, some Zen poetry or other work is something true, something they knew all along, but never heard anyone say, and this is Wu Wu.
Later inquiry tells the reader how they had lived their whole life knowing this but never hearing it said – It can’t be said! Words fail it, words in fact are traps pointing directly away from it as words are sign posts in the world of mind. Wu Wu comes when a bird disappears into the distance leaving you openly gazing into the sky – it disappears when the next thought arises.
Negation is a powerful spiritual tool used in Zen and other practices, it is used in the Tao Te Ching by showing the reader Complimentary or Interdependent pairs of opposites. Dark is not the opposite of light but these are Interdependent, Mutually Arising aspects, inseparable and impossible alone. When it is seen that Beauty is required to know Ugly, The idea of Light is required to know that Dark is dark, Happiness and Sadness are mutual and so on, then the seeker, once they see that one thing is inseparable from the other, is left to discover the oneness.
When skilled in this, when light and dark are seen as inseparable points on a scale and not unique things alone, the seeker may also consider space and time, self and other and more – they should always find now the unreality of the separate concept and a special new position which sees this. This separate point of observation is the key bond to break as once you see that all pairs extinguish and result in a new idea, the final idea is always the observing. That self constantly changes and has no fixed quality, the world is constantly changing and has no fixed quality, the consigning is constantly in motion and has no fixed quality, all we are is the …ing, the process.
Now, knowing that all things in mind always extinguish when the compliment which gives it appearance is considered, the person should, quietly, with no effort, without words, without reason, see this …ing too dissolve, by Wu Wu, into the stateless state, had by no one, outside of Interdependent pairs, EveryNothing.