《公孙龙子·坚白论》
因而，摸得着的便与摸不着的互相隐藏着。既然有互相隐藏，怎能说它们互相不可分离呢？因为 藏 就是不见，不见的当然与可见的有区别而可被分析了。
故有知焉，有不知焉；有见焉，故知与不知相与离，见与不见相与藏。
Therefore, what can be touched hides what cannot be touched. Since there is mutual concealment, how can it be said that they are inseparable? Because "hidden" means "not seen", what is not seen is of course different from what can be seen and can be analyzed.