O'BRIEN, THOMAS C.

Editor, translator, liturgical scholar, teacher; b. Providence, Rhode Island, October 14, 1923; d. Chambersburg, Pennsylvania, June 18, 1991. Thomas O'Brien taught for a number of years at the Dominican House of Studies in Washington, D.C., and became a recognized authority on the writings of St. Thomas Aquinas. In 1966, he left the Dominicans and the following year married Florence Gaudet.

Among his writings on St. Thomas was his study Metaphysics and the Existence of God (Thomist Press 1960). O'Brien joined the team of scholars working under the general editorship of the English Dominican Thomas Gilby in the 1960s to prepare the renowned English-Latin critical edition of the Summa Theologiae. He was responsible for six of the 60 volumes.

From 1966 to 1970 he worked on the editorial staff of Corpus Instrumentorum Publications in Washington, D.C., and from 1970 to 1975 he taught at the Hartford Seminary Foundation in Connecticut. While at Corpus, his projects included the Corpus Dictionary of Western Churches (1970), of which he was general editor. He also completed the editing of the Encyclopedic Dictionary of Religion (3 vols., 1979). Returning to Washington in 1977, O'Brien served as executive editor of volume 17 of the New Catholic Encyclopedia, a thematic and comprehensive account of how the Church had changed as a result of Vatican Council II.

From 1979 until his death in 1991, he served as editor, researcher, and translator on the staff of the International Commission on English in the Liturgy (ICEL). He was editor and translator of the Documents on the Liturgy: Conciliar, Papal, and Curial Texts, 1963–79. O'Brien was a major contributor to the liturgical texts produced by ICEL throughout the 1980s, particularly the Order of Christian Funerals (1985), the Rite of Christian Initiation of Adults (1986), and the Book of Blessings (1987).

O'Brien's principal and enduring work was as research specialist on the Latin texts of the Missale romanum of Paul VI. His research was an essential part of ICEL's project to revise its 1973 edition of the Missale. From this research he compiled "A Lexicon of Terms in the Missale romanum," with more than 500 entries.

[j. m. schellman]