Oh, my dear Vimes, history changes all the time. It is constantly being re-examined and re-evaluated, otherwise how would we be able to keep historians occupied? We can't possibly allow people with their sort of minds to walk around with time on their hands.

Knowing things is magical, if other people don't know them.

Now he knew: They were real. Who’d make up a thing like this? Okay, one of them was a cheese that rolled around of its own accord, but nobody was perfect.

A European says: I can't understand this, what's wrong with me? An American says: I can't understand this, what's wrong with him? I make no suggestion that one side or other is right, but observation over many years leads me to believe it is true.

The most watched programme on the BBC, after the news, is probably 'Doctor Who.' What has happened is that science fiction has been subsumed into modern literature. There are grandparents out there who speak Klingon, who are quite capable of holding down a job. No one would think twice now about a parallel universe.

Why not? If enough people believe, you can be god of anything.

I certainly don't sit down and plan a book out before I write it. There's a phrase I use called "The Valley Full of Clouds." Writing a novel is as if you are going off on a journey across a valley. The valley is full of mist, but you can see the top of a tree here and the top of another tree over there. And with any luck you can see the other side of the valley. But you cannot see down into the mist. Nevertheless, you head for the first tree.