Book SummaryThe Master and His Emissary, by Iain McGilchrist

1-Page Summary1-Page Book Summary of The Master and His Emissary

According to psychiatrist Iain McGilchrist, pop psychology has given us a wrong—and dangerous—impression of the brain and its two hemispheres. In his 2009 book, The Master and His Emissary, McGilchrist cites an array of scientific evidence intended to dispel the myth that the right hemisphere is “minor.” According to this myth, the right hemisphere only grounds supposedly gratuitous functions like artistic ability, imagination, and sentiment, while the left hemisphere grounds vital functions like reason, linguistic understanding, and arithmetic. For this reason, pop culture often calls those inclined toward artistic pursuits “right-brained,” while calling those inclined towards analytical pursuits “left-brained.”

Against this misconception, McGilchrist contends that the right hemisphere is actually dominant over the left hemisphere, as shown by its role in our capacity for attention, value judgments, and comprehending meaning. Further, he argues that when a society puts too much emphasis on left-hemisphere functions, the left hemisphere can begin to exert undue influence that threatens to rob our lives of meaning and happiness. McGilchrist argues that this was the case in historical periods like the Reformation and the Enlightenment and that it’s happening again...

The Master and His Emissary Summary The Differences Between the Two Hemispheres

To start, we’ll examine five of the hemisphere differences that McGilchrist discusses—differences in understanding meaning, perceiving objects, grasping coherent wholes versus individual parts, processing emotions, and thinking intuitively. While these differences will later illustrate the hemispheres’ historical power struggles, they also illustrate one of McGilchrist’s key claims: The myth of left-hemisphere superiority is misguided, as the right hemisphere is responsible for several of the brain’s most essential functions.

Difference #1: Implicit vs. Explicit Meaning

Despite the popular caricature of the right hemisphere as “silent,” McGilchrist contends that it plays a crucial role in understanding language. By examining the effects of injuries to the right and left hemispheres, he argues that though the left hemisphere grasps formal linguistic rules, only the right hemisphere grasps the implicit meaning that language conveys.

He notes that, when people suffer from right hemisphere damage (and therefore rely on their left hemisphere), they often speak sentences that are syntactically and grammatically flawless, but nonsensical. In a similar vein, children...

The Master and His Emissary Summary The Proper Relationship Between the Two Hemispheres

In light of the differences between the two hemispheres, it’s natural to ask another question: How should the hemispheres work together? That is, what’s the proper relationship between the right and left hemispheres? In this section, we’ll examine McGilchrist’s argument that, contrary to the standard view, the right hemisphere should take primacy over the left because the right hemisphere grounds several of the brain’s most crucial functions.

The Sovereignty of the Right Hemisphere

McGilchrist notes that, in popular culture, the left hemisphere is associated with more important work, like logical reasoning and problem-solving, leaving the less important right hemisphere subservient to it. But McGilchrist argues that in an optimally-functioning mind, the right hemisphere is sovereign over the left hemisphere. Although McGilchrist lists a wide array of areas that showcase this right-hemisphere dominance, we’ll focus on three key ones: our value judgments, our capacity for attention, and our ability to grasp meaning.

Area #1: Value Judgments

According to McGilchrist, **the right hemisphere is primarily responsible for our value judgments about the...

The Master and His Emissary Summary Right Hemisphere Primacy Throughout History

Having discussed the proper relationship between the two hemispheres, in which the left hemisphere is subservient to the right, we’ll now examine three historical eras that, according to McGilchrist, embody the primacy of the right hemisphere: classical antiquity, the Renaissance, and Romanticism.

Yet, before beginning, it’s worth clarifying what McGilchrist means when he says that an era can embody hemispheric dominance (and that this embodiment can change over time from one hemisphere to the other). McGilchrist attributes such embodiment to mimesis, a process by which we empathetically imitate certain ways of thinking present in our surroundings, leading to functional shifts in our brain.

For example, though an infant’s brain has the structural hardware needed to process both implicit and explicit meaning, if that infant is surrounded by people who emphasize explicit over implicit meaning, the process of mimesis could sharpen the brain’s function for processing explicit meaning and weaken its function for processing implicit meaning. In this way, McGilchrist says, different functions associated with the left and right hemispheres can become entrenched in different...

The Master and His Emissary Summary Left Hemisphere Primacy Throughout History

Having seen how the brain’s hemispheres worked together properly across several eras, we’ll now discuss the eras in which this relationship went awry and the left hemisphere exhibited too much power. According to McGilchrist, we can see this imbalance in the Reformation, the Enlightenment, and the Modern and Postmodern world.

Era #1: The Reformation

The first of these periods—the Reformation—occurred as dissenters left the Roman Catholic Church in 16th-century Europe, spawning Protestantism and its many denominations. McGilchrist points to a rejection of metaphor and implicit meaning in religious art to argue that the left hemisphere exerted excessive power over the right hemisphere throughout the Reformation.

To begin, McGilchrist notes that participants in the Reformation often destroyed religious art, such as paintings of Jesus and even crucifix necklaces. They did so, McGilchrist relates, because they thought these art forms were idolatrous, meaning the art itself was an object of worship. For instance, Reformation theologians might tear down a statue of Jesus out of fear that the statue itself had become the object of adoration rather than Jesus. ...

The Master and His Emissary Summary The Cost of Continued Left Hemisphere Dominance

Because the left hemisphere has grown increasingly powerful in the modern world, it’s natural to ask the question: What would happen if the left hemisphere never relinquished its power? In other words, what’s the cost of continued left hemisphere dominance? In this section, we’ll examine McGilchrist’s answers to these questions, first addressing his speculation about the nature of a world dominated by the left hemisphere, then discussing his arguments about the possibility of happiness in such a world.

What Would a Left Hemisphere World Look Like?

McGilchrist paints a multifaceted picture of the losses suffered in a left hemisphere-dominated world, but we’ll focus on three key losses: the loss of wisdom, the loss of contact with the

“real world,” and the loss of meaning.

Loss #1: Losing Wisdom to Knowledge

According to McGilchrist, the left hemisphere’s world would prioritize “knowledge” to the detriment of wisdom, because the left hemisphere’s emphasis on narrower, minute details is incompatible with wisdom’s understanding of the bigger picture. McGilchrist reminds us that the left hemisphere is more detail-oriented, as evidenced by its capacity for...

Shortform Exercise: Assess McGilchrist’s Historical Arguments

McGilchrist argues that the left hemisphere’s continued influence threatens to upend contemporary society and leave us without meaning or happiness. In this exercise, reflect on McGilchrist’s predictions and propose ways to address the left hemisphere’s undue power.

In light of the hemisphere differences that McGilchrist cites, how would you describe your own relationship toward your left and right hemisphere? For example, do you resonate more with the specialties of one hemisphere in particular?