Other critics claimed neurological understanding of hemispheric differences falls short of supporting the sweeping conclusions the book draws about Western culture.

Understanding quite what that is has involved a journey through many apparently unrelated areas: not just neurology and psychology, but philosophy, literature and the arts, and even, to some extent, archaeology and anthropology.

Reviewing The Master and His Emissary in the American Journal of Psychiatry, Jacob Freedman wrote the book “valiantly addresses the effect hemispheric asymmetry has had on Western civilization" and that it chronicled "how the left brain's determined reductionism and the right brain's insightful and holistic approach have shaped music, language, politics, and art.

"[7] A review by Bryan Appleyard in Times Online described the book as suggesting "we are thinking more and more like machines, and risk losing what makes us human",[8] while David Cox in the Evening Standard wrote that the author "shows convincingly that the degeneracy of the West springs from our failure to manage the binary division of our brains."

"[9] In another positive review in Standpoint magazine, Professor Adam Zeman wrote that McGilchrist "extends [the] received wisdom with a hugely ambitious, absorbing and questionable thesis: the two hemispheres have radically contrasting personalities; that they live in a state of creative tension, sometimes declining into open war; and that their struggle for supremacy provides the key to understanding the major cultural movements of human history.

[10] In the Times Literary Supplement, W. F. Bynum wrote: "McGilchrist's careful analysis of how brains work is a veritable tour de force, gradually and skilfully revealed.

"[13] Owen Flanagan alleged many shortcomings of the book and delivered a dismissive statement: "The fact is, hemispheric differences are not well understood.