God is beyond time, but every person is firmly planted in it. History impacts us endlessly, including the ways we understand the church and its teachings. This has been the case since the time of the earliest believers. In History and Heresy, Joseph F. Kelly considers heresies and the historical forces that shaped them. In his customarily engaging style, he demonstrates that historical forces and human beings of particular historical eras play a major role in how both orthodoxy and heresy come into being and how they are understood. Far from reducing orthodoxy and heresy to historical forces, he shows rather that a grasp of the historical context of both is essential in understanding them and especially in determining what might be orthodox or heretical. Joseph F. Kelly, PhD, is professor of religious studies at John Carroll University in Cleveland, Ohio. His books include The Feast of Christmas, The Origins of Christmas, The Ecumenical Councils of the Catholic Church, and others, al published by Liturgical Press.