Are we living in a computer simulation? Are we just a video game being played by some snot-noised kid on Alpha Centauri? This idea, or family of ideas, is known as The Simulation Hypothesis and it has been gaining more and more traction since philosopher Nick Bostrom wrote his 2003 paper “Are You Living in a Computer Simulation?
This question is another in a long line of skeptical threats. Skeptical threats are global threats in that they threaten everything we know, think we know, or could possibly know with that ancient epistemological enemy: skepticism. These types of arguments seek to provide one big defeater for all of our human knowledge and leave us with the specter of skepticism looming large over our beliefs. Similar arguments have been presented throughout the history of philosophy including:
- Descartes’ Evil Demon: perhaps in all of our experiences we are being completely misled by a malevolent demon, if this is the case we can’t be said to truly know anything.
- Solipsism/Brain in a Vat: perhaps I’m the only thing that actually exists and everything else and everyone else is just a figment of my imagination; or perhaps I’m not all alone, but some scientists have removed my brain, have put it in a vat or a jar with all the requisite tools to keep my brain alive and they’re feeding me my experiences through electrodes- if either of these are the case then none of my experiences are veridical.
- The Truman Show Threat: perhaps what I think is the real world is just an elaborate tv set where the producers are adjusting my circumstances for the pleasure of the audience(could also be titled the Adjustment Bureau threat)
- Idealism – perhaps what we think is the material world, which is independent of the observer, is really dependent on the human mind after all, or some cosmic mind. Perhaps the most fundamental thing in reality is mind and there is no matter. (There are lots and lots of flavors of Idealism, not all of them could be posed this way, we are referring to the ones that do pose a threat to our notion of the material world and our experience in it.)
While the Simulation Hypothesis is similar in many ways to the skeptical threat arguments mentioned above, it also differs in important ways as we’ll see.
Now, as we jump into the question “Are We Living in a Computer Simulation?” it’s important to clarify what kind of scenario we’re talking about. In a very clear and concise blog post on this very topic, Christian philosopher James Anderson describes three possible scenarios we could be asking about, I will quote him at length because I can’t say it better than he does:
“SCENARIO 1: THE SIMS
On this view, the universe would be a simulation in the way that the popular video game the Sims is a simulation. The difference would be only a matter of scale and complexity. This scenario is easily refuted though, because it’s trivially self-defeating. The “virtual people” in The Sims are entirely fictional. It’s not merely that they aren’t conscious beings; they aren’t beings at all. They no more exist than Sherlock Holmes and Captain America exist. The Sims is, in effect, just a highly interactive CGI movie.
Thus, to suggest that our universe is that kind of simulation is to suggest that we don’t really exist at all. So who’s actually proposing the hypothesis? Um, no one.
SCENARIO 2: THE MATRIX
On this view, we’re living in a simulation in the way that Neo was inhabiting a virtual world in the movie The Matrix. Neo himself wasn’t a simulation (at least, on the most natural interpretation of the first movie). Neo existed independently of the Matrix, but his sensory organs were being manipulated or bypassed so as to present him with experiences of an artificial world indistinguishable (at least phenomenologically) from the real one.
How do we know we’re not in a simulation like the Matrix? After all, if we were, it would look entirely real to us! The first thing to observe is that the question locates the burden of proof in the wrong place.
The question should be: What positive reasons are there to think that we are in a simulation like the Matrix? Short answer: none… What’s more, even if we were living in a Matrix-like simulation, we would still exist independently of that simulation, and we would need some cogent explanation for (1) our independent existence, (2) our consciousness, (3) our capacity for reason and coherent experiences, and (4) the existence of the simulation (and whatever apparatus implements it). All of these ultimately presuppose the existence of God…In other words, there are theistic arguments — especially the transcendental argument — that aren’t the least bit undermined by a Matrix-simulation hypothesis. And if God exists, that provides us with good reason to reject such a hypothesis.
SCENARIO 3: BRAINS IN A COMPUTER
This version of the hypothesis proposes not only that our experiences are the product of a simulation (as in Scenario 2) but also that we ourselves are part of the simulation apparatus. Thus (contra Scenario 1) we actually exist, but (contra Scenario 2) we don’t exist independently of the simulation. The idea here would be that there is something like a super-computer running the entire simulation, and parts of that computer (which is essentially a complex physical machine) are conscious. Indeed, those parts are not merely conscious but self-conscious. Thus, there are multiple conscious subjects that are generated by an underlying physical substrate (computer circuitry, neural network, whatever). But the experiences of these conscious subjects aren’t veridical. They don’t reflect the real world in which the super-computer exists, but instead present a simulated virtual world.”
