Bibliomancy is the use of books in divination. The method of employing sacred books (especially specific words and verses) for 'magical medicine', for removing negative entities, or for divination is widespread in many religions of the world. A book is picked that is believed to hold truth, it is balanced on its spine and allowed to fall open. A passage is picked, with the eyes closed. Among Christians, the Bible is most commonly used (in the Sortes Sanctorum), and in Islamic cultures the Qur'an. In the Middle Ages the use of Virgil's Aeneid was common in Europe and known as the sortes Virgilianae. In the classical world the sortes Virgilianae and sortes Homerica (using the Iliad and Odyssey) were used.