The Symbolism of the Altar

What is a Christian altar?

In liturgical vocabulary, the altar is precisely the table on which the eucharistic sacrifice is celebrated. The Code of Canon Law gives the juridical definition: "The altar, that is, the table upon which the eucharistic sacrifice is celebrated, is called fixed if it is constructed so that it adheres to the floor and thus cannot be moved; it is called movable if it can be transferred."^[3] The General Instruction of the Roman Missal gives, for its part, the theological definition: it is the place "where the sacrifice of the Cross is made present under sacramental signs," but "also the table of the Lord," and "the center of the thanksgiving that is accomplished through the Eucharist"^[4].

The altar is therefore not one accessory among others in sacred space: it is its hearth. Everything converges toward it. That is what the liturgy itself asks when it desires the altar to be, as far as possible, detached from the wall and placed so that it becomes "truly the center toward which the attention of the whole assembly of the faithful spontaneously turns"^[5]. The orientation of gazes, the arrangement of the choir, the place of the ambo and the chair: the whole furnishing of a church is ordered to this one table.

One twofold table: sacrifice and meal

The first paradox of the Christian altar is that it unites two realities that ordinary language separates: sacrifice and meal. This is the central datum that the Catechism states in a dense formula:

"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." — Catechism of the Catholic Church, no. 1383^[6]

The same Catechism had already set out, several hundred paragraphs earlier, the twofold register: "The altar of the New Covenant is the Lord's Cross, from which the sacraments of the paschal mystery flow. On the altar, which is the center of the church, the sacrifice of the Cross is made present under sacramental signs. It is also the table of the Lord to which the People of God are invited."^[7]

In other words, the same stone is Calvary and the Upper Room: the rock where the sacrifice of the Cross is made present, and the table where that sacrifice gives itself as food. The Catechism adds a third register, inherited from the Eastern liturgies: "the altar is also the symbol of the tomb (Christ truly died and truly rose again)."^[8] Sacrifice, meal, tomb: three faces of a single mystery, the paschal mystery, concentrated in a single object.

"The altar is Christ"

This concentration is explained by one last identification, the strongest: the altar signifies Christ in person. The Catechism says it without evasion: "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 the heavenly food which is given to us"^[9]. And it at once grounds this affirmation on Saint Ambrose of Milan, in the fourth century:

"For what is the altar of Christ but the figure of the Body of Christ?" — Saint Ambrose of Milan, De sacramentis, V, 7, quoted by the Catechism of the Catholic Church, no. 1383^[10]

The same Ambrose specified: "The altar represents the Body [of Christ], and the Body of Christ is upon the altar."^[11] Medieval theology would make an axiom of it. Saint Thomas Aquinas, treating of the rites of the Mass, inscribes it in the Summa theologiae: "By the altar is signified Christ himself."^[12] It is this equation that governs all the rest: if the altar is Christ, then one understands why it is kissed, why it is anointed, why a single altar suffices, and why its matter, its form, and its consecration are so carefully regulated.

From the altar of sacrifices to the altar of the Cross

The altar is not a Christian invention. All of salvation history is strewn with altars: those raised by Noah, Abraham, and Jacob, the altar of holocausts in the Temple of Jerusalem where the blood of victims flowed. But the New Testament effects a decisive shift: the true altar becomes the Cross, and the victim, Christ himself. That is why the Catechism writes that "the altar of the New Covenant is the Lord's Cross"^[13], referring to the New Testament verse that most explicitly uses the word "altar" in the sense of the earthly altar of the New Covenant:

"We have an altar from which those who serve the tent have no right to eat." — Letter to the Hebrews 13:10^[14]

The stone altar of churches therefore does not replace the sacrifice of the Cross: it makes it present. Saint Augustine had formulated the principle on which the whole eucharistic liturgy rests: in the sacrifice of Christ, "he is at once the Priest who offers and the Sacrifice offered"^[15]. The Christian altar is the place where this unique sacrifice, offered once for all, crosses the centuries under the signs of bread and wine.

