Can We Know That We’re Not Living in a Simulator?

Description and disclaimer: This two-part article explores why God’s Word, rather than a naturalistic worldview, provides the most intelligible foundation for logic, knowledge, and morality. Part One introduces these concepts, while Part Two applies them to answer an atheistic argument that says reality could be a simulation and that virtual reality is as genuine as physical reality. Please be aware that this paper cites scholars from a variety of theological and philosophical perspectives, some of whom adopt a compromised stance on Genesis and do not reflect the views of the author or of Answers in Genesis.

Are we living in a simulation? This question has garnered massive attention in recent years, with technology tycoon Elon Musk and podcaster Joe Rogan speculating along these lines in a YouTube clip that scored over 10 million views.1 Another prominent proponent for this idea is Nick Bostrom, a former Oxford professor and leading advocate for transhumanism (the belief that humans should transform their own nature through technology).2

Recent research critiques these ideas, known as the “simulation hypothesis,” on mathematical grounds.3 Still, the debate continues.4 As these topics spark conversations about the universe’s origins, Christians will increasingly need to be prepared to answer the simulation hypothesis. This article, Part Two in a series on epistemology, responds by applying a biblical worldview to examine recent arguments about the simulation hypothesis.

As a quick recap, Part One defined epistemology as a branch of philosophy that theorizes about knowledge and belief. There, we saw how only two possible starting points for belief exist: God’s Word or man’s word (human ideas). We also explored how a biblical worldview, but not a naturalistic one, provides a coherent philosophical foundation for concepts including logic, knowledge, and morality.

Here in Part Two, we’ll apply these concepts in conversation with simulation hypothesis arguments from a book by atheistic philosopher David Chalmers, Reality+: Virtual Worlds and the Problems of Philosophy.5 Notably, this is a well-written, engaging book, demonstrating a high level of scholarship. The following discussion seeks only to engage with some of the book’s core arguments from a friendly, biblically informed perspective.

To do so, we’ll start with a quick summary of the book’s arguments. Next, we’ll see how a biblical view can respond to the ideas that (1) virtual worlds are genuinely real and (2) we may be simulations. Finally, we’ll examine whether the simulation hypothesis provides a philosophical foundation for logic, knowledge, and morality, as a biblical worldview does.

A Summary of Reality+

The introduction to Reality+ states, “The central thesis of this book is: Virtual reality is genuine reality. Or at least, virtual realities are genuine realities.”6 One way to argue for this conclusion is to equate reality with human perception.7 But Reality+ adopts a different approach, recognizing that the regularities we perceive in the world suggest an external, objective reality must exist beyond human perception.8 Otherwise, we’d have to say that facets of the universe we haven’t observed don’t exist.9

Reality+ instead argues from a version of the simulation hypothesis, which the book defines as saying, “We are and always have been in an artificially designed computer simulation of a world.”10 As we’ll unpack more later, this hypothesis assumes that some type of (at least artificially) intelligent designer of our universe exists, which the author believes is consistent with naturalism.11

Arguing that “we can’t know that we’re not in a simulation,”12 Reality+ defends this claim on probabilistic grounds, given the vast numbers of simulations intelligent sources can produce.13 In response to any argument against the simulation hypothesis, the book maintains that a possible reply is, “That’s what someone in a simulation would say.”14

The book argues that if we are in a simulator, then reality has always been digital—if only in the sense of digital bits underlying the particles that comprise physical atoms.15 Reality, even if digital, therefore need be no less “real” to us.16 The book then extends this conclusion to argue that virtual worlds can also be (mostly) real.

To build this case, the author proposes a five-criteria “reality checklist” for knowing whether an object is real.17

1. Real objects exist, unlike the tooth fairy. How do we know whether something exists? Here, the book appeals to a form of empiricism,18 saying that, although some existent objects may be imperceptible and some perceived objects may not exist, “If something is perceivable and measurable, that’s a strong indication that it exists.”19
2. Real objects possess “causal power,” the ability to influence their environment.
3. Real objects (unlike imagined entities, illusions, or mirages) “exist independently of our minds.”20
4. Real objects “are as they seem,”21 unlike illusions.
5. Real objects are genuine, in the sense that a given object Z is a genuine Z (e.g., a given sapphire is a genuine sapphire as opposed to costume jewelry).

