PREVENZIONE (of jurisdiction). — It is the legal effect attached to the exercise of priority, whereby a judge, by forestalling the exercise of jurisdiction by another judge who is likewise competent in his own right, becomes the sole person entitled to judge.
Prevention of jurisdiction may occur in two cases: in so-called mixed-forum cases, that is, cases in which both the State and the Church have jurisdiction, and between different competing ecclesiastical tribunals.
I. IN CASES OF MIXED FORUM
In addition to cases that belong exclusively to the ecclesiastical forum, there are other cases that may be handled either in the ecclesiastical forum or in the civil forum, and are therefore called cases of mixed forum.They are either temporal by their own nature, but with an added inseparable spiritual quality, or spiritual cases that present some temporal aspect. Those cases are not, however, of mixed forum which the civil authority judges by concession of the Church, by concordat, or otherwise: for example, cases concerning the separation of spouses, the right of patronage, etc.
Cases of mixed forum may be criminal or contentious, and the latter may belong to the mixed forum either by their nature or by reason of the persons involved. The following contentious cases are of mixed forum by their nature: instruments and contracts accompanied by an oath; the wills of laypersons with attached legacies; the mere existence of a spiritual fact such as marriage or baptism, excluding the question of the validity of the act; etc.
Some of these cases have now been transferred by the Church without qualification to the civil forum (e.g., those concerning the civil effects attached to marriage, unless they are introduced as incidental and accessory to a question directly concerning the marriage: cann. 1016, 1961).
By reason of the status of the persons involved, cases concerning orphans, widows, etc., were once considered to be of mixed forum. Since today the authority of the State, in civilized countries, provides fully for the defense of these rights, they are left to the State. Criminal cases of mixed forum concern offenses punished by both ecclesiastical and civil law (can. 2108). They concern offenses against life, liberty, property, good reputation, and good morals, as well as certain offenses against religion, such as violations of corpses, tombs, and cemeteries, and direct offenses against ecclesiastical persons. In all these contentious and criminal cases of mixed forum, precedence should prevail between the ecclesiastical and civil tribunals (can. 1553 § 2). Consequently, if the suit were pending before the ecclesiastical tribunal, it could not be brought before the civil tribunal, and vice versa. In the ecclesiastical forum, a suit is considered pending from the moment of the summons (can. 1725, n. 5), and remains so as long as the parties or the judge have the possibility of performing some procedural act. Once the instance has been renounced or has lapsed, the proceedings may again be introduced before any tribunal.
Moreover, in such matters, cases judged by the tribunals of the Church should also be valid before the tribunals of the State, and vice versa. The Church considers the decisions of lay tribunals res iudicata. Since, however, the State does not always today respect suits pending before ecclesiastical tribunals or cases judged by the Church, the CIC establishes that anyone who, after having introduced a case in the ecclesiastical forum, refers the same case to the secular forum is immediately deprived of the right to bring an action in the ecclesiastical forum against the same person in the same case and in matters connected with it, and may be liable to penalties according to can. 2222, even without prior warning, if scandal has been caused (can. 1554). The offense is completed by the legally served summons (can. 1725, n. 2). As regards criminal cases, since the State generally also disregards ecclesiastical penalties in this area, the Church, so that offenders will not be punished twice, ordinarily does not proceed against lay offenders after the civil magistrate has provided sufficiently for the public good (can. 1933 § 3), and generally refrains from inflicting the penalty if the offender has been punished, or is expected to be punished, by the civil authority (can. 2223 § 3, n. 2). In practice, therefore, the Church adheres to its own laws while also taking account of the penalties inflicted by the State.
In offenses against the faith and unity of the Church, given the State’s indifference under the present regime of toleration, the Church acts solely according to its own laws.
II. IN THE JUDICIAL ORGANS OF THE CHURCH
In canon law, jurisdiction is determined on the basis of four fundamental criteria: functional, objective, subjective, and territorial. These criteria overlap and combine with one another, so that, notwithstanding the limitations of jurisdiction established by law, there may be multiple fora equally competent in the same case. When, on different grounds, several judges are equally competent, and the plaintiff may of his own accord bring the action before any of them in order to summon the defendant, exclusive competence belongs to the judge or tribunal before which the plaintiff in fact appears and which, after the statement of claim, first issues the summons, lawfully served upon the defendant. By this act the judge seised by prevention takes precedence over every other judge and, by doing so, excludes that judge from the possibility of judging the case (can. 1568; cf. 2, 10, X, I, 29; 2, II, 5 in Clem.). But if one of the parties abandons the case and later begins a new proceeding, the first judge is no longer competent, since this concerns a new dispute.For the p. to be effective, the summons must be valid, in accordance with can. 1711 ff. Nevertheless, contumacy does not annul the effect of the summons with regard to the p., unless the defendant is able to purge his contumacy in accordance with can. 1851.
In criminal cases too, it is the summons that determines the ius praeventionis, so that, even while the investigation is in progress (can. 1939 ff.), the case may, by virtue of the p., be transferred from one judge to another. By analogy, the criterion of p. may also be applied when the same case is pending in two distinct proceedings before the same judge. The purpose for which the legislator established the p. is ne bis de eadem re sit actio. This serves an interest of public order, in order to avoid a useless waste of energy and an excessive burden on the judicial organs, and above all to prevent multiple judgments concerning the same dispute, perhaps contradictory to one another, with manifest discredit to the administration of justice.