The mind uses its faculty for creativity only when experience forces it to do so.

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.

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

Experiment is the sole source of truth. It alone can teach us something new; it alone can give us certainty.

There are no solved problems; there are only problems that are more or less solved.

Mathematics is the art of giving the same name to different things.

If we wish to foresee the future of mathematics, our proper course is to study the history and present condition of the science.