The Breviary itself is divided into four seasonal parts - winter, spring, summer, autumn - and comprises under each part (1) the Psalter; (2) Proprium de Tempore (the special office of the season); (3) Proprium Sanctorum (special offices of saints); (4) Commune Sanctorum (general offices for saints); (5) Extra Services.
The third council of Carthage in 397 forbade anything but Holy Scripture to be read in church; this rule has been adhered to so far as the liturgical epistle and gospel, and occasional additional lessons in the Roman missal are concerned, but in the divine office, on feasts when nine lessons are read at matins, only the first three lessons are taken from Holy Scripture, the next three being taken from the sermons of ecclesiastical writers, and the last three from expositions of the day's gospel; but sometimes the lives or Passions of the saints, or of some particular saints, were substituted for any or all of these breviary lessons.
The various inquiries instituted during the middle ages, such as the Domesday Book and the Breviary of Charlemagne, were so far on the Roman model that they took little or no account of the population, the feudal system probably rendering information regarding it unnecessary for the purposes of taxation or military service.
In the Breviary the psalms are arranged according to a disposition dating from the 8th century, as follows.
The first step in the evolution of the Breviary was the separation of the Psalter into a choir-book.
The Latin Breviary also affirms that his body was afterwards translated to Salerno, where it is said to lie in the church built by Robert Guiscard.
The Theodosian Code and the Breviary of Alaric alike seem to imply a continuance of the municipal system which had been established by the Romans; nor does the later Lex Visigothorum, though avowedly designed in some points to supersede the Roman law, appear to have contemplated any marked interference with the former fora, which were still to a large extent left to be regulated in the administration of justice by unwritten, immemorial, local custom.
The Breviary rightly so called, however, only dates from the nth century; the earliest MS. containing the whole canonical office is of the year 1099 and is in the Mazarin library.
The Roman Breviary has undergone several revisions.
Although some of his quatrains are purely mystic and pantheistic, most of them bear quite another stamp; they are the breviary of a radical freethinker, who protests in the most forcible manner both against the narrowness, bigotry and uncompromising austerity of the orthodox ulema and the eccentricity, hypocrisy and wild ravings of advanced Sufis, whom he successfully combats with their own weapons, using the whole mystic terminology simply to ridicule mysticism itself.