dulterous woman without Penance. Therefore it seems that Penance
is not necessary for salvation.

_On the contrary,_ our Lord said (Luke 13:3): "Unless you shall do
penance, you shall all likewise perish."

_I answer that,_ A thing is necessary for salvation in two ways:
first, absolutely; secondly, on a supposition. A thing is absolutely
necessary for salvation, if no one can obtain salvation without it,
as, for example, the grace of Christ, and the sacrament of Baptism,
whereby a man is born again in Christ. The sacrament of Penance is
necessary on a supposition, for it is necessary, not for all, but for
those who are in sin. For it is written (2 Paral. 37 [*The prayer of
Manasses, among the Apocrypha]), "Thou, Lord, God of the righteous,
hast not appointed repentance to the righteous, to Abraham, Isaac and
Jacob, nor to those who sinned not against Thee." But "sin, when it
is completed, begetteth death" (James 1:15). Consequently it is
necessary for the sinner's salvation that sin be taken away from him;
which cannot be done without the sacrament of Penance, wherein the
power of Christ's Passion operates through the priest's absolution
and the acts of the penitent, who co-operates with grace unto the
destruction of his sin. For as Augustine says (Tract. lxxii in Joan.
[*Implicitly in the passage referred to, but explicitly Serm. xv de
verb. Apost.]), "He Who created thee without thee, will not justify
thee without thee." Therefore it is evident that after sin the
sacrament of Penance is necessary for salvation, even as bodily
medicine after man has contracted a dangerous disease.

Reply Obj. 1: This gloss should apparently be understood as referring
to the man who has a good will unimpaired by sin, for such a man has
no cause for sorrow: but as soon as the good will is forfeited
through sin, it cannot be restored without that sorrow whereby a man
sorrows for his past sin, and which belongs to Penance.

Reply Obj. 2: As soon as a man falls into sin, charity, faith, and
mercy do not deliver him from sin, without Penance. Because charity
demands that a man should grieve for the offense committed against
his friend, and that he should be anxious to make satisfaction to his
friend; faith requires that he should seek to be justified from his
sins through the power of Christ's Passion which operates in the
sacraments of the Church; and well-ordered pity necessitates that man
should succor himself by repenting of the pit