Arius is widely considered to be Rowan Williams's magnum opus. Long out of print and never before available in paperback, it has been newly revised. This expanded and updated edition marks a major publishing event. Arianism has been called the "archetypal Christian heresy" because it denies the divinity of Christ. In his masterly examination of Arianism, Rowan Williams argues that Arius himself was actually a dedicated theological conservative whose concern was to defend the free and personal character of the Christian God. His "heresy" grew out of an attempt to unite traditional biblical language with radical philosophical ideas and techniques and was, from the start, involved with issues of authority in the church. Thus, the crisis of the early fourth century was not only about the doctrine of God but also about the relations between emperors, bishops, and "charismatic" teachers in the church's decision-making. In the course of his discussion, Williams raises the vital wider questions of how heresy is defined and how certain kinds of traditionalism transform themselves into heresy. Augmented with a new appendix in which Williams interacts with significant scholarship since 1987, this book provides fascinating reading for anyone interested in church history and the development of Christian doctrine.