es him in
some way. Now this separation is made complete by mortal sin, and
incomplete by venial sin: because, by mortal sin, the mind through
acting against charity is altogether turned away from God; whereas by
venial sin man's affections are clogged, so that they are slow in
tending towards God. Consequently both kinds of sin are taken away by
penance, because by both of them man's will is disordered through
turning inordinately to a created good; for just as mortal sin cannot
be forgiven so long as the will is attached to sin, so neither can
venial sin, because while the cause remains, the effect remains.

Yet a more perfect penance is requisite for the forgiveness of mortal
sin, namely that man should detest actually the mortal sin which he
committed, so far as lies in his power, that is to say, he should
endeavor to remember each single mortal sin, in order to detest each
one. But this is, not required for the forgiveness of venial sins;
although it does not suffice to have habitual displeasure, which is
included in the habit of charity or of penance as a virtue, since
then venial sin would be incompatible with charity, which is
evidently untrue. Consequently it is necessary to have a certain
virtual displeasure, so that, for instance, a man's affections so
tend to God and Divine things, that whatever might happen to him to
hamper that tendency would be displeasing to him, and would grieve
him, were he to commit it, even though he were not to think of it
actually: and this is not sufficient for the remission of mortal sin,
except as regards those sins which he fails to remember after a
careful examination.

Reply Obj. 1: When man is in a state of grace, he can avoid all
mortal sins, and each single one; and he can avoid each single venial
sin, but not all, as was explained in the Second Part (I-II, Q. 74,
A. 8, ad 2; Q. 109, A. 8). Consequently penance for mortal sins
requires man to purpose abstaining from mortal sins, all and each;
whereas penance for venial sins requires man to purpose abstaining
from each, but not from all, because the weakness of this life does
not allow of this. Nevertheless he needs to have the purpose of
taking steps to commit fewer venial sins, else he would be in danger
of falling back, if he gave up the desire of going forward, or of
removing the obstacles to spiritual progress, such as venial sins are.

Reply Obj. 2: Death for Christ's sake, as stated above (Q. 66, A.
11), obtains