What is the theme in Incognito: The Secret Lives of the Brain by David Eagleman?

The fallibility of the senses is a major theme in this book. Part of Eagleman's argument about the separation of the conscious and unconscious minds rests on the fallibility of the human senses. We simply cannot trust that our senses are representing to our conscious mind what is actually occurring in the outside world. Perception is much more than the mechanical translation of light or sound waves into vision and hearing. Our unconscious brain processes these bits of information and then releases the results to our conscious mind. Furthermore, our conscious minds will trust what the unconscious mind tells us over what we actually sense.