Sentience review: Inside a controversial new idea about consciousness

We are still struggling to account for consciousness. A new hypothesis by psychologist Nicholas Humphrey challenges the basis of the discussion and argues sentience isn’t what we think

By Philip Ball

Sentience: The invention of consciousness

Nicholas Humphrey (Oxford University Press)

THERE is a shelf in my brain – and in my study too – where I store theories of consciousness, and this is where psychologist Nicholas Humphrey’s new book, Sentience, will reside. Each of these theories and hypotheses can seem compelling in the moment, especially given the confidence with which they tend to be presented. They are usually unlike each other; often, they are diametrically opposed.

For example, in Sentience …