Review of The Master and His Emissary

The Master and his Emissary Book Cover

The science of the human brain, in all of its many facets, is an intriguing area of study by its very nature. Because the conclusions of its practitioners often connect with philosophy and theology, it is also of practical interest for those of us who desire to think deeply about these matters. For a few of us, it also has a personal edge—I, for one, am always eager to pop open a book and learn what the latest science has to say about those who are missing the same parts of the brain as I am. For some, I may be thoroughly ill-suited to review such a book as Iain McGilchrist’s The Master and His Emissary. I happen to be missing parts of the very hemisphere he deems to be underrepresented in our present age. I will leave it to the reader to judge for themselves whether I am part of the problem McGilchrist seeks to address.
First published in 2009, The Master has received glowing reviews across the board. There is a good reason for this; the book proves to be a fascinating journey through ancient and modern Western culture from the perspective of recent research on the divided brain (its right and left hemispheres). McGilchrist is clearly well learned, demonstrating not only a mastery of the literature in his own field of psychiatry—particularly in its neurological dimensions—but also many other fields. However, despite the fascinating adventure, this reviewer was not persuaded by McGilchrist’s argument. After giving a summary of the thesis and contents, I will then offer a short evaluation of the argument.


In its opening line, McGilchrist identifies the broad scope of the book: “This book tells a story about ourselves and the world, and about how we got to be where we are now” (1). The story he seeks to tell is reminiscent of the one Hegel sought to tell in his A Philosophy of History. In that book, all human history is interpreted as the instantiation of the idea of freedom through progressive human cultures, reaching its zenith in the Prussian Empire. McGilchrist has a far humbler aim, to show how Western culture can be interpreted as warfare between the Right and Left hemispheres of the brain. Modern and Post-Modern societies are not a positive climax for McGilchrist; instead, in contemporary culture, the Left hemisphere, which ought to be the servant of the Right, seems on the verge of completely closing out the Right’s picture of the world. This is, for McGilchrist, an unpleasant and entirely negative state of affairs. He summarises his argument generally in this way, “I hold that, like the Master and his emissary in [Nietzsche’s] story, though the cerebral hemispheres should co-operate, they have for some time been in a state of conflict. The subsequent battles between them are recorded in the history of philosophy and are played out in the seismic shifts that characterise the history of Western culture. At present, the domain—our civilisation—finds itself in the hands of the vizier, who, however gifted, is effectively an ambitious regional bureaucrat with his own interests at heart” (14). He concludes, “Ultimately what I have tried to point to is that the apparently separate ‘functions’ in each hemisphere fit together intelligently to form in each case a single coherent entity; that there are, not just currents here and there in the history of ideas, but consistent ways of being that persist across the history of the Western world, that are fundamentally opposed, thought complementary, in what they reveal to us; and that the hemispheres of the brain can be seen as, at the very least, a metaphor for these” (461). His argument is divided into two halves.
In Part One, McGilchrist follows the psychological literature concerning the divided brain, arguing that the two hemispheres are in fact asymmetrical. That is, they differ in a fundamental way. He argues that it is not that each side does certain things but, rather, does the same or different things in distinctly different ways. On the one hand, the Left hemisphere focuses and isolates, segmenting the world and blocking out the periphery in order to understand what lies at the centre. This involves abstract and logical reasoning as well as language. In essence, the left hemisphere doesn’t deal with raw experience but represents what is experienced by the right hemisphere. It gives focused experience and interpretation or representation of “reality,” or what the right experiences. The right, on the other hand, grapples with experience in all its bewildering complexity. It is the wide-angle lens, the peripheral or subsidiary focus: it casts its attention on the context, what surrounds and is in relationship with that which is in focus. The burden of this first part is not only to demonstrate that the two hemispheres do different things but that the right hemisphere is properly primary: it is the Master. The Left has an important function but is most capable when it functions as the emissary or servant of the Master. The brain, McGilchrist argues, works best when it moves in a Right–Left–Right pattern, in which the Left analyses what it receives from the Right but submits that back to the Right. However, the Left tends to overestimate its own capacity and take for itself the role of Master, yielding the sort of fruit we witness in the Modern and Post-Modern world. Part 2 brings this general sketch of hemisphere function and their relationship to bear on Western history.

In Part Two, McGilchrist wants to argue that we see in Western history a movement from a sort of culture that embodies the Right hemisphere to a sort of culture that embodies the Left hemisphere and back again until we arrive at the current period in history, where the Left appears to be close to edging out the Right entirely. Such a world would be characterised by the Left’s self-centred, power-hungry, abstracting, isolating, and technocratic tendencies. McGilchrist argues that the answer the contemporary cultural crisis is to achieve the balance where the Left serves its proper role as the servant, analysing and thinking about the world it receives but only so as to give it back to the outward moving, contextual focused Right hemisphere. McGilchrist argues that art and mythos, such as what he perceives to the be the Christian account of the incarnation, are the way to penetrate the hall of mirrors the Left has created for itself and return to a more balanced, holistic way of being.


