It is probably not Musk's most original idea. The notion that we live in a simulation, sometimes called the simulated universe hypothesis, was popularized in the 90s by the Wachowskis in the The Matrix, but the idea has been around for years. In an episode of Doctor Who from 1976 called "The Deadly Assassin," a community of individuals live a simulated life inside a machine called—guess what—the Matrix!In fact, Musk is elaborating a technologically updated version of one of the oldest philosophical puzzles—namely, is the world we live in nothing but a dream? Basically, it is the Kantian idea that experience is a phenomenon, while the real world—the thing in itself—is hidden to us. Or, if one wants to go back to the Greeks (who doesn't?), it is the allegory of the cave: What we believe is the real world is nothing but the distorted shadows cast on the cave's wall by simulacra (statues and silhouettes) of actual objects.Thinkers kickstarted philosophy with the contrast between appearance and reality—i.e., what people took to be real is only a simulacrum of the true world (simulacrum and simulation). And since then, the main point of the philosophers' job description was, of course, to figure out what the true world was, which is what Elon Musk calls "base reality."
"There's a one in billions chance [we're in] base reality… I think it's one in billions. We should hope that's true because otherwise if civilization stops advancing, that could be due to some calamitous event that erases civilization, so maybe we should be hopeful this is a simulation. Otherwise, we will create simulations that are indistinguishable from reality or civilization will cease to exist. Those are the two options."
In a nutshell, what could this simulation be made of? If the reality we see were a simulation, we should assume that the simulator is made of altogether different stuff that, by definition, we could not even conceive (it should be made of something completely different from everything we meet in our world). While the notion that there is a base reality and additional levels of reality is both appealing and enthralling, we have evidence of only one level of reality. The world we live in is just made of objects.After all, this is confirmed by science itself, whose equations describe the flow and interactions of one kind of stuff—matter and energy according to relativity theory and quantum mechanics. No additional stuff appears in the scientific description of reality. We have, say, planets, and computers we use to anticipate what planets will do, but we do not have fancy planets inside computers. Using computers, which are objects, to predict what planets will do is what we call a simulation. There are no little fancy simulated planets anywhere in the computer. There are electronic gates we use to talk about planets. Taking the existence of a simulated level of reality too seriously is akin to believing in the existence of "the nobility" as something over and above the power of the rest of society.
The apple that looks so convincing to Musk on a VR computer screen would be utterly disappointing for a butterfly looking for a home or for a Robin looking for a worm
Bostrom restates, using modern philosophical jargon, the Platonic-Cartesian notion of a level of reality independent from the physical world—a reformulation of Putnam's thesis of multiple realizability. Bostrom says, "First, we formulate an assumption that we need to import from the philosophy of mind in order to get the argument started."In other words, the simulated universe hypothesis requires one to adopt the computational stance. Very simply, this is the assumption in philosophy, cognitive science and AI that computations are sufficient for thought. Bostrom continues, "Suppose that these simulated people are conscious (as they would be if the simulations were sufficiently fine-grained and if a certain quite widely accepted position in the philosophy of mind is correct)." The "certain quite widely accepted position" is known as computationalism—which is the belief that consciousness is isomorphic with or caused by computations. It is nothing short of an article of faith, since we have no empirical evidence that computation, whatever it is, leads to conscious experience.
We have no empirical evidence that computation, whatever it is, leads to conscious experience.
A Mind Needs The WorldFinally, there is one more argument against the notion that we live inside a massive simulation of everything. Suppose that, against all odds, we were living inside a simulation made of something different from the now (in)famous "Musk base reality." If this were the case, the simulated world would be the only world we could access. Such a world would have the properties of the world everyone calls the physical world. Such a simulated world would therefore be identical with what everyone calls the physical world. The base reality would be utterly beyond our grasp and thus it would be, with an unavoidable conceptual twist, immaterial to us. It is a bit like that old joke: after centuries it has been found that William Shakespeare's plays have not been really written by William Shakespeare but by another man called William Shakespeare.Either way, we live in a physical world, where physical is a catchphrase to refer to the world we live in. Once more, embracing an all-encompassing massive world simulation defeats its very nature. If the simulated apple replicates all properties of the apple, the simulated apple is the apple.To recap, Elon Musk's argument—that a) once we had Pong, now we have Doom, therefore b) in the future there is a very good chance that we will live inside simulated worlds (and this might be already the case)—is unconvincing because nothing links b) with a). They are different things, both empirically and conceptually. The world we live in is made of real stuff. Simulations are things made of the same stuff. Musk's argument does not show that we are getting any closer to producing an alternative reality. Rather it shows that we are getting better and better at shaping the physical world.In fact, games are becoming like little aquariums that flesh out with increasing accuracy a piece of the physical world. They are a bit like ultrasmart dynamic HD dioramas. In fact, dioramas are three-dimensional full-size or miniature models, sometimes enclosed in a glass showcase for a museum. Dioramas are physical simulations. A virtual world is like a diorama only that it uses electronic colored surfaces rather than wood or plastic scale models. A screen inside a VR headset is an amazing piece of reality that, like a superfast chameleon, reproduces all colors and shapes. It is not an immaterial figment of one's imagination. It's a piece of matter with colors, mass, and electricity interacting with your brain.If a simulated waterfall is not wet, why should a simulated mind think or feel? A mind, unless one believes in disembodied souls, requires a brain, a body, and a world. A mind without a physical world is a myth. And a simulated world is a myth too. The fact is that all minds we know of, human minds and possibly animal minds, are embodied and situated: they have a body and they partake of the physical world. We have never met a disembodied mind. We always meet bodies in the world.Riccardo Manzotti is a Professor in Psychology at the Institute of Human, Language and Environmental Sciences at the University of Milan, holds a PhD in robotics, and is the author of 50 papers on the basis of consciousness. His website is consciousness.itAndrew Smart is a cognitive scientist and the author of two books, Autopilot: The Art and Science of Doing Nothing and Beyond Zero and One: Machines, Psychedelics and Consciousness (OR Books).