Hildegard of Bingen, the first German mystic, is one of the most influential women in European history. Born in 1098 in Bockelheim on the Nahe River, Hildegard had her first vision at the age of six, a phenomenon she would continue to experience the rest of her life. At the behest of the archbishop of Mainz, Hildegard set upon recording her visions in writing. Her writings soon propelled her from Benedictine abbess to celebrity as determined reformer, castigating seer, theoretical musician, patient adviser, and exorcist. A woman of extraordinarily energetic and independent mind, Hildegard...