The greatest threat to our forests isn’t logging—it’s indifference.

The history of science is the history of men correcting their mistakes.

未来是用来发现的。

If one only wished to be happy, this could be easily accomplished; but we wish to be happier than other people, and this is always difficult, for we believe others to be happier than they are.

所有生而为人者都需要教育，因为他们注定要成为真正的人，而非野兽、愚钝的动物或木头。