o we not offer it up every day in
memory of His death?" Secondly it is called a sacrifice, in respect
of the effect of His Passion: because, to wit, by this sacrament, we
are made partakers of the fruit of our Lord's Passion. Hence in one
of the Sunday Secrets (Ninth Sunday after Pentecost) we say:
"Whenever the commemoration of this sacrifice is celebrated, the work
of our redemption is enacted." Consequently, according to the first
reason, it is true to say that Christ was sacrificed, even in the
figures of the Old Testament: hence it is stated in the Apocalypse
(13:8): "Whose names are not written in the Book of Life of the Lamb,
which was slain from the beginning of the world." But according to
the second reason, it is proper to this sacrament for Christ to be
sacrificed in its celebration.

Reply Obj. 1: As Ambrose says (commenting on Heb. 10:1), "there is
but one victim," namely that which Christ offered, and which we
offer, "and not many victims, because Christ was offered but once:
and this latter sacrifice is the pattern of the former. For, just as
what is offered everywhere is one body, and not many bodies, so also
is it but one sacrifice."

Reply Obj. 2: As the celebration of this sacrament is an image
representing Christ's Passion, so the altar is representative of the
cross itself, upon which Christ was sacrificed in His proper species.

Reply Obj. 3: For the same reason (cf. Reply Obj. 2) the priest also
bears Christ's image, in Whose person and by Whose power he
pronounces the words of consecration, as is evident from what was
said above (Q. 82, AA. 1, 3). And so, in a measure, the priest and
victim are one and the same.
_______________________

SECOND ARTICLE [III, Q. 83, Art. 2]

Whether the Time for Celebrating This Mystery Has Been Properly
Determined?

Objection 1: It seems that the time for celebrating this mystery has
not been properly determined. For as was observed above (A. 1), this
sacrament is representative of our Lord's Passion. But the
commemoration of our Lord's Passion takes place in the Church once in
the year: because Augustine says (Enarr. ii in Ps. 21): "Is not
Christ slain as often as the Pasch is celebrated? Nevertheless, the
anniversary remembrance represents what took place in by-gone days;
and so it does not cause us to be stirred as if we saw our Lord
hanging upon the cross." Therefore this sacrament ought to be
celebrated but once a year.

Obj. 2: Further, Christ's P