I have to admit I found the early chapters in this book a little disconcerting, if not disturbing, as Feinberg describes what happens when parts of the brain go wrong. But the point he makes, similar to Oliver Sacks in The Man Who Mistook His Wife for a Hat, is that the 'self' is extraordinarily resilient. It's in the latter part of the book that Feinberg addresses the philosophical dimensions of this topic, and I think that's what makes the book worth reading. Feinberg's specific approach is of a 'nested hierarchy', which he claims is evident throughout biology whereby the 'whole is greater than the sum of its parts'. His discussion on the difference between the 'subjective' and 'objective' experience of consciousness is the best I've read on the subject. He makes the point that the brain is 'not aware of itself' but of everything else. He argues that the mind is only `material' to the possessor, but `immaterial' to an observer. Therefore, everyone's conscious experience is a 'delusion' to everyone else. He makes a compelling argument that computers will never be sentient and therefore never be alive.