ss.
Therefore the charity of heaven cannot be lost, whereas the charity
of the way can, because in this state God is not seen in His Essence,
which is the essence of goodness.

Reply Obj. 1: The passage quoted speaks from the point of view of the
power of the Holy Ghost, by Whose safeguarding, those whom He wills
to move are rendered immune from sin, as much as He wills.

Reply Obj. 2: The charity which can fail by reason of itself is no
true charity; for this would be the case, were its love given only
for a time, and afterwards were to cease, which would be inconsistent
with true love. If, however, charity be lost through the
changeableness of the subject, and against the purpose of charity
included in its act, this is not contrary to true charity.

Reply Obj. 3: The love of God ever works great things in its purpose,
which is essential to charity; but it does not always work great
things in its act, on account of the condition of its subject.

Reply Obj. 4: Charity by reason of its act excludes every motive for
sinning. But it happens sometimes that charity is not acting
actually, and then it is possible for a motive to intervene for
sinning, and if we consent to this motive, we lose charity.
_______________________

TWELFTH ARTICLE [II-II, Q. 24, Art. 12]

Whether Charity Is Lost Through One Mortal Sin?

Objection 1: It would seem that charity is not lost through one
mortal sin. For Origen says (Peri Archon i): "When a man who has
mounted to the stage of perfection, is satiated, I do not think that
he will become empty or fall away suddenly; but he must needs do so
gradually and by little and little." But man falls away by losing
charity. Therefore charity is not lost through only one mortal sin.

Obj. 2: Further, Pope Leo in a sermon on the Passion (lx) addresses
Peter thus: "Our Lord saw in thee not a conquered faith, not an
averted love, but constancy shaken. Tears abounded where love never
failed, and the words uttered in trepidation were washed away by the
fount of charity." From this Bernard [*William of St. Thierry, De
Nat. et Dig. Amoris. vi.] drew his assertion that "charity in Peter
was not quenched, but cooled." But Peter sinned mortally in denying
Christ. Therefore charity is not lost through one mortal sin.

Obj. 3: Further, charity is stronger than an acquired virtue. Now a
habit of acquired virtue is not destroyed by one contrary sinful act.
Much less, therefore, is charity destroyed by one