I own a copy of The Master and His Emissary by Iain McGilchrist with its original subtitle: The Divided Brain and the Making of the Modern World. This grandiose phrasing was quietly altered in subsequent editions to the slightly less grandiose The Divided Brain and the Making of the Western World. This subtle retreat — hardly acknowledged by the publisher or author — speaks volumes. It suggests that the book’s sweeping claims about the psychological trajectory of humanity were quickly met with skepticism and that McGilchrist or his editors felt compelled to narrow the scope. Yet this gesture, however symbolic, does little to correct the book’s underlying problem: it is a house of sand, erected on the foundations of outdated neuroscience, historical romanticism, and untestable generalizations.
Far from being a bold synthesis of neuroscience and philosophy, The Master and His Emissary is a cautionary tale about what happens when metaphor is mistaken for mechanism, when analogy is dressed up as evidence, and when pseudo-intellectuals, desperate for meaning, embrace grand narratives that flatter their discontents but fail to withstand rigorous scrutiny.
The Core Premise: A Neurological Just-So Story
McGilchrist’s central claim is deceptively simple: the two hemispheres of the brain represent not just different functions, but different ways of being. The right hemisphere is described as holistic, embodied, relational, and open to ambiguity; the left hemisphere is focused, analytical, mechanistic, and obsessed with abstraction. McGilchrist casts this duality as a historical drama: the right hemisphere — the “Master” — once governed, wisely and intuitively, but the “Emissary” — the left hemisphere — has overthrown it, imposing a sterile, reductionist regime on modern civilization. The resulting imbalance, he argues, is responsible for everything from the bureaucratization of life to the alienation of modern man.
It is a romantic and tragic vision. But it is also scientifically baseless.
As neuroscientist and psychologist Chris McManus noted in his review, McGilchrist relies heavily on clinical cases of brain damage and split-brain studies that are not generalizable to normal cognition. The fact that certain language functions or motor skills may be lateralized does not mean that entire ways of seeing the world are encoded in one hemisphere or the other. The brain is an integrated system, with extensive communication across hemispheres via the corpus callosum and other commissures. No credible neuroscientific model supports McGilchrist’s idea of one hemisphere “dominating” the other in the sense he implies.
(When neuroscientists speak of a “dominant” left hemisphere, the term can be misleading. It is primarily shorthand for the fact that, in most right-handed individuals, language functions are concentrated in the left hemisphere. In left-handed people, however, language is often localized in the right hemisphere or more evenly distributed across both hemispheres.)
Indeed, as Dr. Sergio Della Sala has argued, McGilchrist’s claims reflect “neuromythology” — the persistence of attractive but debunked notions, such as the idea that creativity is “right-brained” and logic is “left-brained.” These myths are beloved by corporate training seminars and pop psychology, but they are an embarrassment to contemporary neuroscience.
McGilchrist leans heavily on split-brain research, particularly from the work of Michael Gazzaniga, but misrepresents the implications. Split-brain patients are individuals with a severed corpus callosum, a past treatment for severe epilepsy prior to the development of pharmaceutical alternatives. The behaviors observed in these cases — such as one hand acting independently of the other — do not reveal a battle of hemispheric “worldviews” but instead highlight the importance of hemispheric integration in normal function. Even Gazzaniga has warned against the over-interpretation of these results. McGilchrist elevates these rare clinical curiosities into sweeping metaphors for human civilization — a leap that no serious neuroscientist would endorse.
To the extent that there is validity to any of McGilchrist’s neurological speculations, he may in fact have things exactly backwards. The psychologist Julian Jaynes presents compelling evidence that the hemispheres of the brain are more integrated in the modern era than they were in ancient times. Rather than engage with this directly, McGilchrist attempts to sidestep the challenge by distorting Jaynes’s ideas, misrepresenting them in order to dismiss them.
Evidence by Anecdote, Not Science
Despite its erudition and breadth, the book fails in the very domain it claims as its foundation: evidence. The so-called “science” McGilchrist marshals does not justify his civilizational conclusions. He often leaps from relatively narrow neurological findings — e.g., differences in attention or motor control — to sweeping historical and cultural generalizations. The mechanism of this leap is never convincingly explained, only suggested with rhetorical flourish.
