Nicholas Humphrey is a veteran of consciousness. In the 1980s he became well known as one of the originators of the “social” theory of consciousness which suggested that it evolved in the service of “Machiavellian intelligence”: my consciousness gives me potentially valuable insight into the workings of your mind — valuable, that is, if I wish to manipulate your thoughts and behaviour. In the 1990s Humphrey had a sceptical dalliance with parapsychology, the science of the disembodied mind. In recent years he has written a series of books on the same central question: what sense can we make of the emergence of mind — especially sensation — from the matter of our brains? His new book is a beautifully written and highly original essay on the problem which he now claims to have solved.
Explaining his solution requires some scene setting. Humphrey wears his learning lightly, but Soul Dust (Quercus, £25) gently introduces the reader to many of the dominant scientific and philosophical ideas about consciousness. Scientifically, Humphrey follows the American neurologist Antonio Damasio in drawing a distinction between “core” and “extended” consciousness. Core consciousness is the kind that it seems likely we share with many animals, the awareness of a “thick moment” of subjective time in which we experience complex sensations ranging from the anguish of hunger to the exhilaration of intensity. (Humphrey gives some lovely examples of animals enjoying intense experiences for the own sake, such as “whirlwind riding” in birds.) Extended consciousness is the more specifically human variety that allows us, for example, to travel mentally into our personal past, imagine the future or share ideas, like those I am describing now.
But core consciousness is the primal and primary kind. Humphrey builds on his previous work by describing its origins in the brain. He suggests, like Douglas Hofstadter, that it depends on “strange loops”, by which we have come to internalise processes that originally allowed our very early ancestors to act on the world: the idea that multiple “re-entrant”, looping, pathways in the brain play a key role in perception is indeed widespread in neuroscience, and there is plenty of evidence that they exist.
In his philosophical vein, Humphrey accepts that the “problem of consciousness” looks hard — perhaps, indeed, impossible. When we peek inside the brain we see only “pieces which push against one another and never anything by which to explain perception”, as Leibniz put it. However much we learn about it, however willing we are to heed the scientists, most of us have a deep intuition that “we are also other”. Showing how “the water of the brain gives rise to the wine of experience”, how object gives rise to subject, is like showing that 2 + 2 = 5.
This disconnect is highly topical: research by psychologists and anthropologists alike suggests that we humans may all be “natural Cartesians”, with a deeply ingrained belief in the separateness of invisible mind from visible body. But beliefs, however widespread and compelling, can be false. Child psychologists have established that between the ages of three and five we acquire a “theory of mind” that helps us to appreciate that others have their own perspectives, beliefs and reasons for action. The theory is undoubtedly useful to us in our social lives, helping us to make sense of each other’s behaviour, but perhaps its main term, the mind, is a misleading construct. This thought points the way to one possible solution of the problem of consciousness: to recognise that we may be trying to find a natural, scientific, explanation for a supernatural, imaginary, entity. Such an effort is surely doomed to fail. This is Humphrey’s line of attack. He deploys several beguiling, and sometimes questionable, tactics as he advances, but he is absolutely right to reintroduce the concept of the soul to contemporary discussion of consciousness. This elusive entity still haunts the science — and scientists — of the mind.
The first section of the book asks what consciousness is. Humphrey’s answer is that, au fond, it is an illusion: “a magic show that you stage for yourself inside your own head” — on the basis of those looping loops that circle in our brains. I had some difficulties here. With an illusion like this, who needs consciousness? The subjective qualities of the “magic show” look as if they require about as much explanation as the experiences we thought we were having in the first place. Second, Humphrey rests his case partly on an analysis of a phrase that has been much used in discussion of consciousness since Thomas Nagel’s famous essay, “What is it like to be a bat?” Humphrey argues when we apply this phrase to our experience — saying that it is always “like something” to be conscious — we imply that our experience somehow gives us evidence of another world: “from the subject’s point of view, consciousness appears to be a gateway to a world of as-if entities”. Sometimes it probably does — but when I say that the air I breathe on this spring day is like champagne I seem to be saying something much simpler: there is something, not nothing, my experience is like — i.e. champagne — and that’s extremely welcome!
At the heart of the book, Humphrey asks what consciousness is for. He gives a delightfully unexpected, teleological, answer, finding its explanation in the “selective advantage” it confers, its contribution to our biological fitness. But whereas most recent theorists have sought to identify skills which are somehow honed by consciousness, Humphrey regards it as essentially “encouraging” rather than “enabling”: it evolved, he argues to make life worth living. He suggests that this evolutionary step occurred 300 million years ago, in the primitive reptiles who are our ancestors, allowing them to receive the evolutionary benefits of possessing a core self and relishing “the enchanted world” that only such a self can inhabit.
Over the course of evolution, most spectacularly in our species, the core self “that feels and does” gave rise to the extended one that “thinks, perceives, remembers, dreams, desires — a veritable factory […] whose product is a whole person with a life history”. This extended self, as we born dualists experience and conceive it, appears to have miraculous properties: inscrutable privacy, radical freedom, and the capacity to create the sensory world. Reflection on these properties, in the light of our agonising knowledge of the body’s inevitable death, gives rise, in Humphrey’s view, to the concept of the soul — immaterial, autonomous, persistent, death-defying.
If consciousness evolved to make life worth living, its success is qualified: while there are surely times when we relish existence, human experience is rife with counter-examples. Humphrey would respond that consciousness succeeds in this respect just as well as it needs to: natural selection asks for nothing more, and indeed his explanation for the widespread belief in the soul turns on our fear of death.
Humphrey’s proposed solution to the deep question of how our bodies and brains beget our minds is bound to meet with scepticism. He is right to focus on the notion of the soul, and to emphasise the degree to which we humans are “connoisseurs of consciousness”. If he fails to dispel the mystery of the mind entirely, it is partly because he succeeds so well in evoking it. Soul Dust is an Ode to Being. This may be the least we should expect, but few consciousness enthusiasts have succeeded so well.