This was the second year of the Green Summer Job Corps in Washington.

VOA: special.2009.09.04

So I am willing to introduce these ideas but A, because it's not my training and people who are focusing on cultural differences will do a much better job than I do; and second, because what I hope to look into is the universal, things are common across cultures.

所以我想介绍这些观点，但是首先，因为这不是我的专业,研究文化差异的人会比我做得更好;,其次，因为我所希望研究的是普遍事物，不同文化中普遍的东西。

哈佛公开课 - 幸福课课程节选

In other words, your job is to guess a function whose second derivative is a, and this is called integration, which is the opposite of differentiation, and integration is just guessing.

换言之,你的任务是要猜出一个二阶导数为a的函数,这就是积分,和微分恰恰相反,积分就是猜

耶鲁公开课 - 基础物理课程节选