Pseudonymous Bosch quotes
Only bad books have good endings. If a book is any good, it's ending is always bad - because you don't want the book to end. 
Generally speaking, books don't cause much harm. Except when you read them, that is. Then they cause all kinds of problems. 
Books can also provoke emotions. And emotions sometimes are even more troublesome than ideas. Emotions have led people to do all sorts of things they later regret-like, oh, throwing a book at someone else.