The problem of knowing what is true or real is as old as lying and deception. The modern threat of “deepfakes” began with Descartes, who understood that input from the senses to the brain could maliciously be falsified. He claimed solace in the belief that God would not permit such deception. Until recently, naturalists could take solace that natural selection would not permit it. But human beings have a long fascination with illusion, the unreal, the artificial, the unnatural—ultimately with the prospect of re-creating the world artificially. Consequently, more than half of humanity now live in cities. Even scientific modelling attempts controllable simulations of natural realities: to fake nature.

Digital technology presents easy access to demagogues and influencers—and also an endless arms race of one-upmanship, of coding and code-breaking, encryption and hacking, fake news and cumbersome attempts to defuse it. There is a growing market for protection against malware and now AI deep fakes. Where there is technology to falsify reality, there will surely be technology commercially available to counter that. This arms race has class implications, if only affluent consumers will be able to afford the truth.

So far, these battlegrounds remain largely outside the human nervous system, not yet directly hacked. But precisely because we still believe our senses, the surrogate world presented to them by digital technology is a theatre for manipulation, our perceptual Achilles heel. If our eyes do not deceive us, our screens easily can.

There is much hype about the creative potentials of AI, which includes the possibility to manipulate or fake any digitized content whatsoever. Deep fake video is already upon us, alongside increasingly realistic computer-assisted entertainment. With the creative power of digitation come nefarious use.

Given the power of computation—both as technology and as metaphor—the romance with simulation is perhaps inevitable. After all, our daily experience is a virtual reality created by the brain! If it’s all simulation anyway, why not play with the possibilities? Doesn’t art do that, deliberately blurring the distinction between real and imagined? That may well be half the human story. But, as Freud acknowledged, the other half is the reality principle, with a potentially lethal reality behind it. Individuals who cannot tell the difference between real and imagined don’t survive, or are locked up. Whole societies that cannot tell the difference go berserk.

If our digital interface with the world cannot be trusted, we are in real trouble. Already we live in an ethos of suspicion, with the plethora of would-be “authorities” enabled by social media. In the absence of collective received wisdom, reality is up for grabs. Though we’ve not quite reached that desperation where we dare not trust our screens at all, it may come soon.

We evolved to deal with bad actors face to face. Deception is old as the hills, but so is common sense and intuition based on personal contact. If digitation plays havoc with that confidence, it may be the downfall of civilization. Or, at least, of digital civilization. The hierarchical complexity of modern society depends on complex and energy-intense communication networks, vulnerable to hijacking or outright failure. Since our leaders mostly do not live among us, how can we trust that we are ever dealing with the real them? We could revert to personal contact—face to face rather than Facebook to Facebook. That would mean civilization devolving to a simpler organization. Things would go a lot slower, as they once did, which may be better than going rapidly to hell.