The spirit's foe in man has not been simplicity, but sophistication.

Man's most serious activity is play.

Wisdom comes by disillusionment.

It is a pleasant surprise to him (the pure mathematician) and an added problem if he finds that the arts can use his calculations, or that the senses can verify them, much as if a composer found that sailors could heave better when singing his songs.

Man has an inexhuastible faculty for lying, especially to himself.

To be happy you must have taken the measure of your powers, tasted the fruits of your passion, and learned your place in the world.

If clearness about things produces a fundamental despair, a fundamental despair in turn produces a remarkable clearness or even playfulness about ordinary matters.