Harry Potter and the Order of the Phoenix
How we cite our quotes:
"Don't call them [half-breeds]!" Hermione said furiously, but Umbridge did not have heard her. Still pointing her shaking wand at Magorian, she continued, "Law Fifteen 'B' states clearly that 'any attack by a magical creature who is deemed to have near-human intelligence, and therefore considered responsible for its actions —"
"'Near-human intelligence'?" repeated Magorian, as Bane and several others roared with rage and pawed the ground. "We consider that a great insult, human! Our intelligence, thankfully, far outstrips your own." (33.33-34)
And here, we have an example of why bigotry is bad: check out how quickly this confrontation between half-human-hater Professor Umbridge and all-human-hater Magorian flares up. They both totally offend each other within a second of speaking, which leads to violence very quickly. If they were willing to be less extreme in their prejudices, this showdown between Professor Umbridge and the centaurs would never take place.