For so many in the techno-elite, even those who don't entirely subscribe to the unlimited optimism of the Singularity, the notion of perpetual progress and economic growth is somehow taken for granted. As a former classicist turned technologist, I've always lived with the shadow of the fall of Rome, the failure of its intellectual culture, and the stasis that gripped the Western world for the better part of a thousand years. What I fear most is that we will lack the will and the foresight to face the world's problems squarely, but will instead retreat from them into superstition and ignorance.

Consider how in 375 AD, after a dream in which he was whipped for being "a Ciceronian" rather than a Christian, Saint Jerome resolved no more to read the classical authors and to restrict himself only to Christian texts, how the Christians of Alexandria murdered the philosopher and mathematician Hypatia in 415, and realize that, at least in part, the so-called dark ages were not something imposed from without, a breakdown of civilization due to barbarian invasions, but a choice, a turning away from knowledge and discovery into a kind of religious fundamentalism.

Now consider how conservative elements in American religion and politics refuse to accept scientific knowledge, deride their opponents for being "reality based," and ask yourself, "could that ideology come to rule the most powerful nation on earth? and if it did, what would be the consequences for the world?"

History teaches us that conservative, backward-looking movements often arise under conditions of economic stress. As the world faces problems ranging from climate change to the demographic cliff of aging populations, it's wise to imagine widely divergent futures.

Yes, we may find technological solutions that propel us into a new golden age of robots, collective intelligence, and an economy built around "the creative class." But it's at least as probable that as we fail to find those solutions quickly enough, the world falls into apathy, disbelief in science and progress, and after a melancholy decline, a new dark age.

Civilizations do fail. We have never yet seen one that hasn't. The difference is that the torch of progress has in the past always passed to another region of the world. But we've now, for the first time, got a single global civilization. If it fails, we all fail together.