理论和实践的区别在于，理论上，理论和实践没有区别，但在实践中，却有区别。
The difference between theory and practice is that in theory, there is no difference between theory and practice, but in practice, there is.
知识的真正方法是实验。
1998年就国际外交政策发表观点时引用美国黑手党首领艾尔·卡彭曾经说过的话。
