This book is about all things consciousness, great and small. It starts by pointing to the key characteristic of consciousness, without realizing which it cannot be understood: like everything else about the mind, it is fundamentally a kind of computation. Among many other matters, this explains: how it is that we share some aspects of consciousness with bacteria; how it can arise in artificial machines and not just living ones; how the empty cocoon of the self that it spins ends up pretending to be the butterfly; and how consciousness dooms this virtual butterfly to the splendor and the...