In China during the Seventh Century, Zen Buddhism was divided into two schools. The sudden school of the south gathered around the Sixth Patriarch Hui Neng at T'sao Ch'i mountain just north of Canton. The gradual school of the north followed the monk Shen Hsiu. As the fame of the Sixth Patriarch spread, Shen Hsui became concerned and decided to send one of his disciples as a spy to the south.
Upon entering Hui Neng's assembly, the spy-monk asked, "What kind of Dharma do you teach here?"
The Patriarch replied, "If I said I had a Dharma to give people that would be a lie. I only untie the bonds of each according to their needs so that their original nature can appear."
Zen is unique in that it promotes no teaching and no techniques. When you go to a Zen center you never have to take an oath, study a catechism or recite a creed. Rather you are always told to find out what you really are--to find your true self. Zen Master Seung Sahn many times says, "I only teach 'don't know'." If you keep a don't know mind already your true nature has appeared. This is the teaching of the sudden school, Hui Neng's lineage.
The Third Patriarch Seng Tsang said, "The great way is not difficult, simply cut off all thought of good and bad." The Sixth Patriarch taught that one "...who treads the path in earnest sees not the mistakes of the world. If we find fault with others we too are in the wrong. Restlessly we will pass our days and in the end we will be disappointed." Our school, too, says, "Don't check!" Cutting off your checking mind reveals your true self. Strong medicine.
Zen Master Ko Bong composed a poem:
If you want to understand, You don't understand. If you attain don't-know, That is your true nature.
If you attain don't know, that is your true nature. What does that mean?