This review is available to download as a PDF here.
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Book Review: David J. Chalmers, Reality+: Virtual Worlds and the Problems of Philosophy (London: Penguin 2022)
Hardback: £25, 544pp., ISBN-10 0241320712
Ebook: £15.99, 529pp., ISBN 0241320712
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David Chalmers is currently University Professor of Philosophy and Co-Director of the Centre for Mind, Brain and Consciousness at New York University. Born in Australia, Chalmers was an exceptionally gifted mathematician – winning a bronze medal at the International Mathematical Olympiad – but turned to philosophy after reading Douglas Hofstadter’s writings. He was a Rhodes Scholar at Oxford before moving to Indiana University, Bloomington where he completed a PhD in philosophy and cognitive science under Hofstadter in 1993. In addition to his philosophical education, he has a lifelong interest in virtual reality (VR) matters – mastering BASIC computer language and playing a game called ADVENT at the age of 10 – and he has clearly retained his childlike enthusiasm for the field since the book demonstrates a familiarity with the history and current state of the VR world that is impressively detailed and wide-ranging (Chalmers 2016).
Chalmers famously coined the term the ‘hard problem of consciousness’ (1996) though in this current book he openly confesses that the problem itself has been around for decades and that his substantial reputation in relation to this topic can only be explained by the fact that he was able to present a precise and appealing formulation of the problem. At the core of this problem is the long-standing dilemma of how to explain subjective mental phenomena such as hopes, wishes, intentions, feelings and, indeed, ordinary experiential phenomena such as the taste of coffee or the aroma of perfume (or simply, as Nagel 1974, put it, what it is like to be something) in a world which, according to science, consists only of material objects, forces and processes.
Chalmers’ developing attempts to solve these difficult problems over the years resulted in a number of speculative positions such as naturalistic dualism, panpsychism and panprotopsvchism (2013) which – along with a wide range of epistemological, ethical, linguistic and logical topics – are creatively woven into the philosophical fabric of this book on virtual worlds and arguments about simulation. In dealing with such complex problems of consciousness, Chalmers aligns himself with neo-idealist scientists and thinkers such as Bernardo Kastrup and Donald Hoffman who posit the notion that consciousness is an ontological primitive, and that it is consciousness itself – not spacetime, forces or material objects – that forms the fundamental basis of the cosmos (Hyland 2021). Connecting with the world of VR technology, the book also resonates with the thesis developed by Chalmers about what he labels the ‘extended mind’ (2018), the notion that many of the functions of the mind are now located remotely in digital instruments such as computers, mobile phones and cloud storage systems.
The book substantially expands on Nick Bostrom’s original argument which challenges us to consider seriously whether we might be living in a computer simulation. Bostrom (2003) proposes an argument based on the exponential expansion of computing power (now boosted by operational quantum computers) which would allow human/post-human civilisations – if they continue to advance without destroying themselves – to construct ancestor simulations. After applying some sophisticated statistical procedures to the basic premises, he concludes that there is a 50% chance that the simulation hypothesis may be true. He makes the intriguing suggestion that ‘unless we are now living in a simulation, our descendants will almost certainly never run an ancestor-simulation’ (14).
Such speculative thought experiments have gained immense popularity in the wake of science fiction novels and films such as The Matrix and its sequels, and have been endorsed by, among others, Elon Musk and the futurist thinker, Ray Kurzwiel (Hyland 2019). To be sure, there is a fair degree of wishful and woolly reasoning surrounding this topic, but Chalmers brings order and logical precision to the debate. He had published his own argument called the ‘Matrix Hypothesis’ just before Bostrom’s paper but admits that the ‘simulation hypothesis is a better name than mine’ since ‘the simulation idea is universal, whereas a movie is ephemeral’ (2022,.28-9). Although overwhelmingly sympathetic to arguments such as Bostrom’s (and he cites many similar versions which predate this), Chalmers is not convinced that it works in the form originally set out by Bostrom. His familiarity with and lifelong enthusiasm for artificial intelligence (AI) and VR leads him to offer a far more comprehensive and painstakingly detailed account of the issues than those which characterized previous discussions.
A number of operational definitions and distinctions are crucial to Chalmers’ core argument that ‘virtual reality is genuine reality…Virtual worlds need not be second-class realities. They can be first-class realities’ (ibid,.xvii). A ‘sim’ is defined as an ‘intelligent being in a simulation’ whereas a ‘nonsim is an intelligent being who is not in a simulation’. Given this the following argument is laid out (84-5):
- At least one in ten nonsim populations will each create a thousand sim populations.
