The future is inherently unknowable, and we should be skeptical of anyone, doomer or utopian, who's excessively confident about what it holds

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No one knows the future.

No, scratch that: No one can know the future.

A simple thought experiment shows why. Say you could build a machine that took detailed measurements of the universe down to the level of individual atoms, fed all that data into a computer model programmed with the laws of physics, and ran that simulation faster than real-time to predict what will happen next—a physical instantiation of Laplace’s demon.

But a problem arises: this machine is part of the universe it’s trying to simulate. Its own existence constitutes a causal factor that its model would need to account for. Therefore, it wouldn’t work unless the machine’s simulation included itself simulating itself, which was simulating itself… and so on, in an infinite recursion. This is impossible, so such a machine could never be built. (This is a bigger version of my “Prediction Machine” argument for human free will.)

Because of this paradox, a perfect future-predictor can’t exist, without even considering the irreducibly probabilistic nature of quantum mechanics. You can guess what will happen, and sometimes, you might even be right. But infallible knowledge is impossible to obtain. The future is always hidden from us.

Just to be clear, this isn’t an argument against science’s ability to make reliable predictions. We can and do predict the behavior of natural systems that follow knowable laws—the trajectory of an asteroid, the evolution of a virus, the long-term pattern of the climate. What I’m saying is that we can’t predict the behavior of humans, and the shape of the future depends on the choices that humans make. Any attempt to predict the future, if it influences what people do in response, potentially invalidates itself.

Trying to peek ahead

However, the unknowability of the future notwithstanding, people have always tried to peek ahead. In the past, many of these efforts had a religious or mystical cast, as in the Oracle of Delphi, Nostradamus or the prophets of the Bible. In the modern era, we have hedge-fund traders, political pundits, and others who serve much the same role.

But no matter how smart they are or how richly they’re paid, all these prognosticators face the same dilemma. They can either make testable predictions, which often fail to come true—or they can cloak their predictions in mystical gibberish and ambiguity so they can never be proved or disproved. (The third option is to rig the game by “predicting” things that already happened and trying to backdate your prophecy. The Bible’s authors resort to this strategy on occasion.)

Among those who make unambiguous predictions, there are two factions that garner the greatest amount of interest and media attention.

The Doomers and the Techno-Utopians

One faction—call them the Doomers—points to the looming crisis of climate change and the lack of will to make the radical changes necessary to head it off. The Doomers say that the damage we’ve done to the fragile balance of the Earth is irreversible, and it’s only a matter of time before the consequences hit: coastal cities drown, ecosystems collapse, farmland becomes desert, tens of millions of people become migrants, wars are fought over water, and countries dissolve like sandcastles before the ocean. They foresee a hot, chaotic and violent future, where the scant progress of the last few hundred years is wiped away and we regress to barbarism.

The other faction—call them the Techno-Utopians—points to the exponential acceleration of technology. At first, advances came at a creeping pace: it took tens of thousands of years to go from stone to iron tools. But the more time passes, the faster each subsequent advance comes. Only sixty years after the first airplane flight, we landed on the moon. Computing power has been doubling roughly every two years for decades, unlocking vast advances in our ability to process information, simulate, and predict. The usable energy at our command has been steadily growing as we transition to better power sources.

The unknowability of the future is a blade that cuts both ways.

These utopian forecasters say that this curve has no upper limit, and it’s only a matter of time before humanity becomes so advanced that we can trivially solve any problem. We can program robots to serve us; genetically modify crops to turn every country into a breadbasket; control the weather and reengineer the climate; cure all disease and make ourselves immortal; and travel into space and settle other planets. With no more poverty, hunger or deprivation, we’ll have nothing to fight about, and the human race will be as gods and blossom into a post-scarcity golden age.

Both of these visions have elements of plausibility, and the advocates of both can point to facts that support them. Which one is true? Where’s the point at which these two curves intersect?

I don’t know, and neither do you. But the unknowability of the future is a blade that cuts both ways. It might be worse than we think (so we shouldn’t rest in complacency), but it might be better than we fear (so we shouldn’t surrender to despair). Either way, a good principle is to be skeptical of anyone who’s excessively confident about what the future holds.

That goes both for climate-doomers who give up on having children because they’re positive the future will be an uninhabitable hellscape, as well as Singularitarians who believe that superintelligent AI will come into existence any day now and will solve all our problems with a metaphorical snap of its fingers.

After all, in the golden era of sci-fi, many brilliant people thought the future would be space colonies, flying cars and domed cities. During the Cold War people believed, with at least as much good reason as modern-day pessimists, that global nuclear apocalypse was inevitable. Writers in the 1990s predicted the “end of history” and the eternal triumph of neoliberal democracy. History is a graveyard of failed predictions.

Personally, I try to stay humble, bearing in mind the limits of our predictive ability, and to hedge my bets wherever possible. Based on the large-scale trends of history, I believe the most defensible attitude is a cautious and pragmatic optimism, steering a course between the shoals of self-fulfilling nihilism and foolish Panglossianism. Most of all, I hang on to my willingness to be surprised!

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DAYLIGHT ATHEISM Adam Lee is an atheist author and speaker from New York City. His previously published books include "Daylight Atheism," "Meta: On God, the Big Questions, and the Just City," and most...