Altar (Catholic Church)
In the Catholic Church, an altar is a table or structure on which Mass is celebrated. Relics of martyrs or other saints are commonly set into the altar. Typically centrally located in the sanctuary, the altar is to be the focus of attention in the church. At the beginning of the Roman Rite of Mass, the priest first of all reverences the altar with a kiss and only after that goes to the chair at which he presides over the Introductory Rites and the Liturgy of the Word. Except in a Solemn Mass, a priest celebrating the Tridentine Mass remains at the altar the whole time after saying the prayers at the foot of the altar.
The rite of dedication of a church and of the altar points out that the celebration of the Eucharist is "the principal and the most ancient part of the whole rite, because the celebration of the eucharist is in the closest harmony with the rite of the dedication of a church", and "the eucharist, which sanctifies the hearts of those who receive it, in a sense consecrates the altar and the place of celebration, as the ancient Fathers of the Church often assert: 'This altar should be an object of awe: by nature it is stone, but it is made holy when it receives the body of Christ.
In Greek and some other languages used in the Byzantine Rite, the same word is used for an altar and for the area surrounding it; that is to say, the entire sanctuary. To refer unambiguously to the altar itself the terms "Holy Table" or "Throne" are used.
Obligation
Augustin Joseph Schulte says that Pope Sixtus II was the first to prescribe that Mass should be celebrated on an altar, and that there are accounts according to which Lucian of Antioch celebrated Mass on his breast whilst in prison, and Theodore, Bishop of Tyre on the hands of his deacons.Position
Early Christians faced east at prayer, a practice witnessed to by Clement of Alexandria, Tertullian, and Origen. Churches were generally built with an east–west axis. In the earliest churches in Rome the altar stood at the west end and the priest stood at the western side of the altar facing east and facing the people and the doors of the church. Examples are the Constantinian St. Peter's Basilica and the original Basilica of Saint Paul Outside the Walls. In the East, early churches had the altar at the east end and the priest, facing east, stood at the western side of the altar, with his back to the people and the doors. This later became the common practice also in western Europe. It was adopted in Rome in the 8th or 9th century.The churches that Christians built after the legalization of their religion in the Roman Empire were not modelled on pagan temples, which were not intended to accommodate large numbers of people. The model used was that of the public basilicas that served for meetings such as sessions of law courts. These were generally spacious, and the interior was divided by two or four rows of pillars, forming a central nave and side aisles. At the end was a raised platform, often situated in an apse, with seats for the magistrates. In basilica-style Christian churches the apse was reserved for the bishop and his clergy; the faithful occupied the centre and the side aisles, and between the clergy and people stood the altar.
Material
The earliest altars for celebrating the Christian Eucharist were of wood and identical in form with ordinary house tables, as was doubtless used at the Last Supper. The only such ancient wooden table still preserved is in the Lateran Basilica, and fragments of another are preserved in the Santa Pudenziana church in Rome. A tradition that lacks convincing evidence says that Peter celebrated the Eucharist on both. Optatus of Mileve reproves the Donatists for breaking up and using for firewood the altars of the Catholic churches, and Augustine of Hippo reports that Bishop Maximianus was beaten with the wood of the altar under which he had taken refuge.Helena gave golden altars ornamented with precious stones to the original Church of the Holy Sepulchre. Pulcheria, sister of Theodosius II, presented an altar of gold to the Basilica of Constantinople. Popes Sixtus III and Hilary presented several altars of silver to the churches of Rome.
Gregory of Nyssa speaks of the consecration of an altar made of stone. Since wood is subject to decay, the baser metals to corrosion, and the more precious metals were too expensive, stone became in course of time the ordinary material for an altar. The earliest decree of a council prescribing that an altar which is to be consecrated should be of stone is that of the provincial council of Epeaune, France, in 517.
