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I’m a bit late to the party–it’s hard to shop for English language books here in Germany–but I finally read Erik Hoel’s 2023 book on the science of consciousness: The World Behind the World. Well, this world between the book covers is fantastic. I’m not here so much to review Hoel’s book–which anyone interested in the mind and consciousness should buy–so much as I’m here to celebrate some of its gems while also responding to some of its bolder claims.

Two perspectives

The book begins by establishing the intellectual development of humanity’s two perspectives: the subjective and the objective, or the intrinsic and extrinsic perspectives, respectively. There’s much surprising territory here. Remember how a few years ago, the internet started buzzing with stories about how some ancient cultures didn’t have a word for the color blue? Well, long before this was trendy, Princeton University psychologist and author Julian Jaynes speculated that ancient people didn’t even have an intrinsic perspective in the same way that we do, as characters in many ancient myths and poems generally lack internal dialogue or much of an inner life. Hoel and I both find the strong version of this argument silly: Homo sapiens were obviously conscious before innovations in culture and literature revealed deeper characters with internal experiences, despite Jaynes’ claims to the contrary in his 1976 book The Origin of Consciousness in the Breakdown of the Bicameral Mind. However, a more plausible idea stemming from Jaynes’ work is that human beings simply did not thoroughly develop the concept of an intrinsic perspective, on an intellectual and artistic level, until cultural developments which occurred perhaps a couple of thousand years ago (for example, in Greek theater). My own take on this, which I think departs a bit from Hoel’s, is that ancient people were perhaps more likely to recognize the nondual nature of consciousness, acknowledged in traditions such as Buddhism and Advaita; that is, they had not yet constructed an ego that sits on consciousness, observing the outside world from the inside. This is possibly supported by Jaynes’ observation, retold by Hoel, that some ancient cultures interpreted thoughts as “the commandments of the gods”, having a hallucinatory quality. Such detachment from thought might sound like mental illness to you, but similar experiences are regarded as enlightenment in some Eastern schools of philosophy and religion.

From here, Hoel takes us through the story of the intrinsic perspective from both a literary and scientific perspective, as only a novelist and neuroscientist can. This story brings us to contemporary theories and thought experiments that illuminate the intrinsic perspective. Even if you’re a scholar of consciousness like me, there are many delightful gems to be found here. For instance, you might already know about David Chalmer’s zombie thought experiment–is a world conceivable in which everyone behaves exactly the same way but lacks consciousness? I’ve read much about this thought experiment over the years: if you find this scenario conceivable, then it seems that a materialistic account of the universe is incomplete, as you cannot derive consciousness from physical laws (after all, everything is physically identical between our universe and the zombie universe). However, there’s a particular glitch here that’s long dampened the conceivability of the zombie world for me: how could zombies possibly talk about consciousness? Before reading Hoel’s book, I only knew of this glitch from Chalmer’s appearance on Sam Harris’s podcast, which I’ve written about elsewhere. But Hoel takes this very meta perspective on the zombie argument much further in the chapter “The Tale of Zombie Descartes”. I won’t spoil the fun, but if you like paradoxes, this is your kind of book.

Another absolute gem for me is Hoel’s analogy between the inaccessibility of consciousness, an inherently private phenomenon, to the inaccessibility of the inside of a black hole in the chapter “Phenomenological Theories of Consciousness”. Though Hoel doesn’t make this next point explicitly, it seems straightforward then to argue that psychologists and neuroscientists studying consciousness are legitimate scientists just as cosmologists and physicists studying the inside of black holes are legitimate scientists. Both are peering behind the curtain of observability, into a space that no instrument can directly measure, and even while some of their predictions cannot be tested, enough testable predictions remain that their theories are overall falsifiable.

Why do we need a theory of consciousness?

Much of Hoel’s book is focused on why we need a theory of consciousness. Overall, I couldn’t agree more that we need such a theory. We also agree that it’s unwise to label ambitious theories of consciousness as pseudoscience, a response to developments soon after Hoel’s book was published, and that introspection should play a larger role in neuroscience–the intrinsic perspective must be accounted for alongside the extrinsic perspective if we want to understand the mind. However, Hoel and I disagree slightly on the scope of this issue. In his words echoing biologist Theodosius Dobzhansky, “Nothing in the brain makes sense except in the light of consciousness.” I, on the other hand, think the brain generally makes plenty of sense without consciousness (hence, the zombie thought experiment). Whereas Hoel believes that brains evolved for consciousness, I think it’s straightforward to argue that the brain evolved for motor coordination and movement–everything else is just a nice bonus that came later. Consider, for instance, that many small insects, like fruit flies, obviously have a brain but are not obviously conscious (they might be, but their brains make plenty of sense without consciousness). Moreover, many parts of the human brain, such as the cerebellum (which contains most of the brain’s neurons) and the basal ganglia are heavily involved in motor functions but play little if any role in consciousness. Of course, that observation is itself useful for understanding consciousness; consciousness researchers need neuroscience, but not all neuroscientists need consciousness research.

