世界称之为不道德的书籍，其实是展示世界自身羞耻的书籍。
The books that the world calls immoral are books that show the world its own shame.
世界是残酷的，但它也是美丽的。
要理解现在，我们必须首先直面过去。
The peculiar evil of silencing the expression of an opinion is that it is robbing the human race； posterity as well as the existing generation； those who dissent from the opinion， still more than those who hold it.
没有阴影就没有阳光，了解夜晚是必要的。
The joy of discovery in mathematics is unparalleled.