Semir Zeki is professor of neurobiology at the University of London, a pioneer in the study of the visual brain, and his massive, up-to-date knowledge of the complexity of the visual system is clearly evident on every page. But what is particularly impressive to the reviewer is how he combines such detailed, in-depth knowledge of neuroscience with rich insights into art. Not many have been able to cross disciplinary boundaries with such grace and to such thought-provoking effect.