Among the Jehovah's Witnesses, there is a pervasive sense of impending, eminent, armageddon. But in the early decades of this movement's history, the eschaton was not only eminent, but tied to specific dates. The first date was 1914. Observers noted at the time that the world did not end. So the leaders of the movement concocted an explanation for why the world had not ended but that they were not actually wrong to say so, and pushed the real date forward to 1918. Later, the same prediction was rolled forward to 1925, 1941, and 1975. At none of these points did the world end, and the failure of these predictions to come true did much to discredit the Jehovah's Witnesses -- at least among critics. Alas, the failed prophecies did not do enough to discredit the movement, and it is presently thriving and growing around the world.
I was reminded of this slice of history upon reading an article in Scientific American entitled "Another Inconvenient Truth: The World's Growing Population Poses a Malthusian Dilemma." It contains the usual doomsday predictions made by Malthusians for more than a century: that the world cannot support an increased human population, and that mass famines are inevitable. You may have heard of Paul Ehrlich, a major eschatologist of the 1960s and 70s, whose book The Population Bomb was a best-seller. His dire predictions, extended decade after decade, did not come to pass, yet he still thrives as a paid writer and speaker.
And now another generation of prophets makes the same predictions, based upon the same models, for the near future. Despite their track record, I'm willing to hear them out.
But this is absolutely critical: the current crop of prophets must explain why previous predictions have never come true. They must explain why the Malthusian methodology was flawed, and how their methodology is substantially different.
Otherwise, there's no reason to take them seriously.