I’ve been fascinated by the lateralization of the brain for a while. Its division into left and right halves, each with its own specialities in the construction of consciousness, is an intriguing underpinning to reality, both reflecting and feeding so many potent dualisms. I recall following exercizes in Betty Edwards’ classic Drawing on the Right Side of the Brain as extra-curricular art practice at school. A decade ago I read Chris McManus’ fascinating Right Hand, Left Hand, a more general study of lateralization that traces the dominance of right-handedness to factors such as asymmetry in embryonic cell growth. McGilchrist’s book is a recent, authoritative, and generally accessible summary of the current state of neuroscience with regard to brain lateralization, supplemented by a provocative reading of the history of Western culture in light of this research.

The book begins with lashings of caveats about the shortcomings of the popular understanding of this topic, based as it is on early speculations and the inevitable distortions in the mass diffusion of ideas. For myself, I found this a little odd, as the conclusions of the book about the division of psychic labour between the brain’s hemispheres seem actually to confirm much of what I’ve absorbed from the popular literature. Of course there are important subtleties at work that belie the generalizations—but we can take for granted the relative lack of subtleties in the “takeaway” version of knowledge, the residue that you carry with you day-to-day after finishing hefty books. I guess it depends where you’re coming from. Until relatively recently, the scientific consensus was that the left brain—traditionally the locus of language, rationality, and linear thought—was the “dominant” hemisphere. However, for most of my life I’ve swum in cultural waters where this supposed dominance is, first of all, a reflection of the bias of Western civilization towards linear thinking, and secondly, irrelevant in the face of the right brain’s importance in the juicier non-linear facets of life. McGilchrist’s caveats about the popular knowledge one brings to the book perhaps apply more to those coming from a “scientific” perspective. While he is ever-cautious to not dismiss the importance of the linear left brain in the functioning of consciousness, his arguments heavily champion the holistic right brain. It is the right that is the “master” of the book’s title; the left is the incredibly useful but—in healthy functioning—subservient partner. McGilchrist argues that the left’s visible dominance in Western culture is, ultimately, a historical pathology. Given this, the opening caveats about simplification seem to serve a dual purpose. On the one hand, they are necessary reminders that nothing is genuinely simple—not least when it comes to consciousness and history. On the other hand, they seem to be placatory offerings to readers wary of vulgar prioritizing of the “creative” right brain—a lulling of pedantry before the evidence for the right brain’s actual priority is unfurled.

McGilchrist’s starting point for left/right differences is attention. There’s a little evolutionary vignette that seems to sum things up: a bird that must direct focused, narrow attention on the grain it’s trying to pick out from grit on the floor, but which must also keep a more diffuse, alert eye on the surroundings to watch for predators. Evidence suggests that the split in brain function may owe something to the necessity of maintaining these two very different forms of attention. One can extend this distinction in attention to some of the functional ramifications of brain lateralization. The left brain (focused, narrow attention) attends to manipulating things in the world, using tools and so forth. The right brain (holistic attention prepared for novel occurrences) is more attuned to absorbing the world as it is, not as it has been mapped in order to utilize it.

The first half of this book comprehensively documents the scientific evidence for splits in function such as this between the hemispheres. Certainly McGilchrist makes clear all of the exceptions, subtleties and remaining mysteries in this field. For instance, the role of the front and rear brain areas, and the curious slight twist in cerebral structure (known as the Yakovlevian torque), complexify the left/right dichotomy. But a picture of lateralization emerges from the evidence that is striking enough for McGilchrist to attempt, in the second half of the book, a reading of the history of Western civilization filtered through this image of brain function. This reading is, like the exposition of the neuroscience, amply furnished with nuances and exceptions. But it also hits a good balance between this and the simplicity necessary for accessibility. McGilchrist does not want to throw the modern world away and start again; but he is clear that its unfolding has seen an excessive usurping of power by the left brain. The emissary has overthrown the master. Narrow self-interest, a mechanistic world-view conditioned by a preponderance of tools and artifice, and a dominance of quantitative as opposed to qualitative values; these are the legacies of this coup.

In the construction of this story, many crucial issues arise. For a start, there is the contentious role of “grand narratives”. Postmodern critics attacked the totalizing stories that Western civilization told itself (and subjected others to), aiming to replace them with a diverse array of particular stories. There is a brain lateralization angle on this, in that the left brain is adept at generalizing and abstracting, but the right brain forms our direct interface with the concrete particulars of the embodied world. So in one respect, McGilchrist is guilty of that which he critiques. In constructing a large-scale history—which can only involve many broad generalizations—he is obscuring the intricacies of the living flow of human diversity.