All these criteria assume that human perception and reasoning (1) are the standard for determining truth and (2) can reliably give rise to knowledge about external reality. Reality+ argues that objects in a purely simulated world would meet all five of these criteria with reference to a perceiver inside that simulated world. In this respect, the argument again sees human perception as the grounds for understanding reality, even though the author sees issues with equating appearance and reality.22 The book then argues that virtual objects can meet at least the first four out of five criteria and that “80 percent realism” sufficiently renders VR genuine reality.23 Notably, though, the excluded criterion is genuineness itself. To argue that VR qualifies as genuine reality by meeting enough non-genuineness-related reality criteria is to say that virtual objects are in some sense both genuine and not genuine.

Responding to the “Reality Checklist” Criteria

In reply to Reality+, Steffen Koch, an assistant professor at Bielefeld University, argues that role-plays, which Reality+ concedes are fiction, also meet the first four criteria.24 This is because the objects and events in the role-play are as they seem within the reference frame of the role-play. Only the fifth criterion remains unmet because the objects within the role-play, like virtual objects, are not genuine with reference to the external world. (A cardboard crown, for example, might be a non-illusory crown within a dramatization of Cinderella but is not a genuine crown outside the play.) If the objects in role-plays are fictitious by these standards, then so are virtual objects. By this reasoning, Koch shows that 80% realism is not enough for virtual reality to be genuine.

A theistic outlook does provide a foundation for external reality to exist and be knowable.

Koch’s response presupposes that the physical world outside of VR and role-plays is the real world, the standard for determining genuineness. But how can we know this is true if human perception and reasoning cannot supply objective grounds for knowledge as Part One argued? In contrast, a theistic outlook does provide a foundation for external reality to exist and be knowable. By this outlook, a self-existent, revelatory God created an objectively real, physical cosmos and gave his image bearers capacities for knowing essential truths about this cosmos and its Creator. Christians thus have a reason to recognize the physical realm God created as genuine reality above any contrary perceptions derived from virtual reality. We can know, for example, that a given person wearing VR goggles is really a teenage boy in an empty basement, even if he perceives himself to be a female pirate battling a sea monster. In these ways, theism lets us recognize that VR is not genuine reality, even though VR platforms can facilitate genuine communication and transactions between physical people engaging with physical technologies. This recognition is more consistent with the fact that we are embodied beings who cannot, for example, remain alive by consuming only virtual calories.25

Does Theism Provide a Valid Response to the Simulator Hypothesis?

Along with providing grounds for prioritizing physical reality above virtual reality, a biblical approach to epistemology shows the simulation hypothesis to be self-defeating. Before unpacking why this is the case, we should consider whether someone could respond to biblically based objections to the simulator hypothesis with the rejoinder, “That’s what someone in a simulator would say.”26

This rejoinder argues that anyone who objects to the simulation hypothesis based on theism (or any other reason) could in fact be objecting within the context of a simulation. This rejoinder, if it works, wouldn’t falsify objections to the simulation hypothesis; it would just show the simulation hypothesis to be non-falsifiable.27 However, the rejoinder can only work if the simulation hypothesis provides intelligible grounds for logic, knowledge, and morality. Otherwise, it doesn’t matter what someone in a simulator would say. Without a basis for logic, we’d have no reason to think that either the rejoinder-based argument or the simulated person’s original objection is rational. And without a basis for morality, we’d have no reason to think that if an argument is rational, then we ought to accept it. So the real question is whether the simulation hypothesis, like theism, can provide a basis for logic and morality.

We’ll come back to this question momentarily. First, it’s worth noting one more truth about the rejoinder, “That’s what someone in a simulator would say.” Namely, a simulated person could only argue against the simulation hypothesis within a simulator if that simulator existed in the first place. This raises the question, “What are the grounds for the simulator’s existence?”

Is the simulator, or its ultimate source of being, contingent (i.e., dependent on something outside of itself for its existence) or noncontingent? The former option results in an infinite regress of contingent sources—perhaps naturalistically evolved simulators producing naturalistically evolved simulators, ad infinitum. The latter option requires belief in a self-existent, eternal entity—that is, a being with at least some of the key attributes of God.

