In November the RSA in London held a workshop to discuss Iain McGilchrist’s book The Master and his Emissary. The RSA has now published Divided Brain Divided World, a report of that workshop, together with a long conversation between McGilchrist and Jonathan Rowson, Director of the RSA’s Social Brain Centre.

McGilchrist’s book deals with the social, political and philosophical implications of the lateralisation of the brain, that is, its division into two hemispheres, left and right. The difference between the two hemispheres is not, McGilchrist suggests, as much pop psychology would have it, that the left hemisphere primarily processes language, and the right visual imagery and spacial representation. The difference, for McGilchrist, lies in the manner in which each hemisphere analyses the world, rather than in what it analyses.

‘For us as human beings’, McGilchirst argues, ‘there are two fundamentally opposed realities, two different modes of experience; that each is of ultimate importance in bringing about the recognizably human world; and that their difference is rooted in the bihemispheric structure of the brain’. What opposed realities or modes of existence? ‘The left-hemisphere tends to deal more with pieces of information in isolation, and the right hemisphere with the entity as a whole, the so-called Gestalt’:

The right hemisphere… is vigilant for whatever it is that exists ‘out there’, it alone can bring us something other than what we already know. The left hemisphere deals with what it knows, and therefore prioritises the expected – its process is predictive… The right hemisphere is, in other words, more capable of a frame shift…

The right hemisphere sees the whole before whatever it is gets broken up into parts in our attempt to ‘know’ it.

The right hemisphere takes whatever is said within its entire context. It is specialized in pragmatics, the art of contextual understanding of meaning, and in using metaphor… The left hemisphere, because its thinking is decontextualised, tends towards a slavish following of the internal logic of the situation, even if this is in contravention of everything experience tells us… The left hemisphere is the hemisphere of abstraction, which, as the word itself tells us, is the process of wresting things from their context… Where the left hemisphere is more concerned with abstract categories and types, the right hemisphere is more concerned with the uniqueness and individuality of each existing thing or being.

In the West, however, McGilchrist argues, the left hemisphere of the brain is gradually colonising our experience. The left hemisphere is dependant upon the right, ‘an “emissary” of the right hemisphere, valuable for taking on a role that the right hemisphere – the “Master” – cannot itself afford to undertake’. The emissary is, however, not only unaware of its dependence on the Master, but has ‘has his own will, and secretly believes himself to be superior to the Master’. And ‘he has the means to betray him. What he doesn’t realize is that in doing so he will also betray himself’.

master and emissary

A world in which the left hemisphere suppressed the right, McGilchrist argues, is one in which:

There would be a loss of the broader picture, a substitution of a more narrowly focussed, restricted but detailed view of the world, making it perhaps difficult to maintain a coherent worldview… In general the ‘bits’ of anything, the parts into which it could be disassembled, would come to seem more important, more likely to lead to knowledge and the understanding, than the whole, which would come to be seen as no more than the sum of the parts… This in turn would promote the substitution of information, and information gathering, for knowledge, which comes through experience. Knowledge, in its turn, would seem more ‘real’ than what one might call wisdom, which would seem too nebulous, something never to be grasped.

This, McGilcrist argues, ‘is what the world would look like if the emissary betrayed the Master. It’s hard to resist the conclusion that his goal is within sight’.

McGilchrist’s argument has won considerable support and praise, not least from the participants at the RSA workshop. The workshop opened, however, with a critical review of the argument from Ray Tallis. Tallis’ full talk is in the RSA document, but here is a flavour of his argument. McGilchrist’s thesis, a thesis that is ‘highly systematising, linguistic, explicit etc’ and is built upon ‘massive quantities of painstakingly acquired, precise data, 2,500 sources’, looks, Tallis suggests, ‘rather left hemisphere according to his own characterisation’. The left hemisphere, according to McGilchirst, is ‘out of touch with reality’. ‘Doesn’t this make it rather odd’, Tallis asks, ‘that he relies on the neurological data presumably gathered by that hemisphere to support his extraordinarily ambitious account of ‘reality’, a reality that encompasses the history of mankind?’

