The world you live in is created, millisecond by millisecond, in technicolour virtual reality, by the most complex parallel biocomputer in the universe. But it is just a guess.
Admittedly, it’s a very good guess. It should be, for that guess is based on all your current awareness, your personal experiences, the experiences of your family, of your society, of your culture, and your ancestors right back to the first animals that wriggled through the mud, experiencing the warmth of the Cambrian sun filtering through the shallow waters of their estuary.
Nevertheless, the world you experience moment by moment is still a guess. It is a projected controlled hallucination of what should be there. That is the thesis put forward by Anil Seth, Professor of Cognitive and Computational Neuroscience at the University of Sussex, UK. This view of the predictive brain is rapidly achieving acceptance as the way that the brain and its associated consciousness works.
Seth is undoubtedly a consummate scientist and physicalist, whose explanations of the nature of the world are consonant with the best and most established theories of physics. His book is both broad in scope, grippingly written and entertaining. He is one of those scientists who is at his happiest explaining his research, summarising the work of others, urging his readers to keep an open mind while pointing to one fascinating fact after another which underly his approach. He also has an online presence which is worth exploring along with the book.1
A few decades ago, the subject of consciousness was not considered a profitable scientific endeavour. The advent of precision electroencephalography, positron emission tomography, functional magnetic resonance, transcranial magnetic stimulation and other such non-invasive techniques, coupled with massively increased computing power and artificial intelligence applications have changed all that. Consciousness science is now wide-spread and new journals have arisen to deal with the amount of scientific and philosophical research being reported.
Arguably, philosophical speculation on the nature of consciousness, ancient and formative though it may have been, has done little to explain the phenomenon. More recently, the fashionable, and questionable, resurgence of idealist philosophy has further muddied the waters, reviving mystical, magical or religious explanations for consciousness.
An important recent watershed in the discussion of consciousness was the positing of the so-called “Hard Problem of consciousness” by philosophers Thomas Nagel and David Chalmers. This posed the question of how mere physical entities like atoms, neurons and chemicals, arranged in brains, can give rise to first person subjective experience. This is an unfortunately formulated question, relying as it does on personal incredulity and ignoring the role of development, complexity, emergence and evolution, all of which are well-supported components of much of our scientific explanations of the world.
As has been shown many times, subjective experience and personal intuitions, however convincing, are unreliable guides for ascertaining truth. So it is with consciousness. Wittgenstein made this point graphically in a discourse with one of his students. “Tell me, said Wittgenstein’ “why do people always say, it was natural for man to assume that the sun went round the earth rather than that the earth was rotating?” The student replied, “Well, obviously because it just looks as though the Sun is going round the Earth.” Wittgenstein responded, “Well, what would it have looked like if it had looked as though the Earth was rotating?” Nowadays, Wittgenstein might well have asked Chalmers and Nagel “What would it look/feel like if atoms, neurons and chemicals in the brain manufactured first-person subjective experience”. The answer of course is that it would feel exactly as it does. Viewed in this light, the “Hard Problem” may reflect more a lack of knowledge and failure of imagination that a serious query.
In direct contrast to Chalmer’s “Hard Problem”, Seth poses the “Easy Problem” (explaining how the brain achieves the first-person experience based on brain function and evolutionary purpose). Of course, this “Easy Problem” is not easy and, as yet, no fully developed and accepted theory of consciousness exists. This is hardly surprising as the brain is, thus far, the most complex system that science has ever approached. In fact, it is the most complex system we have found in the universe.
Perhaps the last similar issue which science answered was the nature of life. Here the lack of knowledge (and again the failure of the imagination) led the idealist “vitalist” philosophers to posit (Henri Bergstrom as late as 1919!) a vital spark, some “Elan Vital”, which was necessary before inanimate matter could achieve life. Fortunately, subsequent biochemical research dispelled the ignorance and the “Elan Vital” joined the other such idealist explanations of “unexplainable phenomena” in philosophical oblivion. I suspect the “Hard Problem” will ultimately join them as scientific data replaces ignorance and, as usual, converts the “inconceivable” into everyday knowledge.
So, what is Seth’s overall thesis?
