"What is Tao?" The unspeakable and unexplained fundamental existence is Tao. Tao, as one, was born before heaven and earth. Tao, alone and unchangeable. Tao is pregnant with all things in the world, but it will not decrease at all. Tao runs in all things, but never wears away. Is "Dao" its real name? I want to call him "big", but "big" is not enough to show the true face of "Tao". Tao is "big" and "far". You look up at him and find that he is extremely tall; you look down on him and find that he is very small; you go after it and it will always be...