Sentience - Nicholas Humphrey *****

The first seventy-odd pages of this book are absolutely phenomenal (pun intended, though still true). We start with a near-stream of consciousness prologue - very appropriate for a book on sentience - and then go on to have a description of the early part of Nicholas Humphrey's career in a wonderfully approachable fashion with a writing style somewhere between a deep conversation and a thought process. I particularly loved Humphrey's description of his heading off to Elba to investigate the paranormal claims of the eccentric Hugh Sartorius Whitaker and his experiences with Dian Fossey (not always pleasant) when visiting to study the 'natural psychologist' ability of gorillas.

The book then takes a change of tack, signified by the author heading the next chapter 'To work', as he sets out to build for us his theory on the nature of sentience and 'phenomenal consciousness'. This too is very interesting, but lacks the same storytelling verve. It's also a lot harder to get your head around, as a lot of the time we are dealing with rather wispy philosophical concepts. The central thesis is that sentience is about not the ability to react to sensations (as it originally meant), but to be consciously aware of what it's like to experience sensations (that's phenomenal consciousness, I think - though I need to say 'I think' because it is difficult to take in).

The job Humphrey has is to persuade the reader of his thesis, apparently not accepted across the board by any means, that sentience arises from a particular mechanism in the brain. This, he suggests, was linked to warm-bloodedness, so it is likely that only mammals and birds (presumably potentially also including earlier dinosaurs) have been sentient - though not all to the same level. He gives a (to me) quite convincing argument that, for example, playing is a good indicator of sentience.

There were times when I think there could have been more explanation (and he might have better avoiding some of the confusing technical terms). So, for example, I don't think there is enough distinction between the sensation of redness as we experience it and the quality of an object being red, which is a simple physical property of giving off photons in a certain range of energies. To philosophers used to discussing this topic, there is a yawning gap between the two - but to the ordinary reader they are much closer and the distinction needed better handling. The same is true of some of the other philosophical niceties that are needed to really get your head around this topic.

Despite this resulting in sometimes feeling like I was experiencing Humphrey's ideas like a view through gauze (going all sensational there), reading this book was a real pleasure. 

Hardback:   

Kindle:  

Using these links earns us commission at no cost to you

Review by Brian Clegg - See all of Brian's online articles or subscribe to a weekly digest for free here