Jesus' best-known mandate--after perhaps the mandate to love God and neighbor--was given at the Last Supper just before his death: ""Do this in memory of me."" Indeed, a case can be made that to ""do this"" is the source and summit of the way Christians carry out Jesus' love-mandate. Of course, Christians have debated what it means to ""do this,"" and these debates have all too often led to divisions within and between them--debates over leavened and unleavened bread, reception of the cup, real presence and sacrifice, ""open"" or ""closed"" communion, this Supper and the hunger of the world. These divisions seem to fly in the face of Jesus' mandate, causing some to wonder whether this is ""really"" the Lord's Supper we celebrate (compare 1 Corinthians 11). Everything turns on just what it means to ""do this."" The purpose of the Center for Catholic and Evangelical Theology's 2012 conference was to address at least some of the many aspects of this question--to address them together, as Catholic, Protestant, and Orthodox pastors and theologians, and all participants in the Supper. ""It is a sad irony that the Eucharist, the great sacrament of Christian unity, has become a prime source of division. Happily, the contributors to What Does It Mean to ""Do This""? refuse to accept division as our fate. The essays are uniformly excellent, both scholarly and readable. This book is an exceptional resource for use in both classroom and congregational settings."" --Joseph L. Mangina, Wycliffe College, University of Toronto James J. Buckley is Professor of Theology at Loyola University Maryland. He has contributed to and edited (with Frederick Bauerschmidt and Trent Pomplun) The Blackwell Companion to Catholicism (2007). He is associate director of the Center for Catholic and Evangelical Theology. Michael Root is Professor of Systematic Theology at The Catholic University of America and Executive Director of the Center for Catholic and Evangelical Theology. He was formerly the Director of the Institute for Ecumenical Research, Strasbourg, France.