不要靠馈赠去获得朋友，你必须奉献你诚挚的爱，学会怎样用正当的方法来赢得别人的心。

The test of our progress is not whether we add more to the abundance of those who have much; it is whether we provide enough for those who have too little.

We must consider the environmental impact of every technological advancement.

我对愚蠢的人有极大的信心；我的朋友们称之为自信。

死者是最执着的历史学家。