The human race may well become extinct before the end of the century. Speaking as a mathematician, I should say the odds are about three to one against survival.

Every advance in civilization has been denounced as unnatural while it was recent

All movements go too far.

If one lived for ever the joys of life would inevitably in the end lose their savour. As it is, they remain perennially fresh.

It seems to us unwise to have insisted on teaching geometry to the younger Dionysius, tyrant of Syracuse, in order to make him a good king, but from Plato's point of view it was essential. He was sufficiently Pythagorean to think that without mathematics no true wisdom is possible.

When one admits that nothing is certain one must, I think, also admit that some things are much more nearly certain than others.

The newspapers at one time said that I was dead but after carefully examining the evidence I came to the conclusion that this statement was false.