Exposition is a manner of honouring the Holy Eucharist, by exposing It, with proper solemnity, to the view of the faithful in order that they may pay their devotions before It. We will speak later of the conditions which constitute proper solemnity, but something must first be said of the history of the practice.

HISTORY

There can be no reasonable doubt that the practice of exposition came in the wake of that most epoch-making liturgical development, the Elevation of the Host in the Mass. The Elevation itself, of which we first hear in its present sense about the year 1200, was probably adopted as a practical protest against the teaching of Peter Comestor and Peter the Chanter, who held that the bread was not consecrated in the Mass until the words of institution had been spoken over both bread and wine. Those who believed that when the words "Hoc est enim corpus meum" had been pronounced, the bread was at once changed into the flesh of our Lord, supported their opinion by adoring the Sacrament, and holding It up for the adoration of the people, without waiting for the words to be spoken over the chalice. At Paris, this elevation became a matter of synodal precept, probably before the year 1200. Before long it came to be regarded as a very meritorious act to look upon and salute the Body of the Lord. In this way, even before the middle of the thirteenth century, all kinds of fanciful promises were in circulation regarding the special privileges enjoyed by him, who, on any day, saw the Body of his Maker. He was believed to be protected from sudden death, or from loss of sight. Further, on that day he would be duly nourished by the food he took, and would grow no older, with many other extravagances. The development of these popular beliefs was also probably much assisted by a legendary element current in the romances of the Holy Grail, then at the height of their popularity. What is certain is, that among all classes the seeing the Host, at the moment It was lifted on high in the hands of the priest, became a primary object of devotion, and various devices — for example, the hanging of a black curtain at the back of the altar, or the lighting of torches held behind the priest by a deacon or server — were resorted to, to make the looking upon the Body of Christ more easy.

Whether the institution of the feast of Corpus Christi with its procession, an innovation due to the visions of the Flemish contemplative, St. Juliana Cornelion, is to be regarded as the cause, or rather the effect, of this great desire to behold the Body of Christ is somewhat doubtful. But the evidence points to it as an effect rather than as a cause, for, even before the close of the twelfth century, we find a well-authenticated story of the last moments of Maurice de Sully, Bishop of Paris, according to which, being unable on account of sickness to receive Holy Viaticum, he satisfied his devotion by having the Blessed Sacrament brought to him to gaze upon. An exactly similar incident is recorded of St. Juliana herself, when upon her death-bed. This also seems to show that the devout longing of the faithful to gaze upon the Sacred Host was not confined to the time of Mass. Moreover, we find it debated among scholastic theologians, as early as the thirteenth century, whether the looking upon the consecrated Host was permissible to those in the state of grievous sin, and it was commonly decided that far from being a new offense against God, such an act was praiseworthy, if it were done with a reverent intention, and was likely to obtain for the sinner the grace of true contrition.

In the fourteenth century, we find the practice of Exposition already established, especially in Germany. The "Septililium" of Blessed Dorothea of Prussia who died a recluse, at an advanced age, in 1394, not only bears witness to the saint's extraordinary desire to see the Blessed Sacrament, a desire which was sometimes gratified as often as a hundred times in one day, but also incidentally mentions that in certain churches near Dantzig, the Blessed Sacrament was reserved all day long in a transparent monstrance, so that pious persons like Dorothea could come to pray before It. The practice undoubtedly spread very widely, especially in Germany and the Netherlands. In the fifteenth century, we find numerous synodal decrees passed, prohibiting this continuous and informal Exposition, as wanting in proper reverence. The decree enacted at Cologne in 1452, under the presidency of Cardinal Nicholas de Cusa, altogether forbids the reserving, or carrying of the Blessed Sacrament in such monstrances, except during the octave of Corpus Christi. An earlier decree passed at Breslau, in 1416, speaks of permission having previously been given "for the Body of Jesus Christ, on some few days of the week, to be visibly exposed and shown to public view". But the bishop declares that he has perceived, that, "by this frequent exposition, the indevotion of the multitude only becomes greater and reverence is lessened". It is clear that these prohibitions did not eradicate the custom, but they seem to have led to a curious compromise, by which the Blessed Sacrament, throughout a great part of central Europe, was reserved in "Sakramentshauschen" (Sacrament houses), often beautifully carved of stone, and erected in the most conspicuous part of the church, near the sanctuary. There the Sacred Host was kept in a transparent vessel, or monstrance, behind a locked metal door of lattice work, in such a way that the Host could still be dimly seen by those who prayed outside. In the convent of Vadstena in Sweden, the motherhouse of the Brigittines, we have record of the erection of such a Sacrament House in 1454, in the following terms: "Circa festum Epiphaniae erectum est ciborium, sive columna, pro Corpore Christi, et monstrancia ibi posita cum lampade".

