'... knowledge emerges in (humans). Opposed to knowledge is the spirit. The spirit is formless and is incomprehensible to mundane thoughts.... Knowledge is active mischievous and intelligent. It changes constantly. Spirit on the other hand is the master of humankind. Its origin is in wu-chi.... It is never born and it never dies. The spirit tends toward purity and stillness. Knowledge tends toward action and disturbs the mind so that it cannot be still.... Recognize the difference between the human mind and the mind of Tao. Do not mistake the human mind for the mind of Tao and knowledge for the spirit.'