The human being needs sadness as much as he needs joy.
人类需要悲伤,正如需要欢乐一样。
He who wants to do good knocks at the gate;he who loves finds the gate open.
科学家是真理的爱好者,仅仅因为对真理本身的热爱,无论它通向何方。
You are not your circumstances. You are your possibilities.