Civilizations can only be understood by those who are civilized.

A man of science doesn't discover in order to know, he wants to know in order to discover.

It is a safe rule to apply that, when a mathematical or philosophical author writes with a misty profundity, he is talking nonsense.

The art of progress is to preserve order amid change, and to preserve change amid order. Life refuses to be embalmed alive. The more prolonged the halt in some unrelieved system of order, the greater the crash of the dead society.

Inventive genius requires pleasurable mental activity as a condition for its vigorous exercise

It is not paradox to say that in our most theoretical moods we may be nearest to our most practical applications.

Learning is often spoken of as if we are watching the open pages of all the books which we have ever read, and then, when occasion arises, we select the right page to read aloud to the universe.