In McGilchrist's view, while the right hemisphere grounds our experience, the left dissects it. The right hemisphere is at home in our "embodied existence" in art and in religion. The left is at home in designing tools with which to master and understand the world. The left hemisphere treats us and our environment as an assemblage of machines; the right hemisphere treats us as people. The left systematises while the right empathises.
The cardiologist and scientist John Martin wrote: "I take apart their insides, discover the insides of their insides, until I know the atoms of the molecules that make the cells stick. But where is man desiring beauty?" McGilchrist would undoubtedly answer, "In the right hemisphere!" This view has precedents: when asked to define the role of the right hemisphere, a distinguished researcher on hemisphere differences, John Cutting, answered simply: "It is life, life itself." McGilchrist goes further: the left hemisphere is the "Berlusconi of the brain", with a "Gorgon stare", while the right hemisphere attends to "the body, the spirit and art", which are collectively "the vehicles of love".
The contrasts drawn between the hemispheres in the first part of this long book are used, in part two, to interpret cultural history in terms of the alleged continual tension between the hemispheres. At the risk of caricature, McGilchrist views several periods and movements in human history as expressions of fruitful collaboration between left brain and right, while others reflect the imperialistic and naïve ambition of the left hemisphere, the Emissary, to take charge. Ancient Greek culture, the Renaissance, the Romantic movement and some — somewhat few — aspects of contemporary culture fall into the first category. The Roman Empire, the Reformation, the Enlightenment, the Industrial Revolution and much of modernism are to be found in the second. He believes we have recently entered a dangerous period of left hemisphere ascendancy, characterised by a proliferation of "small, complicated rules".
This is an unusual book, reflecting the unusual trajectory of its author. Three-times elected Fellow of All Souls, McGilchrist has transformed himself from English literature don into psychiatrist, so travelling from the arts to the sciences, from right hemisphere to left-and, with this book, back again. (This three-part sequence, incidentally, is the cerebral itinerary that he recommends for experience in general.)
McGilchrist is immensely erudite. He writes with great clarity, and while the book develops an argument it is also a treasure chest of fascinating detail and memorable quotation. Its thesis is profoundly interesting: most readers who enter here with time to spend will be richly rewarded. On occasion the book overreaches itself, and-as ever-some of its factual claims may be wrong: the degree to which the hemispheres are really in conflict is open to question (and investigation) and McGilchrist's view of schizophrenia, one of the book's many themes, is only one of many.
But the effort to make sense of the totality of our lives in terms of brain function is exhilarating and worthwhile. On one final point I am doubtful: early in the course of this tale of two brains, McGilchrist writes: "It has been said that the world is divided into two types of people, those who divide the world into two types of people, and those who don't. I am with the second group." I am not sure I believe him.
