经济史和经济发展的核心问题是解释政治和经济制度的演变，这些制度创造了一个诱导生产率提高的经济环境。

"The best books are the ones that leave you a little bit different than when you started."

Life is about creating yourself.

He had a way of making her feel safe, even in the most uncertain of times.

The history of life is a history of survival.

每个数学问题都有一个解决方案；只是需要时间和创造力来找到它。

真正的圣贤，决不是愚腐不化。真正的豪杰也绝不是粗鲁疏略。