世界是一本书，不旅行的人只读了一页。

我必须研究政治和战争，以便我的儿子们可以自由地研究数学和哲学。

One tells as few lies as possible only by telling as few lies as possible, and not by having the least possible opportunity to do so.

心理学的研究就是研究生活的智慧。

Sustainable energy solutions will define the 21st century.

不要担心别人不理解你，要担心你不理解别人。