Another custom which seems to have been very prevalent in Germany and the Netherlands, before the close of the fifteenth century, was the practice of exposing the Blessed Sacrament during the time of Mass, apparently to add solemnity to the Holy Sacrifice thus offered. Numerous papal permissions for such Exposition will be found in the "Regest" of Pope Leo X. (See e.g. 3 Nov., 1514; 20 Nov., 1514, etc.) This practice is still a very favourite one in Belgium, though it seems directly to contravene the spirit of many directions in the official "Caeremoniale Episcoporum" prescribing that the Blessed Sacrament should, when possible, be removed from the altar at which High Mass is to be celebrated (Caer. Episc. I, XII, 8-9). Before the Council of Trent, the abuse of such frequent expositions, in Germany and elsewhere, seems to have been very much checked, if not entirely eliminated. In the sixteenth century and subsequently, the development of popular devotion in this matter have been much more restrained, and they have always been subject to strict episcopal supervision. The practice of the Forty Hours' Devotion, and the service now known as Benediction of the Blessed Sacrament, are treated separately, and the reader may be referred to the articles in question. But a good many other varieties of services, involving Exposition of the Blessed Sacrament for a longer or shorter period, began to prevail in the time of St. Philip Neri and St. Charles Borromeo. Of one such variety known as the Oratio sine intermissione, and dating at least from 1574, a full account will be found in the "Acta Mediolanesis Ecclesiae". Not very long after this, we begin to come across various religious institutes founded, with the permission of the Holy See, for the express purpose of maintaining the perpetual adoration of the Blessed Sacrament. See the article PERPETUAL ADORATION, where details are given. In most of these cases we may assume that the Blessed Sacrament is exposed upon the altar, though in some religious institutes of this kind the exposition is only continued by day.

CONDITIONS REGULATING EXPOSITION

The Church distinguishes between private and public Expositions of the Blessed Sacrament; and though the former practice is hardly known in northern Europe, or in America, it is clearly within the competence of a parish priest to permit such private exposition for any good reason of devotion, by opening the tabernacle door and allowing the ciborium containing the Blessed Sacrament to be seen by the worshipers. There is, however, in this case no enthroning of the Blessed Sacrament or use of a monstrance. Public Exposition of the Blessed Sacrament may not take place without the permission, express or implied, or the ordinary. In English-speaking countries, a monstrance is almost always used when the Blessed Sacrament is set upon Its throne, but in Germany, one frequently sees simply the ciborium, covered of course with its veil. A certain solemnity and decorum in the matter of lights upon the altar, incense, music, and attendance of worshipers is also required, and bishops are directed to refuse permission for public Exposition where these cannot be provided for.

When Mass is celebrated, or the Divine Office recited, at the altar upon which the Blessed Sacrament is exposed, a new set of rubrics comes into force, birettas are not worn, genuflexions on both knees are made before the altar, the incense and water are not blessed, the celebrant's hand is not kissed, etc. The Caeremoniale seems only to contemplate the case of Mass before the Blessed Sacrament exposed during the octave of Corpus Christi, and at the Mass of Deposition of the Quarant' Ore, but, as already noticed, in many parts of Europe, local custom has made these Masses before the Blessed Sacrament of very common occurrence. For the candles that ought to burn upon the altar, and for the ritual to be followed the reader may be referred to the articles BENEDICTION, and FORTY HOURS' DEVOTION. Other rubrical directions dealing with such matters as the use of electric light, the arrangement of the throne, etc., are given in detail in manuals like that of Hartmann, or works upon Pastoral Theology such as that of Schulze.

HERBERT THURSTON