An excerpt from the book The Teachings of Lao-Tzu – The Tao Te Ching / translated by Paul Carus / page 30
‘The reason that can be reasoned is not the eternal Reason. The name that can be named is not the eternal Name.
The Unnameable is of heaven and earth the beginning. The Nameable becomes of the ten thousand things the mother.
Therefore it is said:
‘He who desireless is found,
The spiritual of the world will sound.
But he who by desire is bound,
Sees the mere shell of things around.’
These two things are the same in source but different in name.
Their sameness is called a mystery. Indeed, it is the mystery of mysteries.
It is the door of all spirituality.’