在数学中，你不理解事物。你只是习惯了它们。
我不是因为快乐而唱歌；我因为唱歌而快乐。
An eye for an eye will only make the whole world blind.
The end of history will be a very sad time. The struggle for recognition, the willingness to risk one's life for a purely abstract goal, the worldwide ideological struggle that called forth daring, courage, imagination, and idealism, will be replaced by economic calculation, the endless solving of technical problems, environmental concerns, and the satisfaction of sophisticated consumer demands.
"The only way to deal with an unfree world is to become so absolutely free that your very existence is an act of rebellion."