In a crowded field, consciousness has a strong claim to being the strangest thing in the universe. The feeling of being aware is the most fundamental and familiar aspect of anyone’s existence: you can know, with rock-solid certainty, that you’re conscious right now, even if literally all else might be a hallucination brought on by mind-altering drugs. Yet it’s widely held that science has no clue how the spongy physical stuff of your brain could produce something as radically non-physical as your mind. Attempting to solve this puzzle leads respectable scholars to surprising places – for example, to the baffling claim that consciousness is an illusion (even though consciousness is the very thing that experiences illusions); or that everything in the world – sofas and table lamps included – might in some rudimentary sense be conscious.
Entangled with the mystery of how consciousness happens is another: why is it there at all? It’s unclear why evolution bothered to make it feel like something to be you, given that, to paraphrase the philosopher David Chalmers, it seems feasible to imagine a “zombie” version of yourself who could complete your daily to-do list just as successfully, but with no inner experience, only darkness inside. When I accidentally plunge my hand into boiling water, what matters is that my brain and limbs are wired up so as to get my hand out as fast as possible, a straightforward engineering challenge. The fact that I also have an experience of hotness seems like an extravagant metaphysical extra, a flourish of nature that would be inexplicable even if we knew how it worked. Which, as mentioned, we don’t.
Nobody bewitched by these mysteries can afford to ignore the solution proposed by Mark Solms in The Hidden Spring. The chair of neuropsychology at the University of Cape Town, Solms’s hard-science credentials are impeccable, but he is not among those neuroscientists who seem untroubled by the enigma of first-person experience, glibly confident that more lab work will clear things up in the end. On the contrary, he interrupted his work on the brain, and risked his reputation, to train as a psychoanalyst, attracted by the Freudian refusal to treat individual subjective experience as inferior to standard scientific data. The subject is personal, too: the book opens with a childhood memory of the day his older brother fell from a three-storey building, sustaining lasting brain damage. Afterwards, he writes, “it felt as if Lee were simultaneously there but not there … If Lee’s mind was somehow reducible to a bodily organ, then, surely, mine was too. This meant that I – my sentient being – would exist only for a relatively short period of time. Then I would disappear.”
One starting point for Solms’s “journey to the source of consciousness” is that we speak too loosely when we ask how the brain produces it, as a chocolate factory produces chocolate bars. Instead, we need to remember that the brain in the scanner and the experience of awareness are two different perspectives – the third-person viewpoint and the first-person viewpoint – on one and the same thing. So the puzzle is why it feels like something to take the first-person viewpoint of a human brain, when the first-person viewpoint of a mountain or a filing cabinet feels (presumably) like nothing at all.
The book’s most arresting claim is that the answer is to be found not in brain functions such as visual perception or hearing, the usual focus of inquiries into consciousness, but in feelings. On close inspection, feelings, including emotions, don’t seem to be susceptible to Chalmers’s zombie objection. It’s easy enough to imagine a mindless version of me that could detect the presence of a red apple without literally seeing redness. But the idea of a zombie being scared or happy or regretful without feeling scared or happy or regretful makes no sense. “If you do not feel something, it is not a feeling,” Solms notes. Emotions are intrinsically conscious in a way that sensory perceptions aren’t. Using poignant case studies of neurology patients – including children born with brain damage, yet plainly still capable of sadness and joy – he argues persuasively that consciousness ultimately arises not in the cortex, the seat of advanced intelligence, but in the more primitive brainstem, where basic emotions begin.
This shift of focus also promises to resolve another oddity of the way consciousness tends to be discussed, which is that the specific details of what we experience can seem curiously irrelevant. The “problem of inverted qualia” refers to the fact that the experience you call “seeing green” could be identical to the one I call “seeing red”, and vice versa, and we’d never have any way of knowing. We’d both still stop and go at the same traffic lights, despite experiencing them in opposite ways to each other. By contrast, the specific content of a feeling matters greatly: if you feel lust where I feel disgust, we might react very differently when meeting Nigel Farage in public. Taking emotions seriously means taking seriously how it really feels to be human, instead of reducing experience to a soulless sequence of perceptions of traffic lights and apples.
Solms’s challenge, then, is to show that emotions are essential to humanity’s material existence: that a zombie couldn’t be wired so as to mindlessly handle all the crucial tasks our emotions let us navigate. This he attempts in the book’s densest chapters, an uphill climb from the free energy principle in neuroscience, via advanced information theory, to the role of the cortex in the generation of memory, featuring many phrases such as “we can now formalise a self-evidencing system’s dynamics in relation to precision optimisation”. To the best of my understanding, the gist is that feelings are a uniquely effective and efficient way for humans to monitor their countless changing biological needs, in extremely unpredictable environments, to set priorities for action and make the best choices so as to remain within various bounds – of hunger, cold and heat, physical danger, social isolation, etc – outside of which we can’t survive for long. Doing all that without feelings, and doing it as rapidly as survival requires, would take so many computational resources that it would lead to a “combinatorial explosion”, demanding levels of energy a human could never muster.
So, feelings are necessarily conscious; and feelings are essential to human survival; so when you take the first-person perspective of a human system – in other words, you or me, inside our own heads – it makes sense that it would feel conscious to be there. Has the riddle of consciousness thereby been solved? “I must admit to a residue of discomfort,” Solms writes, with admirable candour. Me too. What still baffles me is the very idea of first- and third-person perspectives. What on earth is a point of view, scientifically speaking, and what place does it occupy in reality? What makes me able to take a first-person view of my own brain, but not of a filing cabinet – and isn’t that, in some sense, the remaining conundrum of consciousness?
But perhaps this is to say no more than that this fascinating, wide-ranging and heartfelt book does not succeed in dumping cold explanatory water on every last mystery of human existence. And I confess I would be lying if I said I thought that was a bad thing.
• The Hidden Spring: A Journey to the Source of Consciousness is published by Profile. To order a copy go to guardianbookshop.com. Delivery charges may apply.