GIOSEPPE MARIA TOMMASI, Blessed. - Cardinal, liturgist, historian, and theologian of the Theatine Order, born at Licata (Sicily) on 12 Sept. 1649, died at Rome on 19 Jan. 1713.
The eldest son of the Dukes of Palma and Princes of Palmedusa, he renounced his primogeniture in favor of his brother and entered the Theatine Order in Palermo, where he professed on 25 March 1666. Ordained priest at Christmas 1673, he spent nearly forty years in Rome, mostly at S. Silvestro al Quirinale, devoting himself to the study of Roman liturgy, the Bible, ecclesiastical history, and the Fathers of the Church. He combined his knowledge of classical languages with the study of Oriental tongues—Arabic, Ethiopic, Syro-Chaldean, and Hebrew—which he learned from the learned Rabbi Moses of Cave, whom he had converted to the Christian faith. For his scholarship, for the important research he conducted in archives and libraries, and for the publication of his works (the *Codices Tommasiani*), he was acclaimed, even by Protestants, as one of the most learned men of his age and remains, even today—especially in the field of Roman liturgy—an authority of the first rank. His efforts toward liturgical reform aimed less at innovation than at restoring and preserving the ancient tradition. He held various offices in the Roman Congregations; in 1712 he was created cardinal. He was beatified in 1803; his feast is kept on 19 January.
Among his principal publications, most of which appeared under the pseudonym Giuseppe Maria Caro, the following should be noted in chronological order: *Codices Sacramentorum nongentis annis antiquiores* (1680; these are four extremely ancient sacramentaries from the 7th–8th centuries, namely the *Missale Gelasianum*, *Missale Gothicum*, *Missale Francorum*, and *Missale Gallicanum vetus*; this edition, the first in date and importance, retains its full value even today); *Psalterium iuxta duplicem editionem... Romanam et Gallicanam una cum Canticis et Hymnarium atque Orationale* (1683; with this edition T. restored the use of obeli and asterisks, which had been lost for nearly a thousand years); *Responsorialia et antiphonaria Romanae ecclesiae* (1686, based on 9th–12th-century manuscripts from the Vatican Library and the monastery of St. Gall); *Antiqui libri Missarum Romanae ecclesiae* (1691; namely the Antiphonary of St. Gregory the Great, known as the *Comes*, already corrected by Alcuin, together with the Lectionary and the chapters of the Gospels; thus T. supplemented the *Missale plenarium* of the Roman liturgy). Also important are the *Institutiones theologica antiquorum Patrum* (1709–12), which comprise a series of dogmatic and moral works by the holy Fathers arranged according to an *Indiculus* (1701) or study plan by which T. sought to provide the clergy with a complete course in patristic theology. He also left other original works and numerous pamphlets on historical and biblical criticism, among which those on the reform of the liturgical books of the Roman Church remain of current interest.
Works: *Opera omnia*, ed. A. Vezzosi (2 vols., Rome 1747–69). Other pamphlets edited by Vezzosi in *Scrittori dei Chierici Regolari* (II, Rome 1780, pp. 409, 416–27) and by G. Mercati, *Opuscoli inediti del beato card. G. T.* (Rome 1905).
