Liturgical reforms of Pope Pius XII

The liturgical reforms of Pope Pius XII continued a process initiated by Pope Saint Pius X, who began the process of encouraging the faithful to a meaningful participation in the liturgy. Pope Pius XII redefined liturgy in light of his previous encyclical Mystici corporis and reformed several liturgical practices in light of this teaching. The liturgical teaching of Pius XII is contained especially in his encyclical Mediator Dei of 1947. Although Pius XII felt compelled to reprove the desire for novelty among certain leaders of the Liturgical Movement, the liturgical reforms undertaken later in his pontificate were in fact relatively broad in their scope.

Until Pius XII, the Church celebrated Mass always in the mornings, as a reflection of the original sacrifice of Jesus Christ. In light of the displacement and persecution in much of Europe during World War II, evening Masses were permitted on a provisional basis. They turned out to be popular, opening the Church to new publics.

To allow for the faithful to receive Communion at Masses in the evening and at other times, Pius XII decreed several changes to regulations regarding the Eucharistic fast. Prior to 1953, Catholics were required to abstain from consuming any food from midnight before receiving Holy Communion. This requirement to fast from midnight was changed by the Apostolic constitution Christus Dominus, issued in 1953, by which, the fasting period was reduced to three hours from solid foods and one hour from liquids before communion. Water or medicines did not break the fast. Four years later, in the Motu Proprio Sacram Communionem, the fasting requirements were further reduced.

Combining continuity and innovation, the reforms made under Pius XII to the sacred Liturgy helped to prepare the way for the more dramatic liturgical reforms that would follow the Second Vatican Council (1962–1965), though it is unclear how far Pope Pius XII himself intended these reforms to go. One goal of the liturgical magisterium of Pius XII was to restore a more reverential atmosphere within Church buildings. The use of vernacular language, cautiously favoured by Pope Pius, was hotly debated at his time. He increased non-Latin services, especially in countries with expanding Catholic mission activities. Though insisting on the primacy of Latin in the liturgy of the Western Church (cf. Mediator Dei, par. 60), the pontiff did nevertheless approve the use of the vernacular in the Ritual for sacraments and other rites outside the Mass. All such permissions, however, were to be granted by the Holy See, and Pius XII strongly condemned the efforts of individual priests and communities to introduce the vernacular on their own authority.

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