As long as humans have been around, we’ve been trying to figure out what’s real and what’s not. You find some version of this question in virtually all of the world’s great philosophical traditions — from the West to the East — and the answers are often surprisingly not that clear.
It’s even harder today because the world has become much more complicated. On the one hand, we all have a pretty decent idea of what’s real in our own lives. Whatever we can see, feel, or touch seems real. Our experiences, our thoughts, our relationships — they all seem real. But sometimes our senses can deceive us, so how do we really know?
And what about the virtual world — is that real? Are our experiences online real in the same way that the car I drove this morning, or the chair I’m sitting in now, are real? Or what about our beliefs and our emotions and our values? Are those real, too? Or do they fall into some other category?
A new book by pioneering philosopher David Chalmers takes up these sorts of questions and much more. Chalmers is the co-director of the Center for Mind, Brain and Consciousness at NYU and perhaps best known for his 1996 book The Conscious Mind. His new book is called Reality+, and it makes a very interesting case that virtual realities are genuine realities, invested with just as much meaning as anything that happens in the physical world. As more and more of our lives play out in the virtual space, or the “metaverse,” this is becoming more than an abstract debate.
I reached out to Chalmers for the latest episode of Vox Conversations. We discuss the nature of reality, why he thinks we can live a meaningful life in the virtual world, whether we might actually be living in a simulation, and if he thinks there’s any chance consciousness survives the death of the body. This is a fun conversation, one that might take you back to those late-night chats in your college dorm room, but we lean into that and we do think there’s something serious to ponder here.
Below is an excerpt, edited for length and clarity. As always, there’s much more in the full podcast, so subscribe to Vox Conversations on Apple Podcasts, Google Podcasts, Spotify, Stitcher, or wherever you listen to podcasts.
Defining “reality” seems like a fairly straightforward task, but you argue that a lot of us are confused about what counts as real and what doesn’t. So I’ll just start by asking: Do we even have a consensus definition of reality at this point?
Despite calling my book Reality+, I’m still not entirely sure what the word “reality” has meant to me. There are so many different meanings for the word and philosophers love to make these distinctions. I guess in one meaning, reality is just everything that exists. It’s the entire cosmos. Reality is whatever there is and nothing else.
But then you can also talk about realities. We talk about virtual realities, physical realities, and so on. Part of the theme of this book is that reality might be made up of many different realities, both physical and virtual. In that case, reality is more like an interconnected space of goings-on that are all interacting with each other.
But then there’s the question you’re getting at here, which is, what does it mean to be real? In that sense, reality is something like realness; the property of being real. Some things are real, some things aren’t. Joe Biden is real. Santa Claus, alas, is a fiction. So what is the difference between being real and not being real? One key difference is: something is real if it has causal powers, if it can make a difference in the world.
I think most people would say that the virtual world — by this, I mean the online world, the gaming world, the metaverse, etc. — is less “real” than the physical world, that it’s a second-class reality. Is that wrong?
In some ways, this is an interesting generational divide. People in my generation — I’m in my 50s — are much more inclined to count digital worlds as second-class and not fully real. Whereas people born in the last 20 years or so are basically digital natives who are used to hanging out in digital realities. From their perspective, virtual worlds are part of reality and treated that way.
I’m not sure I’d say that virtual realities are second-class, but maybe I’d say that they’re second-level. We all acknowledge there’s a physical reality and then there are these virtual realities, which are created within the physical reality and to some extent depend on it. So in that sense, they’re second-level realities. And we say things like IRL (in real life) all the time in order to draw a distinction between physical reality and the virtual world. For me, that’s a distinction between original reality and what I’d call a derivative reality — it’s not a distinction between “real” and “unreal.”
Why did you feel like it was important to make the case for virtual realities as genuine realities?
I guess for a lot of reasons. Philosophically, it helps us to think about the relationship between the mind and reality. What can we know about the external world? Can we know anything? Maybe we’re in a simulation and none of this is really happening.
Maybe we’ve got to rethink the relationship between the mind and reality so that simulations are more real than we might have thought. It just became increasingly clear that these are going to be very pressing practical questions in the next few decades. Virtual reality technology is already here. We’re becoming obsessed with the idea of a metaverse in which we’re going to be spending more and more of our time.
So it’s important to think about what kind of life we can actually have in a metaverse. Can we live a meaningful life there? Some people think, by its very nature, it can only ever be escapism or illusion, not something on par with “real” life. But if I’m right that virtual reality is a genuine reality, then you can, at least in principle, lead a meaningful life in a virtual world. I think this really matters.