It is this third scenario that we will spend the rest of our time looking at since this is the scenario put forward in Bostrom’s influential paper and it is what most people have in mind when they ask the question.
In articulating his argument, Bostrom is careful to differentiate between his simulation argument and the simulation hypothesis. While the later hypothesizes that we are currently living in a computer simulation, the former doesn’t make such a strong claim. Bostrom’s Simulation Argument argues for the truth of one of three propositions, the third proposition being that we are living in a computer simulation (the hypothesis), but his argument doesn’t pick which proposition is correct.
- Simulation Hypothesis: we are currently living in a computer simulation
- Simulation Argument: One of these three propositions is true:
- Almost all civilizations go extinct before technological maturity.
- All civilizations lose interest in advanced computer simulations.
- We are almost certainly living in a computer simulation.
As this triad goes, if proposition i. is true then everyone dies before reaching the level of technologically sophistication required to create a computer simulation advanced enough to represent the reality we experience now. If proposition ii. is true then perhaps there are civilizations that have the capacity to create advanced computer simulations but for lack of interest, or perhaps because they find it immoral to create billions of self-conscious digital beings to toy with, they don’t actually create them and so we are not in a computer simulation. But if neither i. or ii. is plausible or probable, then we are left with iii. and we are almost certainly living in a computer simulation.
Now some of you will rightly pull on the reins at this point. How do we end up with iii.? Well, in supporting iii., Bostrom explains that his argument is different than any other skeptical threat in the history of philosophy because instead of starting from a position of universal doubt and saying “prove that we can know anything”, the Simulation Argument starts from exactly what we know right now and asks us to reason a bit down the time line which leads us right into iii. Take what we know about the exponential advance of technology over the past one hundred years. Look at our obsession with video games and virtual reality; consider our race to create AI and the leaps and bounds we’re taking towards robotic transhumanism. Now just imagine how advanced we’ll be in one hundred years from now, or two hundred, or a thousand! All you have to do is follow our trajectory down the line and it’s not too hard to imagine that one day we will create a simulation of our ancestors for any number of reasons including to run various scenarios and learn about our history, to review different outcomes and find out what went wrong and when, or even just for entertainment- a seven-billion-person reality show.
If the argument is cogent thus far, then it follows that if the advanced civilization is capable of running these types of computer simulations with self-conscious persons like us in them, then they would run lots of them over and over for whatever reasons they wanted. For instance, think of the Netflix series Black Mirror. In an episode called “Hang the DJ” in season four, there was an advanced dating app that did almost exactly what we’re considering- it ran thousands of simulations with two digital self-conscious replicas of two of the apps users to find out if they were compatible. Not so hard to imagine us doing, right?
Now, if this is the case and the advanced people run thousands of simulations, each with billions of people, then the majority of self-conscious persons in the universe with the kind of experiences that we have are actually living in a computer simulation. Sure, we might have sixteen or twenty billion real people on earth by the time we can make these advanced ancestor simulations but once we can make them, we will have thousands- if not millions of billions of digital people which far outweigh the measly amount of actual people. Not to mention the fact that if the civilization was advanced enough to make these high-tech simulations, perhaps they can also make simulations in which their simulated people can make simulations in their simulation (some of you will be reminded of the episode of the office where Dwight makes a Second Second life). This gives us a nested simulation argument which greatly exasperates our situation.
At this point we’re primed to feel the full weight of Thomas Metcalf’s finishing blows:
The Empirical Premise: Most of the “people” who think they’re real, flesh-and-blood humans are actually conscious computer programs.
The Indifference Premise: If most people are simulated, then you are probably simulated.
So, if we think that eventually we will have the capacity to create advanced computer simulations of our ancestors, and we don’t think that we will lose interest in doing so, and given that if we had the capacity to run these simulations we would run lots of them, then the vast majority of people who have experiences like ours are actually conscious computer programs. If the vast majority of people are computer programs then you’re probably a computer program. Thus, you are living in a computer simulation.
