The most effective way to promote democracy is not through military intervention but through the slow and steady process of building institutions and promoting economic development.
如果不是现在，那是什么时候？如果不是我，那会是谁？
The improvement of understanding is for two ends: first, our own increase of knowledge; secondly, to enable us to deliver that knowledge to others.
积极情绪不是微不足道的奢侈品，而是最佳功能的关键必需品。
The beauty of mathematics only shows itself to more patient followers.