In the 1990s, my best friend—a brilliant historian with an “I read banned books” bumper sticker on her car—handed me a book that had changed her life. It was Thomas Moore’s Care of the Soul, a 1992 New York Times best-selling spiritual guide for “cultivating depth and sacredness in everyday life.” I could not get past page 30 or so. I found it long-winded, simple-minded, and tedious—an ahistorical mess of Greek myths, Jungian psychology, and cranky critiques of the superficiality …