Abstract: Discusses the role of conscious experiences 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 must meet if they are to be cases of knowledge. I argue that this approach is completely mistaken. Perceptual experiences must provide reasons for empirical beliefs if there are to be any determinate beliefs about particular objects in the world at all. So there are epistemic requirements upon the very possibility of empirical belief. The crucial epistemological role of experience 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. I explain in detail how this is so; defend my position against a wide range of objections; compare and contrast it with a number of influential alternative views in the area; and bring out its connection with Russell's Principle of Acquaintance, and its consequences for the compatibility of content externalism with an adequate account of self-knowledge.

Keywords: Brewer, empirical belief, empirical knowledge, epistemology, externalism, perception, perceptual content, perceptual experience, philosophy, philosophy of mind, reason, self-awareness, self-knowledge