一个好的数学问题的定义是它产生的数学，而不是问题本身。

If you're an artist, you try to make sense out of one thing or another.

Suffering! We owe to it all that is good in us, all that gives value to life; we owe to it pity, we owe to it courage, we owe to it all the virtues.

The meaning of our existence is not invented by ourselves, but rather detected.