Any sensible ruler would have killed off Leonard, and Lord Vetinari was extremely sensible and often wondered why he had not done so. He'd decided that it was because, imprisoned in the priceless, inquiring amber of Leonard's massive mind, underneath that bright investigative genius was a kind of willful innocence that might in lesser men be called stupidity. It was the seat and soul of that force which, down the millennia, had caused mankind to stick its fingers in the electric light socket of the Universe and play with the switch to see what happened - and then be very surprised when it did.
Terry PratchettGranny Weatherwax was often angry. She considered it one of her strong points. Genuine anger was one of the world's greatest creative forces. But you had to learn how to control it. That didn't mean you let it trickle away. it meant you dammed it, carefully, let it develop a working head, let it drown whole valleys of the mind and then, just when the whole structure was about to collapse, opened a tiny pipeline at the base and let the iron-hard stream of wrath power the turbines of revenge.
Terry PratchettI 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.
Terry Pratchett