Guards! Guards! (Discworld, #8)

by Terry Pratchett

Once you’ve ruled out the impossible then whatever is left, however improbable, must be the truth. The problem lay in working out what was impossible, of course. That was the trick, all right.

There was no difference at all between the richest man and the poorest beggar, apart from the fact that the former had lots of money, food, power, fine clothes, and good health. But at least he wasn’t any better. Just richer, fatter, more powerful, better dressed and healthier. It had been like that for hundreds of years.

People were stupid, sometimes. They thought the Library was a dangerous place because of all the magical books, which was true enough, but what made it really one of the most dangerous places there could ever be was the simple fact that it was a library.

Never trust any ruler who puts his faith in tunnels and bunkers and escape routes. The chances are that his heart isn’t in the job.”