Book excerpt: This textbook introduces the concepts and theories central for understanding the nature of knowledge. It is aimed at students who have already done an introductory course. Epistemology, or the theory of knowledge, is concerned about how we know what we do, what justifies us in believing what we do, and what standards of evidence we should use in seeking truths about the world of human experience. The author's approach draws the reader into the subfields and theories of the subject, guided by key concrete examples. Major topics covered include perception and reflection as grounds of knowledge, the nature, structure, and varieties of knowledge, and the character and scope of knowledge in the crucial realms of ethics, science and religion.