"Consciousness matters. Arguably it matters more than anything. The purpose of this book is to build toward an explanation of just what the matter is." "Nicholas Humphrey begins this exploration of the biggest of big questions with a challenge to the reader, and himself. What's involved in "seeing red"? What is it like for us to see someone else seeing something red?" "Seeing a red screen tells us a fact about something in the world. But it also creates a new fact - a sensation in each of our minds, the feeling of redness. And that's the mystery. Conventional science so far hasn't told us what conscious sensations are made of, or how we get access to them, or why we have them at all. From an evolutionary perspective, what's the point of consciousness?" Humphrey offers a daring and novel solution, arguing that sensations are not things that happen to us, they are things we do - originating in our primordial ancestors' expressions of liking or disgust. Tracing the evolutionary trajectory through to human beings, he shows how this has led to sensations playing the key role in the human sense of Self.