Devotion, in the language of ascetical writers, denotes a certain ardor of affection in the things of God, and even without any qualifying prefix it generally implies that this ardor is of a sensible character. On the other hand, by the term "devotions" in the plural, or "popular devotions", we commonly understand those external practices of piety by which the devotion of the faithful finds life and expression. The efficacy of these practices in eliciting feelings of devotion is derived from four principal sources, either:
No doubt other reasons besides these might be found why this or that exercise brings with it a certain spiritual unction which stimulates and comforts the soul in the practice of virtue, but the points just mentioned are the most noteworthy, and in the more familiar of our popular devotions all these four influences will be found united.
Historically speaking, our best known devotions have nearly all originated from the imitation of some practice peculiar to the religious orders or to a specially privileged class, and consequently owe most of their vogue to the fourth of the influences just mentioned. The Rosary, for instance, is admitted by all to have been known in its earliest form as "Our Lady's Psalter". At a time when the recitation of the whole hundred and fifty Psalms was a practice inculcated upon the religious orders and upon persons of education, simpler folk, unable to read, or wanting the necessary leisure, recited instead of the Psalms a hundred and fifty Pater nosters or supplied their place more expeditiously still by a hundred and fifty Hail Marys said as salutations of Our Lady. The Rosary is thus a miniature Psalter. Again, at a time when the most ardent desires of Christendom centered in the Holy Land, and when lovers of the Crucified gladly faced all hardships in the attempt to visit the scenes of the Savior's Passion, those unable to accomplish such a journey strove to find an equivalent by following Christ's footsteps to Calvary at least in spirit. The exercise of the Stations of the Cross thus formed a miniature pilgrimage. Similarly, the wearing of a scapular or a girdle was a form of investiture for people living in the world, by which they might put on the livery of a particular religious institute; in other words, it was a miniature habit. Or again, those who coveted the merits attaching to the recitation of the day and night hours of the clergy and the monks supplied their place by various miniature Offices of devotion, of which the Little Office of the Blessed Virgin and the Hours of the Passion were the most familiar.