Here be rabbit holes.

With that warning in mind, this book examines the question that has deprived philosophers of sleep since times immemorial: do we see the world as it truly is? Professor of Cognitive Sciences Donald D. Hoffman answers with a firm “no”. The resulting case against reality that he constructs is both speculative and thought-provoking, but I also found it a winding, confusing, and ultimately unconvincing read.

The Case Against Reality: How Evolution Hid the Truth from Our Eyes, written by Donald D. Hoffman, published in Europe by Allen Lane in August 2019 (hardback, 272 pages)

Starting with the hard problem of consciousness, i.e. our inability to explain it, Hoffman wonders whether our efforts are hindered by a false belief. Namely, the belief that we see reality as it is. Now, on the face of it, this idea is not that far-fetched for biologists. By now, we understand that the colours human eyes can perceive are only a sliver of the electromagnetic spectrum, with many animals observing other parts of that spectrum, and we know that many animals can hear and communicate in infra- and ultrasound. But that is not what Hoffman means, he takes his idea much further than that.

What Hoffman builds towards over the course of ten chapters is, in short, the following idea: there is no objective material reality, and certainly not one creating consciousness. Instead, what he calls conscious agents are at the basis of everything, and they create the perception of an objective reality, something he calls “conscious realism”.

But before reaching this speculative conclusion, you have to wade through a long and sometimes confusing buildup. One example he uses to illustrate his idea is that of seeing a spoon. If no one is looking, does it still exist? Our intuition says yes, but Hoffman says no.

“there is no objective material reality […] conscious agents are at the basis of everything, and they create the perception of an objective reality.”

So does that mean he believes in solipsism, the idea that only I exist, and everything and everyone I observe might not exist? No, he then clarifies, something continues to exist when you are not looking, but it is not a spoon.

So, are we talking qualia then? This is the term philosophers use for individual instances of subjective conscious experiences, which famously gives rise to the question of whether the red that I see is the same red that you see. Hoffman would rather avoid this term because there is no agreed-upon definition, preferring instead to talk of “conscious experiences”.

But wait now, that spoon you say no longer exists when I close my eyes can still be touched. It tastes of spoon when I put it in my mouth, and it makes a sound when I drop it. And, importantly, I would add, those sensations are the same with my eyes open, suggesting that the spoon continues to exist. Not so, counters Hoffman. Something persists, but it is not a spoon. The spoon, with all its physical properties, ceases to exist when you look away because your consciousness is no longer creating the perception of one.

Hoffman is quick and generous to admit that his ideas are very counterintuitive and confusing. Where I initially thought they were obvious to the point of being trivial, I increasingly felt he was setting up ideas that are by definition unobservable, which made me question their relevance. It elicited the same shrug I reserve for people who claim the existence of an unobservable god: nice handwaving you have going there, but that by definition places it outside of the purview of scientific enquiry.

“If no one is looking, does [the spoon] still exist? Our intuition says yes, but Hoffman says no. […] Something persists, but it is not a spoon.”

And here is another objection. Even when no one is watching, objects in our world can interact with one another, and when our gaze returns to them, we see that things have changed. That flies in the face of the notion that the world ceases to be without observers. Though Hoffman would reply “but something persists, it is just not the material world we know”. Basically, I think he needlessly confuses and conflates things by introducing the controversial notion of the world not existing without observers, but then backpedalling by saying that something persists.

Having said that, his other main metaphor is useful to help the reader understand his ideas. No, not the frequent references to The Matrix (they would have been hip 20 years ago), but what Hoffman dubs the Interface Theory of Perception. He likens our perception of reality to the desktop on a computer screen, with icons representing objects or agents in our world. Just as an icon is a representation of a file stored on a hard drive, so the things we perceive are icons in our interface. An elegant extension of that is that the tools we have developed, e.g. microscopes or bat detectors, allow us to explore more of the interface, but still do not reveal the underlying reality. A similarly elegant riposte is given to the argument that if everything we observe is just icons, we can harmlessly jump in front of an oncoming train. Not so. Even though we should not take our perceptions literally, we should take them seriously.

The other idea in the book that I did like, which is also an important pillar, is that evolution and natural selection do not care about us perceiving truth. What is important is that our perceptions contribute to our fitness, something he dubs the Fitness-Beats-Truth theorem. It agrees nicely with the observation that our sensory organs and brains discard a huge amount of incoming information.

“[His ideas] elicited the same shrug I reserve for people who claim the existence of an unobservable god: nice handwaving you have going there, but that by definition places it outside of the purview of scientific enquiry.”

In intervening chapters, Hoffman makes some excursions into visual illusions, arguing they are the error-correcting codes of the data structure that is our world. And he attempts to give a short introduction to quantum physics (which, I swear, has to be one of the most abused notions in modern science) pointing out how many physicists consider the concepts of space, time, and the resulting spacetime fabric to be doomed. But whether they agree that Hoffman’s ideas make a good substitute? I found this particular excursion poorly explained; hopefully, Carroll’s Something Deeply Hidden will help me better understand it.

Hoffman admits his thesis of conscious realism is purposefully bold so that others, in the spirit of scientific enquiry and debate, may discover its flaws and improve upon it. And, he adds, it also has its work cut out for it to offer an alternative to current explanations in physics and biology.

Normally, I tend to avoid other reviews so as to focus on my own thoughts and opinions when writing a review. But when a book leaves me stumped, it can be useful to see what others think. Two current reviews on Amazon stand out. Barry Clayton makes the worthwhile observation that would explain my difficulties with this book: “This book is not for those who […] are ignorant of cognitive science. A working knowledge of Kantian philosophy, quantum physics and metaphysics will also help.” Author Brian Clegg, meanwhile, questions Hoffman’s understanding of quantum physics. Personally, I think there are some interesting ideas here, but the book left me by and large befuddled. But do not take my word for it. Hoffman gave a nice TED talk that should help you decide for yourself and, if you want to go deeper, a TED interview.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

The Case Against Reality paperback, hardback, ebook, audiobook, audio CD or MP3 CD

Other recommended books mentioned in this review:

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