" Cats were often familiars to workers of magic because to anyone used to wrestling with self-willed, wayward, devious magic—which was what all magic was—it was rather soothing to have all the same qualities wrapped up in a small, furry, generally attractive bundle that looked more or less the same from day to day and might, if it were in a good mood, sit on your knee and purr. Magic never sat on anybody’s knee and purred. "

― Robin McKinley , Spindle's End