From Plato to Quine, this volume provides a concise collection of the essential, classic readings in theory of knowledge.Epistemology, or the theory of knowledge, is one of the oldest and most central branches of philosophy. Do we know what we think we know? What are the sources of knowledge? These are among the perennial questions of philosophy. This volume contains twenty of the most important historical contributions - from the earliest times to Wittgenstein, from China to the USA - to this area of philosophy. Several of the texts address the problem of skepticism, whose challenge to the very possibility of knowledge has been the main inspiration to reflections on knowledge.A substantial introduction by the editor, together with his preamble to each text, helps make this volume an invaluable one for students taking historically informed courses on the theory of knowledge.