Eschatology is the study of the last things: death, judgment, the afterlife, and the end of the world. Through centuries of Christian thoughtfrom the early Church fathers through the Middle Ages and the Reformationthese issues were of the utmost importance. In other religions, too, eschatological concerns were central. After the Enlightenment, though, many religious thinkers began to downplay the importance of eschatology which, in light of rationalism, came to be seen as something of an embarrassment. The twentieth century, however, saw the rise of phenomena that placed eschatology back at...