My favourite fellow of the Royal Society is the Reverend Thomas Bayes, an obscure 18th-century Kent clergyman and a brilliant mathematician who devised a complex equation known as the Bayes theorem, which can be used to work out probability distributions. It had no practical application in his lifetime, but today, thanks to computers, is routinely used in the modelling of climate change, astrophysics and stock-market analysis.

The number of people on whose cooperative efforts your eventual existence depends has risen to approximately 1,000,000,000,000,000,000, which is several thousand times the total number of people who have ever lived.

America is a great disappointment to me. As I said in one of my books, other societies create civilisations; we build shopping malls.

As a rule of thumb, I would submit that if you need to call your floss provider, for any reason, you are probably not ready for this level of oral hygiene.

Have you ever seen Glenn Beck in operation? It is the most terrifying thing. It's so bad that you think he's going to announce in a minute that it's all a great con. He makes Sarah Palin look reasonable and steady.

I can't imagine there has ever been a more gratifying time or place to be alive than America in the 1950s. No country had ever known such prosperity.

The real problem you get with humour is that you only have so many kinds of jokes within you, and you mine that vein a lot. This isn't just common to me; it's anybody who's funny.