Leni
Until recently excommunication was of two kinds, major and minor.
(a) Minor excommunication is uniformly defined by canonists and by Gregory IX (cap. lix, De sent. exc., lib. V, tit. xxxix) as prohibition from receiving the sacraments, what theologians call the passive use of the sacraments. In order to receive the Eucharist and the other sacraments, those who had incurred this penalty had to be absolved therefrom; as it was not reserved, this could be done by any confessor. Indirectly, however, it entailed other consequences. The canon law (cap. x, De cler. excomm. ministrante, lib. V, tit. xxvii) taught that the priest who celebrates Mass while under the ban of minor excommunication sins grievously; also that he sins similarly in administering the sacraments; and finally, that while he can vote for others, he himself is ineligible to a canonical office. This is readily understood when we remember that the cleric thus excommunicated was presumed to be in the state of grievous sin, and that such a state is an obstacle to the lawful celebration of Mass and the administration of the sacraments. Minor excommunication was really identical with the state of the penitent of olden times who, prior to his reconciliation, was admitted to public penance. Minor excommunication was incurred by unlawful intercourse with the excommunicated, and in the beginning no exception was made of any class of excommunicated persons. Owing, however, to many inconveniences arising from this condition of things, especially after excommunications had become so numerous, Martin V, by the Constitution "Ad evitanda scandala" (1418), restricted the aforesaid unlawful intercourse to that held with those who were formally named as persons to be shunned and who were therefore known as vitandi (Latin vitare, to avoid), also with those who were notoriously guilty of striking a cleric. But as this twofold category was in modern times greatly reduced, but little attention was paid to minor excommunication, and eventually it ceased to exist after the publication of the Constitution "Apostolicæ Sedis". The latter declared that all excommunications latæ sententiæ that it did not mention were abolished, and as it was silent concerning minor excommunication (by its nature an excommunication latæ sententiæ of a special kind), canonists concluded that minor excommunication no longer existed. This conclusion was formally ratified by the Holy Office (6 Jan., 1884, ad 4).
(b) Major excommunication, which remains now the only kind in force, is therefore the kind of which we treat below, and to which our definition fully applies. Anathema is a sort of aggravated excommunication, from which, however, it does not differ essentially, but simply in the matter of special solemnities and outward display.
Excommunication is either a jure (by law) or ab homine (by judicial act of man, i.e. by a judge). The first is provided by the law itself, which declares that whosoever shall have been guilty of a definite crime will incur the penalty of excommunication. The second is inflicted by an ecclesiastical prelate, either when he issues a serious order under pain of excommunication or imposes this penalty by judicial sentence and after a criminal trial.
Excommunication, especially a jure, is either latæ or ferendæ sententiæ. The first is incurred as soon as the offence is committed and by reason of the offence itself (eo ipso) without intervention of any ecclesiastical judge; it is recognized in the terms used by the legislator, for instance: "the culprit will be excommunicated at once, by the fact itself [statim, ipso facto]". The second is indeed foreseen by the law as a penalty, but is inflicted on the culprit only by a judicial sentence; in other words, the delinquent is rather threatened than visited with the penalty, and incurs it only when the judge has summoned him before his tribunal, declared him guilty, and punished him according to the terms of the law. It is recognized when the law contains these or similar words: "under pain of excommunication"; "the culprit will be excommunicated".