"But howsoever the works of wisdom are among human things the most excellent, yet they too have their periods and closes. For so it is that after kingdoms and commonwealths have flourished for a time, there arise perturbations and seditions and wars; amid the uproars of which, first the laws are put to silence, and then men return to the depraved conditions of their nature, and desolation is seen in the fields and cities. And if such troubles last, it is not long before letters also and philosophy are so torn in pieces that no traces of them can be found but a few fragments, scattered here and there like planks from a shipwreck; and then a season of barbarism sets in, the waters of Helicon being sunk under the ground, until, according to the appointed vicissitude of things, they break out and issue forth again, perhaps among other nations, and not in the places where they were before." -- Francis Bacon, philosopher, Of the Wisdom of the Ancients, Book XI: Orpheus or Philosophy, 1609
UPDATE: I'm Just Sayin': Flood's a sobering reminder of earth's power.
Earlier this month I caught the end of a Science Friday program on NPR that included some pretty depressing predictions about the future of humankind.
The theme of the program, which featured author Cormac McCarthy, filmmaker Werner Herzog and physicist Lawrence Krauss, was about how art and science converge to inform us about the past, present and future of the universe.
One of the three guests, I think it was McCarthy, said he didn't think Earth would include humans at some point in the not-too-distant future. It might be 500 years or 1,000 years or 2,000 years, but he said he didn't think humans have what it takes to keep the species going beyond a couple more millennia.