The Master and his emissary: The divided brain and the making of the Western world

‘‘This book tells a story . . . ’’. So begins the text of Iain McGilchrist’s masterpiece about the master and his emissary. So who is the master? It is, metaphorically speaking, the nonspeaking right hemisphere of the human brain. And the emissary . . . ? The book sets out to ask how, with a wonderfully constructed yet lopsided human brain, we can understand the world that surrounds us. It also examines how the functions of the two hemispheres of our bicameral brain (to use the term of Jaynes) have shifted, intermingled, conflicted, and competed over evolutionary time, settling for us in the twenty-first century in such a skewed relationship between the left and the right hemisphere that the imbalance puts our very future existence as Homo sapiens in considerable danger. The book thus deals with the relationship between the hemispheres from an evolutionary, but also from a sociological perspective. Asymmetrical biases between the functions of the two hemispheres are noted, as is the way that the so-called ‘‘dominant’’ hemisphere, that which is language rich for propositions, has created for the human mind a ‘‘sort of self reflective virtual world’’, which is essentially parasitical on the master, the right hemisphere. The right hemisphere has virtually all of the attributes that make us human: It is attracted to what is new in the world, it is attentive to the world around us before the left hemisphere, it is the repository of our emotional biographical memories, and it is where our embodied sense of self is located. The left hemisphere, in contrast, deals with only what it knows, suppressing meanings that are not relevant for its objectives. But it is the right hemisphere that tolerates metaphor, that is creative, that is insightful with respect to problem solving; it is deductive, not suppressive. Much neuroscience evidence, in a text which is packed full of references both old and new, is invoked in support of this view of the imbalance between COGNITIVE NEUROPSYCHIATRY 2011, 16 (3), 284 288