A Skeptical Review of Chalmers’ Reality+

David Bentley Hart, Reality Minus, The New Atlantis, February 4, 2022.

Hart’s central move:

But the real problem is that the book breaks down into two broad and equally unsatisfying parts, and neither part lends support to the other: on the one hand, it advances arguments in favor of its central premise that virtual minds are a real possibility, none of which is remotely convincing; on the other, it offers a series of reflections on the moral, social, ontological, and even metaphysical implications of that premise, most of which are reminiscent of an introductory undergraduate course in elementary logic. […] the problem is simply that all the seemingly fascinating questions he would like to raise about life in a virtual reality are in fact not really questions at all, let alone fascinating ones, if one has already granted the fabulous notion that virtual minds are a real possibility.

Hart is skeptical about virtual reality, as am I (see links in my earlier post, Quick reaction: David Chalmers talks about his new book, Reality+). Given that, his dismissal of the second aspect of the book makes sense to me. Keep in mind that I’ve not read the book; my knowledge of it is based on Chalmer’s talk which I present in that earlier post.

A bit more from Hart:

When considering positions suggestively analogous to his own, Chalmers scrolls quickly through Plato’s cave, Zhuangzi dreaming that he is a butterfly, Descartes’s meticulous exorcism of his deceiver demon, Berkeley’s idealist phantasmagory, and so forth, but at the last he arrives at the aptest parallel of all: Kant’s transcendental deduction. Where pure reason is concerned, leave the noumena to themselves; our true dwelling is among the phenomena:

Kant’s realm of appearances is the realm of relations between things, including spatiotemporal relations and causal relations. Kant’s realm of things in themselves is the realm of ˆ properties of things…. The relational properties of reality are knowable, but the intrinsic properties are unknowable.

So, obviously, if conscious, thinking subjects with free will (assuming there is such a thing) could exist together within a simulated world, with the power to affect one another and their shared phenomenal environment for either good or ill, then by that very token they and their world would be no less real than one composed of such physical ingredients as basic particles, molecules, and organic tissues. How can we say otherwise? Whether something counts as “reality” or not is surely not to be determined by the substrate in which it inheres; if it were, all “realities” would be equally vacuous in some sense, inasmuch as all of them would be reducible to — or would at their lowest levels shade away into — a quantum landscape of pure possibilities. The question is not what the world is composed from, but whether anyone is at home when one knocks on its door; and, if the answer to that second question is “Yes,” then the solutions to all those subsidiary questions of ontology and morality and whatnot turn out to be exercises in tautology: if you are really there, you — ontologically, morally, logically, and in every other significant sense — are really there.

For this reason, most of Reality+ consists in a rather banal process of supplying inevitable answers to otiose queries. And this is made all the more tedious if one realizes, as one should, that the correct answer to the essential question is in fact “No”: in a simulated world, only simulated selves could exist; no one — absolutely no one — ever will or could be at home there. Chalmers does not, however, realize this. So, for him, the questions he raises in his book are not mere idle ponderings, but matters of some urgency. He is convinced that at some point in the coming century our virtual realities will become indistinguishable from the non-virtual universe underlying them.

He notes that Chalmers is “is speaking also of possible virtual worlds populated by virtual minds, perhaps existing in some form of cybernetic machinery or perhaps existing wholly in the form of digital code.” Hart is skeptical about that and so am I. He goes on to offer arguments against Chalmers’ position. I recommend them to you.

He concludes by observing that “a large part of the subtext of Reality+ is the looming environmental catastrophe threatening the planet.” If indeed a purely virtual world is as real as our current physical world, then an obvious response to environmental collapse is to decamp for a purely virtual existence.