Lesson Four: "Accidental" and "Essential" Parts of the Office
In earlier lessons, the reader became familiar with the various parts of the Breviary, including the weekly Psalter, the Proper of the Season (containing lessons and material for feriae and seasonal feasts) and the Proper of the Saints (containing lessons and material for sanctoral feasts).
The reader also learned that the Ordinary of the Offices (the A Section) provides the skeleton upon which elements -- such as psalms, lessons, and versicles -- are superimposed to create the unique Office of the day.
The Changeable Elements of the Office
For the purpose of knowing where in the Breviary to find the materials to be used in the Office of the day, the Breviary has classified those elements into two categories: (1) the Psalms with their antiphons at all the Hours, and the lessons with their responds at Matins -- the "essential" part of the Office; and (2) everything else, such as invitatories, chapters, brief responds, antiphons on canticles, etc. -- the "accidental" part of the Office.
The First General Rule
The Breviary's straightforward rule is this: unless the specific Proper of the day states otherwise, the essential part of the Office is always to come from the weekly Psalter (B Section) and Proper of the Season (C Section), while the accidental part of the Office is to come from the Proper of the Saints (E Section) or the appropriate Common (F Section).
Put another way, unless the specific Proper of the day states or provides otherwise, the Psalms with their antiphons at all the Hours, and the Matins lessons with their responds, are to be taken from the weekly Psalter and the Proper of the Season. All other elements of the Office are to come from the Proper of the Saints or the appropriate Common.
The Second General Rule
However, the Breviary has a second general rule, and it is this: where the Proper of the day provides some element of the Office, whether Psalms, or lessons, or direction to a Common, such as "All from Common 17," follow that more specific rule.
Example: The Feast of St. Blase (E81-E82) contains no specific rubrics. It provides only a Collect and a Matins lesson iii. Therefore, following the rules outlined above, the Psalms at all the Hours will come from the weekly Psalter, and the Matins lessons and responds will come from the Proper of the Season, except lesson iii which is given in St. Blase's Propers. The rest of the Office will come from the appropriate Common, that of Martyrs, Common 5.
Example: The Feast of the Purification (E76, et seq.) clearly states, "All from Common I of B.V.M., except" what is given there as proper. Therefore, this more specific direction controls over the general rule that essential parts of the Office are taken from the weekly Psalter and Proper of the Season. The reader, therefore, should absolutely ignore the Psalms and lessons in the B and C Sections, and recite the Office solely according to the Proper on page E76, supplying whatever is missing from Common I of the B.V.M.
With some practice and as the reader learns actual offices in which to use them, these two rules will become familiar.
The next lesson will be the first to introduce an actual office with more than one changeable element. Compline, the first Hour of the Office learned in this program, contains only one changeable element -- that of the daily Psalms. In Lauds, the reader will have to contend not only with Psalms, but a "Chapter" (short scriptural reading), a Hymn, an antiphon on the canticle Benedictus, and a Collect of the Day.
In preparation for the next lesson, please continue reciting Compline and re-reading Lessons Three and Four of this series.