_On the contrary,_ Augustine, in a sermon on Purgatory (De Sanctis,
serm. xli), enumerates certain generic venial sins, and certain
generic mortal sins.

_I answer that,_ Venial sin is so called from _venia_ (pardon).
Consequently a sin may be called venial, first of all, because it has
been pardoned: thus Ambrose says that "penance makes every sin
venial": and this is called venial "from the result." Secondly, a sin
is called venial because it does not contain anything either
partially or totally, to prevent its being pardoned: partially, as
when a sin contains something diminishing its guilt, e.g. a sin
committed through weakness or ignorance: and this is called venial
"from the cause": totally, through not destroying the order to the
last end, wherefore it deserves temporal, but not everlasting
punishment. It is of this venial sin that we wish to speak now.

For as regards the first two, it is evident that they have no
determinate genus: whereas venial sin, taken in the third sense, can
have a determinate genus, so that one sin may be venial generically,
and another generically mortal, according as the genus or species of
an act is determined by its object. For, when the will is directed to
a thing that is in itself contrary to charity, whereby man is
directed to his last end, the sin is mortal by reason of its object.
Consequently it is a mortal sin generically, whether it be contrary
to the love of God, e.g. blasphemy, perjury, and the like, or against
the love of one's neighbor, e.g. murder, adultery, and such like:
wherefore such sins are mortal by reason of their genus. Sometimes,
however, the sinner's will is directed to a thing containing a
certain inordinateness, but which is not contrary to the love of God
and one's neighbor, e.g. an idle word, excessive laughter, and so
forth: and such sins are venial by reason of their genus.

Nevertheless, since moral acts derive their character of goodness and
malice, not only from their objects, but also from some disposition
of the agent, as stated above (Q. 18, AA. 4, 6), it happens sometimes
that a sin which is venial generically by reason of its object,
becomes mortal on the part of the agent, either because he fixes his
last end therein, or because he directs it to something that is a
mortal sin in its own genus; for example, if a man direct an idle
word to the commission of adultery. In like manner it may happen, on
the part of the agent, that a sin genericall