On October 31, 1517, a monk named Martin Luther issued a public protest against traditional Christian doctrines, especially the sale of indulgences to free souls from otherworldly torment. The religious revolution known as the Protestant Reformation began when Luther nailed The Ninety-Five Theses, his short, incisive critique of the medieval traditions of the Catholic Church, on the doors of All Saints’ Church in Wittenberg, Germany. Luther’s writings kindled the anger of traditional Catholics and inspired the enthusiasm of a new generation of Protestant Christians, forever fracturing the unity of doctrine and tradition that characterized the history of Christianity during the European Middle Ages.

Protestants were firm in their belief that purgatory was an invention of the human imagination rather than a divine truth because they could find no testimony of it in the Holy Scriptures. Moreover, they believed that it was presumptuous to assume that living people had any agency to help the souls of the dead, whose fate was determined by the inscrutable judgment of God. Since Protestants held that the souls of the dead went either directly to heaven or directly to hell, they did not believe in ghosts. But the centuries-old tradition of supernatural contact between the living and the dead proved hard to jettison completely. Protestant Christians were at pains, for instance, to explain one of the most well-known ghost stories from the ancient world: the conjuring of the soul of King Samuel by the witch of Endor (see pp. 29–30, above). For their part, Catholic authors responded quickly to the Protestant attack on the existence of ghosts by marshaling long lists of examples of supernatural encounters from antiquity and the Middle Ages in their attempt to show that the sinful dead benefitted from suffrages offered by the living on their behalf.