The rock was Christ

Why did the Christian altar become, over the centuries, an altar of stone? The reason is not only practical. It is scriptural. Saint Paul, rereading the crossing of the desert, identifies the rock from which water gushed with Christ himself:

"For they drank from the supernatural Rock which followed them, and the Rock was Christ." — First Letter to the Corinthians 10:4^[16]

Stone, in the Bible, is not a neutral matter: it speaks of solidity, permanence, foundation — and all of that points to Christ. The First Letter of Peter develops the image:

"Come to him, to that living stone, rejected by men but in God's sight chosen and precious. […] Behold, I am laying in Zion a chief cornerstone, chosen and precious." — First Letter of Peter 2:4-6^[17]

This is exactly the link the liturgy makes when it recommends the fixed altar: it "in a clear and permanent way signifies Christ Jesus, the living stone"^[18]. The stone altar is not a block of mineral: it is a profession of faith in him who is the cornerstone of the spiritual edifice.

Beneath the altar, the souls of the martyrs

One last biblical root governs an immemorial usage: the placing of relics beneath the altar. In his vision in Revelation, John sees, at the opening of the fifth seal, the martyrs gathered in a precise place:

"I saw under the altar the souls of those who had been slain for the word of God and for the witness they had borne." — Revelation 6:9^[19]

This verse nourished the whole Christian practice of the tomb-altar, whose history we shall see. The martyr, who united his own blood to that of Christ, rests literally beneath the place where Christ's sacrifice is offered: his liturgical place expresses his theological place. The Code of Canon Law still keeps it today as a duty: "The ancient tradition of placing relics of martyrs or other saints under a fixed altar is to be preserved."^[20]

The table of the Last Supper and domestic meals

The first Christian altars were not blocks of stone, but tables of wood, after the likeness of that of the Last Supper. So long as worship was celebrated in houses, the Eucharist was made upon the family meal table. The Catholic Encyclopedia notes that "it is probable that [the earliest altars] were made of wood, like that used by Christ at the Last Supper"^[21]. Rome long kept this memory: the Lateran basilica still venerates a wooden table held to be that upon which Saint Peter celebrated.

The tombs of the martyrs and the catacombs

The turning point came with the persecutions. In the catacombs, Christians took the habit of celebrating upon the tombs of the martyrs, notably upon the arcosolia — those arched niches hollowed above a tomb whose slab served as a table. The Liber Pontificalis attributes to Pope Saint Felix I (third century) the decree prescribing the celebration of Mass "upon the tombs of the martyrs"^[22]. From this was born the tomb-altar: the table of sacrifice now rests upon the bones of the witness.

Saint Augustine carefully specified the meaning of this practice, against any suspicion of idolatry: sacrifice is offered not to the martyrs, but to God alone, even when celebrated upon their tomb.

"We do not erect altars over these tombs to sacrifice to the martyrs, but to the one God of the martyrs and our own. […] For it is to God, not to them, that the priest sacrifices, though he sacrifices upon their tomb; for he is the priest of God, not of them." — Saint Augustine, The City of God, book XXII, ch. 10^[23]

This distinction is capital: the altar remains wholly ordered to God. The martyr does not receive worship; he accompanies the sacrifice, as a witness joined to Christ's offering. The Second Council of Nicaea (787) would erect into a rule the presence of relics in altars^[24].

From the wooden table to the stone altar

As the Church emerged from hiding and built basilicas, the stone altar imposed itself. Stone speaks permanence; it evokes the rock-Christ; it befits the definitive character of public worship. The oldest known conciliar decree requiring stone altars is that of the Council of Epaon, in Gaul, in 517^[25]. Little by little, the slab of a single stone became the norm — a rule that current law maintains: "According to the traditional practice of the Church, the table of a fixed altar is to be of stone, and indeed of a single natural stone."^[26]

The great continuity can be read in this overall picture:

The mensa, the stipes, the sepulchrum

A consecrated stone altar is not a uniform block: it has a precise anatomy, and each part has a name and a meaning. The mensa is the table properly so called, ideally cut from a single slab of natural stone; it is upon it that the sacrifice rests. The stipes is the support — single foot, columns, or masoned mass — which raises the table. The sepulchrum, finally, is the cavity hollowed to enclose the relics of the saints^[27].

