No, this is not a religious screed, but a fact-checking item for something likely to come up when writing romance novels or romance subplots in other fiction genres. (It has come up in both “Winter Into Spring”, and in two works in progress.)
Full disclosure and disclaimer: I am not a Christian and hence am an outsider to intra-Christian doctrinal disputes. The following text attempts to summarize the actual situation in canon law (see also Canon Law Made Easy) and makes no value judgments. It is assumed in the discussion below that the partner does not convert to Catholicism — otherwise, there is no difference with a Catholic marriage other than the conversion itself and all it entails.
Otherwise, the RC Church distinguishes between two broad categories:
• “mixed marriage“: the other partner was baptized in a way that the Catholic church recognizes as such. This is the case for the mainline Protestant denominations (Anglican/Episcopal, Lutheran, Presbyterian,…) as well as for the Orthodox Churches. The latter are a special subcase because they are not considered “heretic” but merely “schismatic”, and broadly have the same understanding of marriage as a sacrament.
• “disparity of worship“: the other partner belongs to a non-Christian religion, or to a Christian denomination but never underwent baptism in a way recognized as such by the RC Church. (For instance, LDS/Mormon baptism is not recognized; or the partner may have been raised Baptist but never have undergone adult “Believers Baptism”.)
“Disparity of worship” (Canon 1086) is a “diriment” (separating) impediment in canon law: any such marriage is considered null and void unless a “dispensation for disparity of worship” is obtained.
In contrast, “mixed marriage” (Canon 1124) is merely a “prohibitive” impediment: if, for example, a priest were to marry a Catholic-Lutheran couple without dispensation, such a marriage would be “illicit but valid“. That is, the marriage is forbidden unless a “dispensation for mixed marriage” is obtained, but if the priest were to marry them regardless, the couple are considered married. [Jewish law has a similar situation for a marriage between a cohen — a male direct descendant of the first High Priest Aharon/Aaron — and a divorcée or a female convert to Judaism: the marriage is forbidden by the Torah (Lev. 21:7) but if it were to take place regardless, the parties are married in every respect.]
What is a “dispensation“? In plain English, if a rule is imposed merely by ecclesiastical law rather than by (the Church’s understanding of) natural or Divine law, then in cases where its application would create a hardship, the rule may be relaxed ad hoc by “competent authority”, “for just and reasonable cause”, while it still remains in force for the community at large. In this context, ‘competent authority’ generally means the diocese in which the marriage is taking place.
We have already mentioned two types of dispensation related to marriage: “mixed marriage” and “disparity of worship”. A third that may arise in this context is “departure from canonical form” (Canon 1127), i.e., with a non-Catholic clergyperson (co)officiating at a non-Catholic marriage ceremony. This sample application form illustrates all three forms of dispensation. (The same sample form also states that for Catholic marriage by a priest or deacon, but at a venue other than a Catholic church, a simple request in writing suffices and no dispensation is required.)
For both “mixed marriage” and “disparity of worship” dispensations, the Catholic partner has to undertake in the presence of the sponsoring priest and the other spouse to do everything in their power to raise the children as Catholics.
So what does all this mean, “brass tacks”?
(1) Roman Catholic with a member of a Catholic Church of Eastern Rite (Uniate, Greek Catholic, Maronite,…): from a Catholic POV this is a Catholic marriage in every respect. Subtle issues of “jurisdiction” may arise.
(2a) Roman Catholic with (Greek/Russian/…) Orthodox Christian in an Orthodox Church and ceremony: this is considered a valid marriage even ifythe Catholic partner did not petition for “departure from canonical form”.
(2b) Roman Catholic with (Greek/Russian/…) Orthodox Christian in a Catholic ceremony: in principle “mixed marriage permission” is required before the priest or deacon will marry you, but the marriage is valid even if he married you without permission. (He may be in hot water with his superiors though.)
(3a) Roman Catholic with Anglican, Lutheran,… or other mainline Protestant, by a Catholic priest or deacon in a Catholic Church: “mixed marriage permission” is required, but the marriage is valid even without. Increasingly, as in this sample application form , the reservation “with disparity of cult granted as a precaution” is added.
(3b) Ditto, but in a Protestant church or secular venue, with a Protestant minister officiating: both “mixed marriage permission” and “departure from canonical form” are required, otherwise the marriage is invalid. One recent high-profile case was the marriage of the Dutch Crown Prince, presently King Willem-Alexander (Dutch Reformed) to the Argentinian Princess Maxima (Catholic). This case also arises when a brother, father, or uncle of the Protestant partner is a practicing minister of that denomination and wishes to (co-)officiate.
(4a) Roman Catholic with non-Christian or certain special cases (Baptist who never underwent adult baptism, LDS,…), by a priest in a Catholic church: “disparity of worship” dispensation is required, or the marriage is invalid. This dispensation is generally harder to obtain, for obvious reasons.
(4b) Ditto but at another venue, with an officiant other than an RC priest or deacon: both “disparity of worship” and “departure from canonical form” dispensations are required.
Summary in Table form
||in RC church
||in non-RC partner’s place of worship
||mixed marriage dispensation, otherwise illicit but valid
||canonical form dispensation, otherwise illicit but valid
||mixed marriage dispensation, otherwise illicit but valid
||canonical form dispensation, otherwise invalid
|Others (LDS, Baptist without adult baptism, non-Christians)
||disparity of worship dispensation, otherwise invalid
||both disparity of worship and canonical form dispensations, otherwise invalid
[*] subtle “jurisdiction issues” may arise that are beyond the scope of this post