In ancient times, philosophers speculated that we can’t tell whether the world around us was genuine or whether other people also have minds. Perhaps I am the only one who exists, while the rest of the world is my imagination. It could all be a dream. Some religions claim that gods created this universe and that we are like them. According to the Bible, God said, ‘Let us make mankind in our image, in our likeness.’

For a long time, we couldn’t tell why this world might not be authentic or how the gods could have created it. That changed with recent advances in information technology. This universe could be a simulation. We believe that our senses register an outside reality so that we ignore evidence to the contrary. You may think you see a pipe when watching an image. The caption of the famous painting, The Treachery of Images, by René Magritte, makes you notice: this is not a pipe.

In 1977, science fiction writer Philip K. Dick was the first to assert that our reality must be computer-generated. In a press conference in France, he described his psychotic experiences and strange coincidences that led him to believe this world is fake. He told the audience that his lost memories returned in full for unknown reasons. He also claimed to have had a vision. And a scenario Dick wrote came true. And so, he thought what he had found was of momentous importance to humanity, so he organised that press conference. His last name suggests our Creator, if there is one, likes sexist jokes.

The idea that we live inside a computer-generated world is known as the simulation hypothesis. We could all live in a simulation created by an advanced humanoid civilisation. Professor Nick Bostrom explored the probability of it in the simulation argument. According to Bostrom, there could be many different human civilisations. The humans in those civilisations may, at some point, enhance themselves with biotechnology and information technology, live very long, and acquire capabilities that ordinary humans don’t have. For this reason, these beings are no longer humans, making them in need of a new name, which became post-humans. A post-human might be a biological creature, a humanlike artificial intelligence or a combination of both. They might be brains in vats or have no physical bodies at all.

These post-humans might experience an urge to run simulations of their human ancestor civilisations, so we could be living in one of those simulations. Bostrom argues that at least one of the following options must be true:

1. Nearly all human civilisations terminate before becoming post-human.
2. In any post-human civilisation, only a negligible number of individuals develop an appetite for running simulations of their human ancestor civilisations.
3. We almost certainly live inside a computer simulation.¹

The argument comes with the following assumptions that seem increasingly plausible due to the recent developments in artificial intelligence, but are not proven:

• The computing power of post-human civilisations suffices to run a large number of simulations of human ancestor civilisations.
• It is possible to simulate human consciousness in a computer.¹

Bostrom concludes that if you think our civilisation will one day become post-human and run many simulations of human ancestor civilisations, you must believe we already live inside one.¹ It is a matter of probability. If we invent this technology in the next 10, 100 or 1,000 years, it won’t happen later than that. By then, we will have done it. But millions of years have passed when it could have happened, so it probably did. If we do it within 100 years, and it could have happened a million years ago, the chance it already happened might be (1,000,000 – 100) / 1,000,000 = 0.9999 or 99.99%.

Non-humanoid civilisations are probably not interested in running large numbers of simulations of humans. They might run a few for research, perhaps to investigate human behaviour, but it seems unlikely that our emotions and history entertain beings entirely different from us. Thus, most simulations of human civilisations will likely be run by post-humans.

Non-humanoid civilisations are probably not interested in running large numbers of simulations of humans. They might run a few for research, perhaps to investigate human behaviour. Still, it seems unlikely that our history and emotions interest beings that are entirely different from us so that they will run billions of simulations of human civilisations. And if they exist, they must first learn to travel faster than light to find humans. Thus, post-humans will likely run most simulations of human civilisations. So, our Creator, if there is one, is probably humanoid, but that doesn’t necessarily mean human.

It is a problematic argument. Philosophy is the art of not accepting the obvious because the possibilities are boundless. The obvious often isn’t the case. But with the information we do have, it is our best guess. We think of God as having a human nature because we imagine God. And so, the God in the Bible appears to have human character traits. Conversely, when God imagines us, God probably is humanoid. We would create virtual realities with humans if we could. That is the reason why. However, because we imagine God, that is what we imagine. It seems obvious, but that doesn’t mean it’s true. It is only what our imagination and the evidence suggest is most likely. But we know very little. We can’t go outside the simulation and check.

The simulation argument comes with uncertainties. Post-humans might lack sufficient computing power. Recent developments in quantum computing suggest otherwise. Alternatively, nearly all human civilisations die out before building these simulations. Alternatively, post-humans have evolved and differ from us, so they aren’t interested in running simulations of humans. We may only know this once we have become post-humans. Bostrom doesn’t try to guess the likelihood of the options. He thinks we have no information about whether this universe is real, but that is incorrect. There is evidence.

Latest update: 18 July 2025

Featured image: Inspired By The Treachery of Images.

1. Are You Living In a Computer Simulation? Nick Bostrom (2003). Philosophical Quarterly (2003) Vol. 53, No. 211, pp. 243-255.