ON THE SACRED LITURGY
49. From time immemorial the ecclesiastical hierarchy has exercised this right in matters liturgical. It has organized and regulated divine worship, enriching it constantly with new splendor and beauty, to the glory of God and the spiritual profit of Christians. What is more, it has not been slow - keeping the substance of the Mass and sacraments carefully intact - to modify what it deemed not altogether fitting, and to add what appeared more likely to increase the honor paid to Jesus Christ and the august Trinity, and to instruct and stimulate the Christian people to greater advantage.[47]
50. The sacred liturgy does, in fact, include divine as well as human elements. The former, instituted as they have been by God, cannot be changed in any way by men. But the human components admit of various modifications, as the needs of the age, circumstance and the good of souls may require, and as the ecclesiastical hierarchy, under guidance of the Holy Spirit, may have authorized. This will explain the marvelous variety of Eastern and Western rites. Here is the reason for the gradual addition, through successive development, of particular religious customs and practices of piety only faintly discernible in earlier Times New Roman. Hence likewise it happens from time to time that certain devotions long since forgotten are revived and practiced anew. All these developments attest the abiding life of the immaculate Spouse of Jesus Christ through these many centuries. They are the sacred language she uses, as the ages run their course, to profess to her divine Spouse her own faith along with that of the nations committed to her charge, and her own unfailing love. They furnish proof, besides, of the wisdom of the teaching method she employs to arouse and nourish constantly the "Christian instinct."
51. Several causes, really have been instrumental in the progress and development of the sacred liturgy during the long and glorious life of the Church.
52. Thus, for example, as Catholic doctrine on the Incarnate Word of God, the eucharistic sacrament and sacrifice, and Mary the Virgin Mother of God came to be determined with greater certitude and clarity, new ritual forms were introduced through which the acts of the liturgy proceeded to reproduce this brighter light issuing from the decrees of the teaching authority of the Church, and to reflect it, in a sense so that it might reach the minds and hearts of Christ's people more readily.
53. The subsequent advances in ecclesiastical discipline for the administering of the sacraments, that of penance for example; the institution and later suppression of the catechumenate; and again, the practice of eucharistic communion under a single species, adopted in the Latin Church; these developments were assuredly responsible in no little measure for the modification of the ancient ritual in the course of time, and for the gradual introduction of new rites considered more in accord with prevailing discipline in these matters.
54. Just as notable a contribution to this progressive transformation was made by devotional trends and practices not directly related to the sacred liturgy, which began to appear, by God's wonderful design, in later periods, and grew to be so popular. We may instance the spread and ever mounting ardor of devotion to the Blessed Eucharist, devotion to the most bitter passion of our Redeemer, devotion to the most Sacred Heart of Jesus, to the Virgin Mother of God and to her most chaste spouse.
55. Other manifestations of piety have also played their circumstantial part in this same liturgical development. Among them may be cited the public pilgrimages to the tombs of the martyrs prompted by motives of devotion, the special periods of fasting instituted for the same reason, and lastly, in this gracious city of Rome, the penitential recitation of the litanies during the "station" processions, in which even the Sovereign Pontiff frequently joined.
56. It is likewise easy to understand that the progress of the fine arts, those of architecture, painting and music above all, has exerted considerable influence on the choice and disposition of the various external features of the sacred liturgy.
57. The Church has further used her right of control over liturgical observance to protect the purity of divine worship against abuse from dangerous and imprudent innovations introduced by private individuals and particular churches. Thus it came about - during the 16th century, when usages and customs of this sort had become increasingly prevalent and exaggerated, and when private initiative in matters liturgical threatened to compromise the integrity of faith and devotion, to the great advantage of heretics and further spread of their errors - that in the year 1588, Our predecessor Sixtus V of immortal memory established the Sacred Congregation of Rites, charged with the defense of the legitimate rites of the Church and with the prohibition of any spurious innovation.[48] This body fulfills even today the official function of supervision and legislation with regard to all matters touching the sacred liturgy.[49]