“It’s all in Hogwarts: A History. Though, of course, that book’s not entirely reliable. “A Revised History of Hogwarts” would be a more accurate title. Or “A Highly Biased and Selective History of Hogwarts, Which Glosses Over the Nastier Aspects of the School” … House-elves! Not once, in over a thousand pages, does Hogwarts: A History mention that we are colluding in the oppression of a hundred slaves!”

Hermione, Goblet of Fire, Ch. 15