This structure is not only technical: it restates the mystery. The table is the place of the meal and the sacrifice; the support raises it like an "opening toward heaven"; the relic cavity unites Christ's sacrifice to that of his martyrs. A complete altar is thus a catechesis in stone.

The five crosses: the five wounds of Christ

The most eloquent detail is engraved in the table itself. On the mensa of a consecrated altar, five crosses are incised: one at each of the four corners, and one at the center. They "signify his five wounds"^[28] — the wounds of the hands, the feet, and the side of the Crucified. At the dedication, the bishop pours chrism upon these five crosses, then burns five heaps of incense upon them. The altar thus bears, inscribed in its flesh of stone, the five wounds of Christ: it is not only the place of the sacrifice, it is its marked body.

The same symbolism is found in the five grains of incense set in the form of a cross in the paschal candle, on the evening of the Vigil: they too figure the five wounds of the Risen One^[29]. The grammar of the five wounds thus runs through the altar, the candle, and the whole paschal liturgy — see The Symbolism of Candles.

The altar stone and the portable altar

When Mass had to be celebrated outside a consecrated church — on mission, on a journey, in war — the Latin tradition resorted to the altar stone (or "sacred stone," altare portatile): a small consecrated slab of stone, containing sealed relics, laid upon an ordinary table to receive the chalice and paten^[30]. The principle is eloquent: it is not the wooden table that "makes" the altar, but the consecrated stone — that is, the sign of the rock-Christ. Where the sacred stone was, there was the altar.

The relics beneath the altar

The sepulchrum thus prolongs, down to our churches, the memory of the catacombs. The present liturgy "fittingly retains the custom of placing beneath the altar to be dedicated the relics of saints, even those who are not martyrs," while requiring that their authenticity be verified^[31]. The link is explicit: the martyr made of his death a sacrifice united to Christ's; he therefore rests beneath the place where that sacrifice is made present. The goldsmith's shrine containing these relics belongs to an art of its own — see Reliquaries in Christian Art.

The anointing with chrism: the altar becomes Christ, the "Anointed One"

It is in the rite of dedication that the symbolism of the altar reaches its summit. A fixed altar is not only installed: it is consecrated according to the Roman Pontifical^[32]. The central gesture is an anointing: the bishop spreads holy chrism over the whole table and over the five crosses. Now chrism is the oil of kings, of priests, and of the baptized; it is, par excellence, the sign of the messianic anointing. The rite then makes explicit what it accomplishes:

"The anointing with chrism makes the altar a symbol of Christ, who, before all others, is and is called 'The Anointed One'; for the Father anointed him with the Holy Spirit and constituted him the High Priest, so that on the altar of his body he might offer the sacrifice of his life for the salvation of all." — Rite of Dedication of a Church and an Altar (1977), ch. II, no. 16^[33]

The logic is luminous. The word "Christ" means "Anointed" (in Hebrew Mashiach, "Messiah"; in Greek Christos). In anointing the altar, the Church makes the stone a sign of Christ, the Father's Anointed. By this anointing, the stone table becomes the sacramental sign of what it represents: Christ who, on the altar of his body, offers the sacrifice of his life.

Incensation, clothing, illumination

The rite continues with a series of gestures, each laden with meaning. Incense is burned upon the altar, to signify that Christ's sacrifice, perpetuated there in mystery, rises to God as a fragrant offering^[34] — a meaning found again at every Mass in the incensation of the altar. The altar is clothed with a cloth, because it is the table of the Lord's meal. It is finally illumined, because Christ is "a light for revelation to the Gentiles"^[35]. Anointing, incense, cloth, light: four gestures unfolding, one after another, the facets of the mystery.

An altar perpetually reserved to God

Once dedicated, the altar is withdrawn from every profane use. The law is categorical: "An altar, whether fixed or movable, is to be reserved for divine worship alone, to the exclusion of any secular use."^[36] The same logic makes it preferable to erect, in new churches, only one altar, "which in the assembly of the faithful signifies the one Christ and the one Eucharist of the Church"^[37]. One altar, because one Christ: symbolism governs even architecture.

