The sole aim of Zen is to enable one to understand, realize, and perfect his own mind. Garma C. C. Chang
Zen is based on the recognition of two incompatible types of thought: rational and intuitive. Rationality employs language, logic, reason. Its precepts can be taught. Intuitive knowledge, however, is different. It lurks embedded in our consciousness, beyond words. Unlike rational thought, intuition cannot be "taught" or even turned on.
"The Tao that can be put into words is not the real Tao."
The master Wen-yu summed it up when he answered a demand for the First Principle of Ch'an with, "If words could tell you, it would become the Second Principle."
Note: What is Zen?