A Portrayal of the Elder Races is a book obtainable in The Witcher 3: Wild Hunt.
What is a nonhuman? The answer is simple. As the very name suggests, it is something which resembles, and yet nevertheless is not, a human. Though it walks on two legs, speaks a tongue similar to our own and dresses in similar attire, it all the same has more in common with base beast than noble man.
Dwarves are like moles. They feel best underground and avoid direct sunlight. They like to live in filth, forever smudging themselves in mud and slime. They love everything that can be found within the earth - rocks, metal, minerals of all shape and color. It is also said that, like their kindred moles, they feed most readily on worms, roaches and other nightcrawlers.
Halflings, for their part, are more reminiscent of gophers. Fat, lazy and loud in that typical rodent way, their minds are filled only with thoughts of food and drink, which they steal from other, nobler beasts and greedily squirrel away in their hovels. They are marked by a cruel craftiness. You could be dying of hunger and they would not share a meal with you. You could be howling from poverty, and they could be swimming in gold, and yet they would still fleece you to the last crown. You could do nothing but good to them, and they would still stab a knife in your back.
Elves, in turn, seem related to the birds of prey that dwell in far-off Zerrikania. They care most for colored feathers. They would most readily spend all day staring at their reflections in the water and singing their own praises. They are so awash in self-love that they no longer feel any desire towards members of the opposite sex of their own species. Their appearance, unquestionably pleasant to the eye, is highly misleading, for they are extraordinarily cruel and any who judge them by looks alone they first dupe and then kill in cold blood. The best proof of this? The so-called Scoia'tael, bandits that claim to fight for freedom, but in truth only long to kill humans.
All these vile so-called "elder" races are, to our great fortune, slowly dying out. Joy fills the heart of every right-thinking man at the thought that his great-grandchildren will never know them, that in their day dwarves, halflings and elves will be merely fairy-tale characters used to scare young, impressionable children.