The most important thing is to be able to think, to be able to see, to be able to judge what you see.

我不是因为快乐而唱歌，我因为唱歌而快乐。

The ruling class has the means of material production at its disposal; the proletariat has nothing but their labor power.

在数学中，提出问题的艺术必须比解决问题更有价值。

I believe in the power of intention and hard work.