The Feast of Corpus Christi

The feast of Corpus Christi is cause for major celebration throughout the Church on the Thursday following Trinity Sunday. Over time this feast day had lost its importance and grandeur but is now beginning to gain its rightful place back in the hearts and minds of the faithful. What many do not realize is that the author of the Mass and Divine Office for Corpus Christi was St Thomas Aquinas; the father of Scholasticism who brought such devotion and beauty out of what was considered to be an arid and complex field.

Corpus Christi is a feast that was introduced late into the calendar of the Church. While most of the other feasts in the classical Roman Missal had been established for almost a millennium, the feast of Corpus Christi wasn’t introduced until the 13th century. In August of 1264, Pope Urban IV issued a papal bull, Transiturus, promulgating Corpus Christi as a feast for the Universal Church. He was acting after years of petitions from several sources, most notably from St. Juliana de Cornillon (1193-1252), who had received visions from the Savior requesting such a feast.[1] Pope Urban cast his eyes around the known world for candidates to compose a Mass and Office for the Feast. His search ended with Thomas Aquinas.

St. Thomas reading his work to Pope Urban IV
while Bonaventure humbly tears his own apart.

Most of the Mass and Office he wrote can still be seen and heard in the Liturgy of the Roman Rite. It is work of genius, which the famous Pius Parsch described as, “unquestionably a classic piece of liturgical work.”[2] Testimony to the greatness of work comes also from other great saints, such as St Bonaventure. Having also been commissioned by the Holy See to write an office for Corpus Christi, upon reading just one page of Thomas’ efforts, he immediately took his work – almost certainly a great masterpiece as well – and burned it in front of St Thomas. When the shocked St. Thomas asked, “But why?” Bonaventure replied, “Because I would not have it on my conscience, Thomas, that I had attempted to stand between the world and this.”[3]

When St. Juliana asked Christ why He desired this feast, He responded that it that the liturgical year of the Church would remain incomplete until the Blessed Sacrament had a feast of its own, and He wished it to be instituted for the following reasons: First, in order that Catholic doctrine might receive aid from the institution of this festival at a time when the faith of the world was growing cold and heresies were rife. Second, the faithful who love and seek truth and piety could draw from this source of life new strength and vigor to walk continually in the way of virtue. Third, irreverence and sacrilegious behavior toward the Divine Majesty in the Blessed Sacrament might, by sincere and profound adoration, be extirpated and repaired. Then He bade her to announce to the Christian world His will that this feast should be observed.[4]

For St. Thomas the mystery of Christ's Body and Blood is the mystery of the Incarnate God, the Word made Flesh, and his work does not merely cover the main themes of the doctrine of the Blessed Sacrament. The magnificent texts composed by this Prince of Theologians were so profoundly spiritual and theological, and yet, at the same time readily understood by all; exemplify the universal instructive character of the Sacred Liturgy. Their composition required more than the talents of a poet. Before he could write of the Holy Eucharist with such noble simplicity, St. Thomas was obliged to examine and study everything God has permitted us to know about His most noble Sacraments. The teaching of the Church on the Real Presence, the nature of Christ's sacrificial offering in the Mass, and Holy Communion are not only beautifully expressed, but theologically sound. The Lauda Sion, the sequence for the Mass, reveals much of this fine teaching.


St. Thomas also wrote a hymn for Vespers: Pange Lingua (Sing, tongue, the mystery of the glorious Body), from which we have the Tantum Ergo verses sung at Benediction. His hymn for Matins, Sacris Solemniis (Sacred Solemnity), includes the great Panis Angelicus (Bread of Angels) meditation best known in the setting by Cesar Franck. The third hymn for Lauds is the Verbum Supernum Prodiens (Word Descending from Above), from which we take the other Benediction hymn, O Salutaris Hostia (O Saving Victim). Finally, St. Thomas Aquinas wrote a hymn of Eucharistic thanksgiving, Adore Te Devote (Devoutly I Adore Thee), which in the translation by the Jesuit poet Gerard Manley Hopkins expresses the mystery and wonder of our reception of Jesus in Holy Communion.



