Catechism of the Catholic Church
1383 The altar, around which the Church is gathered in the celebration of the Eucharist, represents the two aspects of the same mystery: the altar of the sacrifice and the table of the Lord. This is all the more so since the Christian altar is the symbol of Christ himself, present in the midst of the assembly of his faithful, both as the victim offered for our reconciliation and as food from heaven who is giving himself to us. "For what is the altar of Christ if not the image of the Body of Christ?" asks St. Ambrose. He says elsewhere, "The altar represents the body [of Christ] and the Body of Christ is on the altar." The liturgy expresses this unity of sacrifice and communion in many prayers.
Thus the Roman Church prays in its anaphora:
We entreat you, almighty God,
that by the hands of your holy Angel
this offering may be borne to your altar in heaven
in the sight of your divine majesty,
so that as we receive in communion at this altar
the most holy Body and Blood of your Son,
we may be filled with every heavenly blessing and grace.
Have you heard Catholics routinely use the word 'table' to promote the understanding that the Mass is mainly or even merely a meal? To describe the altar as a table or even as the table tends to marginalize the sacrificial nature of the Mass and eliminates the understanding that the altar is the place where Christ's unique Sacrifice becomes present. Indeed, as 1383 of the Catechism teaches, it is appropriate to speak of the Mass as a sacrificial meal, the meal of the Sacrifice of the Lamb of God, a meal instituted by Christ Himself on Holy Thursday that anticipates His Sacrifice on Calvary on Good Friday.
We would do well to use the language of the Catechism. The Catechism properly passage speaks of the "table of the Lord" to distinguish the altar from a mere table. The altar is hardly a mere table, just as the chalice is hardly a mere cup. By restoring the word 'chalice' to the Canon of the Mass, the translators of the revised Missal have accurately translated the Latin original which refers to a vessel that, because the word is not used in daily parlance, helps set the Mass apart from an ordinary meal.
- The altar represents the body of Christ, so we vest the altar. The altar is the place upon which the Sacrifice of Calvary becomes present in an unbloody manner. The white "vestments" remind one of both the burial shroud of Christ and His being enrobed in the pure light of the glory and victory of His Resurrection.
In the Ordinary Form, the following should be observed:
Out of reverence for the celebration of the memorial of the Lord and for the banquet in which the Body and Blood of the Lord are offered, there should be, on an altar where this is celebrated, at least one cloth, white in colour, whose shape, size, and decoration are in keeping with the altar's structure. GIRM 304 (see also, #304 below)
What about older forms of the Mass? What are the liturgical requirements?
At the turn of the 20th century the Roman Catholic Church considered only linen or hemp to be acceptable as material for altar cloths, although in earlier centuries silk or cloth of gold or silver were used.
At that time, the Roman Rite required the use of three altar cloths, to which a cere cloth, not classified as an altar cloth, was generally added. This was a piece of heavy linen treated with wax (cera, from which "cere" is derived, is the Latin word for "wax") to protect the altar linens from the dampness of a stone altar, and also to prevent the altar from being stained by any wine that may be spilled. It was exactly the same size as the mensa (the flat rectangular top of the altar).
Above this were placed two linen cloths. Like the cere cloth, they were made of heavy linen exactly the same size as the mensa of the altar. They acted as a cushion and, with the cere cloth, prevented the altar from being dented by heavy vases or communion vessels placed on top. Instead of two cloths, a single long cloth folded so that each half covered the whole mensa was acceptable.
The topmost cloth was the fair linen, a long white linen cloth laid over the two linen cloths. It had the same depth as the mensa of the altar, but was longer, generally hanging over the edges to within a few inches of the floor or, according to some authorities, it should hang 18 inches over the ends of the mensa. On an altar without antependium and consisting of the mensa resting on columns or made after the fashion of a tomb the topmost linen did not have to overhang the edges at the sides. It could be trimmed with lace on the ends and could be ornamented with figures of chalices, hosts and the like. Five small crosses might be embroidered on the fair linen - one to fall at each corner of the mensa, and one in the middle of the front edge. These symbolised the five wounds of Jesus. The fair linen should be left on the altar at all times. When removed for replacement, it should be rolled, not folded. It symbolized the shroud in which Jesus was wrapped for burial.
A coverlet of the same heavy linen as the cere cloth and the linen cloths, and of the same length and width as the fair linen, was left on the altar whenever it is not in use. It simply protects the altar from dust and debris. Catholic Encyclopedia
- The Tabernacle is the place wherein the Body of Christ, i.e., the Real Presence, is reposed. Where parishes have retained the central placement of the tabernacle containing the Body of Christ, people are genuflecting to Jesus present in the tabernacle, not the altar. We genuflect to a person and, in certain special circumstances such as the Veneration of the Cross during the Good Friday liturgy, we kneel in profound appreciation for the victory Christ won for us. Otherwise, a bow is made toward sacred objects. We also genuflect or kneel and bow before the Body of Christ exposed in the monstrance during Adoration and Benediction of the Blessed Sacrament.
