It is a testimony to the genius of William James that scarce a lecture on attention passes without the speaker quoting him on the subject. This has, however, also been a cause for concern: do we really understand any more about this amorphous topic now, than we did when James wrote Principles of Psychology? It might occur to more jaundiced reviewers that the fact that James abandoned psychology completely after finishing this great book implies that he was beaten by the subject of attention, for, in many senses, the study of attention is at the very heart of the science of psychology. And if the founding genius of psychology could not crack the code of attention, is there any hope for the rest of us?