I'm full of liturgical wonderings today, and this one is no abstract case.
Let's say I'm offering Mass. When it comes time for the communion of the faithful, in order to fulfill GIRM 281 and offer the "fuller form" of the sacramental sign (Formam ratione signi pleniorem) I want to offer communion under both kinds. To do this in a convenient way, I want to appoint someone to minister the Precious Blood. I have a choice of three persons assisting at the Mass:
1. A priest who is known to me but who, contra Redemptionis sacramentum 128,* is not concelebrating, but who chooses to assist "in the manner of the lay faithful."
2. A man whom I know is an instituted acolyte, but who is also not serving in his hierarchically ordered role. (Also, contra Redemptionis sacramentum 128, but more softly perhaps.)
3. Someone who is neither a cleric nor an instituted acolyte, but who could be impressed into competent service as an EMoHC for the occasion.
Which one is the correct choice to minister the Precious Blood? Why? What are the values at stake?
* Holy Mass and other liturgical celebrations, which are acts of Christ and of the people of God hierarchically constituted, are ordered in such a way that the sacred ministers and the lay faithful manifestly take part in them each according to his own condition. It is preferable therefore that “Priests who are present at a Eucharistic Celebration, unless excused for a good reason, should as a rule exercise the office proper to their Order and thus take part as concelebrants, wearing the sacred vestments. Otherwise, they wear their proper choir dress or a surplice over a cassock.” It is not fitting, except in rare and exceptional cases and with reasonable cause, for them to participate at Mass, as regards to externals, in the manner of the lay faithful.
Read the whole document here.