Summa Theologica III, q. 82: Of the Minister of this Sacrament
Article 2. Whether several priests can consecrate one and the same host?
Objection 1It seems that several priests cannot consecrate one and the same host. For it was said above (Q[67], A[6]), that several cannot at the same time baptize one individual. But the power of a priest consecrating is not less than that of a man baptizing. Therefore, several priests cannot consecrate one host at the same time.
Objection 2Further, what can be done by one, is superfluously done by several. But there ought to be nothing superfluous in the sacraments. Since, then, one is sufficient for consecrating, it seems that several cannot consecrate one host.
Objection 3Further, as Augustine says (Tract. xxvi in Joan.), this is "the sacrament of unity." But multitude seems to be opposed to unity. Therefore it seems inconsistent with the sacrament for several priests to consecrate the same host.
On the contraryIt is the custom of some Churches for priests newly ordained to co-celebrate with the bishop ordaining them.
I answer thatAs stated above (A[1]), when a priest is ordained he is placed on a level with those who received consecrating power from our Lord at the Supper. And therefore, according to the custom of some Churches, as the apostles supped when Christ supped, so the newly ordained co-celebrate with the ordaining bishop. Nor is the consecration, on that account, repeated over the same host, because as Innocent III says (De Sacr. Alt. Myst. iv), the intention of all should be directed to the same instant of the consecration.
Reply to Objection 1We do not read of Christ baptizing with the apostles when He committed to them the duty of baptizing; consequently there is no parallel.
Reply to Objection 2If each individual priest were acting in his own power, then other celebrants would be superfluous, since one would be sufficient. But whereas the priest does not consecrate except as in Christ's stead; and since many are "one in Christ" (Gal. 3:28); consequently it does not matter whether this sacrament be consecrated by one or by many, except that the rite of the Church must be observed.
Reply to Objection 3The Eucharist is the sacrament of ecclesiastical unity, which is brought about by many being "one in Christ."
Article 3. Whether dispensing of this sacrament belongs to a priest alone?
Objection 1It seems that the dispensing of this sacrament does not belong to a priest alone. For Christ's blood belongs to this sacrament no less than His body. But Christ's blood is dispensed by deacons: hence the blessed Lawrence said to the blessed Sixtus (Office of St. Lawrence, Resp. at Matins): "Try whether you have chosen a fit minister, to whom you have entrusted the dispensing of the Lord's blood." Therefore, with equal reason the dispensing of Christ's body does not belong to priests only.
Objection 2Further, priests are the appointed ministers of the sacraments. But this sacrament is completed in the consecration of the matter, and not in the use, to which the dispensing belongs. Therefore it seems that it does not belong to a priest to dispense the Lord's body.
Objection 3Further, Dionysius says (Eccl. Hier. iii, iv) that this sacrament, like chrism, has the power of perfecting. But it belongs, not to priests, but to bishops, to sign with the chrism. Therefore likewise, to dispense this sacrament belongs to the bishop and not to the priest.
On the contraryIt is written (De Consecr., dist. 12): "It has come to our knowledge that some priests deliver the Lord's body to a layman or to a woman to carry it to the sick: The synod therefore forbids such presumption to continue; and let the priest himself communicate the sick."
I answer thatThe dispensing of Christ's body belongs to the priest for three reasons. First, because, as was said above (A[1]), he consecrates as in the person of Christ. But as Christ consecrated His body at the supper, so also He gave it to others to be partaken of by them. Accordingly, as the consecration of Christ's body belongs to the priest, so likewise does the dispensing belong to him. Secondly, because the priest is the appointed intermediary between God and the people; hence as it belongs to him to offer the people's gifts to God, so it belongs to him to deliver consecrated gifts to the people. Thirdly, because out of reverence towards this sacrament, nothing touches it, but what is consecrated; hence the corporal and the chalice are consecrated, and likewise the priest's hands, for touching this sacrament. Hence it is not lawful for anyone else to touch it except from necessity, for instance, if it were to fall upon the ground, or else in some other case of urgency.
Reply to Objection 1The deacon, as being nigh to the priestly order, has a certain share in the latter's duties, so that he may dispense the blood; but not the body, except in case of necessity, at the bidding of a bishop or of a priest. First of all, because Christ's blood is contained in a vessel, hence there is no need for it to be touched by the dispenser, as Christ's body is touched. Secondly, because the blood denotes the redemption derived by the people from Christ; hence it is that water is mixed with the blood, which water denotes the people. And because deacons are between priest and people, the dispensing of the blood is in the competency of deacons, rather than the dispensing of the body.
Reply to Objection 2For the reason given above, it belongs to the same person to dispense and to consecrate this sacrament.
Reply to Objection 3As the deacon, in a measure, shares in the priest's "power of enlightening" (Eccl. Hier. v), inasmuch as he dispenses the blood, so the priest shares in the "perfective dispensing" (Eccl. Hier. v) of the bishop, inasmuch as he dispenses this sacrament whereby man is perfected in himself by union with Christ. But other perfections whereby a man is perfected in relation to others, are reserved to the bishop.