Such was the theory, anyway, and Amelia never had questioned it. But the Muggle-born witch in the tan denim robes officially knew more about magic at the end of her Hogwarts years than did most Purebloods, and this witch was more magically powerful than at least one Pureblood. Either the witch was lying, despite no body language to hint she was lying, or the theory that the British Purebloods had used for centuries to justify their privileges was wrong.