From ancient times, the position of the priest and the people reflected this understanding of the Mass, since the people prayed, standing or kneeling, in the place that visibly corresponded to Our Lord’s Body, while the priest at the altar stood at the head as the Head. We formed the whole Christ – Head and members – both sacramentally by Baptism and visibly by our position and posture. Just as importantly, everyone – celebrant and congregation – faced the same direction, since they were united with Christ in offering to the Father Christ’s unique, unrepeatable and acceptable sacrifice.
When we study the most ancient liturgical practices of the Church, we find that the priest and the people faced in the same direction, usually toward the east, in the expectation that when Christ returns, He will return “from the east.” At Mass, the Church keeps vigil, waiting for that return. This single position is called ad orientem, which simply means “toward the east.”
Having the priest and people celebrate Mass ad orientem was the liturgical norm for nearly 18 centuries. There must have been solid reasons for the Church to have held on to this posture for so long. And there were! First of all, the Catholic liturgy has always maintained a marvelous adherence to the Apostolic Tradition. We see the Mass, indeed the whole liturgical expression of the Church’s life, as something which we have received from the Apostles and which we, in turn, are expected to hand on intact. (1 Corinthians 11:23)
Secondly, the Church held on to this single eastward position because of the sublime way it reveals the nature of the Mass. Even someone unfamiliar with the Mass who reflected upon the celebrant and the faithful being oriented in the same direction would recognize that the priest stands at the head of the people, sharing in one and the same action, which was – he would note with a moment’s longer reflection – an act of worship.
Even before his election as the successor to St. Peter, Pope Benedict has been urging us to draw upon the ancient liturgical practice of the Church to recover a more authentic Catholic worship.
It would also be a mistaken notion to look at the recovery of this ancient tradition as a mere “turning back of the clock.” Pope Benedict has spoken repeatedly of the importance of celebrating Mass ad orientem, but his intention is not to encourage celebrants to become “liturgical antiquarians.” Rather, His Holiness wants us to discover what underlies this ancient tradition and made it viable for so many centuries, namely, the Church’s understanding that the worship of the Mass is primarily and essentially the worship which Christ offers to His Father. — From Ad Orientem by Bishop Edward J. Slattery, Bishop of Tulsa, OK, August 2009
Mass is celebrated ad orientem at St. Charles Borromeo during the liturgical seasons of Advent and Lent, at other special liturgies, and at the Traditional Latin Mass on the first Fridays of the month.