Controversy erupted after an address given at a recent conference on sacred liturgy held in London. Cardinal Robert Sarah, prefect of the Congregation for Divine Worship, made an appeal to all priests everywhere to begin, with prudence and according to their circumstances, to celebrate Holy Mass ad orientem. That is, he made an unofficial but earnest appeal that during the Eucharistic, clearly sacrificial part of Mass, priests should face the altar on the same side as the congregation. Priest and people together should face toward the liturgical, symbolic east whence Christians have, since earliest times, believed that Christ will return. He made good arguments. There are many good arguments, as a matter of fact.