Do not listen with your ears but with your mind. Do not listen with your mind but with your chi. Ears can only hear, mind can only think, but chi is energy, receptive to all things. Tao abides in emptiness. Emptiness is the fasting of the mind. … It is in emptiness that light is born. There is happiness in stillness. Lack of stillness is called sitting while wandering. If you are open to everything you see and hear, and allow this to act through you, even gods and spirits will come to you, not to speak of men. This is the transformation of ten thousand things, the secret of the wise kings.“
– Chuang Tzu, Book 6.