We keep passing unseen through little moments of other people's lives.

One geometry cannot be more true than another; it can only be more convenient. Geometry is not true, it is advantageous.

Boredom always precedes a period of great creativity.

For every fact there is an infinity of hypotheses.

It is a puzzling thing. The truth knocks on the door and you say, 'Go away, I'm looking for the truth,' and so it goes away. Puzzling.

During periods of root expansion things have always looked as confused and topsy-turvy and purposeless as they do now. The whole Renaissance is supposed to have resulted from the topsy-turvy feeling caused by Columbus’ discovery of a new world. It just shook people up. The topsy-turviness of that time is recorded everywhere. There was nothing in the flat-earth views of the Old and New Testaments that predicted it. Yet people couldn’t deny it. The only way they could assimilate it was to abandon the entire medieval outlook and enter into a new expansion of reason.