- If at least one in ten nonsim populations will each create a thousand sim populations, then at least 99% of intelligent beings are sims.
- If at least 99% of intelligent beings are sims, we are probably sims.
- So: We are probably sims.
Chalmers then proceeds to justify each of the above premises and defend them against ‘sim blockers’, objections which ‘tend to block (or prevent) the existence of sims’ (85-6).
Chief amongst these sim blockers are claims such as intelligent sims are impossible, our descendants would not be interested in creating sims, or sims would take up too much computer power, but Chalmers answers all the challenges and concludes that:
We certainly can’t know that there will be uncomputable laws, insufficient computer power, near-universal extinction, a near-universal choice to avoid simulations, or more efficient nonsims. And if we can’t know that there are sim blockers, then for all we know, most intelligent beings are sims (91).
The idea that future civilisations might not be interested in creating simulations is perhaps the least plausible of all the objections given the huge interest and advance of all types of VR, particularly the recent popularity of ‘immersive’ applications in both cultural and educational contexts (Dhimolea, Kaplan-Rakowski, & Lin 2022).
Much of the improbability and counter-intuitive nature of sim arguments concerns the contested concept of ‘reality’. Surely, the ordinary, nonsim world we live in is ‘real’ whereas a simulated world is surely an illusion, a second-hand copy or a shadowy reflection of the ‘genuine’ world of phenomenal experience. It is at this point that the argument engages with the central questions of philosophy on the difference between appearance and reality which have exercised the minds of thinkers from Plato, through Descartes, Locke, Berkeley and Hume, down to modern linguistic philosophers such as J.L. Austin and Wittgenstein.
Chalmers conducts a detailed analysis in support of his views on virtual realism by suggesting five ways of thinking about what is real: reality as existence, reality as causal power, reality as mind-independence, reality as non-illusoriness, and reality as genuineness (107-114). Drawing on a formidable array of philosophical positions, he concludes that ‘if we’re in a perfect simulation, the objects we perceive are real according to all five of these criteria’. Addressing the counter-intuitive nature of virtual realism, he reminds us that:
Science has taught us that there’s much more to reality than initially seems to be the case. For millennia, we didn’t know that cats and dogs and trees are made of cells, let alone that cells are made of atoms or that those are fundamentally quantum mechanical. Yet these discoveries about the nature of cats and dogs and trees have not undermined their reality…
If I’m right, the discovery that we’re in a simulation should be treated the same way. It will be a discovery about cats and dogs and trees – that they spring from digital processes – but it won’t undermine their reality (117-118).
This goes to the heart of Chalmers’ core argument: why should material objects made of ‘bits’ we now label quarks and electrons subject to superposition, entanglement and uncertainty be somehow more real than simulated objects made of digital ‘bits’?
Acknowledging the possibility that we might be living in some sort of simulated world raises all sorts of ethical, metaphysical and spiritual/theological issues, and Chalmers again addresses these by engaging with the mainstream philosophical canon. There are two categories of moral issues to consider here: those of people living in sim worlds and those concerning the creators of simulated worlds. Like Bostrom, Chalmers takes the view that it would be difficult to find moral justifications for the construction of simulated worlds for purely entertainment purposes. Of course, this judgment also condemns much virtual gaming and a vast swathe of social media output, and the fact that those responsible for all this probably give little or no thought to moral as opposed to economic matters ought to give us much pause for thought about the digital revolution of the last few decades. Morally justifiable virtual worlds might include those aimed at answering, for example, scientific, medical, historical, social, political, economic or other genuine research questions and, currently, computer models linked to climate change and the spread of pandemics would likely take pride of place here. However, what is bound to raise serous moral concerns is the idea of simply simulating some alternative version of our present world (whether the current world is sim or nonsim) which contains the same levels of evil and suffering. The thought that this would be difficult to justify on moral grounds goes to the heart of the problem of evil which for many philosophers offers the most unanswerable argument against the traditional concept of god (Grayling 2010).
