(b) If the impediment is uncertain, no sin is committed when the impediment is one of ecclesiastical law and the doubt is one of law, for in such a case the legislator removes the obligation (Canon 15); nor when the impediment is impotency (Canon 1068), in view of the fact that the general law of propagation of the race leaves a natural presumption against impotency, which can be overcome only by a certain impediment. It would be an intolerable hardship if marriage were made impossible by a doubt where proof is so difficult. There is a serious sin, however, in other cases, because one is either exposing the Sacrament to nullity or is refusing, contrary to a serious command of the Church, to seek a dispensation.
2806. The Impedient or Prohibitive Impediments (Canons 1058-1066).—(a) Vow.—The following simple vows make marriage illicit: the vow of virginity, that of perfect chastity, the vow not to marry, the vow to receive Sacred Orders, the vow to enter religious life, the simple vows of religion. A vow to abstain from the use of marriage is not against the substance of marriage, but it is difficult to keep in the married state; the vows to enter religion, or take Sacred Orders, or not to wed, are incompatible with marriage. Hence, the Church forbids one who has these vows to marry, unless the vow be first dispensed. Those who marry while bound by one of these vows sin gravely, and are held to keep the vow if this is possible or the other party’s rights do not prevent.
(b) Legal Relationship.—In those countries where relationship from adoption makes marriage illicit, there is also an impedient impediment of Canon Law. The Church wishes, in so far as possible, to preserve harmony between her own law and that of the State. Hence, she includes in her Code the civil law regulations that forbid marriage to certain persons on account of the intimate relation that exists between them through civil law adoption. The law of some European (e.g., France, Germany, Switzerland) and South American countries have a prohibitive impediment of adoption, but in the United States, the British Empire, and many other countries adoption is no such hindrance to marriage.
(c) Mixed Religion.—Marriage between two baptized persons, one a Catholic and the other a member of an heretical or schismatical sect, is severely forbidden by the Church. Mixed marriages in themselves are opposed to divine and natural law, inasmuch as they offer an occasion for communication in false worship and a danger of perversion; and hence they have been disapproved from the very beginning of the Church (II John, X. 11; I Cor., v. 10; Tit., iii. 10). But the divine prohibition ceases if appropriate measures are used to safeguard the faith of the Catholic and the children, and the Church will grant a dispensation, though reluctantly and only for just and grave causes.
2807. Duties in Reference to Mixed Marriages.—(a) The Pastor.—A dispensation should not be sought unless there is first a sufficient reason, all things considered, and generally the reason should be the public good (such as the relative fewness of Catholics in a district, hope of conversion of the non-Catholic, avoidance of scandal). Secondly, there must be guarantees given by the non-Catholic that the faith of the Catholic will not be interfered with, and both parties must promise that all the children will receive Catholic and no other baptism and education. Finally, these promises must be such as to produce moral certainty of fulfillment, and as a rule it should be required that they be given in writing. After the marriage has been celebrated the pastor is held both in charity and in justice to do what he can to have the promises faithfully lived up to.
(b) The Parties.—Neither before nor after the marriage in the Catholic Church is it lawful to have any non-Catholic religious ceremony (see 956 sqq.); and if the pastor knows that this has been done or will be done, he may not assist at the marriage without permission from the Ordinary, which is granted for a most grave reason (scandal being avoided). After the marriage the parties are bound in justice to keep the promises made, and the Catholic is held in charity to seek prudently, by good example and advice, to convert the non-Catholic.
2808. Marriages with Bad Catholics.—(a) If the bad Catholic is unworthy in the matter of faith, because he has notoriously given up the Church (even though he has not joined any other religion), or because he is a member of a forbidden society, there is a danger of perversion. In such a case the pastor may not assist at the marriage unless the Ordinary decides that there is a sufficient reason, that the danger of perversion is made remote, and that the Catholic education of the children is provided for.
(b) If the bad Catholic is unworthy in the matter of morals, because he is a public sinner (e.g., one who neglects the Easter duty), or notoriously under censure and therefore a person to whom the Sacraments must be denied, the pastor is confronted with the law that one may not cooperate formally, even by assistance, in the profanation of a Sacrament. As the guilt of the unworthy person is public in these cases, there must be public reparation before the marriage can be sanctioned by the presence of the Church’s representative. The reparation is to be made either by the sinner going to confession or by the censured person obtaining absolution. But since the priest’s presence can be only a material cooperation, it may be permitted by the Ordinary for a grave reason when the unworthy person refuses to comply with the conditions.
2809. Other Obstacles to Marriage.—Other obstacles which forbid marriage, though they are not strictly canonical impediments, are the following:
(a) valid engagement gravely forbids marriage with a third party. This is a natural obstacle which results from the very nature of a binding promise;