In A World Appears: A Journey into Consciousness, Michael Pollan horrifyingly reminds us that four decades ago infants were operated on without anaesthesia, because they were thought to lack consciousness. Now consciousness is all the rage. Few eyebrows were raised in 2024 when a convocation of scientists declared that every vertebrate and even some invertebrates may well have it. Pollan himself is inclined to grant a form of sentience to plants. Machines are next in line. One Google engineer claimed in 2022, albeit implausibly, that one of the company’s AIs was already showing signs of sentience.
In addition to his influential books about food and plants, Pollan has written about psychedelic drugs, which are what sparked his interest in awareness. Feeding chemicals to his brain made him wonder what consciousness is, and even to question whether it arises from the brain in scientifically explicable ways. In search of answers, he has interrogated neuroscientists, philosophers, psychologists and other thinkers, many of whom have, like him, practiced meditation or experimented with hallucinogens. It’s a rewarding tour, thanks to Pollan’s acute intellectual curiosity, though he does rather wander off into happy land in the end.
He begins with a wager laid in 1998 between the neuroscientist, Christof Koch, who bet that the neural basis of consciousness would be found within 25 years, and the philosopher, David Chalmers, who countered that it would not. Koch conceded to Chalmers in 2023 when a set of experiments designed to adjudicate between two rival theories of the brain failed to deliver a conclusive verdict.
Yet even if the mechanisms of mental life had been identified, and Koch had won the bet, this would not have satisfied Pollan, who is troubled by a supposedly deeper puzzle about consciousness known as “the hard problem”. Chalmers coined the term, which has been adopted by many philosophers and scientists and was used by Tom Stoppard as the title of one of his last plays.
According to Chalmers, there are some questions about consciousness that science knows roughly how to address even if it has not yet come up with answers to them. These relatively easy problems include, in Pollan’s words, “figuring out the workings of mental operations like learning, memory, discrimination, and perception”. The “hard problem”, on the other hand, is said to be one that scientists have no clue how to handle. It was originally stated by Chalmers as: “Why is all this processing accompanied by an experienced inner life?” That is, why do learning, perception and the like not go on “in the dark”, with no subjective awareness on the part of the learner or perceiver? The hard problem is also often stated in a rather different way, by Pollan and others, as “the problem of explaining how to connect the operations of the brain to the felt fact of first-person experience”. A recurring motif in Pollan’s book is the idea that subjective inner experience is beyond the reach of what he calls “third-person” (ie, objective) science. Enlightenment on this topic must instead somehow come from within.
Even plants have a form of inner life, according to some of the biologists Pollan talks to. One regards them as “in a sense, these locked-in syndrome patients that somehow cannot flag that they are mentally alive”. Experiments described by Pollan suggest that plants do indeed have a sort of sentience, since they seem able to learn, form memories, send signals to other plants, change their behaviour in response to such signals and even cooperate with plants that they recognise as related to themselves. As an eater who advocates a diet of mostly plants, Pollan is briefly troubled by the thought that his meals may feel pain. Might the scent of freshly mowed grass, he wonders, be “the chemical equivalent of a scream”? An Italian plant biologist reassures him that they do not feel “pain in the sense we understand it”.
Greenery has only an elemental or precursor form of consciousness, Pollan reckons, but it is one worth studying, because it might help explain how the full-blown human sort managed to evolve. And then why stop at plants? Michael Levin, a biologist at Tufts University in Massachusetts, tells Pollan that some varieties of cognition and purposeful problem-solving emerged in evolution long before animals and possibly before plants. Even viruses, Levin believes, might exhibit a form of intelligence. Be that as it may, Levin’s experiments vividly dislodge some assumptions about the physiological underpinnings of intelligent behaviour. For example, he taught a simple task to a planarian – a flatworm that can regenerate body parts – and then chopped off its head. After it regrew its simple brain, the worm somehow remembered what it had learned. (Do not, as they say, try this at home.)
Levin avoids the term “consciousness” when describing his work, according to Pollan, since he’s sceptical of the idea that objective science can come up with satisfactory theories about it. This is because “it’s never going to tell us what it is actually like to be inside the head of another being”. That is an odd demand to make of any sort of science. Why would one need or expect a science of consciousness to tell us what it feels like to be inside someone’s head, when we are already familiar with this feeling from our own case? Perhaps the question of what it is like to be conscious is not too hard for science but too easy for it.
