Pope Benedict has released a new motu proprio titled Omnium in mentum which revises the Code of Canon Law on two points.
First, before getting into the changes, let me offer a high five to canonist Edward Peters for predicting, over ten years ago, that this would be the model followed in the future for changing canon law. Following the codification of canon law in 1917, the Code underwent a thorough revision in 1983. Rather than letting issues build up and then having another thorough revision at some point, John Paul II issued a motu proprio in 1998 that amended specific canons. Ed thereupon predicted that this would be the model for the foreseeable future–tweaking the text of the Code here and there as needed rather than leaving things sit until time for a massive revision.
So what's new in the motu proprio?
Two things: First, some language in the Code has been modified to describe the way that the office of deacon is understood. This brings the language of the Code in line with the language of the Catechism, which was itself brought in line with the language of Vatican II's decree Lumen Gentium (n. 29). I need to do further study on this point before commenting on it in any depth, though, so I'll pass on to the second change.
Second, the exemptions in the Code's marriage laws for those who have formally defected from the Church are now gone (or, rather, they will be when the motu proprio goes into force three months after its publication in Acta Apostolicae Sedis; CIC, can. 8).
This is quite interesting.
One of the things introduced in the 1983 Code was a set of exceptions in the Church's marriage law for those who had defected from the Church by a formal act. Specifically, if you had so defected then you were not obligated to
1) get a dispensation if you want to marry a non-baptized person (cf. can. 1086),
2) observe the Catholic form of marriage (i.e., "get married in the Church;" cf can. 1117), or
3) get permission to marry a non-Catholic Christian (cf. can. 1124).
The purpose of doing this was to allow people who had left the Church to validly enter into marriages of the kinds indicated.
Unfortunately, a lot of problems were generated by the law. For a start, it was unclear what constituted a formal act of defection. To try to rectify the problem, in 2006 the Holy See issued a clarification which set very specific requirements for the act, requirements which resulted in basically nobody committing acts of formal defection.
The clarification was, to my mind, bad law, and it raised a bunch of new headaches which have not subsequently been clarified, so far as I have been able to determine.
The Holy See also seems to have come to the conclusion that the formal defection law was not working as desired, and so it has now gotten rid of the whole thing.
As of the time the motu proprio goes into effect, therefore, anybody who has ever been a Catholic (even if they were baptized one as an infant and then raised something else) must follow the same marriage laws as those who consider themselves Catholic or their marriages will be invalid.
It brings to mind the old saying, "Once a Catholic, always a Catholic." I'm not sure what people always had in mind by this saying–whether they were saying that Catholic culture runs deep in the soul, even if one joins another church; whether they were asserting that it is impossible to truly leave the Church; or whether they were asserting something else.
Whatever was meant, though, and whatever nuances have been introduced theologically about kinds or degrees of ecclesial communion, going forward everybody who has ever been Catholic will be juridically Catholic, attempts at formal defection or no. It was only in its marriage law that the Church made exceptions for formal defection, and now those exceptions are being retired.
This is one way of cutting the Gordian knot. It may or may not be the optimal one, but it's what the law is going to be for now.
As far as I can tell, this creates the following timeline for handling the above marital situations:
- For marriages attempted prior to the promulgation of the 1983 Code, the old law was in force and there was no exception for formal defection.
- From the promulgation of the 1983 Code to the 2006 clarification, the formal defection exception was in effect and was to be interpreted broadly, in keeping with the language of the law. (The 2006 clarification went beyond the language of the law and thus should not be retroactive in force; CIC, can. 16).
- From the 2006 clarification to the effective date of the new motu proprio, the formal defection exception was in effect but formal defection was to be interpreted much more narrowly.
- From the effective date of the motu proprio (should be some time in early 2010), the law reverts to the status quo ante the 1983 Code, so there will be no exception for cases of formal defection.
The potential validity of a marriage involving a case of formal defection will thus depend on which of these four time periods it was attempted in–so far as I can tell.
HERE IS GOOGLE'S MACHINE-ASSISTED/COLLABORATIVE TRANSLATION FROM THE ITALIAN OF THE MOTU PROPRIO.

