Nick Bostrom is back at it again, once again pitching his theory that we live in a universe simulated by extraterrestrials. The argument for this idea goes something like this:
- The universe is billions of years old, and contains billions of galaxies, each containing many millions or billions of stars.
- It is therefore likely that advanced civilizations arose on many planets long ago.
- Such advanced civilizations would have fantastically advanced computing powers, including the ability to create incredibly complicated simulations so realistic they would be indistinguishable from reality.
- Even if only a small fraction of such civilizations created such simulations, the total number of simulations they would create would be incredibly high, probably many times higher than the total number of planets containing civilizations similar to ours.
- We therefore should conclude that we are probably living in such a simulation, rather than living on a real planet in a non-simulated universe.
This reasoning is not convincing. We have not the slightest evidence that any civilization could be capable of simulating human experience in a way that would result in a being who would actually have a flow of consciousness in the way that you and I have a flow of consciousness. There is every reason to suspect that producing such a simulation would be so difficult that it could not even be accomplished by planet-sized computers, particularly given the nearly infinite number of variations that are available in the lives of people such as us who appear to have almost unlimited choices.
We do not understand at all our consciousness, and it seems all too plausible that our experience and consciousness involve some mysterious X factor that cannot be accounted for by mere brain activity. Since it is quite dubious that any technology can produce anything like human experience as a human experiences it, it is very premature to be speculating about some technology that could not only create something like experience as we experience it, but also accomplish the gigantically greater task of producing such a thing within a simulation that tricked you into believing that there was an external physical universe corresponding to what your senses perceive. Bostrom's speculation about a simulated universe is rather like making a speculation about traveling to other stars before anyone has shown that you can even build a rocket.
A person advancing the idea of a simulated universe will try to kind of “keep the monster in the box,” by presenting a scenario that doesn't scrap too much of our basic assumptions about reality. The thinker may describe the simulation as being produced by advanced extraterrestrials like those we have imagined in our science fiction shows. The thinker will also probably suggest that under this simulated universe we can still believe in the reality of other humans that we see with our eyes, and still believe that the human past has happened pretty much as we imagine. The idea is kind of that your life is part of a simulation, and that your neighbor's life is also part of the same simulation --- so your neighbor has experience just like you have, and he's real in the same sense you are.
But once you introduce the idea of a simulated universe, you can't keep the monster in the box. Once you introduce the idea of a simulated universe, all bets are off, and there is no solid rock of reality on which you can stand.
For one thing, if you believe in a simulated universe you can't conclude one blessed thing about those who have created the simulation. You can't reason that they are super-advanced extraterrestrials living on some planet, because there is no particular reason why universe simulators would create a simulated universe similar to their own universe (rather than imaginatively making up something totally different from their universe). So the creators of the simulated universe could be trillion-mile long purple dragons floating in a nonsimulated cotton-candy universe, or any of a million crazy alternate reality ideas you might think of. With such a range of possibilities, science pretty much disappears, and we're in the realm of “anything goes” fantasy and speculation.
For another thing, if you believe in a simulated universe, you can make no conclusion about how long humans have really existed or how long you have existed. For it might be that the computerized simulation of our experience really started, say, two days ago, and that the simulation makers merely uploaded the memories of your past experiences, and that you never really had such experiences.
For another thing, if you believe in a simulated universe, you may well end up in a sick little place that I might call monohumanism. To explain the idea of monohumanism, I may first explain the concept of solipsism. Solipsism (in its most radical form) is the idea that all that exists is the self. A solipsist may say to himself, “I exist, but everyone else is just some image or perception in my mind.” A solipsist may think that he is the only one that exists in the universe.
Monohumanism is a rather similar position, but not exactly the same. A monohumanist is one who believes that he himself is living in a computer simulation created by one or more unknown simulation agents. Using a kind of principle of parsimony, a monohumanist is one who assumes that there is no need to assume that any other human beings exist other than himself. The monohumanist may say to himself, “I exist, in the sense of having the experiences I experience; but there is no need for me to assume that those I see with my eyes or hear with my ears are also people having actual experiences like I have --- they probably only exist as perceptions in my mind, perceptions provided as part of the computer simulation I am experiencing.” So a monohumanist doesn't believe that he is the only mind in the universe. He simply thinks that he is only mind corresponding to a person living on planet Earth.
Once you start believing in a simulated universe, monohumanism seems all too possible. For it is not at all obvious that if a universe simulator was providing you a simulated reality, that such a simulated reality would also be provided to anyone else you saw with your eyes. If you are living in a computer simulation, it could be that when you hear your neighbor talking, his words were chosen not by an external mind corresponding to your neighbor, but instead were chosen by the same computer that is providing the overall universe simulation.
What are the moral consequences of monohumanism? They are absolutely poisonous. Once you get someone believing that the people he sees with his eyes are not really people experiencing pain and pleasure, but are merely “parts of the computer simulation,” then the door to every form of wickedness has been opened. A monohumanist will always feel free to act in any way that pleases him, on the grounds that no matter what he does, he isn't really causing pain or suffering for any other human, since such humans are merely “part of the simulation” not corresponding to individuals who actually suffer.
Speculation may lead you to a weird, distorted view of your fellow humans
This is where speculations about a simulated universe may lead you – to a dark, twisted place in which you have used some fancy speculative reasoning to give yourself a green light for any evil. Ignore such nonsense, which is a big waste of time, and a step on the road to insanity. There is not the slightest evidence that we live in a simulated universe.