divided brain rsa

‘It may be’, Tallis suggests, ‘that my own left hemisphere has atrophied but I would hesitate’ to make the kind of ‘sweeping generalisations’ that McGilchrist does, such as ‘his assertion that ‘the left hemisphere’s purpose is to use the world. It sees everything – education, art, morality, the natural world – in terms of a utilitarian calculus only’. Similarly, Tallis argues, ‘I wouldn’t be at all certain of the truth of such massive claims as that “Far Easterners attend to the world in ways typical of both the left and right hemispheres, and draw on strategies of either hemisphere more or less equally, while we in the West are heavily skewed towards the attentive viewpoint and strategies of the left hemisphere alone”’.

Consider, Tallis asks, McGilchrist’s assertion that ‘since the Industrial Revolution we have constructed an image of the world externally that is an image of the left hemisphere internally’:

Who are ‘we’? What ‘image’ of the world (as if there were only one image and one world) are we talking about? And what would an ‘image of the left hemisphere’ be?

‘Such gigantic generalisations’, Tallis observes, ‘overlook the teaming ocean of particulars that make up our shared world, and overfly the infinite variety of the lives of billions of people and the countless cultures and micro-cultures in which they live’. Finally, Tallis asks,

From what hemisphere is [McGilchrist] able to observe the two hemispheres, pass judgement on them, and see their rivalry as the motor of the unfolding of human cultures? Does he have a third hemisphere? Or does he have something that is not a hemisphere at all? In short, is he talking from a standpoint that transcends his hemispheres?

I suspect he is; it is the standpoint from which we all speak when
we speak about pretty well everything: namely the shared, extracranial human world woven over the millennia out of a zillion human (whole person) interactions. And it is this that he seems to by-pass when he argues that the outcome of the rivalry or balance between the two hemispheres plays a major role in determining the predominant characteristics of cultures, civilisations or epochs. And I would argue that this extracranial viewpoint is the one we adopt when we comment on our own and others’ brains and cultures. This is more relevant than neural circuitry. It is the community of human minds, the human world, which has gradually built up at least over the hundreds and thousands of years, since hominids emerged.

It is here, and not in the intracranial darkness, that we should look for the motors of history, of cultural change and the evolution of civilizations. Histories, cultures, societies, institutions, have their own internal dynamic… that cannot be usefully captured in neural terms.

The irony of Tallis’ criticism is that he adopts what McGilchrist would undoubtedly label a ‘right brain’ posture. Tallis’ long-standing hostility towards what he calls ‘neuromania’ is precisely a critique of a decontextualised understanding of the human condition, and of the growing tendency to locate social, political and philosophical issues in the brain.


I have considerable sympathy with Tallis’ skepticism. (I was invited to take part in the workshop but unfortunately was unable to. I may well do a proper response in time). There are three fundamental questions we can ask of McGilchrist’s argument. First, is McGilchrist’s characterisation of brain lateralisation, and of its consequences, correct? Second, is his understanding of the social and philosophical poblems that Western societies face, and of the history of those problems, plausible? Third, if his characterisation of brain lateralisation and his understanding of the social and philosophical problems that Western societies face both make sense, does it also make sense to link the two in cause and effect terms; that is, does it make sense to view the social and philosophical problems in terms of neurological processes?

