Racism was not a problem on the Discworld, because - what with trolls and dwarfs and so on - speciesism was more interesting. Black and white lived in perfect harmony and ganged up on green.
Terry PratchettYou can't map a sense of humor. Anyway, what is a fantasy map but a space beyond which There Be Dragons? On the Discworld we know that There Be Dragons Everywhere. They might not all have scales and forked tongues, but they Be Here all right, grinning and jostling and trying to sell you souvenirs.
Terry PratchettColon thought Carrot was simple. Carrot often struck people as simple. And he was. Where people went wrong was thinking that simple meant the same thing as stupid.
Terry PratchettHaven't you got any romance in your soul?" said Magrat plaintively. "No," said Granny. "I ain't. And stars don't care what you wish, and magic don't make things better, and no one doesn't get burned who sticks their hand in a fire. If you want to amount to anything as a witch, Magrat Garlick, you got to learn three things. What's real, what's not real, and what's the difference.
Terry Pratchett