The Master and His Emissary: The Divided Brain and the Making of the Western World

by Iain McGilchrist

When people object that each hemisphere is involved in everything we do, they are right. When they assume that means there are no differences, they are wrong. It is not what each hemisphere does, but how it does it that matters. Each hemisphere is involved in everything, true enough; just in a quite different way.

I do not mean to suggest that the brain causes human experience. Clearly there is a correlation between the brain and human experience. A discussion of what we can know of the nature of that correlation would take me too far from the purposes of this preface. However, my position in brief is that the nature and structure of the brain must be reciprocally related to the nature and structure of consciousness, but does not necessarily give rise to it (rather than, say, transduce it). It might, or it might not.

Why is the brain, an organ that exists only to make connections, divided? Why is it asymmetrical in so many measurable respects, both structural and functional, and why does its functioning seem to depend on its being asymmetrical? And why is the major connection between the two cerebral hemispheres, the corpus callosum, getting proportionately smaller, and functionally more inhibitory, rather than larger, and functionally more facilitatory, with evolution?

Max Planck: New scientific ideas never spring from a communal body, however organised, but rather from the head of an individually inspired researcher who struggles with his problems in lonely thought and unites all his thought on one single point which is his whole world for the moment.7

Finally, it would appear to be a literal truth that, as a society, we are becoming more like individuals with right hemisphere deficits. Anecdotal evidence from the teaching profession suggests that between a quarter and a third of children aged as old as five to seven are now having to be taught how to read the human face, something that until recently would have been necessary only in the case of children with autism. And about a third of all children now have difficulty carrying out tasks that a decade ago virtually every child in a mainstream school would have been able to do easily – tasks that depend on sustained attention. Add to that research suggesting that young people today are less empathic than children thirty to forty years ago.

If a neuropsychologist had to choose three things to characterise most clearly the functional contribution of the right hemisphere, they would most probably be the capacity to read the human face, the capacity to sustain vigilant attention, and the capacity to empathise.

I am sometimes asked why, if the left hemisphere ‘take’ on the world is less insightful, it has come to dominate the way we think. And if this has happened not just once, but three times, as I believe, in Western history, how do I account for that fact? These are good questions. I think there are, again, several reasons why this characteristic entrenchment occurs, and indeed is likely to occur whenever a civilisation passes its peak. All of them, to some degree...

First, the left-hemisphere view is designed to aid you in grabbing stuff. Its purpose is utility and its evolutionary adaptation lies in the service of grasping and amassing ‘things’. As such it is seductive. It is probably for this reason that Eastern cultures which used to be more balanced in their outlook are now adopting the current Western model of the world with such enthusiasm, and appear set, very sadly, on outdoing the West at its own pernicious game. It is my view that we should be learning from them, not they from us. In the case of the Greeks, the Romans and the post-Enlightenment West, the decline of civilisation has been associated, not just with more left-hemisphere ways of thinking, but a...

Second, the left-hemisphere view offers simple answers. Its mode of thinking prizes consistency above all, and claims to offer the same mechanistic models to explain everything that exists. This thinking is common to those who espouse naïve reductionist science (‘scientism’), enthusiasts for technological solutions to what are complex human problems, and designers and implementers of bureaucratic systems. When this sort of thinking encounters a problem in reconciling apparent irreconci...

Third, the left hemisphere’s world view is easier to articulate. The left hemisphere is the speaking hemisphere: the right hemisphere has literally no voice. The attempt to make the implicit explicit radically alters its nature; as a result, finding the language to put across the way of being of the right hemisphere is simply harder than doing so for the naturally explicit left hemisphere. The left hemisphere relies on concatenations of serial propositions and the literal aspects of language to make meaning explicit; by contrast, metaphor and narrative are often required to convey the implicit meanings available to the right hemisphere, and in a left-hemisphere-dominated culture, metaphors and narratives are disregarded as myths and fables or, at worst, downright lies. We live in an era where articulating and making explicit are of increasing importance and are treated as a mark of truth, and their inverse treated with increasing suspicion. Partly this is another sign of the ‘move to the left hemisphere’ that I am describing, but that is not the only reason for it: it is also necessitated by large-scale movements of populations with different languages and cu...

