THE Australian-born philosopher David Chalmers has long made waves in the world of consciousness. In 1994, at the age of just 28, he coined the phrase “the hard problem of consciousness” to describe the seemingly intractable problem of subjective felt experience – why there is something it is like to be you. Two years later, he developed the concept of “zombie” thought experiments – using theoretical agents identical to us in behaviour and outward experience but with no inner life – in an attempt to tease out the nature of conscious experience.
In 1998, Chalmers struck a famous bet with neuroscientist Christof Koch that we wouldn’t discover a distinctive signature, or “neural correlate” of consciousness, within 25 years. Although we now understand a lot more about the links between brain activity and consciousness, with little more than a year to go, Chalmers is quietly confident he will win that bet. He thinks consciousness can’t be reduced to a brain process. He has speculated that it is a fundamental attribute of the universe like space-time or mass, perhaps tied to quantum mechanics.
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Now co-director of the Center for Mind, Brain and Consciousness at New York University, Chalmers has turned his attention from our mind’s relationship with the world to our relationship with worlds created by human minds. His new book, , explores existential puzzles, including what reality is, whether we are living in a simulation and how we would know. And, as Meta (formerly Facebook) and other tech companies look to create digital “metaverses” in which we can live our lives, he asks what that will mean for humanity.
Richard Webb: You describe your book as a work of “technophilosophy” – what do you mean by that?
David Chalmers: The name technophilosophy is inspired by the philosopher Patricia Churchland, who coined “neurophilosophy” back in the 1980s for a two-way interaction of neuroscience and philosophy. Technophilosophy is something similar for technology. On the one hand, it involves thinking philosophically about technology – about computers, the internet, artificial intelligence, smartphones, virtual reality and so on: is virtual reality genuine reality?, can AI creatures have minds?, and questions like that. But the second half is using technology to think about philosophy: using AI to shed light on philosophical questions about the human mind and human consciousness, or virtual reality to shed light on big traditional questions about ordinary physical reality. Things like: how can we know about the external world? What is it? What is the world made of? How do mind and body interact? Is there a god?
“How can we know about reality?” was a question philosopher René Descartes posed in the 17th century. Can virtual worlds finally help us answer it?
I think, at the very least, virtual worlds provide a particularly pure illustration of Descartes’s problem. He said: “How do we know we’re not dreaming? How do we know an evil demon isn’t fooling us?” These days, we can just ask how we know we’re not living in a simulation like in The Matrix, where there’s in effect a giant computer program modelling the world that’s generating your experiences, and none of it is in fact “real”. Descartes’s thought turns essentially on the idea that if you’re in one of these simulation-like scenarios, the world that you experience doesn’t really exist. What I want to argue instead is that such a virtual reality is still genuine. I still have hands, there are still tables and chairs and books, there are still people I’m interacting with. Everything is still real, it’s just digital.
Isn’t that what many physicists argue is true of “real” reality anyway?
Yes, it goes back to the physicist John Wheeler and his “it from bit” idea. That’s been interpreted in many different ways, but the basic idea is that physical objects out there – cells, molecules, atoms – are ultimately grounded in a level of bits, of binary information. In that scenario, no one says, “Ah, if the world is made of bits, then none of this is real”. Likewise, if we were to find out we were in a simulation, we say, “OK, physical objects are still real, we just found out there is a level of computation, a digital level, underneath the level of physics”. If we’re in a simulation running on a computer in the next universe up, maybe the digital level itself has got levels beneath that, maybe with our simulations within simulations. Maybe we’re at level 42. There are many productive connections to be made between the simulation idea and this idea from modern physics.
Why should we believe we are in a simulation?
You can make many of the points I make while being totally agnostic on whether we are in a simulation. I believe we can’t rule it out, because, basically, our evidence about reality is indistinguishable from the evidence we would have in a perfect simulation. You might say, “Here’s some proof that we’re not in a simulation”, but any such evidence could be simulated – smart enough simulators could simulate all that.
Furthermore, there are arguments by people like the philosopher Nick Bostrom that simulation technology is already becoming very common in our world, and it’s just going to get better and better. Before long, there are going to be many simulated universes with simulated people, and you can make the case that simulated people may end up greatly outnumbering non-simulated people, and so on. Then it starts to look as if the odds that we’re in a simulation may be quite high.
“I would say we could never prove that we aren’t living in a simulation”
And we would never know?
I would say we could never prove that we aren’t in a simulation. Maybe we could get evidence that we are in a glitchy simulation – say the simulators cut some corners and there are gaps in the physics. Or maybe the simulators will want to communicate with us and reach into the simulation and show us the source code, turn the Sydney Harbour Bridge upside down, or whatever. But as for the hypothesis that we’re in a perfect simulation, indistinguishable from our own world, I think that may be impossible to test. Arguably that means it is not a scientific hypothesis, but nonetheless I think it’s still a perfectly meaningful and serious hypothesis.
So should we regard video gaming in a more positive light rather than seeing time spent in simulated worlds as a failure to engage with the “real” world?
