Surely no child, and few adults, have ever watched a bird in flight without envy.

It is precisely because it is fashionable for Americans to know no science, even though they may be well educated otherwise, that they so easily fall prey to nonsense.

All the hundreds of millions of people who, in their time, believed the Earth was flat never succeeded in unrounding it by an inch.

He had read much, if one considers his long life; but his contemplation was much more than his reading. He was wont to say that if he had read as much as other men he should have known no more than other men.

It is not only the living who are killed in war.

The true delight is in the finding out rather than in the knowing.

Self-education is a continuing source of pleasure to me, for the more I know, the fuller my life is and the better I appreciate my own existence