《老子·德经·第四十一章》
上士听了道的理论，勤恳、坚持不懈地去实行它；中士听了道的理论，半信半疑；下士听了道的理论，大笑不止，认为荒诞不稽。如果不被嘲笑，那就不足以成为道了。
上士闻道，勤而行之；中士闻道，若存若亡；下士闻道，大笑之。不笑不足以为道。
The noble ones hear the theory of the Dao, and diligently and persistently practice it; the middle ones hear the theory of the Dao, and half believe and half doubt; the inferior ones hear the theory of the Dao, and laugh out loud, thinking it is absurd. If it is not laughed at, it is not enough to be the Dao.