There's a lot of science in it, and as Slartibartfast [in The Hitchhiker's Guide to the Galaxy] said: 'I am a great fan of science, but I cannot do a quadratic equation.' I've never, ever been able to do one. I remember one occasion at Warwick University, when Jack and Ian were at their wits' end because I couldn't get it. I felt totally ashamed.

People couldn't become truly holy, he said, unless they also had the opportunity to be definitively wicked.

Sergeant Colon of the Ankh-Morpork City Guard was on duty. He was guarding the Brass Bridge, the main link between Ankh and Morpork. From theft. When it came to crime prevention, Sergeant Colon found it safest to think big.

Christ managed to boil down an awful lot of commandments to a few very simple rules for living. It's when you go backwards through the 'begats' and the Garden of Eden, and you start thinking, 'Hang on, that's a big punishment for eating one lousy apple... There's a human-rights issue.'

He moved in a way that suggested he was attempting the world speed record for the nonchalant walk.

The truth isn't easily pinned to a page. In the bathtub of history the truth is harder to hold than the soap and much more difficult to find.

Modesty is only arrogance by stealth.