As the title suggests, this short book deals with the role of the brain in thought, consciousness and religious experience (all in 170 pages!). The main claims are that certain parts of the brain contain "specialized social hardware" and that this is responsible for: 1) the perception of other people's intentions and emotions; 2) the illusory perception of "presences, spirits, ghosts and gods"; 3) the perception of our own conscious self. The first half of the book approaches these questions in rather general philosophical terms, and the second half focuses on brain function.
The book is an easy and interesting read, intended for those with no specialized knowledge. It has no references at all, but a short list of suggested further reading. As a neuroscientist myself, and therefore not a member of the target readership, I may be too critical, but I feel that new and controversial theses should first be debated before a specialist audience before being presented in a book with no references.
Not that all in the book is new or controversial. Indeed, the first of Graziano's claims is certainly not. He describes with admirable clarity some of the more interesting results of systems neurophysiology over the last fifteen years, including mirror neurons, and gives standard interpretations.
His second claim that "presences, spirits, ghosts and gods" result from the illusory attribution of mind to inanimate objects is also not new, because several anthropologists have made similar proposals since the 19th C to explain the origins of animism. But in claiming that all religious experience is illusory Graziano does brook controversy. He also states with almost no argument that "There are no fundamental moral truths of the universe. Morality is not defined outside of us; it is a physiological construct of the brain." In saying this he appears to commit the fallacy of "nothingbuttery". All beliefs and experiences are presumably constructs of the brain, but does that make them all illusory? Puzzlingly, he also claims that he is not anti-religious and that he does not want to explain away religion, which makes me wonder if I have misunderstood him, but he writes explicitly on p50 "The spirit world ... is a creation of the brain. It is a perceptual illusion".
Graziano's third claim seems to me the most original, and it is here that I would have most wished for a less popular approach. He claims to have no less than a solution to the problem of consciousness (including qualia)! His essential idea is that our social brain machinery, which evolved to represent the minds of others, when turned inwards creates consciousness. I don't know whether this idea is new, but it was to me. I find it very interesting, but not yet well supported and not a solution to the problem of consciousness. Graziano recognizes the difficulty of the problem on p16: "How can awareness itself be explained as the processing of information in the brain? It turns out, however, that even this long-sought philosophical - one might say alchemical - understanding of mind falls into place rather neatly when considering the brain hardware that is tuned to social perception." He deals with this in more detail in chapter 4 ("Explaining Consciousness"). His arguments there do not convince me that he has solved problem of consciousness, but they are interesting.
There are a few minor errors. For example, Graziano writes on p141 that "the emotional content of the hypothalamus was dicovered in the 1950s in rats", forgetting the pioneering stimulation experiments of Walter Hess in Zurich in the 1920s and 1930s (Nobel prize in 1949), which showed in great detail the emotional role of the hypothalamus. But on the whole the science in the book is accurate.
A good book for a train journey, even if it doesn't solve the problem of consciousness.
