But the fact of
being against the eternal law makes a sin to be mortal. Consequently
every sin is mortal. Therefore venial sin is not condivided with
mortal sin.

Obj. 2: Further, the Apostle says (1 Cor. 10:31): "Whether you eat or
drink, or whatever else you do; do all to the glory of God." Now
whoever sins breaks this commandment, because sin is not done for
God's glory. Consequently, since to break a commandment is to commit
a mortal sin, it seems that whoever sins, sins mortally.

Obj. 3: Further, whoever cleaves to a thing by love, cleaves either
as enjoying it, or as using it, as Augustine states (De Doctr.
Christ. i, 3, 4). But no person, in sinning, cleaves to a mutable
good as using it: because he does not refer it to that good which
gives us happiness, which, properly speaking, is to use, according to
Augustine (De Doctr. Christ. i, 3, 4). Therefore whoever sins enjoys
a mutable good. Now "to enjoy what we should use is human
perverseness," as Augustine again says (Qq. lxxxiii, qu. 30).
Therefore, since "perverseness" [*The Latin 'pervertere' means to
overthrow, to destroy, hence 'perversion' of God's law is a mortal
sin.] denotes a mortal sin, it seems that whoever sins, sins mortally.

Obj. 4: Further, whoever approaches one term, from that very fact
turns away from the opposite. Now whoever sins, approaches a mutable
good, and, consequently turns away from the immutable good, so that
he sins mortally. Therefore venial sin is unfittingly condivided with
mortal sin.

_On the contrary,_ Augustine says (Tract. xli in Joan.), that "a
crime is one that merits damnation, and a venial sin, one that does
not." But a crime denotes a mortal sin. Therefore venial sin is
fittingly condivided with mortal sin.

_I answer that,_ Certain terms do not appear to be mutually opposed,
if taken in their proper sense, whereas they are opposed if taken
metaphorically: thus "to smile" is not opposed to "being dry"; but if
we speak of the smiling meadows when they are decked with flowers and
fresh with green hues this is opposed to drought. In like manner if
mortal be taken literally as referring to the death of the body, it
does not imply opposition to venial, nor belong to the same genus.
But if mortal be taken metaphorically, as applied to sin, it is
opposed to that which is venial.

For sin, being a sickness of the soul, as stated above (Q. 71, A. 1,
ad 3; Q. 72, A. 5; Q. 74, A. 9, ad 2), is said to be mortal by
compar