We are careening toward Dec. 21, 2012, the date of the Mayan apocalypse, when the world is supposed to come to an end through a series of cataclysmic upheavals, according to assorted astrologers and mystics ‑ though not the Mayans themselves, who said it was merely the end of their calendar. We are also hurtling toward the Jan. 1 “fiscal cliff,” when the American economy could re-enter a devastating recession ‑ a man-made mini-apocalypse.

What has motivated people, across so many civilizations and centuries, to devise and believe in an apocalypse? Understanding this might help us address the ideological gridlock now propelling Republicans and Democrats toward this fiscal “end of days.”

There have always been groups who believe in a coming apocalypse, suggesting this is inherent in human nature. People who experience life as traumatic, devastating or chaotic are prone to project such nihilistic visions onto the world at large. Anxiety about one’s own death can also evoke a catastrophic apprehension about the end of the entire world.

Yet virtually every story of the apocalypse contains a belief in a rebirth or renewal just before or after the end of days. The apocalypse destroys all that is bad in life, wiping the slate clean for a second chance ‑ like the Second Coming of the Messiah.

This is particularly true in the Judeo-Christian tradition. In the Book of Revelations, the apocalypse is a battle between good and evil, in which the earthly world is destroyed and replaced by an otherworldly paradise. In the New Testament, the horrific pain of existence is replaced by the second chance of being resurrected and joining Jesus, God the Father and the angels in an eternal heaven.