McGilchrist argues, for example, that the Enlightenment, the Industrial Revolution, and the rise of bureaucracy are all signs of the left hemisphere’s encroachment. But this interpretation crumbles under scrutiny. The Enlightenment, while indeed emphasizing reason and analysis, also gave rise to human rights doctrines, the abolition of torture and slavery, and the concept of universal dignity — developments deeply connected to empathy and moral progress, not signs of emotional impoverishment. The Industrial Revolution, far from being purely mechanistic, catalyzed vast improvements in sanitation, nutrition, public health, and literacy. These changes lifted millions from grinding poverty and led to the emergence of social safety nets and labor protections. Even the rise of bureaucracy, which McGilchrist views as an oppressive artifact of analytic thought, has played a critical role in institutionalizing fairness, reducing corruption, and ensuring accountability in complex societies. Rather than evidence of spiritual decline, these developments mark the maturation of civic and ethical life.
Perhaps most egregiously, McGilchrist offers no clear causal mechanism for how hemispheric dominance could shape societies over centuries. He does not explain how neural processes in individuals aggregate to civilizational tendencies — how a structural bias in individual cognition becomes a historical force. Instead, we are treated to a grand narrative supported by cherry-picked quotes, historical trends viewed through a confirmation bias, and a reverent tone that discourages skepticism.
He simplifies entire historical epochs into hemispheric caricatures. The Renaissance is praised as a “right-hemisphere” rebirth, full of art and embodied understanding, yet ignores its rational mathematical breakthroughs, early capitalism, and statecraft. The Enlightenment is blamed for our left-brain malaise, despite being the birthplace of modern human rights, liberal democracy, and abolitionist thought. McGilchrist seems unwilling to consider that rationalism, science, and bureaucracy — traits he deplores as left-hemispheric excesses — might have also helped build the most peaceful, prosperous societies in history.
The truth is that individuals, cultures, and historical periods are far too complex to be simplistically divided into McGilchrist’s reductive binary of “left-” and “right-hemispheric” tendencies. The very premise collapses under scrutiny: a neurosurgeon may exhibit methodical precision in the operating room and then spend the weekend lost in the free-flowing creativity of watercolor painting. To reduce the richness of human behavior or the complexity of historical change to the supposed dominance of one brain hemisphere over another is not just an oversimplification; it’s intellectual sleight of hand. It ignores the profoundly integrated nature of the brain; the countless social, cultural, and historical forces that actually shape our lives; and the rich complexity both of individuals and historical eras. McGilchrist’s narrative only appears persuasive because it leans heavily on cherry-picked anecdotes and selectively curated evidence.
A False Narrative of Decline
McGilchrist’s underlying narrative is that the Western world has declined spiritually, morally, and relationally due to the “takeover” of the left hemisphere. This thesis is not just speculative; it is empirically wrong.
Enter Steven Pinker and The Better Angels of Our Nature, which marshals a vast array of data from criminal records, ethnographies, and historical documents to show a consistent decline in violence across centuries. Pinker documents, for instance, that homicide rates in medieval Europe were 20 to 100 times higher than those in modern Western Europe. He shows that practices like slavery, torture, child execution, and animal cruelty were once not only commonplace but morally accepted — while today, they are virtually unthinkable in much of the world. Pinker attributes these changes to the spread of Enlightenment values, increased literacy, formal institutions of justice, and greater reliance on abstract reasoning and cosmopolitan norms — precisely the traits McGilchrist disparages as the sterile output of a dominant left hemisphere.
While it’s true that the human species carries a legacy of genetically rooted behavioral flaws — such as aggression and violence — the long arc of history has bent toward greater safety, justice, compassion, and peace. Contrary to McGilchrist’s bleak portrayal of a spiritually diminished humanity brought on by a make-believe cognitive coup d’etat, modern Western societies in particular have seen a marked decline in cruelty and a steady expansion of moral concern:
Domestic abuse, child labor, and systemic racism were accepted realities until fairly recently.
Medieval Europe had homicide rates twenty times higher than today.
Slavery was a global norm for millennia; it is now universally condemned.
Witch trials, public executions, and torture were once commonplace.
Ignoring Contradictory Evidence
The psychological literature also contradicts McGilchrist’s narrative, and not merely in abstract terms:
- The Flynn Effect — the steady global increase in IQ scores, particularly in abstract and symbolic reasoning — undermines the notion that analytic or left-hemispheric thought has led to cognitive stagnation. Rather, it suggests a general enrichment of cognitive abilities that are supposedly dominated by the left hemisphere.
- Theory of Mind studies show that modern children in literate, media-rich environments tend to develop perspective-taking skills earlier than those in more traditional societies. This contradicts McGilchrist’s claim that modernity erodes our empathic or relational capacities — traits he attributes to the right hemisphere.
