[In many circumstances,] the most important thing about a proposition is not that it be true, but that it be interesting.

In every age of well-marked transition, there is the pattern of habitual dumb practice and emotion which is passing and there is oncoming a new complex of habit.

It belongs to the self-respect of intellect to pursue every tangle of thought to its final unravelment.

The study of mathematics is apt to commence in disappointment.

It is impossible to meditate on time and the mystery of nature without an overwhelming emotion at the limitations of human intelligence.

Without adventure all civilization is full of decay. Adventure rarely reaches its predetermined end. Columbus never reached China.

Some of the finest moral intuitions come to quite humble people. The visiting of lofty ideas doesn't depend on formal schooling.