This is making me think of the role of fictions in our everyday lives. So many consequential things in the human world are constructed — money, morality, the law, the state — but what makes those things real is mutual interdependence. They’re real because they’re shared, because we all keep waking up and believing in them. So are those things less “real” than trees or mountains? Or they just a different category of “reality”?
I think most of the things that we count as real get their significance from an interaction between the mind and the external world. I think there is a world out there independently of the mind, but our mind invests it all with meaning. Money is basically just a bunch of paper or bits of metal or records of computer code, until people choose to invest that with meaning and take a certain attitude toward it.
Certainly our social environment is largely a product of our mental attitudes. But there are some things in the world that are entirely independent of the mind, like atoms. But I wouldn’t want to say that money is necessarily less real because it’s the result of this interaction.
This is actually important when it comes to thinking about virtual reality. Because once you recognize the role that the mind plays in investing things with meaning and with reality, then it’s easier to to invest virtual things with meaning, just as much as one can invest physical things with meaning.
Maybe that’s what’s now happening with, say, blockchain technology, or non-fungible tokens (NFTs), or something you might have thought was some totally useless digital thing until, aha, people invest them with some importance.
All right, David, let’s get to the important stuff: what’s the best case that we’re living in a computer simulation?
It’s interesting. There’s different kinds of simulations. There’s the so-called perfect simulation, where the simulation is so good that it will always be indistinguishable from physical reality. If we’re in a perfect simulation, we may never be able to know that.
But we could be in an imperfect simulation with glitches, with black cats crossing our paths, where maybe we put too much strain on the simulation and then it breaks down.
Maybe the simulators communicate with us. If they wanted to, they could give us very good evidence. They could take the Empire State Building and turn it upside down in the sky and say, “Here, look at the source code I’m manipulating now.” They could give us evidence that we’re in a simulation, but I think we’ll never get decisive evidence that we’re not in a simulation, because we could always be in a perfect simulation where that evidence is simulated.
And if we did learn that this is all a simulation, would it really matter?
I guess my view is simulated realities are realities, too. It could be that we’re in such a simulation right now. If so, if we discovered this, it would be shocking for a moment. We’d take some time to get used to it, but then at a certain point, life goes on. Likewise, if that’s going on unbeknownst to us right now, then I think that doesn’t somehow rob our lives of meaning. Our lives are just as meaningful as they were before.
Do you think it’s inevitable that we’ll reach a point where the virtual world is practically indistinguishable from the physical world? And if so, how far away do you think that is?
I don’t think it’s very close. To be honest, I think that for the next 20-odd years, probably, VR is going to be okay, but not great. Maybe in 20 or 30 years, we’ll get to really high-quality VR, probably not yet indistinguishable, but at least where things like vision and hearing and so on are concerned.
The real challenge is embodiment and having an experience of your body, the sense of touch, the sense of moving your body, the sensations you get from eating and drinking or sex. That’s a much bigger challenge, and that probably is going to require more than just standard virtual reality or augmented reality, maybe something like brain-computer interfaces.
Once we reach a point where computer processes directly communicate with the areas of the brain associated with the body and with pleasure and so on, you can imagine long-term technologies where that is used to give you a much more realistic sense of living in VR. But I suspect really good brain-computer interfaces like that are probably close to a century away.
Do you think consciousness survives the death of the body?
My default hypothesis is that when I die, I will cease to exist. My conscious self will go out of existence. Maybe if certain hypotheses about consciousness are right, if every biological system has some degree of consciousness, who’s to say there couldn’t be little fragments of consciousness associated with what goes on after my death?
But I’m inclined to say that I will be gone. It’s partly because I don’t really believe in a nonphysical soul which is separable from the physical brain and body. Even if I think consciousness is more than the brain and the body, at least as far as I can tell, it’s tied to it.
Having said that, thinking about the simulation hypothesis does give the prospect of some different ways of thinking about life after death. For example, maybe if we’re all bits of code inside the simulation, then there’s a possibility that upon physical death inside the simulation, that code could be lifted up by the simulators and moved to some other virtual world or some other portion of the simulation. Who’s to say that couldn’t qualify as some kind of life after death?
Thinking about the simulation idea makes me somewhat more open to the idea that perhaps we could have some existence that goes beyond the mirror existence of this physical body, although it may still be tethered to something quasi-physical in the next universe up. I think about that as a somewhat more naturalistic form of life after death that even someone who’s not traditionally religious could still be open to.