The Master and His Emissary, book review
The Master and His Emissary, by Iain McGilchrist, book review
Weighing in at 616 pages, and absolutely packed with research results, this is not a light read. He clearly acknowledges the gaps between data, interpretation, and outright speculation, but even his speculation is firmly rooted in data. Great book if you want to sink your teeth into the newest neuroscience about the human brain hemispheres.
This is hands-down one of my favorite books in quite a while.
The First Half of the Book - the two hemispheres perceive reality differently
The first part of the book puts forth some of the more nuanced ways the brain left & right hemispheres are different (beyond the cocktail discussion level of right-brain-emotional/left-brain-verbal). His distinctions are so varied and nuanced (and did I say constantly backed by experimental evidence...), that now that I am trying to write about it I realize how much this book could use a second read. For example, the right hemisphere sees the world as it is, as the impressions come in, and perceives things as a whole. The left hemisphere is not very good at directly perceiving the world, and largely relies on what the right hemisphere perceives. The left hemisphere then re-presents the world in abstract categories, which are quite lifeless and devoid of any meaning. The right hemisphere directly perceives life and meaning.
The right hemisphere knows context, knows what is implicit - for example, the right hemisphere is very good at understanding stories, which are usually filled with context and implied content. By contrast the left hemisphere is almost incapable of understanding context - to the extent that if the right hemisphere is damaged the person cannot even understand that some of their body parts belong to them - their arm is not "their arm" because that requires too much context, their arm is just "an arm", disembodied.
The left hemisphere is very bad at humor, and requires jokes to be explained. But as we all know, once a joke is explained it is no longer funny.
The left hemisphere can only think in logic, systems, abstractions, utility, control. The left is very poor at seeing the whole, and only sees parts. For example, a patient with right hemisphere damage, when looking at a friend, has a very difficult time comprehending that what is in front of them is their friend, but instead sees only arm, foot, brown hair, pant leg, male, etc... a long list of attributes that could apply to any number of people, while the single, unified, whole called "this particular friend" is only with great difficulty perceived.
One of my favorite examples was about the color blue. For patients that could only use the left hemisphere, blue was described in such terms as "electromagnetic radiation in the 500nm range", or "the wavelength most scattered by Earth's atmosphere", but it is very doubtful that they are perceiving blue. They appeared to be only describing it in abstract categories. In contrast, patients that could only use the right simply perceived blue as blue.
All this then leads to the shocking proposition that neuroscience has for the past 100 years been using only the left hemisphere to study the brain. But we have proof that the left hemisphere can only know parts and cannot understand or perceive the whole.To make things worse, the left hemisphere seems to be the seat of hubris since it does not know about the right hemisphere, though it gets all of its information from the right hemisphere. The left believes it came up with everything, and only its ways of looking at things are correct, and is at times openly hostile towards any way of knowing the world that does not use its own methods of abstract categorization, where the world is a meaningless, dead machine. (And yes, McGilchrist backs up all that with many, many experiments.)
Weaving in philosophy and poetry
Another impressive aspect of the book is the regular weaving in of the works of great philosophers and poets. It shocked me to see Wittgenstein, Goethe, Hegel, Wordsworth, Coleridge, Nietzsche all quoted in their own words ideas that meshed shockingly well with McGilchrist's ideas on the left-right differences.
I am also impressed with his ability to consistently present difficult ideas first in the language of neuroscience, then in the language of philosophy, and finally with a simple practical example. I have to admit I often zoned out during the "long neuroscience description" and waited until the "simple practical example" to arrive :)
The Second Half of the Book - Seeing the roles of the hemisphere in human history
What if there were not human genes for specific abilities, but rather genes the confer the ability to imitate and imagine? For example, one must admit, there is no accepted theory for how any of our genes confer upon us the ability to swim. The DNA theorists are actually completely at a loss to draw any such connection. So why not allow that our DNA does not code for any such thing as the ability to swim, but rather codes for the ability to imitate. Again, using actual studies, McGilchrist points out the odd fact that humans are the only species that can imitate the way another being behaves. (The only known exception is birds, which can imitate other creatures voices.)
Tracing the history of human thought, art, achievements from the perspective of brain hemispheres is an enormous task, but he pulls it off. A perfect example of how his thesis can be seen is when he quotes a dialog of Plato, where the creation myth says that humans were first only heads, perfect heads with just thought. But since they could not get around, the arms and legs, where were just laying about without any connection to anything, were randomly attached to these heads, and hence full bodies formed. This is an exact description of how the left hemisphere perceives a human. It is was a shock for me to see so much of Plato as exemplifying the what of thought of the left hemisphere.
The Reformation and Post-Modernism
It is shocking how well his categories for the left&right hemisphere view points can be seen playing out in major cultural movements. The Reformation, with its outright hate of images, metaphor, meaning, & transcendence, coupled with an all-out push to make the spoken word paramount, make everything explicit, and affirm that the blessed host "represents" the body of Christ rather than "is" the body of Christ, these are all the viewpoints and activities of the left hemisphere.
What does society look like when the left hemisphere takes over?
The last chapter of the book is chilling, as he has prepared out minds to see that our current society is far, far more dominated by left hemisphere views than right. The left hemisphere, without its correct relationship to the viewpoints of the right, cannot easily be controlled. It believe it alone is right. It destroys and vilifies all that does not agree with its viewpoint. It insists on absolute control, surveillance, & mechanization. The human body is seen as no more than a machine. Religion is mocked, or seen as the fantasies of deluded minds. He even draws many connections between schizophrenic patients and where our culture is heading.
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On the down-side, he does sometimes confuses consciousness with intellectual activity. But he does not always do this, which makes me think he wrote different parts of the book at very different times, and understandably did not have time to go back and make sure he was using all terms consistently.
Another difficulty, which he freely admits, is that subject of the book is just so darn complex. There are hundreds of papers coming out each year, by specialists who are focusing on one tiny aspect of how our consciousness relates to the structure of our brains. Who can possibly put this all together? It is an impossible task.