What do we mean when we say we "know" something? What is this knowledge and how do we come by it? What exactly counts as an object of knowledge? And on what basis do we defend our claims to know against thosethe skepticswho deny that knowledge is possible or that our criteria for knowing can ever be satisfied?These questions and many others are addressed in this fascinating collection of essays by leading philosophers, who discuss the nature, meaning, and extent of human knowledge. Included are works by Robert Almeder, William P. Alston, Robert P. Amico, Roderick M. Chisholm, Edmund L. Gettier, Richard Feldman, Peter D. Klein, Keith Lehrer, Kenneth G. Lucey, John Pollock, and others. Several essays are original to this collection and break new ground on such issues as the Problem of the Criterion.