from consecrating, except he be bound to do so, and to
give the sacraments to the people, by reason of his being entrusted
with the care of souls.

But this is said quite unreasonably, because everyone is bound to use
the grace entrusted to him, when opportunity serves, according to 2
Cor. 6:1: "We exhort you that you receive not the grace of God in
vain." But the opportunity of offering sacrifice is considered not
merely in relation to the faithful of Christ to whom the sacraments
must be administered, but chiefly with regard to God to Whom the
sacrifice of this sacrament is offered by consecrating. Hence, it is
not lawful for the priest, even though he has not the care of souls,
to refrain altogether from celebrating; and he seems to be bound to
celebrate at least on the chief festivals, and especially on those
days on which the faithful usually communicate. And hence it is that
(2 Macc. 4:14) it is said against some priests that they "were not
now occupied about the offices of the altar . . . despising the
temple and neglecting the sacrifices."

Reply Obj. 1: The other sacraments are accomplished in being used by
the faithful, and therefore he alone is bound to administer them who
has undertaken the care of souls. But this sacrament is performed in
the consecration of the Eucharist, whereby a sacrifice is offered to
God, to which the priest is bound from the order he has received.

Reply Obj. 2: The sinful priest, if deprived by the Church's sentence
from exercising his order, simply or for a time, is rendered
incapable of offering sacrifice; consequently, the obligation lapses.
But if not deprived of the power of celebrating, the obligation is
not removed; nor is he in two minds, because he can repent of his sin
and then celebrate.

Reply Obj. 3: Weakness or sickness contracted by a priest after his
ordination does not deprive him of his orders; but hinders him from
exercising them, as to the consecration of the Eucharist: sometimes
by making it impossible to exercise them, as, for example, if he lose
his sight, or his fingers, or the use of speech; and sometimes on
account of danger, as in the case of one suffering from epilepsy, or
indeed any disease of the mind; and sometimes, on account of
loathsomeness, as is evident in the case of a leper, who ought not to
celebrate in public: he can, however, say mass privately, unless the
leprosy has gone so far that it has rendered him incapable owing to
the wasting aw