There is an aspect of McGilchrist’s argument that is tremendously plausible. From a laymen’s perspective—and judging by the positive reviews from his fellow specialists—the argument for the asymmetrical hemispherical function is persuasive, as is the identification of these specialisations of each hemisphere in Western history. This latter aspect of his argument is fascinating but not revolutionary. The other part of his argument is prescriptive, attributing a value to each hemisphere and its functions and evaluating Western history from this perspective, including a remedy for its ails. It is here that McGilchrist fails to persuade, primarily because he does not argue why his value judgements ought to be accepted. There is much I found agreeable in the book; I likewise think Modernism and Postmodernism (and ancient Greek philosophy) are problematic and take issue with the sort of universalising reason characterising these movements (which happens to be the topic of my PhD). However, I did not find any reason to accept these things from this book, nor any of those issues I found to be more problematic (on which, see below). We can consider why the books fails to persuade by considering it from the perspective rhetoric, philosophy, and theology.

Rhetorically, McGilchrist argues well for the asymmetry of the Hemispheres but never gives a substantive argument for the interpretation he gives to this data.1 For example, he often employs etymologising to make his argument, which is highly problematic (e.g. 381) (see, for example, James Barr, The Semantics of Biblical Languages; Moises Silva, Biblical Words and Their Meanings). He also uses pervasive pejorative language for things associated with the Left hemisphere, without showing why the value-neutral things he describes should be considered negative (e.g. it is objectifying, self-interested, detached, power-seeking, inauthentic). He also employs speculation about the evolutionary origins, which would be problematic even if we accepted evolution (such as the origin of poetry before prose [which are not so easy to distinguish from one another], music before language, etc.). The problem here is that he often doesn’t argue for the interpretations he presents of the data, and when he does argue, the method is suspect.

Philosophically, he draws on Hegel, Wittgenstein, Merleau-Ponty, and most frequently, Heidegger.2 He never gives a reason why we should follow Heidegger in these matters, so those of us who find Heidegger disagreeable are already prejudiced against a significant aspect of McGilchrist’s argument. It is also not at all clear that substance dualism is false, that mind and brain activity are two different “how”s of the same thing, why the Left hemispheres mode of knowing should be deemed “inauthentic,” and why the Left’s way of being is wholly other than the Right’s way of being. Let alone that what the Right accesses is more real, valid, or accurate than the Left’s (Michael Polanyi offers a far more persuasive picture of the context-focus relationship that seems to cohere with the same data with which McGilchrist is working).3 This is closely related to his pervasive transgression of the is-ought fallacy. Value statements cannot be drawn from data but are given to data from an external perspective. For a highly irrelevant example (though one that is personally significant for my music tastes), no value is implied by the fact that Bach induces a calm heart rate and dissonant music, let’s say Rush or For Today, incites increased heart rate—nor even that the latter would stimulate the same area of the brain as “noxious stimuli.” Similarly, no ontological value can be drawn from the fact that, at least in some subjects, musical instruments stimulate the same part of the brain as “living things” (itself a heavily loaded term). All this data avails itself of many interpretations and contrary value judgments. Finally, his thesis is not only deterministic but implicitly materialistic—despite his claims otherwise. That is, if consciousness and brain are two different perspectives on the same thing, what reason do we have for attributing transcendence to the former? If religious experiences can be explained by misinterpreting brain behaviour (261-262), what room is there for the transcendent? It is resolved into merely another experience within a closed, material world. However, his materialism is of a similar sort as Marx’s, that allows for a transcendent causal force that is instantiated in every particular but is not resolved into any one of them. That is, for Marx’s, the tension between the proletariat and bourgeoisie is inescapable and realised in the life of each individual, yet the tension itself is only seen on the abstracted level of history, in the intersections of all who are the proletariat and the bourgeoisie. Similarly, the “warfare” of the hemispheres does not describe any individual’s experience or even any generation’s experience; it is played out across the tapestry of history as the ideal Left instantiated in every left hemisphere wars with the idealised Right instantiated in every right hemisphere. Such wholesale determinism is hardly convincing and not justified by his data, ignoring as it does all sorts of other forces that may favour the right or left hemisphere but are not clearly caused by either hemisphere. For those of us who are Christians, this is where his argument is particularly problematic.

Theological issues abound. For example, many of us read the Bible literarily and think that Genesis offers a narrative of God’s creating work, which indicates that language pre-existed music. It also implies that prose and poetry were simultaneous, neither evolving out of the other. Significantly, the kingdom mandate given in Genesis 1-2—intimating the whole purpose of creation—is very (though not wholly) left-oriented, involving subduing, creating, and ruling: this is the purpose of the creation, to glorify God by instantiating His rule on earth, not to open oneself to the reciprocity of being or to live an authentic right hemisphere life—whatever that might look like. His account of history also takes the place that the Bible assigns to the cosmological warfare between the kingdom of Satan expressed through unredeemed humanity and God through His redeemed people, the Church.


The Master and His Emissary is a fascinating read, offering a profound look at the complexity with which God has made our brains. However, its overarching argument, where it strives to be most profound and significant, was not persuasive to this reviewer.

  1. On the interpretation of the data of cognitive sciences, especially as it pertains to consciousness, see my review of God on the Brain. []
  2. In this, and other ways, this book is similar to Jordan Peterson’s 12 Rules for Life []
  3. For an introduction, see The Tacit Dimension or Meek’s Longing to Know; see especially Personal Knowledge []

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