"The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion."

In mathematics, truth is always relative to the system you're working in.

人们为了被拯救，会去拯救别人。

圆的周长大于任何内接等边多边形的周长，小于任何外切多边形的周长。

"Doubt is useful for a while. We must all pass through the garden of Gethsemane. If Christ played with doubt, so must we."

The past is a place we can visit but never stay.