Lao-tzu often compares water to the quality of Tao, while Zhuang-zi compared light to things which are similar to Tao.

• 老子总是用水来比喻道的性质，庄子又用光（以光耀命名）来类比接近道的东西，借光耀的话说：“予能有无矣，而未能无无也。”