The kiss of the altar

If the altar is Christ, then the gestures addressed to it are not polite manners: they are acts of veneration addressed to a person. The most visible is the kiss of the altar. At the beginning and the end of Mass, the priest bows profoundly, then kisses the table:

"On reaching the sanctuary, the priest, the deacon, and the ministers reverence the altar with a profound bow. To express veneration, the priest and the deacon then kiss the altar; and the priest, if appropriate, incenses the cross and the altar." — General Instruction of the Roman Missal, no. 49^[38]

This kiss venerates in a single movement the Christ whom the altar represents and the martyrs whose relics are sealed in the stone^[39]. Tradition also saw in it the kiss of the Bridegroom and the Bride: Christ and his Church meet at this table.

The incensation of the altar

At solemn Mass, the priest incenses the whole altar, walking around it. The gesture honors the altar as Christ is honored, and it prolongs the incensation of the dedication: the rising smoke signifies prayer and sacrifice ascending to God. The altar, the bread and wine, the cross, the assembly: all that the incense enfolds is marked with the same respect owed to the mystery accomplished there.

Before the altar, the assembly gathers

All these gestures say one same thing: the altar is the point of convergence of the assembly. That is why the liturgy wants it visible, central, unencumbered, "truly the center toward which the attention of the whole assembly of the faithful spontaneously turns"^[40]. Around this one table the unity of the Church is realized: one altar, one sacrifice, one Body.

Versus Orientem and versus populum

One question runs through the whole history of the altar: in which direction does one pray? For centuries, the general norm was prayer toward the east (versus Orientem): priest and people turned together toward the east, toward the rising sun, image of the risen Christ who is to return. Some great Roman basilicas, including Saint Peter's, nonetheless had Mass celebrated facing the people, for reasons tied to the orientation of the building.

After the Second Vatican Council, celebration facing the people (versus populum) became widespread, favored by the recommendation of an altar detached from the wall allowing it to be walked around and Mass to be celebrated facing the assembly^[41]. The council itself did not impose it, and the versus Orientem remains permitted. On the meaning of this orientation, see Why Are Churches Oriented?.

The cross at the center: the "interior orient"

Cardinal Joseph Ratzinger, the future Benedict XVI, devoted famous pages to this question in The Spirit of the Liturgy (2001). For him, the essential is not whether the priest faces the people or not, but that priest and people look together toward the Lord. Where the altar cannot be reoriented, he proposes a simple sign: placing the cross at the center of the altar, as an "interior orient" toward which all turn^[42]. The altar thus remains what it must be: not the place of a face-to-face between the community and its minister, but the common opening toward God.

William Durand and the Rationale

The Middle Ages brought the symbolic reading of the liturgy to its height. The great reference treatise is the Rationale divinorum officiorum of William Durand of Mende, bishop and canonist, written around 1285-1291. Its first book details the spiritual meaning of the church, the altar, and the ornaments. For Durand, as for the whole tradition, the altar signifies Christ — his divinity and his humanity — but it can also signify, in various passages, the heart of the faithful where the spiritual sacrifice of charity is offered^[43].

The altar of the heart

This interior reading is not a medieval invention: it goes back to the Fathers. Saint Augustine had already made man's heart an altar:

"Our heart, when it is lifted up to Him, is His altar. […] We offer to Him upon the altar of our heart the sacrifice of humility and praise, kindled by the fire of ardent love." — Saint Augustine, The City of God, book X, ch. 3^[44]

Thus the symbolism of the altar does not stop at the stone of the sanctuary. The wooden altar became a stone altar; the stone altar became the sign of Christ; and Christ, in turn, wills to make the heart of each baptized person an altar where the sacrifice of love is offered. The table raised at the center of the church is the visible image of what grace wills to accomplish in the innermost soul.

• The Symbolism of the Tabernacle — the eucharistic reservation, distinct from the altar.
• The Symbolism of Candles — the paschal candle and the five wounds, the altar candlesticks.
• The Symbolism of Incense — the incensation of the altar.
• Why Are Churches Oriented? — versus Orientem and the direction of prayer.
• The Architecture of a Cathedral — the place of the altar in sacred space.
• Reliquaries in Christian Art — the shrine of the relics placed beneath the altar.
• Early Christian Art · The Mosaics of Ravenna — the altar in the first basilicas.