Tao Teh Ching Chapter 41

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。
故建言有之：明道若昧；进道若退；夷道若类；
上德若谷；广德若不足；建德若偷；质真若渝；大白若辱；大方无隅；大器晚成；大音希声；大象无形；道隐无名。夫唯道，善贷且成.
Translation
The ones of higher class, when heard about the Tao, carries it out diligently; The one of the middle class, only carries it intermittently; The one of the lowest class, however, laugh at the Tao. It is not the Tao if it is not laughed at!
Therefore it is said that one understands the Tao he seems slow in wit; he who make progress in the Tao seems to walk backwards; an even way seems to be rugged.
The highest virtue is like a valley, the widest virtue seems insufficient, the established virtue seems flawed, the real nature seems always changing, the greatest glory resembles humiliation, the bigger square has no corner, the biggest vessel is made last, the greatest sound is seldom heard, the biggest image has no form. The Tao is nameless, and yet only the Tao can impart itself and complete all beings.

Comments
Previous chapters already cover a great portion of this chapter. The only portion that is interesting here is the first paragraph when Lao Tzu is talking about the type of people when they here about the Tao. I previously stated that some similarities exist between Taoism and Buddhism. Here is properly where the difference is. In Buddhism, all people are Buddha; the only difference is whether or not one had self-realization or 悟. The realization can be a gradual one or a sudden one, and thus 顿悟, 渐悟. The sixth generation master of Buddhism in China is 惠能, who said:
本来正教，无有顿渐，人性自有利钝。迷人渐契，悟人顿修，自识本心，自见本性，即无差利，所以立顿渐之假名。
The meaning is that according to the nature of the person, the realization can be fast or slow. But the realization or the inner knowledge is present in everyone. Therefore the class is just superficial and can be eliminated when realization is achieved.