McGilchrist has written a book of breathtaking scope – a journey not just through the neurosciences but also philosophy, literature, the arts, archaeology and anthropology – in an attempt to answer whether the lateralisation of cerebral function has influenced history. The breadth of the source material is dazzling, from basic neuroscience experiments to Russian poetry – translations are helpfully provided for those of us who are not polyglots – and the actual writing is, at times, superlative. But is what he says true?

Some may argue that it does not matter whether or not it is true. McGilchrist himself appears ambivalent. He opens with a desire to tell a story and concludes that he would not be unhappy if his thesis was eventually demonstrated to be a metaphor. Many in psychiatry might agree, and I suspect some will have a reverential approach to this work, but the more I read the more concerned I became. The credibility of this book is its foundation in neuroscience. We are interested because McGilchrist talks eruditely and, we hope, from a position of knowledge, about the scientific framework on which he based his more artistic interpretations. However, this foundation does not seem entirely sound and many of the conclusions presented go far, far beyond the available data. The impression of knowledge existing where there are only gaps is a recurrent theme.

McGilchrist has a tendency to acknowledge the limitations of the data, and then swiftly ignore them, selecting only those findings which support his thesis. Some readers may also consider that much of the neuroscience is anthropomorphised: is the off–on binary relationship of two neurons really the same as antagonism at a human relational level? The response, of course, is that this is one of the basic questions of the book. To an extent the question is a tautology: history is a product of the human brain and therefore it can only be shaped by the brain's structure and function. However, the book only serves a purpose if it can demonstrate that there has been a unique contribution to the shaping of history as a direct result of functional asymmetry and in this case the contribution of neuroscience was definitely not proven.

Much of the evidence cited was not from the neurosciences but from other disciplines. The arguments were, again, beautifully expressed but opinion among those better able to judge the content appeared deeply divided. Mary Midgley was an enthusiast, ^{Reference Midgley1} although also appeared to accept the science, but A. C. Grayling was much more cautious and less convinced. ^{Reference Grayling2}

Where did this leave me? Certainly with a deep sense of discomfort. Was this, as Mary Midgley suggested, because the book forced me to ask new questions? I do not think so. I did have ignoble reactions but they were mainly in the domain of envy at McGilchrist's skill as a writer and the breadth of his reading. The disquiet came from a growing concern, not at the questions being asked, but at a growing belief that the book was in fact another pop science misrepresentation of intra-hemispheric differences, albeit exquisitely packaged and persuasively presented. It left me asking an altogether different, perhaps overly Calvinistic, question – was it, as we say in Edinburgh, ‘all fur coat and nae knickers?’