Hopes are always accompanied by fears, and, in scientific research, the fears are liable to become dominant.

It is more important to have beauty in one's equations than to have them fit experiment.

I consider that I understand an equation when I can predict the properties of its solutions, without actually solving it.

Hopes are always accompanied by fears, and, in scientific research, the fears are liable to become dominant.

As time goes on, it becomes increasingly evident that the rules which the mathematician finds interesting are the same as those which Nature has chosen.

A book on the new physics, if not purely descriptive of experimental work, must essentially be mathematical.

Mathematics is the tool specially suited for dealing with abstract concepts of any kind and there is no limit to its power in this field.