The thesis contradicts the commonplace perception that the brain is merely a receiver and organiser of incoming information from the senses. In practice the situation is quite the reverse. The brain already has detailed and flexible models of the world based upon all its experience, both from evolutionary structuring, cultural inputs and extensive personal experience derived from first hand interaction with the world. The function of the senses is therefore to look for any discrepancies between the brain’s current models of reality and the incoming sensory data. Until this view gained traction, anatomists had been confused as to why more neurons were going out to the senses than were actually bringing data in! In Seth’s understanding this is because the purpose of the senses is to detect and minimise errors between the brain’s model and the outside world. Subsequently such error-detecting neurons have been identified.
Those who have studied statistics will recognise the similarity between this view of the brain’s approach and those of both the scientific method (theory refinement via abductive logic) and Bayesian statistics (re-evaluation of likelihood functions). In practice Seth’s ideas are very similar to those of Andy Clark (The experience machine2) and Karl Friston (The Free Energy Approach3). In short, the brain is superbly functional in achieving our survival and successful reproduction because it continually refines generative spacial and temporal models which predict the outside (and inside) world. This modelling achieves far better results than simpler neural systems which can only react to the present. Predicting the future and understanding past experiences give a sophistication in behaviour which allows for detailed planning, profound social interaction, creation of concepts. Moreover, the creative re-purposing of concepts opens the space for more abstract uses such as imagination, creativity and the elaboration of refined emotions, beyond those required for simple survival or reproduction. The work of Lisa Feldman Barrett (How Emotions Are Made: The Secret Life of the Brain 4) is particularly consonant with Seth’s thesis.
In this regard, all the above modelling requires the production of affect, of emotion, of mood and feelings, all in order to produce suitable action. Feelings are especially functional when they are attached to critical information about the physiological state of the whole body or of immediate need, of threat from the environment, or of new opportunities presented In particular, any predicted departure from maintaining bodily safety and physiological homeostasis is critical, as this is the brain’s primary evolutionary function. The production of emotion acts as a motivation for the organism to become conscious of, and act on, sensory indications of errors in homeostatic control or inadequacies in external modelling of the world. The brain’s modelling coupled with the production of affect brings a sophistication to behaviour which is not available to simpler systems.
It is important to note that refining the brain’s generative models is not a passive process and takes place continuously. The popular belief that only 10% of the brain is routinely used is untrue, on the contrary it is fully engaged at all times, mostly in perception. And perception is continuously refined, honed and confirmed by action, if only the focussing of the eyes or the tilting of the head for better sight or hearing. All such action produces new or better perceptions and the more detailed experience achieved defines new (and refines old) concepts within the generative model.
To summarise: the detailed full colour, surround sound, sometimes scary, sometime joyful, internal movie, complete with flashbacks and emotional involvement and running commentary is our first-hand experience of the brain’s high-level summary of the predicted state of the world from its current generative model. Except of course that we now know the movie is not first-hand at all, and it is not the actual state of the world. just a (mostly brilliant) guess translated into a very effective and controlled functional hallucination.
So, Seth’s book welcomes you to your real, always second-hand, apparently first-hand experienced, apparently real but actual virtual, reality. I recommend it strongly to anyone who is wondering what this thing that they are experiencing is, and how it happens. This is one of those books that is already seminal in the area, and which will expand your mind and give you an awe-inspiring respect for the brain. It will also keep you highly entertained throughout its 276 pages.
If you only read one book on consciousness, this is the one you want. It is novel, gripping, readable and easy to follow.
And if you are someone who loves to dig deeper, the 70 pages of explanatory notes which have been included, so as to keep the main text simple, will give you further food for thought and new avenues to explore.
Bill Lockley August 2025
- Anil Seth on youtube. There are many youtube videos involving Anil Seth, here are a few: https://youtu.be/dzC4nw3HCMc, https://youtu.be/lyu7v7nWzfo, https://youtu.be/z7_LwuuPsAE
- The Experience Machine: How our Brains Predict and Shape Reality, Andy Clark, Penguin 2024 . Here is a youtube video of his ideas https://amzn.eu/d/0mHjmIm.
- The Free-energy Principle: A Unified Brain Theory’, Karl Friston, Neuroscience, 11, 127–138 (2010). Friston is a deep thinker and speaks very precisely, as a result he can be difficult to follow. It helps to understand Baysesian statistics and the science/topology of boundaries. However, his overall conclusions for how the brain models the world agree with Seth’s thesis.
