Non-violence is the greatest force at the disposal of mankind.

心理学家必须避免一切目的论的解释。

"I always try to stay positive, even when things are not going my way."

我能给的最好建议是保持谦逊并努力工作。

The future of democracy depends on the ability of democratic societies to reform themselves.

数学中真正的挑战不是解决问题，而是提出正确的问题。