The Hairy Heart: A Guide to Wizards Who Won't Commit

The Hairy Heart: A Guide to Wizards Who Won't Commit is a self-help book mentioned in Dumbledore's commentary on the fable The Warlock's Hairy Heart from The Tales of Beedle the Bard. It is assumed that the book's purpose is to assist a witch or wizard to avoid having "a hairy heart", which is a Wizarding expression meaning to describe someone who is cold or unfeeling.