You are fifty stories high above a city street, toes dangling over the edge of a creaky wooden plank. A voice from seemingly nowhere says, “It’s up to you, but you may now step off the plank.” You take a deep breath, force one foot in front of the other, and step into midair. But instead of plummeting fifty stories to the pavement, you find your footing just a couple of inches below.

So went the protocol of a psychology experiment and short film I completed with colleagues a few years back that studied and documented hundreds of people’s first experiences of virtual reality. We found that most participants were willing to step off the plank when prompted, but this choice seemed to depend on how aware they were of being in virtual reality while in it.

But wait, you may say—how could anyone be unaware they were in virtual reality while in it? Aren’t people in virtual reality wearing a clunky headset, peering around at a video-game-like world, and bumping into furniture in their living room? If you’ve never put on a highly immersive virtual reality headset, such as the Oculus Quest 2, I expect you to maintain some skepticism about the realism of virtual reality. In fact, virtual reality is designed to deceive your senses and make you forget you are in a virtual world—an engineered forgetfulness called, ironically enough for mindfulness practitioners, “presence.”

Reality+: Virtual Worlds and the Problems of Philosophy

By David J. Chalmers
W.W. Norton, January 2022, 544 pages, $32.50, hardcover

If all this makes you pinch your chin and ponder the nature of reality, you’re in good company. In his new book, Reality+: Virtual Worlds and the Problems of Philosophy, one of the most renowned philosophers of our time, David Chalmers, finds fresh inspiration in the emerging technologies of virtual and augmented reality to reflect on some of the biggest questions in philosophy: What is the nature of reality? How can we know about the world? What is the difference between good and bad?

According to Chalmers, these emerging technologies serve up novel approaches to these traditional philosophical questions—an approach he calls technophilosophy. Thus, Reality+ allows him to revisit classic thought experiments such as Zhuangzi’s butterfly dream, Descartes’s evil demon, and Plato’s cave right alongside more modern references such as Ready Player One, Rick and Morty, and The Matrix. It’s an undoubtedly strange mix of old and new but one that I think reflects the spirit of Chalmers’s technophilosophy.

I know, I know. A famous philosopher publishes a book about virtual reality around the same time Facebook decides to change its name to Meta, a fourth Matrix movie is released, and the term metaverse goes mainstream—seems opportunistic. Yet Chalmers’s explorations of this topic are far from superficial. The book even includes an impressive set of scholarly references for those inclined toward the more academic side of philosophy. Reading his book, you cannot help but feel the genuine excitement of Chalmers breaking new ground on age-old questions.

Chalmers’s most productive claim in Reality+ is that virtual reality offers a real reality—a claim with several  mind-bending implications: First, we cannot confirm that our current world is not itself a virtual reality. Second, we may need to update our understanding of what real means. And third, it is possible to live part, or even all, of a good and meaningful life in a virtual reality. Hence the plus sign in the book’s title is meant to carry multiple meanings pushing against the idea that a virtual reality must be a lesser one.

Yet to a large extent these core ideas of Reality+ rely less on the existing state of virtual reality and more on what Chalmers sees as an almost inevitable realization of fully immersive virtual reality in humanity’s future. This view includes things like headsets getting progressively smaller to the point of contact lenses or brain implants and the seamless integration of touch, smell, and taste. Chalmers even guesses that a century from now “we will have virtual realities that are indistinguishable from the non-virtual world.” Whether this vision of the future excites or terrifies you will likely determine how much value you find in the book as a whole.

Despite personally finding value in much of Reality+, there is one key idea with which I struggled. Throughout the book, Chalmers takes on the question of whether our current reality is already a computer simulation—the so-called simulation hypothesis. To be fair, the simulation hypothesis has never resonated with me for two reasons that predate the publication of Reality+. I find it problematic that a highly intelligent life form capable of simulating anything would choose to simulate a world with as much suffering as ours. More to the point, there seems to be a strong risk of generating yet more suffering by convincing even a small percentage of people that everything around them is simulated as in a video game. But even putting these reasons aside, I admit I felt a bit underwhelmed when the ultimate reason why I should take the simulation hypothesis seriously, per Chalmers, was merely that “it’s a possibility we can’t rule out.”

This statement seems like a kind of philosophical sleight of hand that could apply to many other, perhaps more inspired theories about the ultimate nature of reality. Surely more essential than the point that a theory can’t be ruled out is the question why it is more compelling than other theories about reality—that all phenomena are dependently originated, for example, or the theory that my life is a butterfly’s dream. These ideas may be equally impossible to rule out, yet they seem more worthy of serious contemplation to me (who admittedly is very much not the famous philosopher here).

All ideas considered, I found Reality+ to be a riveting, mind-stretching, wakeful read, one I recommend to anyone fractionally interested in topics such as virtual reality, augmented reality, or our looming omni-cyber-meta-verse—whatever we might call it. If nothing else, it gives me pause to know that a famous philosopher has dedicated an entire book to questions related to these emerging technologies. Beyond waxing philosophical, he provides further evidence that each of us will be called on to answer these questions not with ideas and beliefs but a very concrete choice: in which kind of reality will we spend our precious time?