Everything in this world – the sun, the moon, the stars, mountain, rivers, and trees – everything is constantly moving. But there is one thing that never moves. It never comes or goes. It is never born and it never dies. What is this not-moving thing? Can you tell me? If you find that, you will find your true self and attain universal substance. But understanding cannot help you find that point. Even one hundred Ph.D.’s will not show you your true nature. If you were to read all eighty-four thousand sutras, learn all Buddha’s speech, and earnestly study all the teachings of all eminent Zen masters, you would never attain your true self through understanding. None of the struggle and toil that gets you this knowledge can help you as much as one moment of insight into your true nature.
Our true nature cannot be found in books and academic studies because our true nature is before speech and words. It is before thinking. If you find your before-thinking point, then it is possible to attain your true self. So, a long time ago, Descartes said, “I think, therefore I am.” This is where philosophy begins. But if you are not thinking, what? This is where Zen practice begins.
From The Compass of Zen