[quote="superamazingman, post:18, topic:304755"]
Strictly speaking, the couple confers the sacrament on each other, if I remember correctly (although I'm open to correction if you have a document quote).
This is correct. However, an ordained witness is required for validity, except for special circumstances:
Can. 1108 §1. Only those marriages are valid which are contracted before the local ordinary, pastor, or a priest or deacon delegated by either of them, who assist, and before two witnesses according to the rules expressed in the following canons and without prejudice to the exceptions mentioned in cann. 144, 1112, §1, 1116, and 1127, §§1-2.
Can. 1112 §1. Where there is a lack of priests and deacons, the diocesan bishop can delegate lay persons to assist at marriages, with the previous favorable vote of the conference of bishops and after he has obtained the permission of the Holy See.
§2. A suitable lay person is to be selected, who is capable of giving instruction to those preparing to be married and able to perform the matrimonial liturgy properly.
Can. 1116 §1. If a person competent to assist according to the norm of law cannot be present or approached without grave inconvenience, those who intend to enter into a true marriage can contract it validly and licitly before witnesses only:
1/ in danger of death;
2/ outside the danger of death provided that it is prudently foreseen that the situation will continue for a month.
§2. In either case, if some other priest or deacon who can be present is available, he must be called and be present at the celebration of the marriage together with the witnesses, without prejudice to the validity of the marriage before witnesses only.
In the same way that a priest could validly (not licitly) offer Mass without permission from the bishop, a couple, if they fully understand the nature of what they are doing and no priest is around (for example, an engaged couple gets stranded on an island),
Right, but again, the ordinary would have had to have selected the "suitable lay person" who would witness on behalf of the Church, right?
If by "ordination of the witness is not necessary", you meant that the bishop IDed that person to witness the wedding, then sure. But if you were trying to assert that any old ceremony, for a Catholic couple, without a witness on behalf of the Church who was chosen by the Church to act in that capacity, then... no. ;) (Other than your "Blue Lagoon" suggestion, of course... which I'm guessing isn't one that happens very often. ;))