I know very little of neuroscience beyond what I’ve read in this book and I have no way of knowing if the brain’s two hemispheres function exactly as described here. But that didn’t really matter for my appreciation of this work. Beyond an account of the functioning of the brain, The Master and the Emissary offers a rich account of two modes of human experience which are both complementary and oppositional. The account accorded with my own intuitions and clarified much of my own experience. As with most works of of large-scale system building, it seems likely that much of the book's specifics might be discredited by further research. But the staggering ambition of the work is part of what makes is so interesting. I think its relevant that McGilchrist is an independent scholar – I doubt such a work is producible within the academy. I have never read anything by an author so deeply immersed in scientific research who simultaneously possessed such a deep grasp of the humanities. I am used to scientists dismissing philosophers like Hegel, Merleau-Ponty or Heidegger, so it was refreshing to see McGilchrist engage deeply with their work and present a convincing account of how it sheds light on brain function and human experience.

The second part of the book, which analyses the entire history of western culture through the lens of the divided brain, could very easily have degenerated into a selective and potted history. And I am in fact more skeptical of the second part than the first, as I am of all attempts to demonstrate how biological reality shapes human culture. (I am not saying I don’t think links exist between the two, just that our knowledge is too fragmented and partial to provide a sweeping account over thousands of years.) But still there is much that is provocative here, and McGilchrist is nuanced enough to anticipate criticism. I agree with his criticism in the book's later sections of modern art's tendency towards greater abstraction and the move away from intuition in the pursuit of novelty. But I fear that some of the later sections, the one on modernism and post-modernism particularly, could lend grist to the ignorant online right-wing philistines who extol western classical art and culture while denigrating anything modern. This is not to say that McGilchrist has much in common which such people – his own understanding of modernist art is in fact sophisticated and he expresses appreciation for several modernist writers and musicians. Nonetheless, one could quibble with many of his characterizations. For example, he mentions Beckett as a writer particularly prone to an alienated, left-hemisphere orientation. But I think that Beckett, with his emphasis on bodily movement and the subterranean movements of the mind, could easily be shown to have expanded literature in the direction of a right-hemisphere orientation, just as McGilchrist says Merleau-Ponty and Heidegger did for philosophy.