INSTALLATION: Generally, the ceremonial act by which a person ordained and appointed is formally put into possession of an ecclesiastical dignity or benefice. In the English Church the term is applied specially to the office of a canon or prebendary (i.e., the act of placing him in his stall) or to the enthronization of a bishop.

INSTITUTE OF THE BLESSED VIRGIN. See ENGLISH LADIES.

INSTITUTION: In canon law, the final, act by which a person elected by the chapter, or nominated by the government, is appointed by the proper authority to an ecclesiastical benefice, more especially a bishopric.

INTENTION. See SACRAMENT, § 4.

INTERCESSION. See MEDIATOR.

INTERDICT: The prohibition of public worship and of the administration of the sacraments (interdictum officiorum divinorum), as an ecclesiastical penalty. An interdictum locale applies to a definite place or district, an interdictum personale to definite persons. The former is the more frequent, especially the interdictum generale, which the medieval popes pronounced against whole countries in their conflicts with secular rulers. Instances of the use of the interdict may be found as early as the time of Gregory of Tours; but not till the eleventh century did it become a regular part of ecclesiastical law, and only gradually did it assume the character of a definite institution with fixed limitations which it bears in the Corpus juris canonici. The total interdict forbade public worship, the administration of the sacraments, and Christian burial. Mitigations gradually came in; in 1173 Alexander III. allowed the baptism of infants and the absolution of the dying; in 1208 Innocent III. added confirmation and preaching, absolution under certain conditions, the private burial of clerics, the recitation of the canonical hours, and low masses in convents of regulars, extending this last privilege a year later to bishops. These concessions were granted on condition that no excommunicated or personally interdicted persons be present, that the doors be closed, and that no bells be rung. Boniface VIII., who also allowed baptism and confirmation of adults, permitted public worship with open doors and ringing of bells at Christmas, Easter, Pentecost, and the Assumption; Martin V. and Eugenius IV. extended this privilege to the whole octave of Corpus Christi, and Leo X. to that of the Conception. Special exemptions were granted to the Franciscans and other religious orders; but Clement V. and the Council of Trent insisted on their observance of the interdict. A local interdict was last proclaimed by Paul V. in 1606, against the republic of Venice. It is no longer considered a practical part of church discipline, but the right to impose it is theoretically maintained. Both personal and local interdicts may occur as "censures of broad application." The right to impose them is held to be inherent in the pope, councils, bishops (regularly with their chapters, sometimes without them), and in special cases the chapters themselves; monastic superiors may also impose personal interdicts upon their subjects. Interdicts may terminate of themselves if a condition has been expressed; otherwise they are removed by the person who imposed them, his successor, delegate, or superior. Only a bishop can absolve from a local interdict "of broad application"; but any approved confessor may remove a particular personal interdict. This form of penalty does not occur in Protestant ecclesiastical law.

(C. T. G. VON SCHEURL†.)

BIBLIOGRAPHY: Bingham, Origines, XVI., iii. 7; L. Ferraris, Prornpta bibliotheca canonica, s.v. "Inderdictum," 11 vols., Venice, 1782-94; A. L. Richter, Lehrbuch des . . . Kirchenrechts, ed. W. Kahl, pp. 783 sqq., Leipsic, 1886; E. Friedberg, Lehrbuch des . . . Kirchenrechts, pp. 274 sqq., ib. 1895; P. Hinschius, Das Kirchenrecht . . . in Deutschland, v. 19 sqq., Berlin, 1895; Neander, Christian Church, iii. 355-356, 454, iv. 161 et passim; E. B. Krehbiel, The Interdict, its History and its Operation, Washington, 1909.