The present discipline of the Latin Church distinguishes between the "table" of an altar and the supports or base. The latter, provided it is dignified and solid, may be of any material. On the other hand, "in keeping with the Church’s traditional practice and with what the altar signifies, the table of a fixed altar should be of stone and indeed of natural stone", except where the episcopal conference authorizes the use of another material that "is dignified, solid and well-crafted." "A movable altar may be constructed of any noble and solid material suited to liturgical use, according to the traditions and usages of the different regions."
In Eastern Christianity the use of stone, wood or metal is permitted.
Form
The usage of celebrating the Eucharist on the tombs of martyrs is by the Liber Pontificalis ascribed, probably mistakenly, to Pope Felix I. According to Johann Peter Kirsch the usage is likely to have preceded Pope Felix and to have concerned the celebration of Mass privately in the underground cemeteries known as the catacombs: the solemn celebration of the martyrs took place in the above-ground basilicas built over their place of burial.Within the catacomb crypts the Eucharist could be celebrated on a stone slab placed over the grave or sarcophagus of one or more martyrs within a space hollowed out of the tufa walls so as to form an arch-like niche. Both in the catacombs and in the above-ground churches the altar could also be a square or oblong block of stone resting on one or more columns or on a masonry structure that enclosed the relics of martyrs. Instead of masonry, upright stone slabs could be used, thus forming, with the top slab, a stone chest containing the relics. This no doubt brought about both a change of form, from that of a simple table to that of a chest or tomb.
Usually an altar should be fixed and ritually dedicated, but a mere blessing is sufficient for a movable altar. In a church a fixed altar is appropriate, but in other places set aside for sacred celebrations the altar may be movable.
Relics
The practice of celebrating the Eucharist over the graves of martyrs is probably the origin of the rule that demanded that every altar must contain the relics of martyrs.The General Instruction of the Roman Missal directs that relics should be verified as authentic, but that they do not have to be the remains of those who died for the faith.
The Caeremoniale Episcoporum adds: "Such relics should be of a size sufficient for them to be recognized as parts of human bodies; hence excessively small relics of one or more saints must not be placed beneath the altar. The greatest care must be taken to determine whether the relics in question are authentic; it is better for an altar to be dedicated without relics than to have relics of doubtful authenticity placed beneath it. A reliquary must not be placed upon the altar or set into the table of the altar; it must be placed beneath the table of the altar, as the design of the altar permits."
In earlier centuries minute portions of relics were inserted into the table of the altar and also into the altar stones that at that time were called movable altars. The cavity into which they were placed was called the sepulchrum. The relics could be of several saints, but two had to be martyrs until 1906, when the Congregation of Rites decided that it was sufficient to enclose relics of two canonized saints of whom one was a martyr. The relics were placed in a reliquary of lead, silver, or gold, large enough to contain also three grains of incense and a small attestation of consecration on a piece of parchment. In an altar stone, the relics were inserted directly, without a reliquary. There were precise rules also about where exactly in the altar the relics were to be placed and about the stone cover for the cavity.
In ancient churches in which the altar is built over the tomb of a saint or over the relics that have been placed there, a niche below the altar offered a view of the tomb or reliquary and allowed the faithful to touch it and to place in contact with it that would then be venerated as second-class relics. The best known example is the Niche of the Palliums in St. Peter's Basilica in the Vatican. It is now approached by descending steps, since the present floor is considerably higher than that of the original basilica. Other churches also have in front of the altar a similar semicircular hollow area, known as the confessio, even if the altar is not built over a holy tomb, as in the Lateran Basilica and the Basilica di Santa Maria Maggiore.
Surroundings
According to the General Instruction of the Roman Missal the altar should be located in the sanctuary and set apart from the rest of the church in some way.The sanctuary or chancel or presbytery, as well as being elevated above the floor level of the rest of the church, is often, though less frequently than in the past, demarcated by altar rails.
Even within an elevated sanctuary, the altar itself is often placed on a higher platform set off by one or more steps. The platform is known as the predella.
The altar may also be marked with a surmounting ciborium, sometimes called a baldachin.
As well as the altar, the sanctuary contains the credence table, the ambo and the seats for the clergy.