In his 2003 encyclical on the Holy Eucharist, Ecclesia de Eucharistia, Blessed John Paul II praised these hymns and poems of the Solemnity of Corpus Christi: “Let us make our own the words of Saint Thomas Aquinas, an eminent theologian and an impassioned poet of Christ in the Eucharist, and turn in hope to the contemplation of that goal to which our hearts aspire in their thirst for joy and peace."[5] Each of these hymns provides great doctrinal statements of the truths of the Incarnation, the Paschal Mystery, and the Eucharist while expressing devotion to Jesus Christ as Lord and Redeemer.

At the end of Holy Mass on this feast day there is often a procession of the Blessed Sacrament, generally displayed in a monstrance, outside the church building. The procession is followed by Benediction of the Blessed Sacrament. A notable Eucharistic procession is that presided over by the Pope each year in Rome, where it begins at the Archbasilica of St. John Lateran and passes to the Basilica of Saint Mary Major, where it concludes with Benediction of the Blessed Sacrament. This procession is a time when Catholics can show their love for Christ in the Real Presence by honoring Him in a very public way. It is also a wonderful way in which we can show our love for our neighbors by bringing Our Lord and Savior closer to them.

The Procession begins at St. John Cantius Church.

First Communicants lead the priests and religious
before out Eucharistic King out into the streets of Chicago.

Hundreds walk in procession around the
 neighborhood of the Church.

Benediction at one of the outside altars.

The second nocturn of Matins contains St Thomas’s own writings, the very ones for which Christ spoke to him from a crucifix and said, “Thou hast written well of me, Thomas.” They are sermons written by the saint, from which I take here a brief extract:

O banquet most precious! … Can anything be more excellent than this repast, in which not the flesh of goats and heifers, as of old, but Christ the true God is given us for nourishment? What more wondrous than this Holy Sacrament! In it bread and wine are changed substantially, and under the appearance of a little bread and wine is had Christ Jesus, God and perfect man. In this sacrament sins are purged away, virtues are increased, the soul is saturated with an abundance of spiritual gifts. No other sacrament is so beneficial. Since it was instituted unto the salvation of all, it is offered by the Church for the living and the dead, that all may share in its treasures.

When St. Thomas first heard his brethren singing the Office he had composed and arranged, it is said that he started to cry, weeping tears of love and gratitude to the Eucharistic Lord who had inspired such a thing of splendor.[6] Did God, I wonder, give Thomas a glimpse, perhaps, of the mighty future his Feast was to have? Did He show him the millions joining in Eucharistic processions throughout the years; walking through cities, towns, countrysides, and villages with our enthroned Lord? Did he see the flowers strewn on the streets of Italy for the enthroned Body of Christ or the sawdust carpets intricately designed throughout the alleys of Spain? Whether he knew it or not, St. Thomas had written the prayers and hymns by which Christ’s bride, the Church, would forevermore praise her divine Spouse.

O Sacrament most holy! O Sacrament divine!

All praise and all thanksgiving, be every moment thine!

[1] Johner, Dom Dominic, Chants of the Vatican Gradual, St. John's Abbey Press, (Collegeville MN, 1940), 233.
[2] Chegwidden, James, Corpus Christi and Thomas Aquinas, Centre for Thomistic Studies, Sydney, Australia, Universitas, Vol. 2 (1998), No. 2.
[3] Johner, Chants of the Vatican Gradual, 234.
[4] Chegwidden, Corpus Christi and Thomas Aquinas.
[5] Pope John Paul II, Ecclesia De Eucharistia, Encyclical Letter, (Rome, 2003), retrieved at: http://www.vatican.va/holy_father/special_features/encyclicals/documents/hf_jp-ii_enc_20030417_ecclesia_eucharistia_en.html
[6] Chegwidden, Corpus Christi and Thomas Aquinas.