McGilchrist’s is a sophisticated account of the consequences of brain lateralisation, underpinned by a mountain of data. The trouble is, there is considerable cherry-picking and idiosyncrasy in the presentation of that data. As Owen Flanagan, professor of philosophy and neurobiology at Duke University, put it in a review in New Scientist, ‘McGilchrist promises to avoid glib pop theorising about right-brain/left-brain dichotomies… But the expressed caution is all pretence.’ In truth, Flanagan pointed out, ‘Hemispheric differences are not well understood’ and certainly not well enough to make the kinds of claims that McGilchrist does. For instance, McGilchrist insists that ‘The left’s hemisphere’s world is ultimately narcissistic’. It is ‘driven forward by a desire for power and control’. It has a tendency for ‘dangerously unwarranted optimism’. It ‘sees itself as the passive victim of whatever it is not conscious of having willed’. It ‘misunderstands altruism as a version of self-interest’ and sees it as ‘a threat to its power’. The left hemisphere ‘must conceive of society as an aggregate of individuals, seen as equal, but inert, units. The right hemisphere alone can understand that individuals are unique and reciprocally bound in a network, based on a host of things that could never be rationalised, creating something much greater than the sum of its parts, a society’. The left hemisphere is responsible for ‘the destruction and despoliation of the natural world and the erosion of established cultures’. It has ‘set about neutralising or neutering the power of art’. The left hemisphere, whose ‘version of liberty is a mere concept, not the freedom which can be experienced only through belonging’ was apparently responsible for ‘the mayhem and carnage of the French Revolution’. Democracy, as the American Revolutionaries saw it, on the other hand, which apparently was ‘essentially local, agrarian, communitarian, organic’ was ‘in harmony with the ideals of the right hemisphere’. And so on. After a while one almost begins to pine for the days in which the left hemisphere was merely ‘logical’, the right ‘creative’.


I have some sympathy with McGilchrist’s claim that there is a growing tendency to decontextualise knowledge, to think of the parts as more important than the whole, which is often regarded as no more than the sum of the parts, to substitute information for knowledge. But this is only one side of the story. Another trend, equally important, is the downgrading of reason, the celebration of tradition, intuition and myth, the glorification of the holistic, the organic and the local. If we are forced to use McGilchrist’s terminology and imagery, we might say that the problem is not that the left hemisphere has control over the right but that there has been a tendency to develop both ‘left hemispheric thinking’ and ‘right hemispheric thinking’ in isolation and that both are, in isolation, equally troublesome. Or to put it anther way, the problem is increasingly that reason has become mechanistic, contextualisation anti-rational.

McGilchrist seems unable to see this because he is primarily in tune with what he would call ‘right hemisphere thinking’. He dismisses the idea, for instance, that a ‘greater capacity to control and manipulate the world for our benefit’ is a good. He is dismayed with ‘urbanization, globalization and the destruction of local cultures’ because these developments have ‘led to a rise in the prevalence of mental illness’. The fact that ‘over history intuition has lost ground to rationality’ seems like an indication of progress only because ‘we have already fallen for the left hemisphere’s propaganda.’ He bemoans ‘the left hemisphere’s attack on religion’ arguing that ‘when we decide not to worship divinity, we do not stop worshipping: we merely find something else less worthy to worship’. In other words, even though McGilchrist insists that what he desires is a proper balance between the two hemispheres, what is clearly drawn to is the holistic, organic, local forms of ‘right hemispheric thinking’. The very praise showered upon The Master and his Emissary suggests that he is not alone in this.

Finally, even if I am wrong, and McGilchrist right, both about the consequences of brain lateralisation and about the character of contemporary intellectual problems, does it make sense to see these problems in neurological terms?


The left hemisphere usurping the right, the emissary betraying the master – these are striking metaphors. But if these are metaphors then all that McGilchrist would be saying is that a particular form of thinking, which we can metaphorically label ‘left hemisphere thinking’, has squeezed out another form of thinking, metaphorically ‘right hemisphere thinking’, to our detriment. Whatever the merits of that argument, it has no neurological significance.

But McGilchirst insists that the Master and Emissary, and the idea of the one usurping the other, are more than simply metaphors. What could this mean? It could mean that because we live in a world which has decontextualised knowledge, fetishised reductive thinking, elevated information over knowledge, etc, and because these are forms of thinking embodied in different hemispheres, so we are increasingly relying on one hemisphere to do our thinking for us. There are all sorts of problems with such a claim, but it is nevertheless a plausible argument to make. It is also an argument in which the neurology, interesting though it may be, has little to say about the social and intellectual problems we face. To put it another way: If we want to ensure, say, that we always think contextually, or if we want to elevate the importance of knowledge over information, we could do so without any understanding of  brain lateralisation; and having an understanding of brain lateralisation would not give us better insights into how to make thinking more contextual, or how to elevate knowledge over information.