Reality+ seems to concede that an infinite regress is untenable, requiring belief in a “stopping point.” But the book states, “It’s not obvious why bringing in God and then stopping makes more sense than any other stopping point.”28 Yet Christian philosopher Peter Williams argues that “the first physical event must have had a non-physical, personal cause outside and independent of itself (and this, of course, is a part of what theists mean by ‘God’).”29 Only a self-existent, atemporal, transcendent God possesses the attributes required for a self-explanatory stopping point.

Reality+ takes issue with the idea that God is self-existent, asking, “What explains the design of that designer, or of the whole system of designers? Someone might say that God is exempt from explanation, but this looks like special pleading.”30 Special pleading is an informal logical fallacy that unfairly fails to treat similar things or individuals alike by asking for an arbitrary exception for one of them. God, however, possesses unique attributes such that he is not similar to anyone or anything else, precluding special pleading. One of these unique attributes is that God, as the only necessary (or noncontingent) being, is self-explanatory by nature. God is the only legitimate stopping point for the infinite regress.

God is the only legitimate stopping point for the infinite regress.

The only atheistic alternative to this infinite regress is an eternal, self-existent cosmos. Reality+ seems to argue for this possibility, stating, “If an eternal God doesn’t need a cause, neither does an eternal universe.”31 However, an eternal universe or cosmos would need to be self-existent and self-explanatory, bearing key attributes of God. Also, belief in such a universe raises at least three further problems.32

1. An eternal universe cannot provide a basis for knowledge and certainty, for the reasons described in Part One.
2. Relatedly, belief in an eternal (but impersonal and non-self-revelatory) universe must be accepted on a type of blind faith, unlike a personal revelatory God whose existence provides the grounds for knowledge, logic, and certainty.
3. Belief in an eternal universe (especially one that is still subject to natural laws, as Reality+ describes33) runs into philosophical and scientific problems that Williams discusses elsewhere, such as preclusion by the natural laws of thermodynamics.34

So far, we’ve seen that belief in a simulator requires something very much like theism (or at least, deism35) to explain the simulator’s ultimate grounds for existence. Now, let’s get back to the question of whether the simulator can provide a basis for logic, knowledge, and morality.

Why the Simulation Hypothesis Is Self-Defeating

The simulation hypothesis defeats itself because it can’t provide the ultimate grounds for logic, knowledge, and morality required to make arguments for the simulation hypothesis. Let’s explore why not.

According to the simulation hypothesis, our world’s “creator” is not necessarily a self-existent, revelatory, omnibenevolent God whose nature is the source of truth. Instead, to accommodate naturalism, Reality+ allows for the simulation’s creator to be any not-quite-divine entity, such as “a teenage girl in the next universe up.”36 How can this scenario provide philosophical grounding for logic, knowledge, and morality?

Regarding logic, why should the reality governing the simulator and the cosmos beyond it be orderly, logical, and predictable enough to sustain the simulator and simulation? Reality+ seems to portray natural laws as governing these concepts.37 But as philosopher Danny Frederick argues, “The existence of natural laws . . . seems puzzling because it implies that mindless bits of matter behave in a consistent and co-ordinated way.”38 Frederick considers and rejects various nontheistic solutions to this puzzle, concluding that only some kind of theism can provide grounds for the existence of natural laws. Even the “teenage girl in the next universe up” would have to abide by natural laws and the laws of logic according to Reality+,39 so she could not be the source of these cosmic regularities. The simulation hypothesis thus requires blind faith in inexplicably self-existent logic, law, and order, which sounds more like the divine logos of Greek paganism than atheism can comfortably accommodate.40

What about knowledge? If Reality+ were correct that (1) God does not exist and that (2) we cannot know we do not inhabit a simulation, then one of two possibilities would describe our real status. First, we are not in a simulator but exist as purely physical, evolved beings. As Part One described, however, naturalistic evolution provides no grounds for knowledge or certainty. The second possibility is that we are in a simulation, but our simulator has not revealed themself or explained any details about our programming. In this case, we have no way to know whether we are programmed with the capacity for genuine knowledge. We could, for example, have been programmed with faulty perceptions and reasoning abilities that don’t correspond to external reality, but we would have no way of realizing this. So neither of the two possibilities that Reality+ leaves open can provide a basis for knowledge or certainty.

