Prescribing the right book

Between ourselves, there is no such thing, abstractly, as a "good" book. A book is "good" only when it meets some human hunger or refutes some human error. ... My pleasure is to prescribe books for such patients as drop in here and are willing to tell me their symptoms. Some people have let their reading faculties decay so that all I can do is hold a post mortem on them. But most are still open to treatment. There is no one so grateful as the man to whom you have given just the book his soul needed and he never knew it.

Christopher Morley, The Haunted Bookshop