This is the Simulation Argument of Nick Bostrom. But Bostrom himself thinks that the probability that we are currently living in a computer simulation (the Simulation Hypothesis) is less than 50% likely. But as this argument and hypothesis have made their way into the popular zeitgeist, it’s been bastardized and misconstrued. The folk version of this idea, even as it is promoted by prominent public intellectuals such as Neil deGrasse Tyson and Elon Musk, usually depends on anecdotal evidence that like coincidence and déjà vu.
Coincidence and any evidence of what Christians might call ‘providence’ are attributed to the simulation designers’ whims. There are times where either everything turns out just a little too perfectly or perfectly- almost comically wrong. This must be evidence that someone is controlling our reality- of course it couldn’t be understood as the eternal plan of God, though, don’t be an idiot! Instances of déjà vu on the other hand are used to support Philip K. Dick’s hypothesis given in his speech at the Metz Sci-Fi Convention in 1977 where he claimed that “we are living in a computer-programmed reality, and the only clue we have to it is when some variable is changed, and some alteration in our reality occurs.” He then famously claimed that the experience of déjà vu is our signal for knowing that something has in fact been changed.
This folk level simulation hypothesis can get pretty hairy. Bostrom has even recounted receiving emails from people who have claimed to see glitches in the simulation and pixilation in their mirrors. This is most likely the kind of anecdotal evidence you’ll bump into in your day to day but Bostrom discounts these experiences. In Bostrom’s view, appearances of pixels or glitches in the simulation can always be attributed to psychopathy, delusion, hallucination, paranoia, etc. We’d expect these things to take place even if we weren’t living in a computer simulation, thus they can’t really count for or against the hypothesis. He also claims that if the advanced simulation designers were savvy enough to create this advanced simulation, they’d also be able to rewind the simulation and scrub out any glitches, or erase your memory of them if they didn’t want you to know where you really where. Thus, again this type of evidence has no sway.
But other than chalking its proponents up as nut jobs, how should we think about the simulation hypothesis? Once again, we return to James Anderson. Anderson’s first critique of the Hypothesis is one which Bostrom himself acknowledges: the problem of consciousness. Bostrom acknowledges that the Hypothesis depends on a specific theory or mind, known as functionalism or computationalism, which though in vogue at the moment, is certainly not without its detractors. Although there is all sorts of talk of artificial intelligence buzzing around the media and internet lately, we have yet to produce artificial conscious minds like our own and there are lots of philosophers who doubt we will ever be able to. Anderson notes,
“there’s no reason to think that consciousness can arise out of purely physical structures, no matter how complex; indeed, there are very good reasons to think that it’s metaphysically impossible. Mental properties are categorically different than physical properties (e.g., minds exhibit subjectivity and intentionality, which can’t be reduced to anything like material properties). If it’s impossible in principle for a physical machine (or any kind of physical structure) to be conscious, then Scenario 3 is flat-out impossible. It can’t get off the ground. It can’t even taxi onto the runway.”
In another post on the Hypothesis, Anderson takes issue with Metcalf’s indifference premise (If most people are simulated, then you are probably simulated.) which is the linchpin of the entire argument for the Hypothesis. Anderson retorts, “Most people have the following feature: not being me. Should I therefore guess that I’m probably not me too?” So good!
But if these weren’t reasons enough to abandon the simulation hypothesis, Anderson, in Plantingian fashion, deals the final blow as he argues that the Hypothesis is actually self-defeating,
“The simulation hypothesis itself is based on scientific theories and concepts derived from our experiences of the world. It is predicated, at least in part, on what we take to be empirical scientific knowledge (what brains are and do, what computers are and do, etc.). But if we accept the simulation hypothesis then we acquire a defeater for all of our empirical beliefs and thus for all of our scientific beliefs. Simply put, if the simulation hypothesis is true, we can’t trust the science on which the simulation hypothesis is based, in which case it would be irrational to believe the simulation hypothesis. It looks like the simulation hypothesis has a deeply self-defeating character to it.”
So, are we living in a computer simulation?
Check out the latest Sons of Thunder episode to hear my brother and I discuss this question in conversation with the Bible.
[Photo cred: Joel Settecase]
 Philosophy Quarterly vol. 53, no. 211, pg. 243-255.
 Cited by Rizwan Virk in The Simulation Hypothesis (Bayview Books, 2019) 2.