The purpose of this arrangement was alluded to by Pope Benedict XVI in his homily at the Easter Vigil; "conversi ad Dominum" - turn towards the Lord. In short, it is a way to begin re-orienting our focus during the liturgy back toward God and contrary to any notion of the liturgy as a "self-enclosed circle" -- a point that Ratzinger critiqued about so much modern liturgical practice and theology.
(An example of this arrangement outside of a Roman Basilica)
As the Pope noted during his homily and elsewhere in his writing, this has historically been expressed by either by the literal turning toward the East (as was always the case in the Roman basilicas), or by the common direction of the priest and people facing toward a symbolic "liturgical East" -- ad orientem liturgicum.
Of course, the Pope had noted that there could be pastoral circumstances where this may not be immediately a practical option, and so the practice of at least placing an altar cross back upon the centre of altar was one means to begin that process of liturgical re-orientation.
Evidently the Pope is not suggesting that this interim step must be employed in all cases, or that a priest should not or could not simply determine to turn back to the liturgical East as it is traditionally expressed. The Pope himself celebrated Mass in this traditional way on the occasion of the Solemnity of the Baptism of the Lord in the Sistine Chapel -- an event that was, as many pointed out, as near as one can get in the Holy See to a normal parish like situation, with Catholic families coming to have their children baptized by the Pope. Indeed, many priests have pointed out that with some catechesis and preparation -- which need not be a matter of years -- it would not be terribly difficult to return the priest to his traditional place at the altar beginning with a few of the parish Masses.
Writing as a Cardinal as well, however, the Pope noted that monasteries were in a particularly good position to lead the way in this restorative reform for they did not bear the same pastoral burden that might slow this down in some typical parish settings.
I was put to mind of all of this again when my attention was thankfully drawn to the English Benedictine Abbey of Oulton in Staffordshire.
The abbey church was designed by E.W. Pugin, son of the famed Augustus Welby Northmore Pugin, the great gothic revivalist. I am told that E.W. Pugin even served at the Mass of the consecration of this church in 1854, and that he was only 18 or 19 years of age at the time that he designed this, his first church.
Returning to the point at hand, this Benedictine church used to have an arrangement very similar to that found in so many churches within Europe and some within the new world, that of another, free-standing altar placed before the older high altar.
As you can see, they had used a simpler variant upon the central altar cross and candles at that time -- as I've noted before, I believe something taller and more substantial works much better to effect the liturgical re-orientation that this ordering of the altar aims for. I digress.
However, two years ago the Benedictines here determined to remove this altar and simply restore the use of the original high altar, thereby also restoring the celebration of the liturgy ad orientem liturgicum as well.
This is noteworthy for its own sake of course, but it also struck me as illustrating well the natural conclusion to what Benedict has proposed as a Cardinal and employed as Pope. Namely, that it ultimately tends back toward the reclamation of common sacred direction within the liturgy, whether that means reclaiming the older high altar as was done here (and if there is one, it should be reclaimed for it was never required that they should be abandoned), or, in other cases and where it is structurally possible, by having the priest come around to the liturgically-Western side of the free-standing altar.
How quickly and how often this will happen will vary from place to place, but it seems important that, as with the reform of the reform itself, we keep in mind that this is a matter of stages and degrees, and we keep our eyes fixed upon this end, for this matter of the orientation of the priest at the altar is one of the singlemost important matters facing and affecting the liturgy today.
