The desire to understand the world and the desire to reform it are the two great engines of progress, without which human society would stand still or retrogress.

The triumph of science has been mainly due to its practical utility, and there has been an attempt to divorce this aspect from that of theory, thus making science more and more a technique, and less and less a doctrine as to the nature of the world. The penetration of this point of view to philosophers is very recent.

Artists are on the average less happy than men of science.

To be able to concentrate for a considerable time is essential to difficult achievement.

Americans need rest, but do not know it.

Freedom in education has many aspects. There is first of all freedom to learn or not to learn. Then there is freedom as to what to learn. And in later education there is freedom of opinion.

So far as I can remember, there is not one word in the Gospels in praise of intelligence.