Reality+ dismisses the alternative, theistic possibility that truth is grounded in God, citing four main objections.41

1. The book asks, “How do we know that God exists?” Christian theism responds that Scripture, the Holy Spirit, and the capacities God has given us to perceive him through creation (Romans 1:19–20) enable warranted knowledge of God.42
2. Reality+ asks, “Why do we need God [as the grounds for knowledge]?” In answer, only a being with divine attributes such as self-existence and transcendence can supply the philosophical grounds for knowledge, as Part One described.
3. The book asks whether “the God scenario [is] just a mild variant” of Descartes’ speculation that reality could be an illusion concocted by a deceptive spirit.43 In reply, these scenarios totally differ because God, as the greatest possible being,44 by definition possesses an omnibenevolent, nondeceptive, self-revelatory nature.
4. Reality+ asks, “[Why] isn’t the God scenario ruled out because there’s no appearance of God?” Christian theism answers that God has made himself known through creation, Scripture, and Jesus’ incarnation, rendering the denial of God indefensible (Romans 1:20; John 15:22–24).

In these ways, a biblical worldview overcomes all the objections Reality+ leverages against God as the grounds for knowledge.

As for the grounds of morality, Reality+ considers and dismisses both utilitarianism and Kantianism as secular frameworks for ethics. Instead, the book seems to promote virtue ethics, which defines actions as moral if they accord with standards such as justice, courage, and kindness.45 But within a naturalistic worldview, how can we define these virtues, know that they are good, or explain the grounds for this knowledge? The “teenage girl in the next universe up” is not necessarily good,46 so she cannot be the grounds for morality. The simulation hypothesis cannot explain (1) where goodness comes from, (2) how we can define and know goodness, or (3) why we should be good in terms of ultimate accountability, rewards, or punishments. In contrast, a theistic worldview explains all three concepts, providing consistent philosophical grounds for morality.

Again, Christian theism readily withstands the proffered objections.

Noteworthily, Reality+ dismisses the idea that morality stems from God’s commands, on account of the Euthyphro dilemma.47 This dilemma poses a false dichotomy that either (1) God commands moral actions because they happen to be right, or (2) moral actions are right because God happens to command them. In the first case, the basis for morality is outside of God; in the second case, morals are arbitrary. However, a third alternative easily answers the Euthyphro dilemma: Moral actions are right because they are grounded in God’s omnibenevolent character.48 Again, Christian theism readily withstands the proffered objections.

For all these reasons, the simulator hypothesis cannot explain the grounds for logic, knowledge, or morality. Therefore, arguments for this hypothesis are self-defeating.

Summing Up

In summary, this article series argued that a theistic outlook, instead of a naturalistic worldview, yields the most intelligible epistemic framework. To build this case, Part One argued that unlike naturalism, theism provides the ultimate grounds for logic, knowledge, certainty, science, and morality.49 Part Two then applied this theistic outlook to engage with arguments in Reality+, which built upon the simulation hypothesis to say virtual worlds are genuinely real worlds.

This discussion unfolded in three stages. The first stage showed that Christian theism allows Steffen Koch’s critique of the “reality checklist” in Reality+ to stand because theism provides a basis for Koch’s assumption that the physical world is the standard for genuineness.50 The second stage answered the rejoinder that theistic arguments against the simulator hypothesis are “what someone in a simulator could say.” This rejoinder cannot justify dismissing theism, especially because the simulator hypothesis itself presupposes a type of theism. Even though Reality+ seems to suggest that a naturalistic designer in an uncreated, eternal cosmos could explain the simulation’s existence, this scenario still presupposes some sort of self-existent, transcendent, ordering force akin to the Greek logos. Belief in such a force, however, requires blind faith51 and does not compute with strict atheism. The third stage unpacked how the simulation hypothesis cannot provide the foundation for the concepts of logic, knowledge, and morality that are necessary to argue for the simulation hypothesis.

The simulation hypothesis is not the best foundation for a coherent epistemological framework.

Ultimately, despite speculations by Elon Musk, Joe Rogan, and Nick Bostrom, the simulation hypothesis is not the best foundation for a coherent epistemological framework. God’s Word is.52 And God’s Word assures us that not only does truth exist, but he also has a name: Jesus (John 14:6). Jesus is guaranteed to return as the warrior King who will reign forever. He has offered salvation to all who place their faith and hope in him. “For he says, ‘In a favorable time I listened to you, and in a day of salvation I have helped you.’ Behold, now is the favorable time; behold, now is the day of salvation” (2 Corinthians 6:2).