The universe may have a purpose, but nothing we know suggests that, if so, this purpose has any similarity to ours.

When there are rational grounds for an opinion, people are content to set them forth and wait for them to operate. In such cases, people do not hold their opinions with passion; they hold them calmly, and set forth their reasons quietly. The opinions that are held with passion are always those for which no good ground exists; indeed the passion is the measure of the holder's lack of rational conviction.

Of all forms of caution, caution in love is perhaps the most fatal to true happiness.

What is new in our time is the increased power of the authorities to enforce their prejudices.

My sad conviction is that people can only agree about what they're not really interested in.

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.

The Axiom of Choice is necessary to select a set from an infinite number of socks, but not an infinite number of shoes.