One of the most significant barriers to people doing things in the world, to actually introducing change is that they underestimate their ability to bring about change.

人若想在世间有所为,真正实现改变，面对的最显著障碍之一,是他们低估自己实现改变的能力。

哈佛公开课 - 幸福课课程节选

So now we've said something about the economic change and something about the political change, and next hour, I'll start with the story of the military change that has so many significant consequences. Okay.

这节课我们讨论了经济变革,和政治变革,接下来,我们将会学到军队的变革,及其重要的历史意义,好的,下课

耶鲁公开课 - 古希腊历史简介课程节选