This book explores the idea of truth and the communication of truth through witnessing.From the religious standpoint, witnessing is what makes it possible for people to believe in divine revelation.It is deeply present in many Biblical texts and especially in John’s gospel, and goes to the heart of Christian evangelization.Properly understood, witnessing avoids the opposite extremes of fundamentalism and skepticism.The book provides an overview of philosophical and theological epistemology, introduces the notion of witnessing in philosophers, and examines the way in which Jesus Christ gives witness to the truth by sacrificing his life on the Cross, and by being raised up by his Father at the Resurrection.This dynamic is applied to Christians who give witness to the truth in a variety of ways.The author considers the rationality of the witnessing process that leads to a person-centered anthropology.