Fourth, since the Industrial Revolution, but particularly in the last fifty years, we have created a world around us which, in contrast to the natural world, reflects the left hemisphere’s priorities and its vision. Today all the available sources of intuitive life – the natural world, cultural tradition, the body, religion and art – have been so conceptualised, devitalised and ‘deconstructed’ (ironised) by self-consciousness, explicitness and the systems and theories used to analyse them, that their power to help us see intuitively beyond the hermetic world that the left hemisphere has set up has been largely drained from them. For many, TV screens and computers supplant direct face-to-face experience of reality. The cerebral and the abstract – for example, management and its systems – have become more highly valued than the hands-on task that management exists to serve, with the odd effect that the higher you rise in your craft, skill or profession, the more you will be removed from its performance in order to manage it. A century ago, the physical environment was for most of humanity that of the natural world, with its rhythms and cycles, its organic, ever-growing and ever-ch...

Fifth, built into the relationship between the hemispheres is that they have a different take on everything – including on their own relationship. Neurological research reveals a consistent picture of how the two hemispheres contribute to the richness of experience. Essentially this is that the right hemisphere tends to ground experience; the left hemisphere then works on it to clarify, ‘unpack’ and generally render the implicit explicit; and the right hemisphere finally reintegrates what the left hemisphere has produced with its own understanding, the explicit once more receding, to produce a new, now e...

This could be thought of as similar to the way a performer learns a piece of music. First, he or she is attracted to the piece as a whole and has a sense of how it works overall; then the piece is taken apart, its harmonic structure analysed, certain passages of notes practised repeatedly, and so on; but, finally, all that must be banished from the performer’s mind if the performance is not to be hobbled and stilted. This is not to deny the importance of the left hemisphere’s contribution, just to make clear that it works its necessary effects at an intermediate stage. Problems arise when this is treated as the end stage. In terms of the metaphor of the Master and his emissary, the Master realises the need for an emissary to do certain work on his behalf (which he, the Master, must not involve himself with) and report back to him. That is w...

The right hemisphere’s view is inclusive, ‘both/and’, synthetic, integrative; it realises the need for both. The left hemisphere’s view is exclusive, ‘either/or’, analytic and fragmentary – but, crucially, unaware of ...

Sixth, a culture that exemplifies the qualities of the left hemisphere’s world attracts to itself, in positions of influence and authority, those whose natural outlook is similar. People with certain autistic traits will be attracted to, and be deemed especially suitable for, employment in the areas of science, technology and administration which have, during the last hundred years, been immensely influential in shaping the world we live in, and are if anything even more important today. Thus a culture which already has some prominent autistic characteristics attracts to positions of influence individuals who will help it ever further down the same path. This is not the only vicious circle involved. Increasing technologisation and bureaucratisation of life help to erode the more integr...

Finally, though the ‘takes’ of the two hemispheres are made to work together below the level of conscious awareness, they are not strictly compatible. This is most obvious when, as in our society, our thinking is no longer embodied in the practices, traditions and rituals of a community, but is developed in explicit, public, often political debate, where much of its subtlety, and tolerance of necessary ambiguity, gets lost. Once dragged into the light of day and scrutinised, the hemisphere ‘takes’ are seen often to pull in opposite directions. The catch is that in such a society as ours, any apparent inconsistency is treated as a sign of error or intellectual muddle. Ambiguity is no longer a strength, given that truth is known to be complicated and many-layered; it is a weakness, since truth is thought of as single and straightforward. It is therefore easier to accept the left hemisphere’s point of view, which is easily articulated and unambiguous and simply stands in contradiction to the right hemisphere’s view, than to accept that of th...

I believe that reductionism has become a disease, a viewpoint lacking both intellectual sophistication and emotional depth, which is blighting our ability to understand what is happening and what we need to do about it.

There are, it seems to me, four main pathways to the truth: science, reason, intuition and imagination. I also believe strongly that any world view that tries to get by without paying due respect to all four of these is bound to fail. Each on its own has its virtues and its vices, its gifts and its inherent dangers: only by respecting each and all together can we learn to act wisely. And each is a blend of elements contributed by either hemisphere. However, the same proviso applies in each case, namely that for each to be successful, what the left hemisphere can offer must be used in service of what the right hemisphere knows and sees, not the other way round. This is as important in the case of science as in that of imagination, in the case of reason as in that of intuition. The left hemisphere is a wonderful servant, but a very poor master. We also need to be aware of the sheer extent to which the left hemisphere is, in the most down-to-earth, empirically verifiable way, less reliable than the right – in matters of attention, perception, judgment, emotional understanding, and indeed intelligence as it is conventionally understood. And that means that we should be appropriately sceptical of the left hemisphere’s vision of a mechanistic world, an atomistic society, a world in which competition is more important than collaboration; a world in which nature is a heap of resource there for our exploitation, in which only humans count, and yet humans are only machines – not eve...