Review of The Master and His Emissary

It’s the ultimate conspiracy theory: Society is being reshaped by a sinister force. A force that drives us toward our own destruction yet prevents us from even realizing that anything is wrong. A force that’s inside us all…

…[ominous music]…

The left hemisphere of the human brain.

(OK, so it’s really more of a dextral force than a sinister one.)

McGilchrist is careful to include lots of caveats and hedging, but he’s claiming that something like the following is approximately true:

• The left hemisphere and the right hemisphere think in significantly different ways.
• The left hemisphere’s perspective is being overemphasized in contemporary Western society.
• This overemphasis is self-reinforcing—it causes society to be restructured such that excelling in the left hemisphere’s specialties is rewarded more than excelling in the right’s.
• This is dangerous because one characteristic of the left hemisphere is an inability to recognize information that does not fit its preconceptions.

To make his case, McGilchrist first goes heavy into the neuroscientific evidence for differences in the hemispheres (part 1 of the book) and then does a tour of world history in search of evidence that the relative dominance of each hemisphere has varied across different eras and societies (part 2 of the book).

Do I buy this? No. But I really just don’t have the background knowledge—i.e. an extensive knowledge of history—to evaluate the arguments. McGilchrist presents some interesting examples to support his claim that one hemisphere or the other has been more influential in different periods, e.g.:

…Brener cites the work of Hans-Joachim Hufschmidt, a German scholar who has studied the direction of gaze in 50,000 portrayals of the human face over time. This work, published in 1980, yields a remarkable finding. It seems that early two-dimensional representations tend to show the face either looking straight ahead or looking towards the viewer’s right. However, during the period between the sixth century BC and the Hellenistic period, there is a clear shift of orientation, so that the majority of portraits come to face in the opposite direction, towards the viewer’s left. … This reveals a distinct shift towards favouring the right hemisphere in the appreciation of representations of the human face from the sixth century BC onwards. According to Brener and Hufschmidt, the tendency was lost again in the Dark Ages, but re-emerged at the Renaissance.¹

But how does one determine whether that really means anything, or if it’s just a shift in fashion, a cherry-picked pseudopattern from the infinite sea of historical data? I don’t know, and I default to skepticism. When the concluding chapter claims to “try to imagine what the world would look like if the left hemisphere became so far dominant that, at the phenomenological level, it managed more or less to suppress the right hemisphere’s world altogether”,² the subsequent description sounds suspiciously like the author just listed a bunch of stuff he doesn’t like about the modern world and then kept whichever ones he could make sound left-hemisphere-ish. But I lack the expertise to have any confidence in that assessment one way or another.

(Also, I have to confess that the amount of art history and longwinded continental philosophy in part 2 just made it very boring for me.)

I like the book for two main reasons:

First, the information in part 1 is really fascinating and much of it was new to me. McGilchrist covers a large number of cases and studies to paint a picture of how the left and right hemispheres differ. Some of those differences include (again, don’t take these as strict or universal):

• handling “pieces of information in isolation” (left) vs “the entity as a whole”³
• handling the “familiar” (left) vs “new experience … new information or new skills”⁴ (right)
• “focussed attention” (left) vs “breadth and flexibility of attention”⁵ (right)
• recognizing “abstract categories and types” (left) vs “uniqueness and individuality”⁶ (right)
• “impersonal” (left) vs “personal”⁷ (right)
• “linear, sequential argument” (left) vs “some [other] types of reasoning, including deduction, and some types of mathematical reasoning”⁸ (right)
• “major key” music (left) vs “minor key”⁹ music (right)
• “need[ing] certainty” (left) vs “hold[ing] several ambiguous possibilities in suspension together without premature closure”¹⁰ (right)
• “unrealistic about its short-comings” (left) vs “more realistic”¹¹ (right)

Perhaps most importantly for the book’s larger argument: the left hemisphere confabulates.

Although the left hemisphere does not see and cannot understand what the right hemisphere understands, it is expert at pretending that it does, at finding quite plausible, but bogus, explanations for the evidence that does not fit its version of events. It will be remembered from the experiments of Deglin and Kinsbourne that the left hemisphere would rather believe authority, ‘what it says on this piece of paper’, than the evidence of its own senses. And remember how it is willing to deny a paralysed limb, even when it is confronted with indisputable evidence?¹²

That brings me to the second thing I like about the book. The tendency to get so attached to a particular model of the world that we are simply unable to recognize any evidence that contradicts that model is, I think, an easy trap for humans to fall into—perhaps especially easy for those who are relatively gifted at constructing good models! (To give a controversial example which McGilchrist also touches on: I think reductionist forms of physicalism about consciousness represent this sort of attachment-to-the-model-at-all-costs.) And even when we know, in the abstract, that we have this vulnerability, it’s often difficult to believe it on a gut level—to truly retain some openness to the possibility that key parts of your worldview may be mistaken. I think the book’s overarching narrative somehow helped me feel that possibility more than I did before, regardless of whether that overarching narrative is true.

I also found the book’s discussion of metaphor interesting. I would be prone to viewing metaphor as a sort of ornament, a mere rhetorical flourish which is not truly necessary to convey any given idea. McGilchrist challenges this:

A metaphor asserts a common life that is experienced in the body of the one who makes it, and the separation is only present at the linguistic level. Our sense of the commonality of the two ideas, perceptions or entities does not lie in a post hoc derivation of something abstracted from each of them, which is found on subsequent comparison to be similar, or even one and the same thing; but rather on a single concrete, kinaesthetic experience more fundamental than either, and from which they in turn are derived. Thus a clash of arguments and a clash of cymbals are not seen to have something in common only after the disembodied idea of a ‘clash’ is abstracted from the one and from the other, and found - aha! - to be similar; it is rather that these experiences - a clash of arguments and a clash of cymbals, or, for that matter, a clash of swords, or a clash of colours - are felt in our embodied selves as sharing a common nature.

When the metaphor is paraphrased or replaced, whatever had been extralingual, unconscious, and therefore potentially new and alive in the collision of these two entities gets reconstructed, this time in terms only of what is familiar. The point of metaphor is to bring together the whole of one thing with the whole of another, so that each is looked at in a different light.¹³