So clearly McGilchrist is saying more than simply that we are over-relying on one hemisphere. He is suggesting that the way the two hemispheres operate has somehow allowed the emissary to usurp the Master, the left hemisphere to usurp the right, and to colonize our experience. And it has done so independently of our desires or needs or wishes. For only then would the neuroscience be relevant to the social issues that McGilchrist raises. But in what way is it operating independently? Presumably, McGilchrist is not suggesting that the hemispheres are agents in their own right. So what is he suggesting? He does not say. And as Ray Tallis asks, ‘From what hemisphere is he able to observe the two hemispheres, pass judgement on them, and see their rivalry as the motor of the unfolding of human cultures?’

A final point: In a previous post on Oriental Enlightenment I mentioned briefly the tendency to think about East and West as ‘opposed ways of thinking’, to insist on what the Indian historian Raghavan Iyer has called ‘the dubious notion of an eternal East-West conflict, the extravagant assumption of a basic dichotomy in modes and thoughts and ways of life’, to create the self-serving distinction between, in the words of another Indian historian Sarvepalli Radhakrishnan, the West’s ‘rationalistic’ and ‘positivistic’ mind and ‘the Eastern mind [which] is more inclined to inward life and intuitive thinking’.

McGilchrist takes this trope, reverses the value assumptions (placing greater store on what are traditionally seen as ‘Eastern’ ways of thinking) and transfers the schism to the brain. Indeed, at the end of the book, McGilchrist suggests that his critique of left-hemispheric thinking ‘would be more intuitively understandable within an Oriental culture’. According to McGilchrist, ‘The pattern of psychological differences between Oriental people and Westerners suggests the possibility of a different relationship between the hemispheres’. Orientals’ ‘experience of the world is still effectively grounded in that of the right hemisphere’. They have ‘a more holistic approach’. The ‘differences between the way in which Westerners and East Asians see the world’ are to ‘do with the balance of the hemispheres’. In other words, McGilchrist writes, ‘the emissary appears to work in harmony with the Master in the east, but is the process of usurping him in the West’. McGilchrist has taken a long-standing dubious argument about cultural differences and modernized it by locating it in the brain. Doing so has not made a dubious argument any less dubious.

Update: Iain McGilchrist has written a long response to this, which I have published as a separate post (together with my own reply).


  1. This kind of stuff amazes me. As you suggest, why link these arguments to the brain? I wonder if you might be giving him too much credit to assume that he does not think the hemisphere’s contain agent-like capacities. It seems implicit in the language he uses: ‘it sees itself as a passive victim.’ In what sense does a hemisphere have a ‘self?’

    He wouldn’t be the first person to believe that consciousness exists within, and is caused by, the brain (both dubious claims). I don’t see why he would be making this kind of argument unless he somehow assumed one or the other.

  2. Geoff Bartholomew

    Very interesting piece. As a victim of a right hemispheric stroke, my resultant physical limitations are obvious but I have been wondering since my stroke 5 years ago, just what intellectual effect it had on me. Self analysis would be pointless without a base comparator. Because I can understand and appreciate the various points put forward in the piece, does that indicate damage or no damage?

    • Neither. A model like this is way too coarse to provide insight into what a stroke would do that affected a particular part of the brain. There are some very interesting studies done by Sperry and others of people damaged by strokes, etc., and by so-called split-brain patients, whose hemispheres were able to be isolated and interacted with individually by a researcher- those studies might yield you some insights you can relate to or learn from. Right side damage tends to be a lot nicer to have, though- a lot less depression, and less communication/symbol processing issues.

  3. Is the reference to the late Raghavan Iyer, the “Indian historian,” correct? Raghavan Iyer, the political science professor (in fact, a political philosopher), wrote a study of the political ideology of the Raj in India: Utilitarianism and All That (Chatto & Windus, 1960), as well as a nonpareil examination of Gandhi’s moral and political ideas: The Moral and Political Thought of Mahatma Gandhi (Oxford University Press, 1973; second ed., Concord Grove Press, 1983), among other titles. He was one of my undergraduate teachers, his son, the writer PIco Iyer, is a dear friend, and Pico’s mother (Raghavan’s wife), my best friend (who brought me into the academic world in my mid-40s!). The quote sounds like something that might have come from Raghavan’s edited volume, The Glass Curtain between Asia and Europe (1965).