Because we cannot understand consciousness, the very thing that Hoel believes brains evolved for, he views neuroscience as an immature science lacking fundamental principles (that is, the field is “pre-paradigmatic”). Besides dedicating an entire chapter of his book to this issue, Hoel has also summarized his views in an online essay (I’ll be reflecting on this chapter in a later post). While I’m not convinced that we always need to put subjective experience (the intrinsic perspective) first to understand the brain (the extrinsic perspective), one area where this approach makes perfect sense to me is our quest to understand dreaming. Neuroscientists still have virtually no idea why we dream each night, and Hoel’s “overfitted brain hypothesis” from 2021 is a brilliant use of the phenomenology first approach. In a research paper published in the journal Patterns, Hoel has put forth the most convincing theory of dreaming I’ve ever encountered: dreams and their bizarre phenomenology are necessary for us to learn to generalize from our daily experiences to novel situations. Even if neuroscience isn’t preparadigmatic, the field of dream research certainly was, in my view, until Hoel’s theory.

Does free will exist?

Despite my nitpicking, Hoel and I generally agree on more things than we disagree. The only place where I found area where I firmly diverge from Hoel’s perspective is the book’s last chapter, “The Scientific Case for Free Will”. Here, Hoel argues that humans have free will because of emergent causation. This concept tells us that brains and behavior cannot always be reduced to the microscopic level of individual cells, for many microscopic brain states correspond to the same mental state or behavior. I agree that the correct spatial scale to study the brain isn’t always the firing of single cells. I even agree with Hoel that Benjamin Libet’s famous prediction of volitional decisions from earlier brain activity isn’t really a knockout blow to free will. But I also don’t think we even need neurobiology to see that free will doesn’t make sense. And since Hoel’s argument for free will is really the climax of the book, I feel some need to respond to it.

To give my perspective, I’ll paraphrase Sam Harris, who also views neuroscience as a distraction for understanding the illusion of free will. Let’s suppose reductionism is false. Let’s even suppose, just for the sake of argument, that you believe in a soul. A person born with a good soul or an evil soul isn’t free; they didn’t create themselves or their soul. They aren’t responsible for their personality, their likes and dislikes, their preferences, their decisions, or anything about themselves. Even if they read self-help books and “choose” radical self-improvement, that decision is still caused by interactions between their character and their environment. You don’t need neuroscience to see any of this, though the details just become more material and obvious when you do. When you substitute large neural populations at the relevant spatial scale for a human soul, nothing actually changes.

Finally, Hoel argues that viewing free will as an illusion is bad for us, citing a 2016 study by Crescioni and colleagues which reported, in Hoel’s words, that “the belief in free will has been correlated with … a greater tendency to forgive”. I have a very different intuition – if I believe that someone who has wronged me could have done otherwise, why would I be more likely to forgive them? So I looked into the literature and found that a 2023 metaanalysis which included the study in question, alongside over a hundred other studies, found no evidence for these negative psychological effects stemming from free will skepticism. Like Sam Harris, I think that relinquishing the belief in free will is far from nihilistic and likely has a net positive effect on our ethics: we are more likely to feel compassion for others, as they couldn’t have done differently, and more likely to feel connected to the world around us, as we don’t exist as a separate free agent outside its causal structure. In other words, it relaxes another illusion, the illusion of self.

Conclusion

For me, The World Behind the World offers just the right balance of material to agree and disagree with to make it an exceptionally enjoyable read (after all, too much of either is boring). I hope Hoel writes more books in the near future, and in the meanwhile, I’ll be reading his novel, The Revelations, and continuing to follow his Substack newsletter, The Intrinsic Perspective.

Stella Dorrestein (pictured) is a medical doctor currently pursuing a PhD in psychopharmacology at the Centre for Human Drug Research in Leiden, the Netherlands while researching new drugs for psychiatric disorders. She is interested in psychedelic substances like DMT and ketamine which are receiving thorough investigation for their potential applications in treating conditions such as depression, with promising results.

Writing and photos by Joel Frohlich.