[1] The encyclical suggested new directions and active participation instead of a merely passive role for the faithful in the liturgy, in liturgical ceremonies and in the life of their parish.

No less erroneous is the notion that it consists solely in a list of laws and prescriptions according to which the ecclesiastical hierarchy orders the sacred rites to be performed.

"[4] Whenever their pastors could summon a little group of the faithful together, they set up an altar on which they proceeded to offer the sacrifice, and around which were ranged all other rites appropriate for the saving of souls and for the honor due to God.

[...] Exterior worship [...] reveals and emphasizes the unity of the mystical Body, feeds new fuel to its holy zeal, fortifies its energy, intensifies its action day by day: 'for although the ceremonies themselves can claim no perfection or sanctity in their own right, they are, nevertheless, the outward acts of religion, designed to rouse the heart, like signals of a sort, to veneration of the sacred realities, and to raise the mind to meditation on the supernatural.

"[8] On the authority of the pope over the liturgy, Pius XII wrote: "the Sovereign Pontiff alone enjoys the right to recognize and establish any practice touching the worship of God, to introduce and approve new rites, as also to modify those he judges to require modification.

Bishops, for their part, have the right and duty carefully to watch over the exact observance of the prescriptions of the sacred canons respecting divine worship.

This notwithstanding, the temerity and daring of those who introduce novel liturgical practices, or call for the revival of obsolete rites out of harmony with prevailing laws and rubrics, deserve severe reproof.

He goes on to say that: "[One] would be straying from the straight path were he to wish the altar restored to its primitive table form; were he to want black excluded as a color for liturgical vestments; were he to forbid the use of sacred images and statues in Church; were he to order the crucifix so designed that the Divine Redeemer's Body shows no trace of his cruel sufferings.

The encyclical teaches that the congregations' singing of hymns or answering the priest "in an orderly and fitting manner" is approved and recommended, but "are by no means necessary to constitute it [the sacrifice] a public act or to give it a social character.

"[13] Mediator Dei advises bishops to create offices to encourage active participation and dignified services, and to ensure that individual priests do not use the Eucharist as experiments for their own purposes.

For research in this field of study, by tracing it back to its origins, contributes valuable assistance towards a more thorough and careful investigation of the significance of feast-days, and of the meaning of the texts and sacred ceremonies employed on their occasion.

It likewise attempts to reinstate a series of errors which were responsible for the calling of that meeting as well as for those resulting from it, with grievous harm to souls, and which the Church, the ever watchful guardian of the 'deposit of faith' committed to her charge by her divine Founder, had every right and reason to condemn.

[53] For perverse designs and ventures of this sort tend to paralyze and weaken that process of sanctification by which the sacred liturgy directs the sons of adoption to their Heavenly Father of their souls' salvation".

'"[20] Progressive theological advocates of modernism, many of whom were subsequently censured and silenced after Pius XII's promulgation of Humani generis in 1950, especially in France, (Henri de Lubac, Yves Congar) presented a highly colored interpretation of the encyclical.

[22] An unsigned editorial in the journal Life of the Spirit suggested that some eccentric German liturgical reformists went too far "and are now told to look at the depths of the dogma".

[24] An American journal, Orate Fratres, issued by Saint John's Abbey in Minnesota, wrote that with this encyclical of Pope Pius XII, liturgy ceases to be an unimportant composite of ceremonies and regulations.