  4. I found the first part of his book very helpful- the second, where he gets philosophical, less so. I think his whole metaphor has a serious flaw in it at the individual brain level, though I agree with him that there is likely brain origin of ignoring the great gestalts available to solve mankind’s serious problems.

    Gestalt shouldn’t be thought of as a sacred sense of great truth that must always be heeded: it should be thought of as holistic framing, which may be either successful or unsuccessful (interestingly, gestalt therapy from psychology addresses a very similar distinction in some detail, because of the problems the idealized version of gestalt causes in therapy). The weakness of Dr. McGilchrist’s model, at least at the individual level, is his too-quick assumption that the gestalt creator should be the master. Actually, gestalt is often not available as an option, and it’s often not accurate, as in the shadow-is-a-bear problem (and many other situations, particularly where bias, assumption and abstraction play a role). It’s more reasonable to assume that gestalt should be tossed in with every other important sensing and processing input needed to succeed at a task.

    Pulling this assumption out shows the model implicitly relies on gestalt to justify a right hemisphere ‘master’. Absent that requirement for sacred insight, why should the right side be the boss? It’s not clear.

    I think his model may have validity in cultural tendencies, or in the subset of our decisions that are about new, important things, where gestalt might add the key insight to be acted upon. But that seems to me to be very narrow applicability, if for no other reason than that even the decisions using gestalt are typically using one that we reused for many decisions, which the left hemisphere takes as a given by definition.

  5. ivanmq

    Very interesting subject. As I have found out on recent articles and books on the subject, the idea of a divided working brain would enter into the brain diseases catalog. Taking separately just couldn’t work right, in order to work right and eficiently it must make use of all its components including the stem, thalamus and cerebellum. The activity on each side I belive varies according to phisiological aspects.

    What I found most interesting about the post is the relation between left/right side output into the world and its consecuences in culture. There’s no doubt, in my view, that cultures emerged and maintain themselves according to different and selective ways of making use of right/left dominance and its flexibility to see the world differently.

  6. Jon W

    Discussions of what the two hemispheres of the brain can and cannot do often neglect the kinds of plasticity that enable, for example, someone without any left hemisphere at all to communicate normally. My son had a hemispherectomy at 1 year of age – it is the only solution for some kinds of epilepsy where seizures always start on one side of the brain but are diffuse within that hemisphere. In my son’s case it was the right hemisphere that was removed, but research on children who have had their left hemisphere removed shows that if the right hemisphere becomes the only hemisphere by one year of age, language will move into that hemisphere, and can ultimately be unimpaired. In the case of my son it’s my hope that his left hemisphere, which is not only able to take on functions usually associated with the right hemisphere but even physically expands to fill about 2/3rds of the cranium, will similarly allow him to compensate for the missing brain “real estate”. Knowing that it’s possible for language to be seated in the right hemisphere makes it all the more mysterious, to me, that under normal conditions it always develops in the left hemisphere.

    • A great insertion. It is astounding and unintuitive that such a complex entity would have the built-in wherewithal to self-reorganize using radically different physiology, presumably along priority lines it creates and executes on somewhat by default. Why/how would evolution create such a capability based on fitness? Or is it more basic than that- is the plasticity itself somehow integral to operation, so that your son’s potential reassignment of function is a variation or extension of an early-life core capability? And is plasticity related to the common module placement variations?

      I see a big difference between the kind of robust, dynamic model of bicameral operation you’re asking for (which would presumably incorporate plasticity/variability, normal vs. emergency, affect/emotion, and development/maturization) and the relatively static model of a master-emissary process, focusing on control usurpation by the emissary. This latter seems a much less ambitious subset of the former, even if it does seem to us to cover a lot of ground. McGilchrist is trying to address relatively specific dimensions of both neuroscience and culture. That specificity, at least in model output given a set of conditions, is why I have hope we can isolate and test his hypotheses in some way,

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