Later generations will regard Mengenlehre (set theory) as a disease from which one has recovered.

Later generations will regard Mengenlehre (set theory) as a disease from which one has recovered.

A first fact should surprise us, or rather would surprise us if we were not used to it. How does it happen there are people who do not understand mathematics? If mathematics invokes only the rules of logic, such as are accepted by all normal minds...how does it come about that so many persons are here refractory?

Just as houses are made of stones, so is science made of facts.

If we knew exactly the laws of nature and the situation of the universe at the initial moment, we could predict exactly the situation of the same universe at a succeeding moment.

We also know how cruel the truth often is, and we wonder whether delusion is not more consoling.

Often when works at a hard question, nothing good is accomplished at the first attack. Then one takes a rest, long or short, and sits down anew to the work. During the first half-hour, as before, nothing is found, and then all of a sudden the decisive idea presents itself to the mind.