- The altar is the place where Christ's eternal sacrifice is made present, the place upon which heaven meets earth. A bow is the appropriate gesture of respect that helps us recall the altar of the Lord's Body symbolized by the altar. A bow acknowledges the Lord's Sacrifice and gift of salvation.
General Instruction of the Roman Missal
IV. SOME GENERAL NORMS FOR ALL FORMS OF MASS
Genuflections and Bows
274. A genuflection, made by bending the right knee to the ground, signifies adoration, and therefore it is reserved for the Most Blessed Sacrament, as well as for the Holy Cross from the solemn adoration during the liturgical celebration on Good Friday until the beginning of the Easter Vigil.
During Mass, three genuflections are made by the priest celebrant: namely, after the showing of the host, after the showing of the chalice, and before Communion. Certain specific features to be observed in a concelebrated Mass are noted in their proper place (cf. nos. 210-251).
If, however, the tabernacle with the Most Blessed Sacrament is present in the sanctuary, the priest, the deacon, and the other ministers genuflect when they approach the altar and when they depart from it, but not during the celebration of Mass itself.
Otherwise all who pass before the Most Blessed Sacrament genuflect, unless they are moving in procession.
Ministers carrying the processional cross or candles bow their heads instead of genuflecting.
275. A bow signifies reverence and honor shown to the persons themselves or to the signs that represent them. There are two kinds of bows: a bow of the head and a bow of the body.
a) A bow of the head is made when the three Divine Persons are named together and at the names of Jesus, of the Blessed Virgin Mary, and of the Saint in whose honor Mass is being celebrated.
b) A bow of the body, that is to say a profound bow, is made to the altar; during the prayers Munda cor meum (Almighty God, cleanse my heart) and In spiritu humilitatis (Lord God, we ask you to receive); in the Creed at the words Et incarnatus est (by the power of the Holy Spirit . . . and became man); in the Roman Canon at the words Supplices te rogamus (Almighty God, we pray that your angel). The same kind of bow is made by the deacon when he asks for a blessing before the proclamation of the Gospel. In addition, the priest bows slightly as he speaks the words of the Lord at the consecration.
II. ARRANGEMENT OF THE SANCTUARY FOR THE SACRED SYNAXIS (EUCHARISTIC ASSEMBLY)
295. The sanctuary is the place where the altar stands, where the word of God is proclaimed, and where the priest, the deacon, and the other ministers exercise their offices. It should suitably be marked off from the body of the church either by its being somewhat elevated (predella) or by a particular structure (communion rail!) and ornamentation. It should, however, be large enough to allow the Eucharist to be celebrated properly and easily seen.
The Altar and Its Appointments
296. The altar on which the Sacrifice of the Cross is made present under sacramental signs is also the table of the Lord to which the People of God is called together to participate in the Mass, as well as the center of the thanksgiving that is accomplished through the Eucharist.
297. The celebration of the Eucharist in a sacred place is to be carried out on an altar; but outside a sacred place, it may be carried out on a suitable table, always with the use of a cloth, a corporal, a cross, and candles.
298. It is appropriate to have a fixed altar in every church, since it more clearly and permanently signifies Christ Jesus, the living stone (1 Pt 2:4; cf. Eph 2:20). In other places set aside for sacred celebrations, the altar may be movable.
An altar is called “fixed” if it is attached to the floor so as not to be removeable; otherwise it is called “moveable.”
299. The altar should be built apart from the wall, in such a way that it is possible to walk around it easily and that Mass can be celebrated at it facing the people, which is desirable wherever possible. [Fr. John Zuhlsdorf offers a more accurate translation of GIRM 299—Altare maius exstruatur a pariete seiunctum, ut facile circumiri et in eo celebratio versus populum peragi possit, quod expedit ubicumque possibile sit. The main altar should be built separated from the wall, which is useful wherever it is possible, so that it can be easily walked around and a celebration toward the people can be carried out. Fr. Z continues: The Latin does not say that celebrations versus populum are desirable. It says that separation of the altar from the wall is desirable (or useful or fitting) wherever possible.] The altar should, moreover, be so placed as to be truly the center toward which the attention of the whole congregation of the faithful naturally turns. The altar is usually fixed and is dedicated.
300. An altar whether fixed or movable is dedicated according to the rite prescribed in the Roman Pontifical; but it is permissible for a movable altar simply to be blessed.
