“The following example is not perfect but it may help me explain the relationship of emptiness to thought. There is rather unusual Japanese noodle dish called wanko soba. One is served a small amount of noodles, which one proceeds to slurp down.
As soon as one is finished, the waitress brings a second serving. If the customer downs these noodles as well, another batch is served immediately. Because the quantity of soba is small enough to be consumed in a single gulp, this cycle of serving and eating repeats itself numerous times. The customer cannot easily control his eating speed, since he must follow the brisk rhythm created by the waitress. Whenever she brings another serving of noodles, she pours them into his bowl and adds the empty serving bowl to the stack in front of him, so the bowls pile higher and higher. Customers may take this as a challenge to eat more than the others in the restaurant, or at least feel some sense of achievement watching the pile grow, so they continue eating. The mounting pile of bowls seems like a proof of their accomplishment.
The act of thinking is a lot like a reversal of the process of eating wanko soba. In short, the customer looks at the empty bowl piled up before his eyes and fills them with his “thoughts” rather than with “noodles.” He follows a certain rhythm when he does this; first one thought fills one bowl, then, in a flash, another, then another… In this manner, like conditioned reflex, “thought” accumulates before our eyes. I have no idea of the exact path our thoughts take, but the example of the empty noodle bowls reflects the general mechanism. In short, our brains automatically insert “answers” into small spaces. In this fashion, emptiness carries our thinking process forward.”
White by Kenya Hara