Three centuries ago, the philosopher Leibniz tried to imagine what it would be like to walk around inside a thinking machine. He was performing a thought experiment aimed at undermining the idea that mental activity could be explained mechanically:
If we imagine that there is a machine whose structure makes it think, sense and have perceptions, we could conceive it enlarged… so that we could enter into it, as one enters into a mill… When inspecting its interior, we will only find parts that push one another, and we will never find anything to explain a perception.
Metaphors for the brain have typically reflected whatever is the most hyped technology of the day, as Pollan notes. For Leibniz in the early 18th century, that was clockwork and hydraulic machines. Now it is digital devices. Pretending that brains are computers, and that our mental life is a form of information processing, is “metaphor parading as fact”, as Pollan puts it.
Some artificial-intelligence researchers tell Pollan that it would be prudent to try to create an AI that was conscious and had feelings, as the alternative would be a pitiless superintelligence who might have no qualms about wiping us out. Yet that would be a risky strategy, as Pollan observes. In Mary Shelley’s novel, it was, after all, the possession of feelings that made Frankenstein’s monster so dangerous: “misery made a fiend”, the creature tells his creator. Although Pollan is sceptical of the boosterish faith that conscious forms of artificial intelligence are just around the corner, he notes that a simulation can more or less become reality when “we settle for it”. That is, we might choose to treat an impoverished simulacrum of awareness as if it were the real thing, just as we have chosen to simplify our expressions of feeling with emoji, and to act as if we were the appendages of our smartphones.
One American researcher who pondered what it might take to engineer feelings into a machine had a change of heart after ingesting a psychedelic derived from toad poison. The experience of falling out of time and realising that the world is love made him think that there is “more to consciousness than I can hope to build with my dinky little machine”. Or so he tells Pollan, who concludes that there may be less to be learned about consciousness from trying to build artificial versions of it than there is to be found by exploring it from within.
For this Pollan turns to stream-of-consciousness novelists, from James Joyce’s Ulysses to Lucy Ellmann’s Ducks, Newburyport, with its stupendously long sentences, and to the vibrant descriptions of inner life in William James’s Principles of Psychology, among others. One long-running research project, in which Pollan takes part, generates random snapshots of inner life by prompting subjects to jot down what they are thinking whenever a beeper goes off. This methodical fishing in the stream of consciousness lands some intriguing results. According to Russell Hurlburt of the University of Nevada, who runs the study, inner speech seems to be relatively rare, even though most people believe that they do their thinking in words. Another psychologist, at the University of British Columbia, objects that such studies are tainted by the biases and preconceptions of investigators, and contends that psychedelic mushrooms are “the only legitimate teacher when it comes to capturing inner experience”. This seems to overlook the possibility that the mushrooms have, as it were, an agenda of their own.
The use of psychedelics leads to a state of “complete egolessness”, Pollans reports. Listening to some Bach after a dose of psilocybin, he dissolved into the music and has been “less tightly yoked” to his ego ever since. This poses a puzzle in his mind: if subjective experience is what makes consciousness an intractable topic for objective science, what is one to make of states of consciousness in which there seem to be no subject or ego? Towards the end of his journey, Pollan is not sure what to think, and even ponders the possibility that it is consciousness and not matter which is the fundamental stuff of the universe. This desperate gambit makes the mind less of a lonely outlier in the physical world, but only by rendering the whole universe more mysterious.
A closing coda finds Pollan in a spartan cave on a Zen retreat near Santa Fe, chopping wood and meditating for hours. He becomes “fully, freshly present to the universe” and thus acquires, as he puts it, a different way to look at consciousness – not as a scientific or philosophical problem to be solved, but “more as a practice, a way to once again be altogether here”. But how does he know that he is already “fully” present to the universe? Perhaps there is more enlightenment yet to come. It’s an unsatisfying anticlimax of an ending, not because Pollan fails to explain consciousness, but because he mystically withdraws into an inner landscape, leaving his readers behind.
A World Appears: A Journey into Consciousness
Michael Pollan
Allen Lane, 320pp, £25
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[Further reading: How we became obsessed with the human face]
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This article appears in the 04 Mar 2026 issue of the New Statesman, Trump's global terror
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