301. In keeping with the Church’s traditional practice and the altar’s symbolism, the table of a fixed altar is to be of stone and indeed of natural stone. In the dioceses of the United States of America, however, wood which is worthy, solid, and well-crafted may be used, provided that the altar is structurally immobile. The supports or base for upholding the table, however, may be made of any sort of material, provided it is worthy and solid.
A movable altar may be constructed of any noble and solid materials suited to liturgical use, according to the traditions and usages of the different regions.
302. The practice of placing relics of Saints, even those not Martyrs, under the altar to be dedicated is fittingly retained. Care should be taken, however, to ensure the authenticity of such relics.
303. In building new churches, it is preferable to erect a single altar which in the gathering of the faithful will signify the one Christ and the one Eucharist of the Church.
In already existing churches, however, when the old altar is positioned so that it makes the people’s participation difficult but cannot be moved without damage to its artistic value, another fixed altar, of artistic merit and duly dedicated, should be erected and sacred rites celebrated on it alone. In order not to distract the attention of the faithful from the new altar, the old altar should not be decorated in any special way. [Consideration for the "people's participation" amounts to a ruse to alter the direction of worship. Catholic worship is properly directed to God Who arrives from the East or the liturgical East. A simple study of this ancient orientation of the Liturgy would reveal that the current practice of versus populum worship, which tends to place the focus of worship on the congregation rather than God, is not the norm practiced for the better part of 1900+ years in the Catholic Church. Click here for the Ad Orientem Page.]
304. Out of reverence for the celebration of the memorial of the Lord and for the banquet in which the Body and Blood of the Lord are offered on an altar where this memorial is celebrated, there should be at least one white cloth, its shape, size, and decoration in keeping with the altar’s design. When, in the dioceses of the United States of America, other cloths are used in addition to the altar cloth, then those cloths may be of other colors possessing Christian honorific or festive significance according to longstanding local usage, provided that the uppermost cloth covering the mensa (i.e., the altar cloth itself) is always white in color.
305. Moderation should be observed in the decoration of the altar.
During Advent the floral decoration of the altar should be marked by a moderation suited to the character of this season, without expressing prematurely the full joy of the Nativity of the Lord. During Lent it is forbidden for the altar to be decorated with flowers. Laetare Sunday (Fourth Sunday of Lent), solemnities, and feasts are exceptions.
Floral decorations should always be done with moderation and placed around the altar rather than on its mensa.
306. Only what is required for the celebration of the Mass may be placed on the mensa of the altar: namely, from the beginning of the celebration until the proclamation of the Gospel, the Book of the Gospels; then from the Presentation of the Gifts until the purification of the vessels, the chalice with the paten, a ciborium, if necessary, and, finally, the corporal, the purificator, the pall, and the Missal.
In addition, microphones that may be needed to amplify the priest’s voice should be arranged discreetly. ["Only what is required for the celebration of the Mass may be placed on the mensa of the altar"... excepting microphones, of course. If a microphone is necessary, it might be exceedingly preferable to attach a condenser microphone to the top of the Missal stand so as to avoid cluttering up the altar with excessive technology. Since a priest would likely be directing his head toward the Missal to read it, a microphone attached to the Missal stand travels with, so-to-speak, the Missal. Wireless condenser microphones free of cables can be adapted to serve the purpose. As for concelebrants, they do not need to use the Missal stand microphone. The concelebrating priest's prayers do not need to be heard by the people because—point of fact—the priest is praying to God, not the people.]
307. The candles, which are required at every liturgical service out of reverence and on account of the festiveness of the celebration (cf. no. 117), are to be appropriately placed either on or around the altar in a way suited to the design of the altar and the sanctuary so that the whole may be well balanced and not interfere with the faithful’s clear view of what takes place at the altar or what is placed on it. [This instruction assumes versus populum worship. It's inclusion tends to obscure the orientation of the Mass which is properly assumed, in the Missal at least, to be ad orientem, i.e., people and priest facing in the same direction toward the east or liturgical east signified by the crucifix. The rubrics in the Missal, currently and for the most part ignored by priests, direct the priest to turn to the people at certain points. If the priest is facing the people, as GIRM 307 suggests, why then is the priest directed in the Missal at specific points to turn and face the people?]
308. There is also to be a cross, with the figure of Christ crucified upon it, either on the altar or near it, where it is clearly visible to the assembled congregation. It is appropriate that such a cross, which calls to mind for the faithful the saving Passion of the Lord, remain near the altar even outside of liturgical celebrations. [Why not state that there should be one crucifix, i.e., a cross with the crucified body of Christ on it, centrally stationed above an ad orientem altar? This rather dubious rubric tends to permit clumsy placements of crucifixes that divide the attention of the congregation.]