Bill Brewer sets out an original view of the role of conscious experience in the acquisition of empirical knowledge. Most epistemology of perception takes a person's possession of beliefs about the mind-independent world for granted and goes on to ask what further conditions these beliefs mustmeet if they are to be cases of knowledge. Brewer argues that this approach is completely mistaken. Perceptual experiences must provide reasons for empirical beliefs if there are to be any determinate beliefs at all about particular objects in the world. The crucial epistemological role ofexperience lies in its essential contribution to the subject's understanding of certain perceptual demonstrative contents, simply grasping which provides him with a reason to endorse them in belief. Brewer explains in detail how this is so, defends his position against a wide range of objections,and compares and contrasts it with a number of influential alternative views in the area. He brings out its connection with Russell's Principle of Acquaintance, and examines its conseqences for the compatibility of content externalism with an adequate account of self-knowledge. Perception and Reasonoffers a fresh approach to epistemology, turning away from the search for necessary and sufficient conditions for knowledge and working instead from a theory of understanding in a particular area.