People my age are often inclined to be quite dismissive of virtual worlds, but younger people who grew up in a strongly digital world have this attitude much less. You can lead a meaningful life in a virtual world, that’s what I try to argue. Video games are a bit of a special case, because games are, by their nature, a kind of escapism, but not all virtual worlds need to be video games. We’ve already seen it in a small way with a world like Second Life. Even though it’s not a full-scale immersive virtual reality, people have built very meaningful lives, they’ve formed relationships, they’ve had jobs, they make money and they have many of the forms of social interaction you’d have in physical reality.
I want to argue that this is as real as physical reality, but just different: you’re in fact having known illusory experiences of a virtual digital world. Of course, there are many dangers with virtual worlds. Abandoning physical reality would be one of them. Physical reality is super-important: we’ve only got one of it, and if we lose it, we also lose the basis for all these virtual realities. But I’d like to think that we’re smart enough to worry about climate change and nuclear weapons and social justice and all these things within physical reality and also explore virtual realities. It may even be that virtual worlds offer some opportunities. For many people, physical reality is pretty awful. For at least some of them, life in virtual worlds could be a step up.
In a future where our planet becomes more crowded and degraded, virtual worlds could provide an increasingly attractive alternative. Will physical reality ever go out of fashion?
In the short term, into the next 100 years or so, physical reality is always going to be central and virtual reality will be somehow an extension of it, not least because of the role of the body. In current VR technology, we’re pretty good with vision and hearing, and so on, but anything that happens to the body is very hard to simulate: eating and drinking, not to mention birth and death. You can imagine that a century-plus down the track maybe there’ll be the possibility for people to upload themselves completely to a virtual world where there is nourishment inside the simulation. For long-term simulated worlds, I think all bets are off, but that’s getting more to the realm of science fiction.
Do virtual worlds tell us anything about consciousness – about our subjective experience of the world and what is objectively out there?
The relationship between physical reality and subjective experience is a very deep and complicated issue, but I’m inclined to think that physical reality and virtual realities are somewhat analogous. In both cases, we’re having a subjective experience of a physical reality. I call this our Garden of Eden picture of reality, with solid coloured objects out there in an absolute three-dimensional space. We experience the “real” world like the original Garden of Eden. In a virtual reality we think, it’s not really like that, it’s a whole bunch of digital circuits in a matrix – it’s different from the Garden of Eden. But I think the same is also true for physical reality.
Quantum mechanics and relativity and a bunch of associated developments all very strongly suggest that the physical world we experience is not the Garden of Eden world. If we’re in the world of quantum wave functions that evolve in an abstract way and occasionally collapse, or in the world of general relativity where there’s no absolute space and time, or in the world of string theory or some other conception of quantum gravity where there’s maybe not even space or time at the fundamental level, then physical reality is very different from our intuitive models as well. What I try to argue is that virtual reality is at least as real as that kind of physical reality.
What do you make of the idea that evolution has blinded us to the truth about reality because, as cognitive scientist Donald Hoffman and others have argued, we experience only what is necessary to survive?
In some ways, I’m sympathetic about the idea that our model of the world is not exactly the same as reality. But I think, at a more fundamental level, we can still have accurate beliefs about the world, even if we’re not in the Garden of Eden, even if we’re in the world of quantum mechanics, or relativity. A sort of structuralist conception of reality – that the world isn’t intrinsically the way we thought it was, but still has a similar sort of structure – is very strongly suggested by modern science. Once you accept that, then the Hoffman-style arguments fall away.
One question you set out to answer in your book is how we should build virtual societies. What conclusions do you come to?
Social and political and moral philosophy is not my speciality, and I would say my discussion of these issues is very preliminary. But it’s a question of what kind of societies we want to live in. One major question that comes up right now is the role of corporations in setting up virtual societies. We’ve seen that Facebook changed its name to Meta, and corporations are running with the idea of setting up metaverses, very large-scale virtual realities.
If virtual worlds are genuine realities, as I argue, then this raises the possibility that corporations are going to have a very large degree of control over these genuine realities. Another theme in the book is that the creators of virtual realities are kind of like gods of those realities with a whole lot of powers over them. They’re all-powerful, they’re all-knowing. Do we really want Facebook or its descendants to be controlling every aspect of our reality when we’re in virtual worlds?
It’s not as if I have a replacement model in mind, but I think the corporate metaverse is something we should try to resist. Maybe something like the internet – where nobody controls the whole – provides a better model: there will be virtual worlds controlled by corporations, but also the virtual worlds controlled by governments and states, by collectives of people and by individuals. I kind of hope, at the end of the day, there’s going to be a cornucopia of virtual worlds run on many different models that people will be able to choose their virtual world with some autonomy.
Is all the misinformation and strife we are experiencing a sign that we are already living in a virtual world controlled by an evil overlord?
Yeah, people speculate that it’s all a giant experiment, and every now and then the simulators throw a spanner in the works like Brexit, or Donald Trump or a pandemic. It’s easy to think that, but I don’t think there’s very strong evidence. Even in an ordinary reality, you expect unexpected things to happen pretty often. But who’s to know? Insofar as there are full-scale world simulations, they’re probably going to want to simulate all kinds of extreme conditions. Let’s put Donald Trump in there and see if they even accept that, or is that just going to be a step too far?
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