I don’t usually have to spend much time on it since basically nobody says they didn’t understand that marriage is a permanent relationship or says they couldn’t comprehend what it meant to be in a permanent relationship (permanence, as you note, is not the same as indissolubility).
Be that as it may, I’d say something like this.
Speaking of “maturity to discern” puts us squarely in the terms of canon 1095.2 which says those who suffer from a grave lack of discretion of judgment concerning the essential, matrimonial rights and obligations which are to be mutually given and accepted are incapable of marriage. Like I said earlier, this means that a person who is not able to discern about a choice of marriage cannot marry. It is not a matter of discerning wrongly. It’s a matter of not being able to carry out even a rudimentary examination of what it would mean to be married to so-and-so. Concerning permanence, the person has to be aware of the permanent nature of marriage (i.e., it’s not a temporary relationship with a predetermined expiration date, (cf. c. 1096) and be able to comprehend what it would mean to be in stable relationship with this other person.
If a person is unable to enter into even the basics of this consideration, then he can’t marry. If he has a plan of being in a “marriage relationship” for only a certain length of time, then he was necessarily able to evaluate and discern regarding permanence. So, in such a case, something other than a lack of discretion is going on.
Due to fallen human nature, people act contrary to marital obligations all the time, sometimes in light matters and sometimes in weighty ones. People commit adultery. People restrict the ius in corpus. People separate and divorce. They aren’t necessarily unable to be married, though. As John Paul II said in the 1987 address to the Rota: “Moreover, the breakdown of such a marriage union is never in itself proof of such incapacity on the part of the contracting parties. … (The parties) may have failed to accept the inevitable limitations and burdens of married life, either because of blocks of an unconscious nature or because of slight pathological disturbances which leave substantially intact human freedom, or finally because of failures of the moral order.”
Such actions can be symptoms of a marital incapacity, yes, but that can be symptoms of other defects of consent, too (such as simulation). The determining factor is whether or not the person was suffering from a psychic disorder that made it impossible for him to marry. That happens but is gravely abnormal (both in itself and in comparison to the general population).
Something like that.
Dan
Prayers that all will return to the Church.