When it comes to the question of how we ought to behave if we lived in simulated worlds, the question is informed by the original position that virtual sim reality is as genuine as nonsim reality. Sims will be subject to the same motives, needs, feelings and moral challenges as nonsims, and the same ethical theories and principles can be used to make more judgments and decisions to act. According to Chalmers, ‘simulated humans have the same moral status as ordinary humans’ (345), and this brute fact will guide all ethical judgments whether we take a deontological or utilitarian approach to the central challenges of life. In the last analysis, what matters according to this approach is a ‘Principle of Personhood’ which leads Chalmers to apply the Kantian argument that ‘we should never treat sims merely as means to an end but as ends in themselves’ (348). Good and evil, suffering and well-being, will present the same challenges whether we live in a sim or a nonsim world (Hyland 2019).
Considering spiritual and theological matters within the framework of simulated world perspectives results in some fascinating notions and reflections. Bostrom had suggested that the notion of hierarchies of simulated worlds – sims creating worlds within sim worlds – might lead to what he called a ‘naturalistic theogony that would study the structure of this hierarchy, and the constraints imposed on its inhabitants by the possibility that their actions on their own level may affect the treatment they receive from dwellers of deeper levels’ (2003, 12). Chalmers takes up this theme by suggesting that creators of simulated worlds might indeed be considered to be ‘gods’. He follows this up with the intriguing idea that – as the transhumanist philosopher David Pearce has proposed – the ‘simulation argument is the most interesting argument for the existence of God in a long time’ (2022, 124). Fascinatingly, he confesses that – as a lifelong atheist – he now takes the idea of some sort of god more seriously. However, this has nothing in common with any of the conventional, supernatural conceptions of god; this god/simulator is naturalistic and ‘can be explained by the natural laws of the cosmos’ (135). Thus, though there may be religious/theological implications of simulation theory, none of these requires any form of worship or reverence. After all, the simulators will likely be our own human/posthuman descendants living in, say, the 23rd century or even an enthusiastic and technologically adept teenager running a sim world in the next universe up! (142-45).
Chalmers’ comprehensive and thoroughly well-informed explorations in ‘technophilosophy’ (p.xviii) are fully in line with the long history of similar thought experiments from Plato’s Cave, though Descartes’ Evil Demon, down to the brains-in-vats and philosophical zombies of modern epistemological speculation. The central arguments are bound to be contentious and challenging but they are well worth taking seriously by educators and, indeed, by academics in any discipline. For philosophers of education, they raise issues central to the core business of teaching and learning (Akgun & Atici 2022) and, for lecturers and teachers, they provide fascinating material for reflection and discussion with young people who, very likely, will know much more about and have far more working experience of VR matters than their tutors. Indeed, since not all of us will have the vast working knowledge of these matters displayed by Chalmers, it might just be that our students would probably take the lead in any discussions in this sphere.
References
Akgun, M., & Atici, B. (2022). The Effects of Immersive Virtual Reality Environments on Students’ Academic Achievement: A Meta-analytical and Meta-thematic Study. Participatory Educational Research, 9(3): 111-131
Bostrom, N. (2003). Are You Living in a Computer Simulation?. Philosophical Quarterly. 53(211):243‐255 https://www.simulation-argument.com/simulation.html. See also TED talk – Nick Bostrom – What Happens When Our Computers Get Smarter Than We Are? https://youtu.be/MnT1xgZgkpk; accessed 21.5.22.
Chalmers, D. (1996) The Conscious Mind. (Oxford: Oxford University Press)
Chalmers, D.(2013). Panpsychism and Panprotopsychism; 2013 Amherst Lecture in Philosophy. http://consc.net/papers/panpsychism.pdf; accessed 21.9.22.
Chalmers, D. (2016). The Philosophy of Virtual Reality. Aeon Video https://youtu.be/1ur7eIKiwuA; accessed 21.7.22.
Chalmers, D. (2018). The Extended Mind – Interview by Robert Lawrence Kuhn for Closer to Truth on Youtube. https://youtu.be/Jg00gK43Id4; accessed 13.7.22.
Dhimolea, T.K., Kaplan-Rakowski, R. & Lin, L. A. (2022). Systematic Review of Research on High-Immersion Virtual Reality for Language Learning. TechTrends 66:810–824. https://doi.org/10.1007/s11528-022-00717-w.
Grayling, A.C. (2010). Against All Gods. (London: Oberon)
Hyland, T. (2019). Imagining Virtual Worlds: Philosophy, Ethics and the Educational Potential of Nick Bostrom’s Simulation Arguments. International Journal of Ethics, 14(3):1-23
Hyland, T. (2021). Perspectives on Panpsychism. (Mauritius: Omniscriptum Publishing)
Nagel, T. (1974). What is it like to be a bat?; Philosophical Review, 83: 435-450
