Celtic liturgies show the wide-ranging influence of the Irish missionary-monks, who tended to appropriate liturgical elements from all parts of the Greek and Latin churches. The Celtic liturgy emphasizes a strong personal relationship with Christ and with the Trinity.
The term Celtic rite has been used for the ancient liturgy celebrated in Ireland, Scotland, Britain, Gallicia, and Brittany before these churches gradually adopted the calendar and liturgy of Rome (as early as 633 in Gallicia and as late as the eleventh century in Scotland). In a more restricted sense, the “Celtic rite” refers to the liturgy celebrated in the churches and monasteries of Ireland and regions heavily influenced by Irish missionary-monks from the late sixth to the early ninth century.
With regard to the Mass, the liturgy represented by the few books and fragments that are of Irish provenance do not possess a sufficient cohesion nor do they reflect a work sufficiently autonomous and original to constitute a separate rite. While all rites borrowed elements from other traditions, the Irish seem to have done very little in the way of composing original prayers or codifying texts, and arranging ceremonies. Some evidence indicates the adoption of an expanded Roman ordinary with few variable texts (exemplified in the Stowe Missal) while other sources follow a Gallican or Spanish order (as in the sacramentary fragments of Fulda and St. Gall). When the work of an Irish hand does appear, it betrays a remarkable familiarity with obscure patristic writings and liturgical formularies from all over the Christian world—Egypt, Rome, Gaul, but especially Spain and Milan—genuine “souvenirs” of the missionary activity of Irish monks.
In outline, the structure of the Mass in the Stowe Missal follows:
CONFESSION
Confession of sins and litany of saints (Roman and Irish)
[preparation of gifts at the altar]
Several collects
Gloria
Collects
EPISTLE
Psalm and collect
Diaconal litany
Collects post preem
GOSPEL
Alloir: Alleluia
Oratio super evangelium
Partial uncovering of the gifts
Creed
Full uncovering of gifts
Collect
[Names or litany]
Oratio post nomina
Additional collects
[Pax]
Preface Dialogue
Celtic preface and Sanctus
According to the “tract” that follows the Masses in the Stowe Missal, the Mass was sung in its entirety. Although no written melodies survive from the Celtic chants, the Irish are known to have taught them to the monks of Northumbria (northern England) who abandoned them when John the Archcantor from St. Peter’s was “borrowed” to teach the Roman chants (c. 675).
Dependence on continental sources is also discernible in the Celtic celebration of the hours, though similarities to other Western rites are not as pronounced as in the Mass. What survived of the early cathedral office in Irish monastic rules relates closely to the cathedral tradition in the rest of the West; lauds in the Antiphonary of Bangor (late seventh century) is almost identical to the office at Milan. The purely monastic hours, on the other hand, show remarkable creativity. None of the Gallican monastic rules followed Cassian’s description of Egyptian monastic practice as closely as the Irish who arranged the psalms for the horae diurnae (secunda [sic] prime, terce, sext, none, vespers), assigning three thematically appropriate psalms to each. For the night office, the Irish monastic rules are unique: Columba assigned twelve psalms to the first two night hours (initium noctis: Gallican duodecimä, medium noctis) but during the third hour (matutinum or vigilia) his monks prayed anywhere from 24 (summer weeknights) to 75 psalms (Saturdays and Sundays from November 1–January 31). The division of the night office into three hours is itself unique to the Irish.
Unlike the liturgists of the Mediterranean rites, the Irish authors had neither an ancient liturgical patrimony nor a tradition of Christian-Latin literature of their own as a basis for formulating Celtic euchology. The fact that they used a language that was not their own may explain, at least in part, the extent of their eclecticism. But the Irish monks were avid scholars, collectors, and copyists of everything they could obtain—Greek and Latin. Their particular choice of elements from so many liturgical traditions betrays, if anything, a fascination with the unusual and the obscure.
The Irish proved themselves most original in the illumination of manuscripts and the composition of hymns and collects for the office. They used the idioms, language, ideas, and forms that had grown out of the various traditions of the church and transformed them into artistic and poetic forms that clearly reflect their native genius. The Eastern influence can be discerned in their illuminations which are nevertheless filled with Gaelic serpents and dragons. Though in Latin, many of the hymns and collects in the Antiphonary of Bangor are composed in a meter that does not reflect either classical or accentual rhythmic patterns but instead follow the ancient meters of their native poetry, replete with rhyme and alliteration.
The devotional practices and original texts of the Celtic authors reflect a lifestyle that is centered more on a person than on an ecclesial relationship with Christ and the ever-present Trinity. The most obvious and influential example is the practice of private penitence which followed the missionary monks on all their journeys. This typically Irish individualism was absorbed into the “renaissance” of the Carolingian era and reflected in its reshaping of the Western liturgy. The piety which produced long lists of apologiae (prayers of unworthiness) and influenced the Romano-Frankish or Romano-Germanic liturgy for the rest of the Middle Ages was manifest quite early in the liturgical texts of Ireland.