The main idea of this book is that perceiving is a way of acting. Perception is not something that happens to us, or in us. It is something we do. Think of a blind person taptapping his or her way around a cluttered space, perceiving that space by touch, not all at once, but through time, by skillful probing and movement. This is, or at least ought to be, our paradigm of what perceiving is. The...