In the first place there are purely ecclesiastical festivals whose celebration is confined within the four walls of the Church (_festa chori_), and festivals which have their bearing upon the common life of the people, chiefly on account of the rest from labour which is conjoined with them (_festa fori_). The so-called _feriæ_ and the festivals strictly so called are clearly distinguished from one another. According to the practice of the Church, the ordinary days of the year have their place in the liturgy, and share to a certain extent in the festal character of the season, although distinguished from those days on which is commemorated some mystery of our redemption or the memory of a saint. These latter are holy days (_festa_) in a higher sense. These holy days again are divided into greater or lesser feasts—in the language of the rubrics, into _festa duplicia_ and _simplicia_, with an intermediate class, the _semi-duplicia_. This is more marked in the arrangements of the Breviary than in the Missal. This does not exhaust the differences between festivals, for there are further distinctions in their rank, especially in the case of the festivals of our Lord and of the chief mysteries of our redemption, _i.e._ _duplicia majora_, and _duplicia primæ_ and _secundæ classis_. The _festa duplicia primæ classis_ are usually kept up for eight days—the so-called octave; so too some of the _secundæ classis_. The different rank of feasts is not so elaborate among the Greeks and Russians, for they divide their festivals simply into greater, intermediate, and lesser, which are marked in their Calendars by special signs.