«LAUDA SION SALVATOREM». - Sequence of the Mass for Corpus Christi, composed by St Thomas Aquinas, probably at Orvieto in 1264, on the occasion of the bull Transiturus, with which Urban IV established the Eucharistic solemnity for the whole Church, in imitation of the feast instituted at Liège in 1246 by Bishop Robert de Torote under the influence of the revelations of Blessed Juliana of Cornillon (q.v.).
The attribution of the Office and the Mass (which contains the sequence) to St Thomas was contested by the Bollandist D. Papebroch (Acta SS. Aprilis, I, Antwerp 1675, pp. 903 ff.), but was immediately vindicated by the Dominicans J. de Maison (Dissertatio historica pro officio Corporis Christi Divi Thomae, 3rd ed. Paris 1679) and A. Natalia (Dissertationes historicae et criticae quibus officium ven. Sacramenti s. Thomae vindicatur, Paris 1680); this vindication was accepted even by Papebroch himself (Conatus chronologico-historicus ad universum seriem Romanorum pontificum. Propylaeum ad Acta SS. Maii, Antwerp 1688, pp. 374-376: here is found dissertatio XLIII alias XXIII: De officio pro festo Corporis Christi Urbani IV inusu per s. Thomam composito. Moreover, in the Acta Sanctorum Bollandiana apologeticis libris in unum volumen nunc primum contractis vindicata, ibid. 1755, pp. 438-43, the Accusatio contra Papebrochium is reproduced, followed by a Responsio). Today criticism is decidedly favourable to the Dominican thesis, since the valuable testimony of St Thomas’s contemporary and friend, Tolomeo da Lucca, cannot be diminished by the belated liturgical appearance of the Office; this delay is in fact satisfactorily explained by special historical circumstances: after the death of Urban IV, the Holy See, entirely absorbed by the great difficulties of the moment, could not oversee the application of the bull Transiturus; only after the Council of Vienne (1511), where Clement V had revived Urban IV’s provisions, did the feast of Corpus Christi begin to spread, and it was therefore called the ‘new solemnity’. Since neither Urban IV nor Clement V had imposed the Office composed by St Thomas, this appeared only a few decades later and became almost universal, rapidly replacing, on account of the superiority of its content and the growing prestige of its author, the Office and Mass that the Roman Curia had to use before accepting the work of the Aquinate (cf. F. Baix–C. Lambot, La dévotion à l’Eucharistie, Gembloux–Namur 1946, p. 94).
The sequence, only verbally inspired by the hymns of Adam of Saint-Victor, is composed of 24 strophes, which follow one another in close logical sequence: after the solemn opening
Constituted by an insistent invitation to praise and joy (1-5), the rhythm broadens in the swift evocation of the shadows of the Old Testament (6-8), realized in the Eucharist (9-10), which, by multiplying in the mystery of Transubstantiation the presence of Christ “non conclusus, non confractus, non divisus,” makes Him the food of all souls (11-15), from which souls draw fruits of life or death according to the dispositions with which they receive Him (16-20). A moved cry of admiration (“Ecce panis Angelorum”) and a tender prayer to the Divine Shepherd conclude this luminous and geometrically structured composition, surrounded by the fervor of immense love.
The symmetry of the Lauda Sion is not artificial, but arises from the logical interiority of thought: it is the Gothic of poetry; just as the cathedral of Cologne is a powerful bundle of stark lines reaching toward the heavens, almost arms in prayer, so the rhythm of St. Thomas ascends in the conceptual linearity of the text toward the spaces of lofty speculation, only to transform itself, with lyrical impetus, into a warm supplication. These strophes, so limpid as to form as many articles of a perfect Eucharistic creed, so robust as to be deemed verses cast in bronze, constitute the pearl of Catholic liturgy and make their author the “Eucharistiae praece et vates maximus” (Pius XI, enc. Studiorum ducem, Sept. 29, 1923; in AAS, 15 [1923], p. 320).