Prince Hui's cook was cutting up an ox. Every touch of his hand, every heave of his shoulder, every move of his feet was in perfect rhythm — like the dance of the Mulberry Grove. 'I work with my mind and not with my eye,' he said. 'My mind works along without the control of the senses. Falling back upon eternal principles, I glide through the great joints as they are. A good cook changes his chopper once a year — because he cuts. An ordinary cook, once a month — because he hacks. I have used this chopper for nineteen years, yet its edge is still as keen as if fresh from the grindstone. Because I always work in accordance with the natural constitution of the animal.'

Chuang Tzu, Chapter 3 – The Secret of Caring for Life