ison with a disease, which is said to be mortal, through
causing an irreparable defect consisting in the corruption of a
principle, as stated above (Q. 72, A. 5). Now the principle of the
spiritual life, which is a life in accord with virtue, is the order
to the last end, as stated above (Q. 72, A. 5; Q. 87, A. 3): and if
this order be corrupted, it cannot be repaired by any intrinsic
principle, but by the power of God alone, as stated above (Q. 87, A.
3), because disorders in things referred to the end, are repaired
through the end, even as an error about conclusions can be repaired
through the truth of the principles. Hence the defect of order to the
last end cannot be repaired through something else as a higher
principle, as neither can an error about principles. Wherefore such
sins are called mortal, as being irreparable. On the other hand, sins
which imply a disorder in things referred to the end, the order to
the end itself being preserved, are reparable. These sins are called
venial: because a sin receives its acquittal (_veniam_) when the debt
of punishment is taken away, and this ceases when the sin ceases, as
explained above (Q. 87, A. 6).

Accordingly, mortal and venial are mutually opposed as reparable and
irreparable: and I say this with reference to the intrinsic
principle, but not to the Divine power, which can repair all
diseases, whether of the body or of the soul. Therefore venial sin is
fittingly condivided with mortal sin.

Reply Obj. 1: The division of sin into venial and mortal is not a
division of a genus into its species which have an equal share of the
generic nature: but it is the division of an analogous term into its
parts, of which it is predicated, of the one first, and of the other
afterwards. Consequently the perfect notion of sin, which Augustine
gives, applies to mortal sin. On the other hand, venial sin is called
a sin, in reference to an imperfect notion of sin, and in relation to
mortal sin: even as an accident is called a being, in relation to
substance, in reference to the imperfect notion of being. For it is
not _against_ the law, since he who sins venially neither does what
the law forbids, nor omits what the law prescribes to be done; but he
acts _beside_ the law, through not observing the mode of reason,
which the law intends.

Reply Obj. 2: This precept of the Apostle is affirmative, and so it
does not bind for all times. Consequently everyone who does not
actually refer a