However, it is surely important to note that experiments with people with damage to either the left or right hemisphere clearly demonstrate that the appreciation of narrative—and thus, surely, history, when considered as a roughly coherent story—is a right-brain skill:

In fact virtually all aspects of the appreciation of time, in the sense of something lived through, with a past, present and future, are dependent on the right hemisphere … [T]he understanding of narrative is a right-hemisphere skill; the left hemisphere cannot follow a narrative. (p. 76)

McGilchrist includes some basic but finely crafted thoughts on the self-reflexive problems of studying consciousness and the brain. Since such study is necessarily a product of consciousness, can we ever expect this product to comprehend that which produced it? But while this tricky issue is brought forward to moderate its impact on the neuroscience half of the book, little seems to be made of the relevance to the second half of how the brain processes history. McGilchrist sees modernism in art and literature as demonstrating the ascendancy of the left-brain view of the world, and mentions the dissolution of coherent narrative as a particular instance of this. (His analysis here owes much to the important work of Louis Sass, who argued that schizophrenia, rather than being the eruption of unwieldly irrational forces in the psyche—as the common view holds—is actually a pathological excess of rationality, a disease of alienation from the body. That is, a right-brain deficiency.) Thus, for McGilchrist, the postmodern resistance to “grand narratives” would surely be as much to do with this schizoid left-brain excess as it would be to do with the obvious necessity of challenging Western civilization’s totalizing self-mythology.

Such large-scale readings of history as McGilchrist attempts seem to tread precisely in the liminal zone where a delicate balancing of left- and right-brained thinking is necessary. Completely abandoning “history as story” does seem to be a capitulation to the left brain’s fragmentation of narrative. However, the specificity involved in this fragmentation, the lack of appreciation for the whole, is not the only kind of specificity. Histories that deal with particular events or periods, eschewing any wider narrative context, are not purely “left-brained”. Grappling with the concrete details of historical circumstance, the lived realities of everday lives in all their complexity, is an emphatically right-brained endeavour. Thus it seems that these two approaches to history—the wide-angle “grand narrative”, and the more focused “case study”—both involve right-left collaboration. The former involves the right’s appreciation for narrative wholes, and the left’s abstract generalizing; the latter involves the right’s attention to concrete specifics, and the left’s isolation of incidents from the wider narrative context.

In the end, such a historical survey is a tool, allying it strongly with the left brain’s important affinity for tools and human artifice. But McGilchrist’s argument is against the dominance of artifice and utilitarian thinking—not against tools and fabricated environments themselves. As he admits at the end of the book, much of his argument may well only really function at the level of metaphor—but metaphor, a particular skill of the right brain, is fundamental to our reality. His historical reading must be handled properly, without the literalism and lack of narrative feeling that left-brain dominance brings.

One criticism inevitably levelled at this book’s history is its focus on “the West”. The defence that this is a bias admitted to in the very title, and that the history of the West is the only history the author is qualified to deal with, is not conclusive, but I think it carries weight nevertheless. Some relevant aspects of Oriental cultures are dealt with, but generally this is a view onto the well-established grounds of Western civilization: from ancient Greece to modern Europe. Now, while I appreciate the limits that the author of a book on such a broad topic must assign, for myself I found the almost total lack of attention to precivilized cultures a grave flaw. In a single-paragraph preamble to Greece, it is noted that there are virtually no depictions of human faces in prehistoric art. The agricultural world before Plato is smudged together with the extensive millennia of hunter-gatherer life, into a realm in which, it is implicitly suggested, the right brain (which is crucial for “reading” faces and their emotional expressiveness) is underdeveloped. Perhaps the ethnography which would confirm or deny this link between lack of artistic representation of faces and a deficit in actually appreciating faces doesn’t exist. However, I find it hard to believe that hunter-gatherers, whose delicately balanced social egalitarianism relies on constant negotiation, bickering, gossip, and other personal interactions, might be deficient in right-brain skills such as facial literacy. This in turn makes me wonder exactly how close the coupling between cultural artifacts and actual psychology and behaviour is—a general point that is perhaps a necessary qualification to such surveys as this, which chart cultural consciousness via cultural products.

In the end, again, it becomes an issue of wielding this tool that McGilchrist presents us with, this map of history, in the proper way. Held tightly, and approached as if it is expected to be used to the exclusion of all other tools, it is a blunt, inelegant thing. Held lightly, and applied with the grace that reasoned, flexible metaphorical consciousness supplies, it seems to be incredibly useful.

Critiques of the over-rational modern West are far from new. But in the present world, dominated to a grotesque degree by capitalist geeks whose profoundly abstract instruments seem to be some pinnacle of left-brain tyranny, such critiques seem more necessary than ever. Indeed, a list of traits characterizing the left brain—abstracted, unrealistically confident, focused on manipulation and power, disconnected from lived realities, narrowly self-interested—when set next to the financial world that currently dominates the planet, make this book’s diagnosis of left-brain excess uncannily believable. McGilchrist’s work strikes me as a hugely important contribution to the left brain’s gradual awakening to its proper place in the world. Along with Sass’s perception of schizophrenia as a disease of rationality, Antonio Damasio’s work showing the importance of emotions in all cognition, and Lakoff & Johnson’s work on the fundamental nature of metaphor, it helps chart modern science’s discovery that the doctrines about the superiority of rational thought that it built up during its complex formative years are deeply flawed, and are playing an ongoing role in the troubles afflicting our world.