Asked if he believes in one G-d, a mathematician answered: "Yes, up to isomorphism".

The mathematician is in much more direct contact with reality. ... [Whereas] the physicist's reality, whatever it may be, has few or none of the attributes which common sense ascribes instinctively to reality. A chair may be a collection of whirling electrons.

No one has yet discovered any warlike purpose to be served by the theory of numbers or relativity, and it seems unlikely that anyone will do so for many years.

If I could prove by logic that you would die in five minutes, I should be sorry you were going to die, but my sorrow would be very much mitigated by pleasure in the proof.

The study of mathematics is, if an unprofitable, a perfectly harmless and innocent occupation.

Exposition, criticism, appreciation, is work for second-rate minds.

I was at my best at a little past forty, when I was a professor at Oxford.