ove (A. 5). Therefore this definition
does not include every sin.

Obj. 2: Further, Augustine says (De Duab. Anim. xii): "Sin is the
will to retain or obtain what justice forbids." Now will is comprised
under desire, in so far as desire denotes any act of the appetite.
Therefore it was enough to say: "Sin is a desire contrary to the
eternal law," nor was there need to add "word" or "deed."

Obj. 3: Further, sin apparently consists properly in aversion from
the end: because good and evil are measured chiefly with regard to
the end as explained above (Q. 1, A. 3; Q. 18, AA. 4, 6; Q. 20, AA.
2, 3): wherefore Augustine (De Lib. Arb. i) defines sin in reference
to the end, by saying that "sin is nothing else than to neglect
eternal things, and seek after temporal things": and again he says
(Qq. lxxxii, qu. 30) that "all human wickedness consists in using
what we should enjoy, and in enjoying what we should use." Now the
definition in question contains no mention of aversion from our due
end: therefore it is an insufficient definition of sin.

Obj. 4: Further, a thing is said to be forbidden, because it is
contrary to the law. Now not all sins are evil through being
forbidden, but some are forbidden because they are evil. Therefore
sin in general should not be defined as being against the law of God.

Obj. 5: Further, a sin denotes a bad human act, as was explained
above (A. 1). Now man's evil is to be against reason, as Dionysius
states (Div. Nom. iv). Therefore it would have been better to say
that sin is against reason than to say that it is contrary to the
eternal law.

_On the contrary,_ the authority of Augustine suffices (Contra Faust.
xxii, 27).

_I answer that,_ As was shown above (A. 1), sin is nothing else than
a bad human act. Now that an act is a human act is due to its being
voluntary, as stated above (Q. 1, A. 1), whether it be voluntary, as
being elicited by the will, e.g. to will or to choose, or as being
commanded by the will, e.g. the exterior actions of speech or
operation. Again, a human act is evil through lacking conformity with
its due measure: and conformity of measure in a thing depends on a
rule, from which if that thing depart, it is incommensurate. Now
there are two rules of the human will: one is proximate and
homogeneous, viz. the human reason; the other is the first rule, viz.
the eternal law, which is God's reason, so to speak. Accordingly
Augustine (Contra Faust. xxii, 27) includes tw