- How Emotions Are Made: The Secret Life of the Brain, Lisa Feldman Barrett, Mariner Books, 2017, ISBN 10: 0544133315 / ISBN 13: 9780544133310. Here is a youtube talk. She has made many others on aspects of affect. https://youtu.be/KliAI9umFyY
I find this article fascinating and convincing. To me it helps explain how people in the same spot can see such different versions of reality. And how hard we have to work to understand what other people are actually experiencing and maybe trying to communicate.
I see Seth’s theory as a plausible physical and evolutionary explanation of human consciousness. Personally I see human consciousness as operating on more than one level: so for example a lot of our subjective experience will be one of internal conflicts, maybe wanting something but being aware that our brain or our conscience is telling us that it’s a bad idea!
And then there is the issue of our feelings and instincts – which no doubt have an evolutionary origin. But they give us a constant bitter-sweet feedback on our situation, which we surf while attempting to be rational and sensible.
I accept that there will one day be a full scientific understanding of the mechanics of consciousness. But at the same time the quality of the subjective feeling in each different person may not be quantifiable.
And also that our human feelings – made up of the instincts inherited in our DNA and the whole of our lived experience – may be a truer guide to our value choices than any single theory adopted by our rational intelligence. Though the two will interact.
Without being a philosopher, it seems to me that some “idealist ideas”, such as a notion of justice or beauty or goodness or infinity, may be useful ways of understanding our subjective worlds – the nature of “the films we project.” They are simply not applicable to the objective external world explored by science.
Where apparent conflict occurs is when our subjective narratives – of say a creation myth, or a heroic figure seen as in some way divine or a source of meaning or love in our lives – stories that are essentially metaphors for human experience – are taken to be factual history which contradicts the scientific explanations that we now base our lives around.
I greatly enjoyed this resume, but would like to pick up on one point.
Bill Lockley offers us:
*’Nowadays, Wittgenstein might well have asked Chalmers and Nagel “What would it look/feel like if atoms, neurons and chemicals in the brain manufactured first-person subjective experience”. The answer of course is that it would feel exactly as it does. Viewed in this light, the “Hard Problem” may reflect more a lack of knowledge and failure of imagination that a serious query.’
This seems persuasive at first site, together with a complementary dig towards those who still consider the Hard Problem hard.
But think further. “What would it look/feel like if the blue cheese which you ate manufactured first-person subjective experience”. The answer of course is that it would feel exactly as it does. The argument made is clearly fallacious.
In the case of the Earth/Sun example, there are only two realistic alternatives, and Wittgenstein makes the valid point that the experience is the same irrespective of which of the two possible causes are chosen. So, I suggest that this was valid logic.
In contrast, there are over 200 theories of consciousness (R.L. Kuhn – ‘A Landscape of Consciousness: Toward a Taxonomy of Explanations and Implications’). I am not suggesting for an instant that any of these are correct or even have merit – though of course they may have. The point I am trying to make is that any one of them could be inserted into the statement above (*), and the ‘what it would feel like’ under consideration would still feel exactly the same!
The comparison above (*) gives no clue as to how one’s brain may in fact create 1st person experience. The challenge may include a concern as to how the physical brain may create an experience which on the face of it has no mass, extension or measurable aspect (assuming we exclude neural correlates, which I do, since correlates are not experiences).
So I submit that the question as posed above (*) leaves the hard problem of consciousness irredeemably intact.
I think Human Consciousness is not so much the Hard Problem as the Interesting Problem.
Today I was in a shared meeting for worship with Quakers and Muslims. I enjoy the chaotic silence in my head at a Friends’s meeting. I occasionally speak.
I was thinking how all humans share a distinctive moral self-awareness, which used to be called the soul. And we intuit it in other people, the quality of their inner life, when we sit with them in silence. Maybe more than when we are rabbiting on.
It struck me that Science has given us a good answer to WHY we have consciousness and HOW it operates. But it doesn’t, I think, tell us WHAT it is, subjectively, to the person who experiences and lives it.
I think that the fact that humans share a soul, driven by the same kind of conflicting moral feelings, might offer hope for international co-operation, beyond the barriers of the obsolete creeds and dogmas of literalist religion and ideologies.