The only way to save a rhinoceros is to save the environment in which it lives, because there's a mutual dependency between it and millions of other species of both animals and plants.

了解心灵的方法是对其进行逆向工程：弄清楚自然选择设计它来完成什么任务。

历史不仅仅是关于过去；它也关乎现在和未来。

Your most unhappy customers are your greatest source of learning.

"The world is a book, and those who do not travel read only a page."

The surest way to corrupt a youth is to instruct him to hold in higher esteem those who think alike than those who think differently.

有一个快乐的境况出现，但就有一个不快乐的境况相对立；有一处优美的风景出现，但就立即有一处不优美的风景相抵销。

解释：闻知有道德的人不予荐举，听说有善良的人不去寻求，见到有才能的人不予使用，那是很危险的。