- Embodied cognition research (e.g., Lakoff & Johnson, Varela, Barsalou) emphasizes that even high-level abstract thought is grounded in bodily experience and sensorimotor processes. This directly refutes McGilchrist’s dichotomy in which modern cognition is increasingly disembodied and left-hemisphere driven.
These studies collectively point to a more integrative and enriched cognitive landscape in modern societies — precisely the opposite of the impoverishment McGilchrist warns against.
McGilchrist also fails to explain how supposedly left-hemisphere thinking has led to widespread adoption of mindfulness, somatic therapies, and systems thinking — practices that explicitly aim to reconnect body and mind, individual and context. Movements in integrative medicine, trauma therapy (e.g., somatic experiencing), and ecological ethics all exhibit precisely the kinds of holistic awareness he claims are missing.
The Appeal: Aesthetic, Not Analytical
So why has The Master and His Emissary been so successful? Not because it is right, but because it feels right. It provides a compelling myth for those disillusioned by modernity. It gives intellectual cover to anti-modern sentiments, making alienation seem not just understandable, but inevitable.
Its structure is affective, not empirical. It resonates emotionally, tapping into the modern longing for lost unity. It seems persuasive to some, because only things that fit the author’s narrative are presented, while all of the contradictory evidence is ignored. Readers likely enjoy the feeling of being let in on a vast, previously undiscovered conspiracy, centuries in the making. And it flatters readers: your discomfort with modern life is not only valid, but the result of a grand neurological betrayal.
McGilchrist’s narrative also bears the unmistakable tone of oikophobia — a disdain for one’s own culture or civilization masked as intellectual critique. His portrayal of the modern West as spiritually barren, emotionally stunted, and epistemologically broken fits neatly within a broader pattern of cultural self-rejection common among segments of the political left. Rather than acknowledging the tremendous moral and material progress achieved through Western institutions — such as liberal democracy, human rights, and scientific inquiry — McGilchrist frames these as symptoms of left-hemispheric dysfunction.
This tendency to romanticize the past and denigrate the present, to idealize pre-modern cultures while pathologizing the modern West, resonates with those who seek existential explanations for cultural unease. The greatest appeal of McGilchrist’s thesis, then, is likely not neurological or philosophical, but ideological: it flatters a particular worldview that finds virtue in repudiating its own origins.
Yet this is precisely why it must be challenged. McGilchrist’s narrative lulls readers into fatalism. It displaces systemic, political, and educational problems onto the folds of the cerebral cortex. It romanticizes pre-modern life without acknowledging the suffering and ignorance that once accompanied it.
Conclusion: The Emperor Has Two Hemispheres, But No Clothes
The Master and His Emissary is not a work of science; it is a speculative fable disguised as intellectual history. Its core thesis — that our world is in decline because the wrong hemisphere of the brain is in charge — is unsupported by credible neuroscience, contradicted by much of what we know about historical and modern societies, and propagated largely through rhetorical persuasion rather than empirical evidence.
McGilchrist’s defenders often point to the book’s breadth and literary sophistication as evidence of its merit. But eloquence is no substitute for accuracy. The book’s continued popularity is not a testament to its insight but a reflection of a deeper problem: the erosion of critical thinking skills and a high degree of gullibility, even among the educated. We live in an age where poetic rhetoric, sprinkled with neurological jargon, can be mistaken for intellectual depth. But neuroscience is not metaphor. Culture is not cortex. And civilization does not rise and fall based on which side of the brain is “in charge.”
McGilchrist’s thesis is a modern myth — compelling, to be sure, and admirably ambitious in scope, which is precisely what his supporters often highlight. They may argue that even if the neurological specifics are overstated, the metaphor still captures something meaningful about our cultural discontents. Others contend that McGilchrist is not offering a scientific thesis but a philosophical framework, one meant to inspire reflection rather than provide falsifiable hypotheses. Yet this defense conveniently blurs the line between metaphor and mechanism — between poetry and empiricism.
If McGilchrist intended his work as allegory, it should have been labeled as such. Instead, he invokes clinical studies, evolutionary theory, and neuroanatomy to claim scientific legitimacy. And once a claim purports to be grounded in neuroscience, it must be judged by scientific standards. By those standards, the book fails. It is beautifully told, but fundamentally untrue. That so many have taken it seriously is not an indictment of science or society, but of our collective longing for narratives that soothe rather than clarify, that explain rather than confront — essentially adult fairytales for disaffected pseudo-intellectuals. The Master and His Emissary is not a warning about the brain. It is a warning about our susceptibility to the kind of story it tells.